PowerBot™ Operations Manual

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PowerBot™ Operations Manual | Manualzz

PowerBot™

Operations Manual

with

Hitachi H8S-based microcontroller

&

ActivMedia Robotics Operating System Software

Copyright © 2003, ActivMedia Robotics, LLC. All rights reserved.

Under international copyright laws, this manual or any portion of it may not be copied or in any way duplicated without the expressed written consent of ActivMedia Robotics.

The software on disk, CD-ROM, and/or in the microcontroller’s FLASH, which accompany the robot and are available for network download by ActivMedia Robotics customers, are solely owned and copyrighted or are licensed products distributed by ActivMedia

Robotics, LLC.

Developers and users are authorized by revocable license to develop and operate custom software for personal research and educational use only. Duplication, distribution, reverse-engineering, or commercial application of the ActivMedia Robotics software and hardware without the expressed written consent of ActivMedia Robotics,

LLC, is explicitly forbidden.

The various names and logos for products used in this manual are often registered trademarks or trademarks of their respective companies. Mention of any third-party hardware or software constitutes neither an endorsement nor a recommendation.

ActivMedia Robotics’ PowerBot Operations Manual, version 1.2, February 2003

ii

ActivMedia Robotics

Important Safety Instructions

Read the installation and operations instructions before using the equipment.

Avoid using power extension cords.

To prevent fire or shock hazard, do not expose the equipment to rain or moisture.

Refrain from opening the unit or any of its accessories.

Keep wheels away from long hair or fur.

Don’t Void the Warranty!

Disable power with the service switch before opening PowerBot.

Otherwise, you risk damage to yourself and to the robot.

Inappropriate Operation

Inappropriate operation voids your warranty! Inappropriate operation includes, but is not limited to:

Failure to disable power with the service switch before opening the robot

Dropping the robot, running it off a ledge, or otherwise operating it in an irresponsible manner

Overloading the robot above its payload capacity

Getting the robot wet

Continuing to run the robot after hair, yarn, string, or any other items have become wound around the robot’s axles or wheels

All other forms of inappropriate operation or care

iii

TABLE OF CONTENTS

CHAPTER 1 INTRODUCTION................................................................................................................. 1

R OBOT P ACKAGE ........................................................................................................................................ 1

Basic Components .................................................................................................................................. 1

Optional Components and Attachments (partial list) ............................................................................. 1

A DDITIONAL R ESOURCES ............................................................................................................................ 2

Support Website...................................................................................................................................... 2

Newsgroups ............................................................................................................................................ 2

Support ................................................................................................................................................... 2

CHAPTER 2 WHAT IS POWERBOT?..................................................................................................... 4

P IONEER R EFERENCE P LATFORM ................................................................................................................ 4

P OWERBOT ' S M ICROCONTROLLER AND O PERATING S YSTEM S OFTWARE .................................................... 5

C LIENT S OFTWARE ...................................................................................................................................... 6

ActivMedia Robotics Basic Suite ............................................................................................................ 6

ARIA ....................................................................................................................................................... 7

Saphira ................................................................................................................................................... 7

Laser Navigation and Localization......................................................................................................... 7

ACTS....................................................................................................................................................... 8

M ODES OF O PERATION ................................................................................................................................ 8

Server Mode............................................................................................................................................ 8

Maintenance and Standalone Modes...................................................................................................... 8

Joydrive and Self Test Modes ................................................................................................................. 8

CHAPTER 3 SPECIFICATIONS & CONTROLS ................................................................................... 9

M AIN C OMPONENTS .................................................................................................................................... 9

Deck...................................................................................................................................................... 10

Body...................................................................................................................................................... 10

Batteries and Power ............................................................................................................................. 11

Motors, Wheels, and Position Encoders ............................................................................................... 12

Sonar with Gain Adjustments ............................................................................................................... 13

User Control Panel............................................................................................................................... 14

P ROTECTIVE S ENSORS AND S TRATEGIES ................................................................................................... 15

Ledge-Sensing IRs ............................................................................................................................... 15

Bumpers................................................................................................................................................ 16

Emergency Stop .................................................................................................................................... 17

Stalls and Watchdogs............................................................................................................................ 17

I NTEGRATED PC ........................................................................................................................................ 17

PC Power Controls and Indicators ...................................................................................................... 18

Standard and Expansion Interfaces...................................................................................................... 18

Ethernet Networking............................................................................................................................. 19

C OMMON A CCESSORIES ............................................................................................................................ 20

PTZ Robotic Camera ............................................................................................................................ 20

Laser Range Finder .............................................................................................................................. 20

PowerBot Arm ...................................................................................................................................... 21

CHAPTER 4 QUICK START................................................................................................................... 24

P REPARATIVE A SSEMBLY .......................................................................................................................... 24

Install Batteries..................................................................................................................................... 24

M OTORS S ELF -T EST .................................................................................................................................. 25

O PERATING THE O NBOARD PC.................................................................................................................. 25

ARIA D EMONSTRATION P ROGRAM .......................................................................................................... 26

Client Server Connection...................................................................................................................... 26

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ActivMedia Robotics

A Successful Connection .......................................................................................................................27

Operating the ARIA Demonstration Client............................................................................................27

Disconnecting........................................................................................................................................28

Shut Down .............................................................................................................................................28

D EMO T ROUBLESHOOTING .........................................................................................................................28

SRIsim ...................................................................................................................................................28

CHAPTER 5 JOYDRIVE AND SELF-TESTS ........................................................................................30

J OYDRIVE M ODE ........................................................................................................................................30

Engaging Joydrive.................................................................................................................................30

Joystick Calibration ..............................................................................................................................30

Joystick Operation.................................................................................................................................30

JoyDrive Speed Controls.......................................................................................................................31

M OTORS S ELF -T EST ...................................................................................................................................31

CHAPTER 6 ACTIVMEDIA ROBOTICS OPERATING SYSTEM.....................................................32

C LIENT -S ERVER C OMMUNICATION P ACKET P ROTOCOLS ...........................................................................32

Packet Checksum...................................................................................................................................33

Packet Errors ........................................................................................................................................33

S ERVER I NFORMATION P ACKETS ...............................................................................................................34

C LIENT C OMMANDS ...................................................................................................................................35

T HE C LIENT -S ERVER C ONNECTION ............................................................................................................37

Autoconfiguration (SYNC2)...................................................................................................................37

Opening the Servers—OPEN ................................................................................................................38

Keeping the Beat—PULSE....................................................................................................................38

Closing the Connection—CLOSE..........................................................................................................38

M OTION C OMMANDS .................................................................................................................................38

ActivMedia Robots in Motion................................................................................................................39

PID Controls .........................................................................................................................................40

Position Integration...............................................................................................................................40

S ONAR .......................................................................................................................................................41

........................................................................................................................42

STALLS AND EMERGENCIES

A CCESSORY C OMMANDS AND P ACKETS ....................................................................................................43

Packet Processing .................................................................................................................................43

CONFIGpac and CONFIG Command ..................................................................................................43

AUX port communications ....................................................................................................................44

Encoder packets ....................................................................................................................................44

Sounds ...................................................................................................................................................45

Onboard PC ..........................................................................................................................................45

TCM2.....................................................................................................................................................46

I NPUT O UTPUT (I/O) ..................................................................................................................................46

User I/O.................................................................................................................................................46

Bumper and IR I/O ................................................................................................................................47

Expansion I/O........................................................................................................................................47

IO packets..............................................................................................................................................47

CHAPTER 7 UPDATING & RECONFIGURING AROS ......................................................................49

W HERE TO G ET AROS S OFTWARE ............................................................................................................49

AROS M AINTENANCE M ODE ....................................................................................................................49

S IMPLE AROS U PDATES ............................................................................................................................49

AROS CF ....................................................................................................................................................50

S TARTING AROS CF ...................................................................................................................................50

C ONFIGURING AROS O PERATING P ARAMETERS .......................................................................................51

Interactive Commands...........................................................................................................................51

Changing Parameters............................................................................................................................51

S AVE Y OUR W ORK ....................................................................................................................................52

PID P ARAMETERS ......................................................................................................................................52

T ICKSMM AND R EVCOUNT .........................................................................................................................54

S TALL V AL AND S TALL C OUNT ...................................................................................................................54

B UMPERS ...................................................................................................................................................54

v

CHAPTER 8 MAINTENANCE & REPAIR............................................................................................ 56

T IRE I NFLATION ........................................................................................................................................ 56

D RIVE L UBRICATION ................................................................................................................................. 56

B ATTERIES ................................................................................................................................................ 56

Charging............................................................................................................................................... 56

Changing Batteries ............................................................................................................................... 56

P LATFORM T ILT ........................................................................................................................................ 57

G ETTING I NSIDE ........................................................................................................................................ 57

Opening the Deck ................................................................................................................................. 57

F ACTORY R EPAIRS .................................................................................................................................... 58

APPENDIX A.............................................................................................................................................. 59

S YSTEMS AND P OWER D IAGRAM ............................................................................................................... 59

APPENDIX B.............................................................................................................................................. 61

H8S P ORTS & C ONNECTIONS .................................................................................................................... 61

H8S Microcontroller............................................................................................................................. 61

Power Connector.................................................................................................................................. 61

Serial Ports........................................................................................................................................... 62

User I/O-Gripper Port.......................................................................................................................... 62

The Expansion I/O Bus ......................................................................................................................... 63

Bumper Ports........................................................................................................................................ 64

Motors, Encoders, and IR Sensors........................................................................................................ 64

User Control Interface.......................................................................................................................... 64

Joystick Port ......................................................................................................................................... 65

APPENDIX C.............................................................................................................................................. 66

P OWER D ISTRIBUTION ............................................................................................................................... 66

G ENERAL P OWER AND S IGNAL D ISTRIBUTION B OARD .............................................................................. 66

Power Distribution and User Power .................................................................................................... 66

M AIN P OWER D ISTRIBUTION B OARD ........................................................................................................ 68

APPENDIX D.............................................................................................................................................. 69

ARIA/S APHIRA P ARAMETERS F ILE ........................................................................................................... 69

WARRANTY & LIABILITIES ................................................................................................................ 71

vi

ActivMedia Robotics

Chapter 1

Introduction

Congratulations on your purchase and welcome to the rapidly growing community of researchers, developers, and enthusiasts of ActivMedia Robotics’ intelligent mobile robots.

This PowerBot Operations Manual provides both the general and technical details you need to operate your new PowerBot™ mobile robot and to begin developing your own robotics hardware and software.

Figure 1. ActivMedia robots first appeared commercially in 1995.

R OBOT P ACKAGE

Our experienced manufacturing staff put your mobile robot and accessories through a

“burn in” period and carefully tested them before shipping the products to you. In addition to the companion resources listed above, we warranty your ActivMedia robot and our manufactured accessories against mechanical, electronic, and labor defects for one year. Third-party accessories are warranted by their manufacturers, typically for

90 days.

Even though we’ve made every effort to make your ActivMedia Robotics package complete, please check the components carefully after you unpack them from the shipping crates.

Basic Components

One fully assembled PowerBot mobile robot

Two batteries

Two sonar arrays; 28 total sonar front and rear

Four fixed-range IR ledge sensors

Full-sized onboard PC

H8S-based AROS robotics controller

CD-ROM containing copies of ActivMedia Robotics software and documentation

Hex wrenches

Replacement fuses and assorted replacement screws

Set of manuals

Registration and Account Sheet

Optional Components and Attachments (partial list)

Digital stereo vision system

Pan-Tilt-Zoom robotic camera and color-tracking system

Range-finding laser with navigation software

Global Positioning System

Inertial navigation device

Compass

Six-DOF PowerBot arm

Many more…

1

Congratulations

A DDITIONAL R ESOURCES

New ActivMedia Robotics customers get three additional and valuable resources:

A private account on our support Internet Web server for software, updates, and manuals

Access to private newsgroups

Direct access to the ActivMedia Robotics technical support team

Support Website

We maintain a 24-hour, seven-day per week World Wide Web server where customers may obtain software and support materials: http://robots.activmedia.com

Some areas of the website are restricted to licensed customers. To gain access, enter the username and password written on the Registration & Account Sheet that accompanied your robot.

Newsgroups

We maintain several email-based newsgroups through which ActivMedia robot owners share ideas, software, and questions about the robot. Visit the support http://robots.activmedia.com website for more details. To sign up for pioneer-users, for example, send an e-mail message to the –requests automated newsgroup server:

To: [email protected]

<your return e-mail address goes here>

Subject:

help (returns instructions)

lists (returns list of newsgroups)

subscribe

unsubscribe

Our SmartList-based listserver will respond automatically. After you subscribe, send your email comments, suggestions, and questions intended for the worldwide community of

Pioneer users: 1

To: [email protected]

<your return e-mail address goes here>

Access to the pioneer-users newslist is limited to subscribers, so your address is safe from spam. However, the list currently is unmoderated, so please confine your comments and inquiries to issues concerning the operation and programming of Pioneer or PeopleBot robots.

Support

Have a problem? Can’t find the answer in this or any of the accompanying manuals? Or do you know a way that we might improve our robots? Share your thoughts and questions with us from the online form at the support website: http://robots.activmedia.com/techsupport

1 Note: Leave out the –requests part of the email address when sending messages to the newsgroup.

2

ActivMedia Robotics

or by email: [email protected]

Please include your robot's serial numberwe often need to understand your robot's configuration to best answer your question.

Your message goes directly to the ActivMedia Robotics technical support team. There a staff member will help you or point you to a place where you can find help.

Tell us your robot’s SERIAL NUMBER.

Because this is a support option, not a general-interest newsgroup like pioneer-users, we reserve the option to reply only to questions about problems with your robot or software.

See Chapter 8, Maintenance & Repair, for more details.

3

Chapter 2

What is PowerBot?

The PowerBot™ is a mobile robot specially designed and equipped for autonomous, intelligent navigation and handling of large payloads. It is a member of ActivMedia

Robotics’ Pioneer family of mobile robots, which are research and development platforms that share a common architecture, foundation software, and employ a client-server robotics control architecture that was originally developed by Kurt Konolige, Ph.D., of SRI

International, Inc. and Stanford University.

Figure 2. The PowerBot can transport up to 100 Kg of payload at up to 6 kph autonomously for nearly 2 ½ hours.

P IONEER R EFERENCE P LATFORM

ActivMedia robots set the standards for intelligent mobile platforms by containing all of the basic components for sensing and navigation in a real-world environment. They have become reference platforms in a wide variety of research projects, including several US Defense Advanced Research Projects Agency (DARPA) funded studies.

Every ActivMedia robot comes complete with a sturdy aluminum body, balanced drive system (two-wheel differential with balancing casters or four-wheel skid-steer), reversible

DC motors, motor-control and drive electronics, high-resolution motion encoders, and long-life battery power, all managed by an onboard microcontroller and mobile-robot server software.

Besides the open-systems

ActivMedia Robotics Operating

System (AROS) software in the robot’s microcontroller, every

ActivMedia robot comes with a host of advanced robot-control client software applications and applications-development environments. Software development includes our own foundation ActivMedia Robotics

Figure 3. PowerBot comes with state-of-the-art robotics-applications development software.

Interface for Applications

(ARIA), released under the GNU

Public License and complete with fully documented C++ libraries and source code. SRI International’s Saphira robotics development system with simulator and GUI, as well as support for advanced localization and gradient-based navigation comes bundled, too. Several third-party robotics applications development environments also have emerged from the research community for ActivMedia robots, including Ayllu from Brandeis University, Pyro from Bryn

Mawr and Swarthmore Colleges, and Player from the University of Southern California.

Available applications software include the ActivMedia Robotics Basic Suite and Basic

Suite Pro with state-of-the-art autonomous and guarded operation of the robot and accessories for surveillance, delivery, and a variety of other remote-agent applications.

Every ActivMedia robot also comes with a plethora of expansion options, too, including built-in hardware support for sonar and bump sensors and lift/gripper effectors, as well as

4

ActivMedia Robotics serial-port and server software support for a number of sensors, effectors, and control accessories, like an onboard PC system, six-degrees of freedom PowerBot Arm, robotic pan-tilt cameras, and much, much more.

P OWERBOT ' S M ICROCONTROLLER AND O PERATING

S

YSTEM

S

OFTWARE

At its most basic level, your PowerBot operates as the server in a client-server environment: Its drive system, integrated sensors, and microcontroller handle the low-level details of mobile robotics, including maintaining the platform’s drive speed and heading over uneven terrain, acquiring sensor readings, such as from the sonar and encoders, and managing attached accessories like a PTZ camera.

To complete the client-server architecture,

ActivMedia robots require a client connection: software running on a computer connected with the robot’s microcontroller via the HOST serial link and which provides the high-level, intelligent robot controls, including obstacle avoidance, path planning, features recognition, localization, gradient navigation, and so on.

Figure 4. ActivMedia

Robotics’ H8S-based controller is the server in the intelligent robotics client-server architecture.

Your PowerBot operates from an H8S-microprocessor-based mobile-robotics microcontroller. The controller has a variety of expansion power and I/O ports for attachment and close integration of a client PC, sensors, and a variety of accessories— all accessible through a common application interface to the robot server software,

AROS.

Features include:

18 MHz Hitachi H8S/2357 with 32K RAM and 128K FLASH

Optional 512K FLASH or SRAM expansion

3 RS-232 serial ports (4 connectors) configurable from 9.6 to 115.2 kbaud

4 Sonar arrays of 8 sonar each

2 8-bit bumpers/digital input connectors

1 P2 Gripper/User I/O connector with 8-bits digital I/O and 1 analog input

1 Expansion/bus connector containing

5 Analog input

2 Analog output

8-bit I/O bus with r/w and 4 chip-selects

2-axes, 2-button joystick port

User Control Panel

Controller HOST serial connector

Main power and bi-color LED battery level indicators

AUX power switches with related LED indicators

RESET and MOTORS pushbutton controls

Piezo buzzer

Motor/Power Board (drive system) interface with PWM and motor-direction control lines and 8-bits of digital input

With the onboard PC, wireless Ethernet, and advanced navigational software, your

PowerBot becomes a fully autonomous agent ideal for research and commercial applications that require precision delivery of large payloads.

5

C LIENT S OFTWARE

An important benefit of ActivMedia Robotics’ client-server architecture is that different robot servers can be run using the same high-level client. For example, we provide a robot simulator that runs on the host machine that can look and act just like your real robot. With the simulator, you may conveniently perfect your application software, then download and run it without modification on your PowerBot. Several clients also may share responsibility for controlling a single mobile server, which permits experimentation in distributed communication, planning, and control.

Currently available client software and development environments for the Microsoft

Windows or Red Hat© Linux-based computing platform of your choice include:

2

ActivMedia Robotics Basic Suite with WorldLink Internet surveillance and control

ActivMedia Robotics Interface for Applications (ARIA)

SRIsim ActivMedia robot simulator

SRI’s Saphira client-development suite with Colbert

Versions and updates for supported computing platforms are available to passwordregistered customers for download from our software website:

http://robots.activmedia.com

ActivMedia Robotics Basic Suite

To better support our customers, ActivMedia

Robotics software designers have blended and refined the best of advanced mobile robotics software found in the many development environments into a suite of state-of-the-art software tools and applications. We call this suite

ActivMedia Robotics Basic Suite, and it includes the following five modules plus a robot simulator:

Figure 5. Navigator and

WorldPass guide the robot to a goal with a click of the mouse.

N AVIGATOR is the crown jewel—a sophisticated graphical-user control module with which you access your ActivMedia robot’s many intelligent capabilities, from guarded teleoperation to selfguided navigation along a planned path to a goal that you select onscreen with a click of the mouse.

Navigator also lets you remotely share, connect and operate the robot from the

Internet, or a local area network. You can see and hear from afar what your robot sees and hears through its camera and microphone. Navigator even lets you chat and exchange audio and video with others who may be connected simultaneously.

W ORLD P ASS is a free version of Navigator that lets you share your robot with colleagues, friends, and family. WorldPass provides all the networking and remote-control functionality of Navigator, including network video and audio, but only connects with a robot through a host running Navigator, not to one directly. You may distribute WorldPass to anyone you want to use your robot, but it will not appear on your own menu since it copies functionalities of Navigator, which you may not distribute.

M APPER provides the tools you need to construct a map of your robot’s real operating space (“world”). Navigator and WorldPass use this map floor plan to plan a path from one point to another within a space.

2 Most software comes bundled with your PeopleBot. Other packages require purchase for licensing. Some software also are available for alternative operating systems, such as Macintosh, SunOS, Solaris, and BSD Unix.

6

ActivMedia Robotics

T RAINER is a programming editor and robot interface in which you create and perfect your own intelligent mobile robot-control programs with the simple, yet powerful Colbert programming language.

S IMULATOR is not a separate module of Basic Suite. It is a connection option that provides a virtual replacement for your robot. By connecting to the simulator instead of a real robot, you can test Colbert programs, maps, and so on, when the real robot isn’t practical or available.

A MIGO S OUNDS is for AmigoBot only.

With AmigoSounds, you assemble recorded sounds stored on your

PC’s disk into a playlist of sounds for your AmigoBot. With AmigoSounds, you may give AmigoBot different audio-based personalities.

ARIA

ActivMedia Robotics’ Interface for

Applications (ARIA) is a C++-based open-source development environment that provides a robust clientside interface to a variety of intelligent robotics systems, including your ActivMedia robot’s microcontroller and accessory systems, such as PowerBot’s laser range finder accessory.

Figure 6. ActivMedia Robotics' Interface for

Applications (ARIA) intelligent robotics-control foundation software.

ARIA is the ideal platform for integration of your own robot-control software, since it neatly handles the lowest-level details of client-server interactions, including TCP/IP networking and serial communications, command and server-information packet processing, cycle timing, and multithreading, as well as a variety of accessory controls, such as for the PTZ robotic camera, the PowerBot Arm, scanning laser-range finder, motion gyros, among many others.

What’s more, it comes with source code so that you may examine the software and modify it for your own sensors and applications.

Saphira

Saphira, including the Colbert language, is a full-featured robotics control environment developed at SRI International’s Artificial Intelligence Center. Saphira and its ARIA foundation form the robotics-control and applications-development foundation for much of the ActivMedia Robotics Basic Suite and many other ventures. The complete, licensed Saphira robotics development environment, including C/C++ libraries, GUI interface and Simulator, comes bundled with your ActivMedia robot.

Laser Navigation and Localization

A separate Laser Navigation and Localization package is available as a Saphira add-on.

It is a comprehensive suite of software tools and applications by which, with your laserscanning/range-finder enabled robot, you automatically create, edit, and use maps and floor plans for advanced robotics applications including localization and gradient navigation.

7

ACTS

ActivMedia Robotics’ Color Tracking System (ACTS) is a GUI program that works with your color camera and video frame grabbing hardware to identify and track colored objects in its field of vision. The software comes with your PowerBot’s vision system and interfaces with your robot-control client software. Please consult the ACTS Manual for operation and programming details.

M ODES OF O PERATION

You may operate your PowerBot in one of five modes:

Server

Joydrive

Self-test

Maintenance

Standalone

Server Mode

Your PowerBot’s H8S microcontroller comes with fully programmable 128K FLASH and 32K dynamic RAM included in its Hitachi 18-MHz H8S/2357 microprocessor. An additional

512K of dynamic RAM or FLASH-ROM is available as optional equipment. But we don't recommend that you start learning H8S programming. Rather, the robot comes to you installed with ActivMedia’s latest AROS robotics server software.

In conjunction with client software, such as ARIA, Saphira, or ActivMedia Basic Suite

Navigator running on the onboard PC or other user-supplied computer, AROS lets you take advantage of modern client-server and robot-control technologies to perform advanced robot tasks.

Most users operate their ActivMedia robot in server mode, because it gives them quick, easy access to its robotics functionality while working with high-level software on a familiar host computer.

Maintenance and Standalone Modes

For experiments in microcontroller-level operation of your robot’s functions, you may reprogram the onboard FLASH for direct and standalone operation of your ActivMedia robot. We supply the means to download, but not the microcontroller's programming software, for you to work in standalone mode.

The utilities we provide for you to reprogram the H8S-based microcontroller's FLASH also may be used to update and upgrade your robot’s AROS. In a special Maintenance

Mode, you also adjust your robot’s operating parameters that AROS uses as default values on startup or reset. See Chapter 7, Updating & Reconfiguring AROS, for much more detail.

We typically provide the maintenance utilities and AROS upgrades free for download from our http://robots.activmedia.com

website, so be sure to sign up for the pioneerusers email newslist. That's where we notify our customers of the upgrades, as well as where we provide access to ActivMedia robot users worldwide.

Joydrive and Self Test Modes

Finally, we provide onboard software and microcontroller hardware that lets you drive

PowerBot from a tethered joystick when not otherwise connected with a controlling client. And we provide some self-test programs that exercise your robot’s hardware and software. We examine these modes in some detail in Chapter 5, Joydrive and Self-Tests.

8

ActivMedia Robotics

Chapter 3

Specifications & Controls

PowerBot is for autonomous-robot studies and applications that require highperformance intelligent-robotic mobility with a heavy payload. Accordingly, the robot is quite large and very strong relative to other ActivMedia robots.

Measuring 900 millimeters long, 660 millimeters wide, and 480 millimeters tall, PowerBot’s sturdy aluminum frame rides on two 263 millimeter-diameter pneumatic tires attached to high-power (2.08 kilogram-meters), independent, reversible DC motors with two rearmounted casters for balance. PowerBot’s strength and durability enables the platform to carry payloads up to 100 kilograms.

An integrated microcontroller with robotics software servers provide server-level robotics motion and sensor controls. An integrated, full-size PC hosts state-of-the-art intelligent mobile robot software and advanced sensors.

Figure 7. PowerBot features and dimensions

Standard sensors and accessories include odometry encoders on each wheel and ranging sonar fore and aft. Independent motor brakes, two easy-access emergency stop buttons on the deck, segmented bump sensors fore and aft, and forwardpointing, fixed-range infrared sensors provide platform operation safety.

Optional vision systems and a laser-range finder accessories attach in front just beneath the robot’s deck. Added sensors not only enhance the platform’s ability to finely navigate its surroundings, including around people and objects, but with special mapping and navigation software, turns your robot into a fully autonomous machine.

Accordingly, PowerBot’s physical dimensions and advanced intelligent robotics systems lend themselves very well to heavy payload applications that require intelligent navigation and interactions within tight quarters and cluttered spaces that may also include people.

M

AIN

C

OMPONENTS

The PowerBot is composed of several main parts and integrated accessories:

Deck

Body

Batteries and Power

Motors, Wheels, and Position Encoders

Sonar with Gain Adjustments

User Control Panel

Protective Sensors and Strategies

Integrated PC

Ethernet Networking

Common Accessories

9

Specifications and Controls

Deck

PowerBot’s deck is simply the flat, anodized aluminum top-plate where you mount accessories and other payloads, such as the PowerBot Arm accessory. It is roughly a

625 x 830 millimeter oval hinged in the middle so that you may access internal components after removing a few, not all, mounting screws.

Two large red Emergency Stop (E-STOP) buttons are mounted on each side near the rear of the robot, out of the way and easily accessible even when the PowerBot

Arm is deployed rearward. See Protective

Sensors and Strategies later in this chapter for details.

Figure 8. PowerBot top dimensions and turn diameter

A plastic-capped port in the center near the front of the deck lets you easily run accessory cables into the body of PowerBot, such as the signal and power cables for the Arm.

A thumb-screw secures a panel door at the rear of the deck. Recessed inside is the User

Control Panel, joystick port, and optional A/V Control Panel. The transparent, smokedplastic panel door lets you readily inspect the operations indicator LEDs while protecting the controls and switches.

When mounting additional accessories, you should try to center the robot's payload over the drive wheels. If you must add a heavy accessory to the edge of the deck, counterbalance the weight with a heavy object on the opposite end. See Chapter 8,

Maintenance & Repair, for access details.

Body

Your PowerBot’s sturdy aluminum body is built around a strong aluminum-tube frame for strength and durability.

The body houses the batteries, drive motors, electronics, PC, and many other common components. Bumpers and sonar arrays mount to the body front and rear. The PTZ camera and laser range-

Figure 9. Additional PowerBot dimensions and features finder optional accessories mount just below the front sonar and behind the protective bumpers.

A spring-levered door on the right side of the robot provides access to PowerBot’s power switches, indicators, and battery charge port. A similar door on the left side of the body accesses the onboard PC’s interface connectors and expansion card ports, including the keyboard, monitor, and mouse, serial, USB, and 100-baseT Ethernet connectors.

A two-swivel latch-secured rear door opens a sliding cradle that holds the robot’s batteries.

10

ActivMedia Robotics

Batteries and Power

Your PowerBot contains two sealed lead-acid batteries accessed though the dual-swivel latched door and slide tray at the rear of the robot. Each battery is an 88 ampere-hour,

12 volts direct-current (VDC) sealed lead/acid unit. They are wired in series to provide a total of 2,112 watt-hours @ 24 VDC of power when fully charged.

Twist the swivel latches to release the rear door and pull to slide the battery tray out of the robot. Note that the robot will tip backwards onto the rear bumper, so step aside.

Use caution when accessing the batteries:

Step back; the robot tips back as you slide out the tray.

Twist the maintenance breaker to OFF.

Don’t short either positive terminal (+) to the robot chassis.

The main power cables are insulated and short in length to minimize spark hazard.

Insulated, plastic-capped connectors bolt directly to the battery terminals. At the other ends, the positive (+) battery cable (red) attaches through a 150 ampere inline fuse to a

125 ampere “maintenance” circuit breaker which is mounted in the left panel just inside the battery compartment and which you should twist to OFF when accessing the power system. The black negative (-) battery cable connects to common, chassis ground.

Main power goes through the maintenance breaker to the Main Power

Distribution board, found just beneath the rear deck on the left side of the robot.

The negative (black; --) terminal is the common return (battery ground) and connected to the robot chassis.

Power throughout the robot is switched from the Main Power pushbuttons on the

Power Control Panel, found behind a spring-levered access door on the right side of the PowerBot. Both the MAIN

POWER ON and OFF switches are lowcurrent, signal-level pushbuttons that trigger a redundant, self-checking array of power relays, providing faultless mainpower distribution throughout the

Figure 10. PowerBot's Power Control

Panel platform, including power for the PowerBot Arm accessory, the PowerBot’s motor- and accessory-power control board, the motors, PC power and other subsystems.

3 A main

power indicator LED is found on the User Control Panel.

Additional power control for the onboard PC, as well as the accessory PowerBot Arm and laser-range finder are on the Power Control Panel, as described elsewhere in this manual. See the Appendix A for a power distribution diagram. All subsystems are protected by automotive spade-type fuses on the Main Power Distribution board.

The BRAKE RELEASE pushbutton on the Power Control Panel routes battery power to release the brakes so that you may push the robot manually when power is off.

4

3 The E-STOP buttons on the deck also are low-current, signal level switches to the Power Distribution board that trigger a redundant, self-checking array of relays that unconditionally remove power to the drive motors and the PowerBot Arm accessory, as well as engage the brakes. Power to other subsystems is not disrupted by the

4

E-STOP.

Requires battery power; maintenance circuit breaker and fuse must also be engaged.

11

Specifications and Controls

The CHARGE port on the Power Control Panel, of course, is where you plug in the

PowerBot Charger to recharge the batteries. The batteries are not hot swappable, but you may operate all the robot’s onboard systems except the drive motors while recharging.

Battery life for autonomous duty, of course, depends on the configuration of accessories and motor activity. Under normal conditions, PowerBot drives continuously for two or more hours. Battery recharge time with the recommended PowerBot Charger, robot main power off, is roughly 1.5 to 2.0 times the discharge time; or over three hours after two hours of autonomous service.

Figure 11. The User Control Panel has main power and battery-level indicators.

The User Control Panel has a bicolor LED labeled BATT that visually indicates current battery voltage.

The control panel’s buzzer also sounds a repetitive alarm if the battery voltage drops consistently below the FLASH LowBattery level

(see below). If the battery voltage drops below 21 volts, PowerBot’s microcontroller watchdog server automatically shuts down a client connection and notifies the onboard PC, via the SERIAL HRNG pin, to shut down, thereby preventing data loss or systems corruption due to low power.

Motors, Wheels, and Position Encoders

Your PowerBot’s 2-wheel differential drive system uses high-speed, high-torque (2.08 kilogram-meters), reversible-DC motors. Two high-current (30 amperes continuous, 50 amperes maximum) motor drivers provide differential power, as moderated by pulsewidth-modulated signals (0-100% pulse width in a 200 microsecond duty cycle) from the

PowerBot controller.

Each motor has an integrated brake which normally is engaged stopping the wheels from rolling even when robot main power is off. The BRAKE RELEASE pushbutton on the

Power Control Panel releases the brakes so you can push the robot around manually.

Otherwise, the brakes release under software control when driving in Joydrive Mode, when the MOTOR pushbutton on the User Control Panel is pressed while connected with a client program, or via a client command. See subsequent chapters for details.

Each drive shaft is equipped with a high-resolution optical quadrature shaft encoder for precise position, direction, and speed sensing (odometry) and advanced deadreckoning. Motor gearhead ratio is 22.3:1, with 1024 encoder ticks-per-revolution. AROS converts most client commands and server information from platform-independent distance units to and from platform-dependent encoder ticks, as expressed in the

Ticksmm controller-FLASH parameter, calculated as the encoder counts (4 times 1024 ticks) times gearhead ratio (22.3) divided by the product of wheel circumference (~250 millimeters times π), equal to ~100 ticks per millimeter, depending mostly on tire inflation and payload weight.

Inflate the tires evenly or your robot won’t drive properly.

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ActivMedia Robotics

AROS’ position integrator also uses a RevCount factor, which is the differential number of encoder ticks for one complete (360 degree) rotation of the robot. Like Ticksmm and depending on the actual wheelbase (tire inflation, in particular) and operating conditions, this value can vary and usually determined empirically. Current default for smooth, hard surface operation is 50,800 ticks per 360-degrees.

In any configuration, be careful to inflate the tires evenly and adjust the respective

Ticksmm and revcount FLASH parameters for proper operation. We ship with the tires inflated to 23 pounds per square inch each.

Sonar with Gain Adjustments

Your PowerBot comes standard with two sonar arrays, one in front and one in the rear. Sonar geometry is identical on each array: one sonar on each side, ten facing forward or rearward at

10-degree intervals, and two others at the sides. Together, fore and aft arrays of 24 total sonar provide 360 degrees of nearly seamless sensing.

ActivMedia’s sonar-ranging electronics manage up to eight sonar per board,

Figure 12. PowerBot sonar array and the robot’s controller software,

AROS, configures and implements each board individually and simultaneously.

Accordingly, from AROS’ standpoint, the front and rear PowerBot sonar actually are divided into four groups of seven sonar each. When configuring the sonar in FLASH, such as to set the default pinging sequence, the arrays are numbered as sonar1 (left front), sonar2 (right front) sonar3 (right rear), and sonar4 (left rear), and each group’s sonar are numbered one through seven clockwise. The eighth sonar per group is not used.

AROS numbers the sonar differently when reporting ranging data to a connected client: 5

Working clockwise around the robot beginning with the front left sonar, the sonar1 are numbered zero through six; sonar2 are eight through 13; sonar3 are 15 through 22; and sonar3 are 24 through 30. Notice that the sonar seven, 14, 21, and 31 are missing. These are the unused eighth sonar per group. ARIA and Saphira refer to a special powerbot.p parameters file stored in their respective params/ directories to relate a sonar number to the individual geometry on the robot.

Each sonar group fires one sonar simultaneously every 40 milliseconds (25 Hz). Sensitivity ranges from ten centimeters (six inches) to over six meters. The sonar ranging data (timeof-flight) get acquired by AROS and reported in millimeters to the connected client in the standard Server Information Packet. See the AROS chapters for details. You also may control the sonar’s firing pattern through software; the default is left-to-right in sequence

1 through 7 for each group.

The driver electronics are each calibrated at the factory. However, you may adjust the sonar sensitivities to accommodate differing operating environments. A Gain

Adjustment potentiometer is on the underside of each sonar driver board, which is attached to the floor on each side of the PowerBot’s sonar arrays.

Sonar sensitivity adjustment controls are accessible directly. For the front sonar, for instance, locate the respective access holes near the front underside of the array.

Access the rear sonar array’s gain sensitivity potentiometers similarly, but up through the

5 Ranging data gets including the standard server information packet. See the AROS chapters for details.

13

Specifications and Controls battery door. Using a small flat-blade screwdriver, turn the gain control counterclockwise to make the sonar associated with that array group less sensitive to external noise and false echoes.

Low sonar-gain settings reduce the robot’s ability to see small objects. Under some circumstances, that is desirable. For instance, attenuate the sonar if you are operating in a noisy environment or on uneven or highly reflective floora heavy shag carpet, for example. If the sonar are too sensitive, they will “see” the carpet immediately ahead of the robot as an obstacle.

Increase the sensitivity of the sonar by turning the gain-adjustment screw clockwise, making them more likely to see small objects or objects at a greater distance. For instance, increase the gain if you are operating in a relatively quiet and open environment with a smooth floor surface.

User Control Panel

The User Control Panel is where you have access to your PowerBot’s AROS-based onboard microcontroller. Find it beneath a smoked-plastic panel door at the rear of the

PowerBot’s deck.

The red PWR LED is lit whenever main power is on.

The green STAT LED states depend on the operating mode and other conditions: It flashes slowly when the microcontroller is awaiting a connection with a client; it flashes quickly when in Joydrive Mode or when connected with a client and the motors are engaged; and it flashes moderately fast when in Maintenance

Mode, for example.

The BATT LED’s apparent color depends on your

PowerBot’s battery voltage: green when fully charged (>24.5 volts), through orange, and finally red when the voltage is below 22 volts.

When in maintenance mode, the BATTERY LED glows bright red only, regardless of battery charge.

Figure 13. PowerBot’s

User Control Panel

The CHR LED is supposed to indicate when the batteries are charging. It is not implemented in current versions of the User Control Panel.

A built-in piezo buzzer (audible through the holes just above the STAT and PWR LEDs) provides audible clues to the robot’s state, such as upon successful startup of the microcontroller and a client connection. An AROS client command lets you program the buzzer, too, to play your own aural clues.

The SERIAL connector, with incoming and outgoing data indicator LEDs (RX and TX, respectively), is through where you may interact with the H8S microcontroller from an offboard or piggyback computer for tethered client-server control and for AROS system maintenance. The port is shared internally by the HOST serial port, to which we connect the onboard computer. Digital switching circuitry disables the internal HOST serial port if the computer is OFF. However, serial port interference will be a problem if the HOST and

User Control SERIAL ports are both occupied and engaged. Accordingly, turn off computer power if you intend to use the SERIAL port, or remove the SERIAL port cable when using the onboard PC.

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ActivMedia Robotics

AUX1 PWR and AUX2 PWR are logic-level pushbutton switches which engage or disengage power to the respective devices

6 on the Motor/Power Interface board. See

Appendix C for power connections. Respective red LEDs are lit when power is ON.

The red RESET pushbutton acts to unconditionally reset the H8S microcontroller, disabling any active connections or microcontroller-attached devices, including the robot’s motors.

The white MOTORS pushbutton’s actions depend on the state of the microcontroller.

When connected with a client, push it to manually enable and disable the motors, as its label implies. When not connected, press the pushbutton once to enable Joydrive

Mode, and again to enable the motors self-test.

To engage AROS Maintenance Mode, press and hold the white MOTORS button, press and release the red RESET button, then release MOTORS. In the future, the white MOTORS button may engage other modes, such as when in AROS standalone mode.

P ROTECTIVE S ENSORS AND S TRATEGIES

PowerBot comes with several built-in features and systems watchdogs that act at the controller level as well as under client control for safe operation of the robot. These are in addition to obstacle-avoidance and other safe-navigation behaviors that come as part of the client software development environments, including ARIA and Saphira.

Electronically and programmatically, PowerBot responds to its protection sensors at two levels. First, activation of one or more sensors causes the robot’s controller to take reflexive action, typically by disabling the motors and setting the brakes, such as when it bumps into something or an E-STOP button gets pressed. At the next level, the robot servers inform the client of the condition so that it may take evasive action, such as extricating itself from a stall.

Ledge-Sensing IRs

PowerBot is outfitted with two pairs of fixedrange IR sensors on each side of the robot that face down and forward to detect ledges, such as stairways or holes. The detectors respond to nearly any surface except glass or other mirrored surfaces, and can detect objects as thin as a human finger.

The lower two IRs are one-meter fixed range aimed to look forward approximately two meters from the wheels and detect a ledge at least 50 millimeters deep. The upper IRs are one-half meter fixed-range devices calibrated to detect a ledge 300 millimeters away from the wheels and at least 50 millimeters deep, the maximum traversable step.

Figure 14. PowerBot's ledge-sensing, fixed-range IRs

The IRs’ protective actions are controller-FLASH configurable (LedgeIRs) and under software control (LEDGE_BEHAV) when connected with a client. When configured, the robot servers may impose a speed limit (<150 millimeters per second forward motion) if the lower, far-sensing IRs lose contact with the floor, and may stop, not allowing any

6 Radio modem or other accessory connected to its power port, not radio Ethernet.

15

Specifications and Controls further forward motion, when the nearest-sensing IRs lose contact with the floor.

7 The IRs are digital devices which states appear in the IR byte of the IOpac server-information packet. The upper-left IR is bit 0; its lower partner is bit 1.

Table 1. Standard SIP FLAGS integer bits

BIT

1

2

3

4

5

6

7

8

CONDITION IF SET (1)

Sonar array #1 enabled

Sonar array #2 enabled

Sonar array #3 enabled

Sonar array #4 enabled

Emergency STOP button pressed

Emergency stall engaged

Far ledge detected (IR)

Near ledge detected (IR)

9 Joystick button 1 pressed

10-15 Reserved

Similarly, the upper IR on the right side is bit 2, and the lower IR on that same side is bit 3 of the IR IOpac byte. Normally off (digital bit set to

0), the respective IR bits reset to digital 1 when they lose contact with the floor.

Also, when the IR servers sense a far ledge, they set the eighth bit (bit 7) of the FLAGS integer in the standard server information packet, and set the ninth bit (bit 8) when the near

IRs sense a close ledge. For additional details, please consult the chapters on AROS.

By default, the protective behaviors of the IRs are not implemented because IRs are very sensitive to surface color and texture. They, therefore, are prone to false positive readings in unknown or uncontrolled environments. Accordingly, we recommend that your software client monitor the status of the ledge-sensing IRs, and that you implement the protective behaviors only within a known and controlled floor environment where the instances of false-positive readings are minimized and rare.

Bumpers

Bump rings fore and aft provide contact sensing for when other PowerBot sensing has failed to detect an obstacle. The rings are segmented for contact positioning, too, so that the autonomous client may more efficiently extricate the robot from a tight spot.

Normally off (digital zero), the respective bits in the front

(bits 1-7) and rear (bits 1-5) bumper bytes of the IOpac server information packet change to on (digital one) when the bumper gets triggered. Respective bits also change in the standard server information packet’s left

(front) and right (rear) STALL bytes.

PowerBot’s server response to a bump contact is preset by default, but can be modified by a client command

(BUMP_STALL): When a front bumper gets triggered and the robot is moving forward, the PowerBot immediately stops and engages its stall behavior. Similarly, a rear bump when the robot is moving backwards stop the robot and generates a stall.

See the AROS chapters and Stall section of this chapter for more details.

Figure 15. PowerBot's front and rear segmented bumpers

7 These are not default behaviors, nor is the speed limit imposed when operating in VEL2 drive mode. Also, the joystick button #1 overrides the ledge-sense behaviors for manual operation.

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ActivMedia Robotics

Emergency Stop

Two large, red E-STOP buttons sit prominently on the deck of PowerBot. When pressed, either button disengages and brakes the motors and PowerBot arm and signals a stall. A separate digital sense line to the microcontroller activates the standard server information packet’s E_STOP flag, to distinguish the event from a bump-related or other common stall.

To release the button, press it in and twist. You also will have to manually (MOTORS button on the User Control Panel) or have your client software programmatically re-enable the motors.

Stalls and Watchdogs

Besides the protective IR, bumper, and E-STOP hardware, your PowerBot’s controller also contains a client-server communication watchdog that will halt the robot’s motion if the connection between your PC client and the robot server is disrupted for a set time interval (watchdog FLASH parameter; default 2 seconds), such as if the PC program fails. The robot automatically resumes activity, including motion, as soon as communications are restored.

AROS also contains a stall monitor. If the robot’s drive system exerts a PWM control signal that equals or exceeds a configurable level (stallval) and the wheels fail to turn, motor power is removed, with the brakes set, for a configurable amount of time

(stallwait). The server software also notifies the client through the standard Server

Information Packet which motor is stalled. When the stallwait time elapses, motor power automatically switches back on and motion continues under server control.

There also is the LowBattery FLASH parameter that sets off an audible warning when the batteries fall below that safe charge level. To avoid systems corruptions, the AROS servers also force a soft system shutdown when the batteries fall below approximately 21 volts. The soft shutdown includes disconnection from a connected client. If you have

Linux on board the PC, a genpowerd daemon which monitors the HRING and DSR signals on the HOST serial port, causes shutdown of the onboard PC.

All these “failsafe” mechanisms help ensure that your robot will not cause damage or be damaged during operation. You may reconfigure the various FLASH-based parameter values to suit your application. See Chapter 7, Updating & Reconfiguring AROS, for details.

I

NTEGRATED

PC

The PowerBot comes standard with an onboard, internally integrated PC to act as the client platform in the robot’s client-server architecture. Mounted inside the body, the fullsized PC motherboard and auxiliary board port connectors are accessed through a spring-levered door on the left side of the robot.

The PC contains at least a 1 gigahertz processor, 256 megabytes RAM, and a 10 gigabyte, 2.5-inch shock-mounted hard-disk drive.

The onboard PC communicates with PowerBot’s H8S microcontroller through its HOST serial port and the dedicated serial port COM1 under Windows or /dev/ttyS0 on Linux systems. Automatic systems on the microcontroller switch in that HOST-to-PC connection when PC-based client software opens the serial port. Otherwise, the PC doesn’t interfere with externally connected clients through the shared SERIAL port on the User Control

Panel.

17

Specifications and Controls

Note also that some signals on the H8S microcontroller’s HOST serial port as connected with the onboard PC or other accessory can be used for automated PC shutdown or other utilities: Pin 4 (DSR) normally is RS232 high when the controller operates normally; otherwise it is low when reset or in maintenance mode. Similarly, pin 9 (RI) normally is low and goes RS232-level high when the robot’s batteries drop below a set (nominally 11

VDC) voltage level.

PC Power Controls and Indicators

Power for the PC is from a 24:5 VDC power system which is connected to the main power of the robot. The PC’s power control and indicator panel is part of the main Power

Control Panel on the right side of the robot. There, the POWER LED glows green when the

PC is running, and the amber HDD LED flashes as the system accesses its onboard harddisk drive. The red RESET pushbutton forces a “soft” restart of the PC without removing power to the onboard system.

The COMPUTER POWER pushbutton acts differently depending on the state of the PC system. When off, press the COMPUTER POWER button to start the PC. When on, press and hold the COMPUTER POWER button for one second to have the PC’s systems and software shut down and power off just as if you had issued a Linux halt or shut down the PC from Windows’ Start menu’s Shutdown… option.

If instead, you hold the COMPUTER POWER button in for a longer period—typically a little more than four seconds, the

PC will power off without delay just as if you had removed main power from the robot. Forced power down on the PC may result in loss of data.

With onboard Linux OS, a power-level watchdog,

GENPOWERD, or ups.exe under Windows, coupled with

PowerBot’s microcontroller watchdog server, automatically shuts down the onboard PC when battery power falls below

21 volts, thereby preventing data loss or systems corruption due to low power.

Figure 16. PowerBot's PC power, reset, and HDD indicator panel

Finally, the HDD LED on the computer power panel lights when the onboard PC accesses the hard-disk drive.

Standard and Expansion Interfaces

All interfaces to the computer are accessible through the Computer Access

Panel on the left side of the robot. These include ports for a monitor, keyboard, and mouse, as well as an RJ-45 connector for

10/100-BaseT Ethernet LAN.

Two RS232 standard serial communications ports come on the motherboard. The serial port COM1 (/dev/ttyS0 under Linux) is a dedicated interface to the robot’s controller. COM2 (/dev/ttyS1) typically is allocated to the laser range finder. The PC also supports four USB 1.1 and two USB 2.0 connectors and AGP-type graphics.

18

Figure 17. PowerBot's PC accessory ports are inside the left side panel.

ActivMedia Robotics

For additional functionality, the onboard PC supports standard PCI expansion cards in standard card slots. Your PowerBot comes with wireless Ethernet. Other accessories, such as an expansion serial I/O card a CANBUS card for the PowerBot arm may also be installed.

Do note that, although the onboard is very similar to common desktop systems, it has been configured to work with the PowerBot and its systems and should not be expanded or reconfigured without support from ActivMedia Robotics technical staff. For example, although the Linux-based onboard PC comes with common RedHat version 7.3, it does use a modified and recompiled kernel, which sources and makefile may be found in

/usr/linux/src.

Ethernet Networking

The RJ-45 connector on the Computer Control Panel provides wired 10/100Base-T

Ethernet networking directly with the onboard PC. We also provide 11 megabits-persecond wireless Ethernet in one of the PC slots. The wireless Ethernet antenna sits atop

PowerBot’s deck.

To complete the wireless installation, you will need to provide an IEEE 802.11b standard

Access Point module, which comes as an accessory, attached to your local network.

We use the default operating mode: “managed” client-server.

We ship integrated PC systems’ preset and tested at a fixed IP address with class-C

Ethernet network configuration. We allocate the same IP to both the wired and wireless

Ethernet ports, typically 192.168.100.32. Although you need not fuss with drivers or lowlevel device settings, before you may establish a network connection with the onboard

PC (not the robot’s microcontroller!), even if just through a cross-over Ethernet cable to another PC’s Ethernet connector, you’ll need to reconfigure the robot’s PC network settings. Please consult with your network systems administrator for networking details.

Briefly, with Windows, go to the Control Panel’s Network and Dialup Connections wizard and choose the networking device’s Properties to change the IP address and other details. Under Linux, there are similar, GUI-based tools under X-Windows to help you set up the network, such as netcfg, but we prefer to edit (emacs or vi) the salient network settings in /etc/sysconfig/network and in the specific device configuration files found in /etc/sysconfig/network-scripts/, such as ifcfg-eth0 (wired

Ethernet) and ifcfg-eth1 or ifcfg-wlan0 (wireless).

From Windows, use the Network and Dialup Connections tool to enable or disable a particular device. From Linux, use ifup and ifdown to enable or disable an Ethernet device. For example, as superuser, type ‘ifdown eth0; ifup wlan0’ to switch from a tethered to a wireless Ethernet connection.

For remote connections over Ethernet to your onboard PC, simply use telnet or the more secure ssh with your Linux system. Allow X-windows server connections at your remote PC

(xhost +[hostname or IP]) if you plan to export the X-Windows display from the robot

PC for remote GUI-based controls (export DISPLAY=remote’s hostname or IP:0, for example).

With Windows, you will need a special remote-control application to establish a connection from a remote computer to the onboard PC over the network; VNCserver, for example, or Timbuktu.

Please note that you may not connect with the robot’s microcontroller directly over the network: That is, you cannot run a client application, such as the ARIA demo or Saphira, on the remote PC and choose to directly connect with the robot server by selecting the

19

Specifications and Controls robot PC’s IP address. Rather, either run the client application on the onboard PC and export the display and controls over the network to the remote PC (preferred), or use the

ARIA-based IPTHRU programs (see program sources in Aria/examples) to negotiate the

IP-to-serial conversions needed by the client-server connection.

C

OMMON

A

CCESSORIES

Most PowerBot’s come installed with some common accessories, including a PTZ robotic camera for vision applications, a laser range finder for advanced mapping and navigation, and/or a 6-DOF PowerBot Arm.

PTZ Robotic Camera

PowerBot’s color video camera with 16X zoom lens comes on a programmable robotic pan-tilt base. The unit is attached underneath the robot’s top deck and atop a shelf that holds the laser range finder accessory, or beneath the shelf with laser above.

Camera power is connected through the AUX power port and therefore switched by the AUX PWR control on the User Control Panel. Camera power also is switched by Main

Power, its handheld controller, and through software.

Figure 18. PowerBot's PTZ color camera accessory with framegrabber and software provides for a fully robotic vision sensor and color-tracking system.

Camera control is through the handheld controller or programmatically through the AUX1 serial port on the robot’s H8S microcontroller. Special ARIA-based software facilities (ArVCC4) provide full client software control of the device for pan, tilt, and zoom. You also may use the AROS TTY client commands for direct control by a connected client. Please see the ARIA documentation and examples source code and the AROS chapters in this manual for details. Use the ARIA demo program to test and exercise the camera, too.

The analog video signal from the PTZ robotic camera is attached to a supporting analog framegrabber card on the PC. The framegrabber is integrated with the ActivMedia

Color Tracking System, Basic Suite Navigator, and other vision-sensor applications. See their respective manuals for details.

Laser Range Finder

ActivMedia Robotics’ Laser Mapping & Navigation system for PowerBot comes in two products: The Laser

Integration package contains the hardware and

ARIA/Saphira integration software you need to operate a SICK LMS-200 laser range finder (LRF) and to provide its data to your own applications. The separate Laser

Navigation and Localization package is a comprehensive suite of software tools and applications by which, with your laser-enabled robot, you automatically create, edit, and use maps and floorplans with your laser for advanced robotics applications including localization and gradient navigation.

Figure 19. Laser range finder accessory power switch on PowerBot's

Power Control Panel

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ActivMedia Robotics

The laser comes mounted at the front bump of PowerBot in one of two positions: atop the bump ring or higher up atop what normally is the shelf for the PTZ camera. The laser’s range-finding beam is thereby 220 mm or 360 mm above the floor, respectively.

Power to the laser is under manual as well as software control. A three-position toggle switch on the Power Control Panel sets the power mode. When OFF, the laser always remains off. When ON, the laser powers up when main power is switched on the robot. In

COMP mode, your client software switches power to the robot.

Data from the scanner is serial, acquired through the COM2 (Linux /dev/ttyS1) serial port on the onboard computer. Please see the ARIA and Laser Navigation manuals for control and data-acquisition details.

Within a single plane, the precision of the scanning range-finding laser is some 25 times that of the other common range-finding sensor: 180 readings in 180 degrees versus one reading in eight degrees for a sonar disc.

Moreover, because the laser beam is highly focused and not readily distorted or absorbed by the reflecting medium, the precision of range-finding with lasers is much superior to sonar with many fewer false-positive readings.

The laser can sense objects much further away, too: out 10 to 50 meters, while sonar are limited to three to six meters. Since rooms, and especially commercial spaces, commonly are Figure 20. Height of PowerBot’s laser beam in the common one of two positions on the robot. eight or more meters square, a sonar-based robot can easily get into voids wherein reflecting objects like walls are outside their detection limits. Without feature clues, navigation becomes severely imprecise; lost in space, so to speak. The precision and range of a laser, on the other hand, makes nearly error-proof localization and very fine gradient-based navigation possible.

The one disadvantage of the laser is its scanning height – a single plane of less than one degree. Sonar cone of operation provides broader sensing for proprioception, such as acute obstacle avoidance, which is why ActivMedia Robots operate best when equipped with both sonar arrays and an LRF.

PowerBot Arm

The PowerBot Arm is a industrial-quality accessory for research and applications. It’s a six-DOF arm plus gripper constructed of interchangeable modules that can lift up to a two kilogram payload at its end-effector.

We provide here some operating features and guidelines; please consult the manufacturer’s provided documentation for a full description of operations and programming.

Driven by seven, reversible 24 VDC motors, the arm is bolted to PowerBot’s at the front deck and can reach up to 800 millimeters from the center of its rotating base to the tip

Figure 21. The PowerBot Arm with gripper reaches 800 mm out from the robot and handles up to 2 kg of payload.

21

Specifications and Controls of its closed gripper. The robot counterbalances the fully-extended arm so that you can pick up a two-kilogram object from the floor and set it on a table without tipping.

Joints include: rotating base pivoting shoulder rotating arm pivoting elbow rotating arm pivoting wrist gripper

All joints, except for the gripper fingers, pivot or rotate ±160° or more. PowerBot’s deck or other accessories may reduce the arms envelope of operation motion. An integrated

EyeCam digital camera with firewire-based interface to the onboard computer is mounted to the gripper for vision-precise operation.

The PowerBot arm comes with a CANBus interface and drivers installed in the onboard

PC. The arm’s manufacturer, Amtec Robotics, provides a rich collection of arm control and development software for advanced kinematics. ARIA’s ArPowerCubeArm C++language class is a wrapper around the manufacturer’s libraries. Designed for simplicity and usability, the ARIA class contains the basic functions needed to operate the arm including: initialization of the CANBus controller homing the arm (necessary calibration before use) individual joint control (± degrees for joints; millimeters for gripper) velocity and acceleration control position reflection error condition reflection parking of the arm

The PBArmTest ARIA example program demonstrates some of the ArPowerCubeArm’s class features. Use the program, too, to test the arm and place it into its PARK position, safely tucked on top of the robot and out of the way for other mobile activities.

CAREFUL!

The PowerBot Arm is strong and fast. ALWAYS be aware of its position and keep out of its envelope of operation.

To operate the PowerBot Arm, switch its power on from the simple power toggle switch found next to the User Controls in the User Control Panel well (robot’s main power on, too, of course). The arm must be HOME’d every time you use it, including after someone has pressed an E-STOP button. Homing automatically rotates each module plus gripper to their zeroed positions—arm straight out from the robot—thereby calibrating the joints.

The arm won’t accept any movement commands until homed.

You must first HOME/CALIBRATE the PowerBot Arm before you may control its joints after power-up or E-STOP.

STAY BACK while HOMING—the arm straightens out from the robot.

PARK the arm for safety after every session.

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ActivMedia Robotics

Of course, be careful when operating the arm: It’s fast and strong. Be sure to keep the

PowerBot deck clear of obstructions and have everyone stand back and away from the arm’s envelope of operation.

When finished with a session, PARK the arm to protect it and the robot. The PARK’d

PowerBot Arm lays flat atop the robot’s deck, tucked in from the sides so that it does not interfere with the robot’s mobility.

23

Quick Start

Chapter 4

Quick Start

This chapter describes how to quickly set up, test, and operate your new PowerBot with the ARIA demonstration software. For more details about programming and operating your ActivMedia mobile robot with ARIA, Saphira, or other client software, see their respective programming manuals.

P REPARATIVE A SSEMBLY

Your PowerBot comes fully assembled and ready for out-of-the-box operation, including the onboard PC and demonstration software. All you need to install are the batteries.

Optional devices like the laser range finder accessory need installing, too, but you don’t need them to complete the Quick Start tests. If for any reason you need to install PC system and/or other software, please follow the software’s README instructions or contact ActivMedia Robotics’ support email for instructions.

Figure 22. PowerBot's batteries install through the rear door.

The ARIA client software-development environment, including the ARIA demonstration programs and robot simulator, come installed in your robot’s onboard PC. You also may obtain

ARIA and related software and updates from our support website: http://robots.activmedia.com

With Windows, ARIA is in the C:\Program

Files\ActivMedia Robotics\ARIA directory.

The ARIA demonstration program and simulator

(SRIsim) get put into the bin\ subdirectory. For convenience, you may access all these from the

Start Menu’s Programs option. The demonstration program’s source code and

MSVC++ project and workspace files are in the examples\ subdirectory.

Linux ARIA gets installed in /usr/local/Aria. The ARIA demonstration program and simulator get put into the bin/ subdirectory. The demonstration sources and makefile are in the examples/ subdirectory.

Linux users should also be sure they have permission to read/write through their PC’s serial port that connects with the robot. The default is /dev/ttyS0. ARIA is a terminal application that does not include a GUI, so its programs do not require X-Windows.

Install Batteries

Out of the box, your PowerBot comes with its batteries fully charged, although shipped separately. Install two batteries into the robot’s battery tray through the back door:

1. Access the battery tray by releasing the rear door latches sliding the tray out.

Careful, the tray acts as a strong lever in this position so that you will tip the robot down in the back and raise its front and wheels off the ground with little effort.

2. Place one battery in the battery tray with the terminals facing up, positive (+) terminal forward.

3. Remove the bolt from the positive (+) terminal of the battery and slide the red power cable onto the lug. Position the the cable so that it runs down the center of the battery, then secure the connection with the bolt.

4. Push the battery all the way forward in the tray.

24

ActivMedia Robotics

5. Similarly attach the red-tipped end of the 25 centimeter (10-inch) power-jumper cable to the second battery. The wire should point toward the center of the battery, too.

6. Place the second battery into the tray up on end so that the terminal with the attached jumper cable is on the bottom.

7. Connect the black tipped end of the power-jumper to the negative (-) terminal of the first battery.

8. Connect the remaining black power cable in the robot to the negative (-) terminal of the second battery. Run the wire so that it points down.

9. Carefully slide the battery tray into the robot and secure the rear door latches.

M OTORS S ELF -T EST

Position your PowerBot on the floor in an open space, or up on blocks if you have a monitor, keyboard, or mouse attached to the Computer Control Panel. Open the Power

Control Panel door and press the green MAIN POWER ON button. You should hear an audible beep, and the MAIN PWR and BATT LEDs on the User Control Panel should glow while the STATUS light blinks rhythmically. The same AROS initialization sequence occurs whenever you press the red RESET button on the User Control Panel, too.

Now press the white MOTOR button twice to engage the motors self-test. If your robot is working properly, it should move or rotate the wheels in four brief, but distinctive turns, forward and back, left and right. If not, please contact [email protected]

for assistance.

Press the red User Control Panel RESET button to prepare for a client connection.

O

PERATING THE

O

NBOARD

PC

This is a brief overview of operating the onboard PC. Please consult the Computer

Systems Documentation and the OS manufacturer’s documentation for more detail on your particular configuration.

ActivMedia Robotics’ software runs over either Microsoft Windows® (currently

Windows2000) or RedHat® Linux (currently version 7.x). Accordingly, we prefer (the latter, in particular) and support those OSes on the onboard PC.

When we perform the PC installation and configuration, we install our software typically in /usr/local on Linux systems, or in C:\Program Files\ActivMedia Robotics under

Windows. Of course, we also install and configure the appropriate drivers for the various accessory expansion cards, such as for a framegrabber, sound card, and wireless

Ethernet. Please consult the respective ActivMedia Robotics application software manuals, such as the ACTS manual for the video framegrabber or the Festival documentation for the sound card.

The first time you access the onboard PC, we recommend that you put the robot up on blocks so that it cannot inadvertently move and wreak havoc with external connections.

Then attach a keyboard, monitor, and mouse to their respective sockets inside the

Computer Access Panel on the left side of the robot. After starting up the robot, switch computer power on by pressing the COMPUTER POWER green pushbutton on the Power

Control Panel.

After bootup, log in to the PC system. We’ve already created two users: one with common systems and file read/write permissions (guest) and one with full-access to the

PC software and OS—root (Linux) or administrator (Windows). If there is a password

(usually not), it’s activmedia. When connected directly, we recommend you log in with full-access capabilities so that you can do systems setup and maintenance, such as change passwords, add users, and set up the network. Do note that with Linux systems,

25

Quick Start you cannot log in remotely over the network as root; you must log in as a common user and use the ‘su –‘ command thereafter to attain superuser (root) status.

Once logged into a Windows system, it’s simply a matter of clicking the mouse to select programs and applications. With Linux, use the ‘startx’ command to enable the X-

Windows desktop and GUI environment. You might perform some of the Quick Start activities this way, although motion is impractical because of the monitor, mouse, and keyboard tethers. You may remove these while the system is active at your own risk.

ARIA D EMONSTRATION P ROGRAM

If you haven’t done so already, now is a good time to put the robot up on blocks and attach a monitor, keyboard, and mouse to their respective connectors inside the

Computer Access Panel on the left side of the PowerBot.

8 Power up the robot and then

press the COMPUTER POWER button to start up the onboard PC.

By default, the ARIA demo connects with your robot server through your client PC’s COM1 (Windows) or /dev/ttyS0 (Linux) serial port.

You must alter the demo source and recompile for a different serial port.

Client Server Connection

Table 2. ARIA demo operation

First, please note well that you cannot connect with and control your PowerBot from a remote client over the network without special software that converts IP packets into

MODE io laser

HOT

K EY l i

DESCRIPTION

Displays the closest and furthest readings from the robot’s laser range finder

Displays the state of the robot’s digital and analog-to-digital I/O ports

serial data.

9 Instead, you

must run the client software on the robot’s PC or on a PC that is connected to the User

Control Panel’s SERIAL port. You may, of course, export the controls and display over the network. position bumps sonar camera p b s c

Displays the coordinates of the robot’s position relative to its starting location

Displays the status of the robot’s bumpers

Displays the robot’s sonar readings

Controls and exercises the robot’s pantilt-zoom robotic camera gripper g Controls, exercises, and displays status of the robot’s Gripper Windows users, select the

ARIA demo from the Start menu in the ActivMedia wander w Sends the robot to move around at its own whim, while avoiding obstacles

Robotics\ARIA program group. Otherwise, start it from the bin\ directory in

Program Files\Activteleop t Allows the user to drive and steer the robot via the keyboard or a joystick connected to the computer

Media Robotics\ARIA.

Linux users will find the compiled ARIA demo in /usr/local/Aria/bin/ and in examples/. You don’t need to start X-Windows to run the text-based ARIA demo:

8 Of course, if you’ve already gotten the wireless network up and running, you may operate these Quick Start

9 demonstration programs from a remote terminal.

Look in the Aria/examples directory for a program called ipthru. It converts IP to serial and back again for remote-control clients.

26

ActivMedia Robotics

A Successful Connection

ARIA prints out lots of diagnostic text as it negotiates a connection with the robot. If successful, the client requests various AROS servers to start their activities, including sonar polling, position integration, and so on. The microcontroller sounds an audible connection cue, and you should hear the robot’s sonar ping with a distinctive and repetitive clicking. In addition, the motors-associated STATUS LED on the User Control

Panel should light continuously (was flashing slowly while awaiting connection). The ARIA demo automatically engages your robot’s motors though a special client command.

Normally, the motors are disengaged when first connecting.

The amber SERIAL port indicator LEDs on the robot’s User Control Panel should blink to indicate ARIA-client to AROS-server communications, too.

Operating the ARIA Demonstration Client

When connected with the ARIA demo client, your PowerBot becomes responsive and intelligent. For example, it moves cautiously: Although it may drive toward an obstacle, your robot should not crash because the ARIA demo includes obstacleavoidance behaviors which enable it to detect and actively avoid collisions.

Table 2. Keyboard teleoperation

KEY

The ARIA demo displays a menu of operation options. The default mode of operation is teleop. In teleop mode, you drive the PowerBot manually using the arrow keys on your keyboard.

space

ACTION

Increment forward velocity

Decrement forward velocity

Incremental left turn

Incremental right turn

All stop

While driving from the keyboard, each keypress speeds the robot forward or backward or incrementally changes its direction incrementally. For instance, when turning, it is often useful to press the left- or right-turn key rapidly several times in a row, because the turn increment is small.

ATTENTION!

The ARIA client to robot server connection is SERIAL only.

You may not connect ARIA or other client software with the robot microcontroller over a network TCP/IP link.

Rather, EXPORT the onboard PC (display, keyboard, and mouse) to a remote terminal over the network but run ARIA or other client software locally on the onboard PC.

The other modes of ARIA demo operation give you access to your robot’s various sensors and accessories, including encoders, sonar, laser, a pan-tilt-zoom robotic camera, I/O port states, bumpers, and more. Accordingly, use the ARIA demo not only as a demonstration tool, but as a diagnostic one, as well, if you suspect a sensor or effector has failed or is working poorly.

27

Quick Start

Access each ARIA demo mode by pressing its related hot-key; ‘t’, for instance, to select teleoperation. Each mode includes onscreen instructions and may have sub-menus for operating of the respective device.

Disconnecting

When you finish, press the Esc key to disconnect the ARIA client from your robot server and exit the ARIA demonstration program. Your PowerBot should disengage its drive motors, apply the brakes, and stop moving, and its sonar should stop firing.

Shut Down

Be careful to shut down the onboard PC properly, either with the Linux halt command

(requires superuser-level privileges) or from the Windows Start: Shut Down… menu option, or by pressing the COMPUTER POWER button on the Power Control Panel. Wait a few moments for the PC to shut down before removing main power to the robot.

Note that Simultaneously pressing the Ctrl-Alt-Del keys when you have a keyboard attached to the onboard PC (not from an exported-control keyboard) reboots the Linux

PC and activates a shutdown dialog in Windows.

D

EMO

T

ROUBLESHOOTING

A common mistake with Linux is not having the proper permissions on the connecting serial port, typically /dev/ttyS0 should be rw for the current user.

Make sure your PowerBot’s batteries are fully charged (battery LED green). The robot servers shut down and won’t allow a connection at under approximately 21 volts.

The most common problems occur with the serial connection itself. If you are using the onboard PC, the serial connection is internal and established at the factory; you should not have problems with those cables. Remove any serial cable that is plugged into the

User Control Panel as it may interfere with internal serial communication.

With a serial connection through the User Control Panel, make sure to use the proper cable: a “pass-through” one, minimally connecting pins 2, 3, and 5 of your PC’s serial port. If you access the wrong serial port, the ARIA demonstration program will display an error message. If the robot server isn't listening, or if the serial link is severed somewhere between the client and server (cable loose, for instance), the client will attempt "Syncing

0" several times and fail. In that case, RESET the microcontroller and check your serial connections.

If for some reason communications get severed between the ARIA client and AROS server, but both the client and server remain active, you may revive the connection with little effort: simply fix the connection.

Communications also will fail if the client and/or server is somehow disabled during a session. For instance, if you inadvertently switch off the robot’s Main Power or press the

RESET button, you must restart the connection. Turning the Main Power switch OFF and then back ON, or pressing the RESET button puts the robot servers back to their wait state, ready to accept client connections again. Restart the ARIA demo or other client application and reconnect with the AROS servers.

SRIsim

To verify proper installation of the software, you might run the robot simulator, SRISim. It is in the same directory as the ARIA demonstration program. Start SRIsim first, then the

28

ActivMedia Robotics

ARIA demo program. ARIA should successfully connect with the simulator if the software has been installed correctly.

Linux users take note: SRIsim is a GUI program that graphically displays a simulated robot and its world environment in which it operates. Accordingly, you will need to be running X-windows (typically “startx”) to use it.

SRIsim looks like a real robot to the ARIA client, so you can operate the demo as you do your own ActivMedia robot. SRIsim includes simulated worlds and different robot profiles which you select from the Files menu, too, so you can see how different robots might navigate in a real or imagined space.

29

Quick Start

Chapter 5

Joydrive and Self-Tests

Your PowerBot comes with joystick connector inside the User Control Panel well, and

AROS contains a Joydrive server for manual operation of the robot. AROS also comes with a short self-test routine for your robot’s drive system.

To run in either joydrive or motors self-test mode, start up or RESET the robot into its AROS wait state. You may press the RESET button at any time to disable self-test and joydrive modes. You have about 10 seconds to engage and complete the joystick calibration and begin driving the robot or to enter into motors self-test mode before the microcontroller automatically cancels joydrive mode and reverts to waiting for a client connection.

You may also enable AROS’ joydrive server while connected with a client by sending the client command number 47 with the integer argument value of one.

J

OYDRIVE

M

ODE

You may manually drive your PowerBot even when connected with a client.

Engaging Joydrive

To joydrive your robot when not connected with a client program, switch the robot’s main power on or RESET the controller, then press the white MOTORS button on the User

Control Panel once. Listen for a rhythmic, low-tone beeping indicating joydrive mode.

To joydrive your robot while it is connected with a client (overrides client-based drive commands for manual operation while recording a map, for instance), you must have the client software send the AROS command number 47 with an integer argument value of one to enable the joydrive servers. The first time you press and release the joystick fire button after AROS receives the command, you engage self-calibration mode (see below). Have your client send the AROS joydrive command number 47 with an integer argument value of zero to disable the joystick drive-override.

Joystick Calibration

The joystick is self-calibrating: When you first enable joydrive mode, either by the client command or when in self-test joydrive mode, AROS detects the joystick’s center and extreme positions and saves these values to balance the driving action. Accordingly, rotate the joystick around its extreme limits and then let the joystick handle find its default centered position before pressing the fire button and starting to joydrive the robot. Try exiting (RESET or client command 47, depending on mode) and restarting joydrive mode if the joystick doesn’t seem to function well.

Joystick Operation

The joystick’s fire button #0, typically in the handle, acts as the joydrive “deadman”: press it to start driving; release it to stop the robot’s motors. The robot should drive forward and reverse, and turn left or right in response and at speeds relative to the joystick’s position and the controller-FLASH JoyVelMax and JoyRVelMax parameters.

When not connected with a client control program, releasing the joystick fire button stops the robot. However, when connected with a client, the client program resumes automatic operation of your robot’s drive system. So, for example, your robot may speed up or slow down and turn, depending on the actions of your client program.

30

ActivMedia Robotics

AROS maintains the appropriate safety features and servers when you operate the robot manually in joydrive mode, generating stalls and stopping when an E_STOP button is engaged, for example.

Same for the ledge-sensing IR behaviors. However, for full, manual control of the robot’s drives, AROS lets you over-ride the lege-sensing behaviors: Pressing the joystick button #1

(typically on the tip of the joystick) lets you keep driving the robot even when the nearsensing IRs detect a drop-off. Of course, you could drive the robot over a cliff or down a stairway this way, but you won’t, will you?

JoyDrive Speed Controls

You may adjust the maximum translational and rotational speeds, even disable joydrive mode, through AROS FLASH configuration parameters. See Chapter 7, Updating &

Reconfiguring AROS, for details.

M

OTORS

S

ELF

-T

EST

To enable motors self-test mode, press the white MOTORS button twice after startup or

RESET.

10

ATTENTION!

Have everyone step back before engaging motors self-tests.

Currently, the only AROS self-test exercises your PowerBot’s drive motors. During this test, the robot is not at all conscious of bystanders. Please have everyone step back and remove any obstacles from within a diameter of four to five feet around before engaging the self-test.

The motor’s self-test begins by engaging the left drive wheel, first forward, then in reverse, each to complete a partial turn clockwise, then counterclockwise. Similarly, the right wheel engages, first forward, then reverse to complete partial turns, first counterclockwise, then clockwise.

The H8S-AROS microcontroller reverts to its client-connection wait state after completing the motors self-test.

10 As described above, the first MOTORS press and release puts the robot into joydrive mode.

31

ActivMedia Robotics Operating System

Chapter 6

ActivMedia Robotics Operating System

All ActivMedia robots use a client-server mobile robot-control architecture originally developed by Dr. Kurt Konolige of SRI

International and Stanford University. In the model, the robot’s microcontroller servers work to manage all the low-level details of the mobile robot’s systems. These include operating the motors, firing the sonar, collecting sonar and wheel encoder data, and so onall on command from and reporting to a separate client application, such as Saphira, ARIA, or Basic Suite

Navigator.

With this client/server architecture, robotics applications developers do not need to know many details about a particular robot server, because the client insulates them from this lowest level of control. Some of you, however, may want to write your own robotics control and reactive planning programs, or just would like to have a closer programming relationship with your robot.

This chapter explains how to communicate with and control your ActivMedia robot via the ActivMedia Robotics Operating System

(AROS) client-server interface. The same

AROS functions and commands are supported in the various client-programming environments that accompany your robot or are available for separate license.

Figure 23. ActivMedia Robotics client-server control architecture

Experienced ActivMedia robot users can be assured that AROS is upwardly compatible with all ActivMedia robots, implementing the same commands and information packets that first appeared in the Pioneer 1-based PSOS and in the original Pioneer 2-based

P2OS. AROS, of course, extends the servers to add new functionality, improve performance, and provide additional information about the robot's state and sensing.

C LIENT -S ERVER C OMMUNICATION P ACKET P ROTOCOLS

ActivMedia robots communicate with a control client using special client-server communication packet protocols, one for command packets from client to server and another for server information packets (SIPs) from the server to client. Both protocols are bit streams consisting of five main elements: a two-byte header, a one-byte count of the number of subsequent packet bytes, the client command or SIP packet type, command data types and argument values or SIP data bytes, and, finally, a two-byte checksum.

Packets are limited to a maximum of 253 bytes each.

The two-byte header which signals the start of a packet is the same for both clientcommand packets and SIPs: 0xFA, 0xFB. The byte count value counts the number of all subsequent bytes in the packet including the checksum, but not including the byte count value itself of the header bytes.

32

ActivMedia Robotics

Data types are simple and depend on the element (see descriptions below): client commands, SIP types, and so on, are single 8-bit bytes, for example. Command arguments and SIP values may be 2-byte integers, ordered as least-significant byte always first. Some data are strings of up to a maximum 200 bytes, prefaced by a length byte. Unlike common data integers, the two-byte checksum appears with its mostsignificant byte first (opposite order).

Packet Checksum

Calculate the PSOS/P2OS/AROS client-server packet checksum by successively adding data byte pairs (high byte first) to a running checksum (initially zero), disregarding sign and overflow. If there is an odd number of data bytes, the last byte is XORed to the low-order byte of the checksum. int calc_chksum(unsigned char *ptr)

{

int n;

int c = 0;

n = *(ptr++);

n -= 2;

// ptr is array of bytes

// first is data count

/* Step over byte count */

/* don't include checksum word */

while (n > 1)

{

c += (*(ptr)<<8) | *(ptr+1);

c = c & 0xffff;

n -= 2;

ptr += 2;

}

if (n > 0)

c = c ^ (int)*(ptr++); return(c);

}

NOTE: The checksum integer is placed at the end of the packet, with its bytes in the reverse order of that used for data integers; that is, b

0

is the high byte and b

1

is the low byte.

Packet Errors

AROS ignores a client command packet whose byte count exceeds 252 (total packet size of 255 bytes) or has an erroneous checksum. The client should similarly ignore erroneous SIPs.

AROS does not acknowledge receipt of a command packet nor does it have any facility to handle client acknowledgment of a SIP. Accordingly, when designing client applications, keep in mind serial communication limitations, particularly data rates and physical linkage. Communication between an onboard PC client connected with the server via a signal cable is much more reliable than over radio modems, for example.

And don’t expect to send a client command every millisecond if the HOST serial port’s baud rate is set to 9,600 kbps.

Because of the real-time nature of client-server mobile-robotics interactions, we made a conscious decision to provide an unacknowledged communication packet interface.

Retransmitting server information or command packets would serve no useful purpose, because old data would be virtually useless in maintaining responsive robot behaviors.

Nonetheless, the client-server interface provides a simple means for dealing with ignored command packets: Most of the client commands alter state variables in the server. By

33

ActivMedia Robotics Operating System examining those values in respective SIPs, client software may detect ignored commands and re-issue them until achieving the correct state.

S

ERVER

I

NFORMATION

P

ACKETS

Like its PSOS and P2OS predecessors, AROS automatically and repeatedly sends a packet of information over its HOST serial port to a connected client. The standard AROS

SIP informs the client about a number of operating states and readings, using the order and data types described in the nearby Table.

Table 3. Standard Server Information Packet

NAME VALUE DESCRIPTION

HEADER int

BYTE COUNT byte Number of data bytes + 2 (checksum), not including header or byte-count bytes

STATUS / PACKET 0x3S = Motors status

TYPE 2

XPOS int

YPOS int to convert to millimeters.

THPOS

L VEL

Sint

BATTERY

Sint byte

Orientation in platform-dependent units—multiply by

AngleConvFactor ‡ for degrees.

Wheel velocities in mm/sec (VelConvFactor

R VEL Sint

‡ = 1.0)

Battery charge in tenths of volts (101 = 10.1 volts, for example)

STALL AND

BUMPERS int

Wheel-encoder integrated coordinates; platform-dependent units; multiply by DistConvFactor

CONTROL

FLAGS

Sint

Sint

Motor stall and bumper indicators. Bit 0 is the left wheel stall indicator, set to 1 if stalled. Bits 1-7 correspond to the front bumper I/O digital input states (accessory dependent). Bit 8 is the right wheel stall, and bits 9-13 correspond the rear bumper I/O states, also accessory- and application-dependent.

Setpoint of the server’s angular position servo—multiply by

AngleConvFactor ‡ for degrees

Bit 0 motors status; bits 1-4 sonar array status; bit 5 E_STOP button status, bit 6 set if E_STALL behavior engaged; bits 7& 8 set if near/far IR ledge-sensors triggered; bit 9 joystick button #1.

COMPASS

SONAR COUNT byte byte

Electronic compass accessory heading in 2-degree units

Number of new sonar readings included in SIP

NUMBER

RANGE byte int

… REST OF THE SONAR READINGS …

If Sonar Count>0, is sonar disc number 0-31; reading follows

Sonar range value; multiply by RangeConvFactor ‡

GRIP _ STATE

ANPORT

ANALOG

DIGIN

BYTE

BYTE

BYTE

BYTE

Gripper state byte (Pioneer 2 Gripper only)

Selected analog port number 1-5

User Analog input (0-255=0-5 VDC) reading on selected port

Byte-encoded User I/O digital input

DIGOUT BYTE Byte-encoded User I/O digital output

CHECKSUM

INTEGER checksum

Client-side data-conversion factor. Consult the ARIA parameter file your robot.

Explicitly a signed integer.

AROS also supports several additional SIP types. These include an “alternative” SIP that currently is not supported by Saphira or ARIA.

11 See following sections in this chapter for a

description of the extended SIP types.

11 Indeed, if enabled, the alternative SIP apparently will “break” the client software. Read carefully.

34

ActivMedia Robotics

C LIENT C OMMANDS

AROS has a structured command format for receiving and responding to directions from a client for control and operation of your ActivMedia robot or the Simulator.

Table 4. AROS/P2OS/PSOS client command packet protocol

COMPONENT BYTES VALUE

HEADER

BYTE COUNT

COMMAND

NUMBER

ARGUMENT

TYPE

ARGUMENT

CHECKSUM

2

1

1

0xFA, 0xFB

N

0 - 255

DESCRIPTION

Packet header; same for client and server

Number of command/argument bytes plus

Checksum’s two bytes, but not including Byte Count itself or the header bytes. Maximum of 249.

Client command number; see Table 7.

1

0x3B or

0x1B or

0x2B

Required data type of command argument: positive integer, negative or absolute integer, or string (ARGSTR) n

2 data computed

Command argument; always 2-byte integer or string containing length prefix

Packet integrity checksum

Table 5. AROS/P2OS/PSOS command set

COMMAND

SYNC

SYNC

SYNC

0

1

2

ARGS DESCRIPTION

Before Client Connection

AROS P 2 OS PSOS

0 none Start connection. Send in sequence. AROS echoes 1.0 1.0 3.x

1 none synchronization commands back to client, and

2 none robot-specific autosynchronization after SYNC2.

PULSE

After Established Connection

0 none Resets server watchdog

OPEN

CLOSE

1 none Starts the AROS servers

2 none Close servers and client connection

POLL ING

ENABLE

3 string Change sonar polling sequence (see text)

4 int 1=enable; 0=disable the motors

SETA 5 deceleration, if negative; mm/sec/sec

1.0 1.0 3.x

1.0 1.0 3.x

1.0 1.0 3.x

1.0 1.0 3.9

1.0 1.0 –

1.0 1.0

SETV

SETO

MOVE

ROTATE

SETRV

6 int Sets maximum translational velocity; mm/sec

7 none Resets local position to 0,0,0 origin

8 Sint Translate (+) forward or (-) back mm distance

9 Sint Rotate (+) counter- or (-) clockwise degrees/sec

10 int Sets maximum rotational velocity; degrees/sec

1.0 1.0 4.8

1.0 1.0 3.x

1.0 1.0 –

1.0 1.0 –

1.0 1.0 4.8

VEL

HEAD

DHEAD

11 Sint Translate at mm/sec forward (+) or backward (-)

12 Sint Turn to absolute heading; ±degrees (+ = ccw )

13 Sint Turn relative to current heading; (+) counter- or

(–) clockwise degrees

SAY 15 string As many as 20 pairs of duration (20 ms increments) /tone (half-cycle) pairs

CONFIG 18

1.0

1.0

1.0

1.0

3.x

4.2

1.0 1.0 3.x

1.0 1.0 4.2

ENCODER

RVEL

19 int Request one (1), a continuous stream (>1), or stop

(0) encoder SIPs

1.0 1.4 –

21 Rotate at (+) counter- or (–) clockwise; 1.0

35

ActivMedia Robotics Operating System

RVEL 21 Rotate at (+) counter- or (–) clockwise; degrees/sec

DCHEAD

SETRA

22 Sint Heading setpoint relative to last setpoint;

± degrees (+ = ccw)

23 Sint Rotational (+)acceleration or

(-)deceleration, in degrees/sec/sec

SONAR

STOP

28 int 1=enable, 0=disable all the sonar; otherwise, use bit 0 to enable (1) or disable (0) a particular array

1-4, as specified in argument bits 1-4.

29 none Stops robot; motors remain enabled

DIGOUT 30 bytes

Bits 8-15 is a byte mask that selects the output port(s); Bits 0-7 set (1) or reset (0) the selected port(s).

VEL bytes

Independent wheel velocities; Bits 0-7 for right wheel, Bits 8-15 for left wheel; PSOS is in

±4mm/sec; AROS/P2OS in 20mm/sec increments

GRIPPER

ADSEL

33 int Gripper server commands. See the Pioneer 2

Gripper or PeopleBot manual for details.

35 int Selects the A/D port number for reporting Anport value in standard SIP.

GRIPPERVAL 36 int Gripper server values. See Pioneer 2 Gripper or

PeopleBot manual for details.

GRIPREQUEST 37 none Request one (1), a continuous stream (>1), or stop

IOREQUEST

(0) Gripper SIPs. See Pioneer 2 Gripper or

PeopleBot manual for details.

40 none Request one (1), a continuous stream (>1), or stop

(0) IO SIPs

PTUPOS 41 bytes

Msbyte is port number (1-4), lsbyte is pulse width in 100µsec units PSOS or 10µsec units

P2OS

TTY 2

GETAUX

42 string Sends string argument to serial device connected to AUX (AUX1 on H8S) port

43 int Request to retrieve 1-200 bytes from the AUX

(AUX1 on H8S) serial port; 0 flushes the buffer.

BUMP _ STALL 44 int Stall robot if front (1), rear (2) or either (3; AROS default) bumps contacted. Off (P2OS default) is 0.

TCM 2

DOCK

JOYDRIVE

45 int TCM2 Module commands; see TCM2 Manual for details.

46 int Default is OFF; 1=enable docking signals;

2=enable docking signals and stop the robot when docking power sensed.

47 int Default is O=OFF; 1=allow joystick drive from hardware port while also connected with a client

E _ STOP 55 none Emergency stop, overrides deceleration

E _ STALL

LEDGE

STEP

TTY 3

ROTKP

_

BEHAV

GETAUX 2

56 int 1 (AROS default)=Emergency stop button causes stall; 0 (P2OS default)=off

57 int 0 if no ledge_sense behaviors engaged (default);

1 to stop when near-IRs sense ledge; 2 if impose speed limit when far IRs sense ledge; 3 for combined server-level behaviors

64 none Single-step mode (simulator only)

66 string Sends string argument to serial device connected to AUX2 H8S serial port

67 int Request to retrieve 1-200 bytes from the AUX2

H8S serial port; 0 flushes the buffer.

82 int Change working rotation Proportional PID value

(not FLASH default)

1.0 1.0 4.2

1.0

1.0 1.0

1.0 1.0 –

1.0 1.0 –

1.0 1.2 4.2

1.0 1.0 4.1

1.0 1.3 4.0

1.0 1.2 –

1.0 –

1.0 1.E –

1.0 1.E –

– 1.2 4.5

1.0 1.0 4.2

1.0 1.4 –

1.0 1.5 –

1.0 1.6 –

– 1.C –

1.0 1.G –

1.0 1.8 –

1.1 1.E –

1.5 – –

1.0 1.0 3.x

1.0 – –

1.0 – –

1.1 1.M –

36

ActivMedia Robotics

ROTKV

ROTKI

TRANSKP

TRANSKV

TRANSKI

REVCOUNT

PLAYLIST

SOUNDTOG

83 int Change working rotation Derivative PID value

(not FLASH default)

84 int Change working rotation Integral PID value (not

FLASH default)

85 int Change working translation Proportional PID value (not FLASH default)

86 int Change working translation Derivative PID value

(not FLASH default)

87 int Change working translation Integral PID value

(not FLASH default)

88 int Change working revcount value

(not FLASH default)

91 none Request AmigoBot sounds playlist packet

92 int 0=mute or 1=enable buzzer

╪ Signed integer; otherwise absolute/unsigned.

1.1 1.M –

1.1 1.M –

1.1 1.M –

1.1 1.M –

1.1 1.M –

1.1 1.M –

1.0

1.0

1.E

The number of client commands you may send per second depends on the HOST serial baud rate, average number of data bytes per command, synchronicity of the communication link, and so on. AROS’ command processor runs on a one millisecond interrupt cycle, but the server response speed depends on the command. Typically, limit client commands to a maximum of one every 3-5 milliseconds or be prepared to recover from lost commands.

T

HE

C

LIENT

-S

ERVER

C

ONNECTION

Before exerting any control, a client application must first establish a connection with the robot server via a serial link through the robot microcontroller’s HOST port. After establishing the communication link, the client then sends commands to and receives operating information from the server.

When first started or reset, AROS is in a special wait state, listening for communication

packets to establish a client-server connection.

12 To establish a connection, the client application must send a series of three synchronization packets containing the SYNC0,

SYNC1, and SYNC2 commands in succession, and retrieve the server responses.

Specifically, and as examples of the client command protocol, the synchronization sequence of bytes is (in hexadecimal notation):

SYNC0: 0xFA, 0xFB, 0x03, 0x00, 0x00, 0x00

SYNC1: 0xFA, 0xFB, 0x03, 0x01, 0x00, 0x01

SYNC1: 0xFA, 0xFB, 0x03, 0x02, 0x00, 0x02

When in wait mode, AROS echoes the packets verbatim back to the client. The client should listen for the returned packets and only issue the next synchronization packet after it has received the appropriate echo.

Autoconfiguration (SYNC2)

AROS automatically sends robot configuration information back to the client following the last synchronization packet (SYNC2). The configuration values are three NULLterminated strings that comprise the robot’s FLASH-stored name, class, and subclass.

You may uniquely name your ActivMedia robot with the FLASH configuration tool we provide. The class and subclass are constants normally set at the factory and not changed thereafter. (See next chapter for details.)

The class string typically is Pioneer. The subclass depends on your robot model; P2D8 or P2AT8, for example. Clients may use these identifying strings to self-configure their

12 There also is monitor mode for AROS downloads and parameter updates; see next chapter for details.

37

ActivMedia Robotics Operating System own operating parameters. ARIA, for instance, loads and uses the robot’s related parameters file found in the special Aria/params directory.

Opening the Servers—OPEN

Once you’ve established a connection with AROS, your client should send the OPEN command to the server, which causes the ActivMedia robot microcontroller to perform a few housekeeping functions, start its various servers, such as for the sonar and motor microcontrollers, listen for client commands, and begin transmitting server information to the client.

Keeping the Beat—PULSE

A safety watchdog expects that, once connected, your robot’s microcontroller receives at least one communication packet from the client every watchdog seconds (default is two). Otherwise, it assumes the client-server connection is broken and stops the robot.

Some clients—ARIA-based ones, for instance—use the good practice of sending a PULSE command just after opening the AROS servers. And if your client application will be otherwise distracted for some time, periodically issue the PULSE command to let your robot server know that your client is indeed alive and well. It has no other effect.

If the robot shuts down due to lack of communication with the client, it will revive upon receipt of a client command and automatically accelerate to the last-specified speed and heading setpoints.

Closing the Connection—CLOSE

To close the client-server connection, which automatically disables the motors and other server functions like sonar, simply issue the client CLOSE command.

Once connected, send the ENABLE command or press the white MOTORS button on the User Control Panel to enable your robot’s motors.

M

OTION

C

OMMANDS

The AROS motor-control servers accept several different client-motion commands of two mutually exclusive types: either independent-wheel or platform translation/rotation movements. The AROS servers automatically abandon any translation or rotation setpoints and switch to independent wheel-velocity controls when your client issues the independent-wheel VEL2 command, and vice versa.

Note that once connected, ActivMedia robots’ motors are disabled, regardless of their state when last connected. Accordingly, you must either enable the motors manually

(white MOTORS button on the User Control Panel) or send the motors ENABLE client command with the argument value of one.

13 Monitor the status if the motors with bit 0 of

the Flags integer in the standard SIP.

When in independent-wheel velocity mode (VEL2), the robot’s motion-control servers do their best to maintain precise wheel velocities. In practice, wheel slippage and uneven terrain will cause the robot to change heading, which your client must detect and compensate. When in translational/rotational (TR) motion control mode

13 Alternatively, disable the motors with the ENABLE command argument of zero.

38

ActivMedia Robotics

(recommended), your robot’s servers work to maintain both platform speed and heading.

Table 6. AROS motion commands

Rotation

HEAD (#12) Turn to absolute heading at SETRV max velocity

DHEAD (#13),

DCHEAD (#22)

Turn to heading relative to control point at SETRV max velocity

ROTATE (#9) Rotate at SETRV velocity

Translation

VEL (#11) Translate forward/reverse at prescribed velocity (SETV maximum)

MOVE (#8) Translate

Independent Wheel

VEL 2 (#32) Set velocity for each side of robot (SETV maximum)

ActivMedia Robots in Motion

ActivMedia robots use position, as opposed to velocity, motion controls to translate the platform a certain distance and turn it to a particular heading. To achieve constant translation (VEL), rotation (ROTATE), or independent-wheel (VEL2) velocities, the servers simply set the target position well ahead of the robot’s current position. max velocity

o v e, max velocity not reached v e l o c i t y a c c e l decel s p tart osition time position achieved positio achiev n e d

Figure 24. ActivMedia robots trapezoidal velocity profile

When the robot microcontroller receives a motion command, it accelerates or decelerates the robot at the translational SETA (TR and VEL2 modes) and rotational

SETRA (TR mode only) rates until the platform either achieves its SETV maximum translational and SETRV maximum rotational speeds, or nears its goal. Accordingly, rotation headings and translation speeds are achieved by a trapezoidal velocity function, which AROS recomputes each time a new motion command is received.

14

AROS automatically limits VEL2-, VEL-, and RVEL-specified velocities to previously imposed, client-modifiable SETVEL and SETRV maximums, and ultimately by absolute, platform-dependent, FLASH-embedded constants. Similarly, the distinct acceleration

14 Note that acceleration and deceleration are distinct values, settable via SETA for translation and SETRA for rotation.

39

ActivMedia Robotics Operating System and deceleration parameters for both translation and rotation are limited by FLASH constants. AROS initializes these values upon microcontroller startup or reset from related

FLASH parameters. The speed limits, either from FLASH or when changed by SETV or

SETRV commands, take effect on subsequent commands, not previously established velocity or heading setpoints. And the changes persist for the duration of the current

client-server connection.

15

Note that the emergency stop (E_STOP) command number 55 and the Emergency STOP button on your PowerBot override deceleration and immediately stop the robot in the shortest distance and time possible. Accordingly, the robot brakes to zero translation and rotation velocities with very high deceleration and remains stopped until it receives a subsequent translation or rotation velocity command from the client or until the

Emergency STOP button is reset and the motors re-engaged. (See E_STOP and E_STALL later in this chapter.)

PID Controls

The AROS drive servers use a common Proportional-Integral-Derivative (PID) control system to adjust the PWM pulse width at the motor drivers and subsequent power to the motors. The motor-duty cycle is 200 microseconds; pulse-width is proportional 0-500 for 0-

100% of the duty cycle.

The AROS drive servers recalculate and adjust your robot’s trajectory and speed every five milliseconds based on feedback from the wheel encoders.

The default PID values for translation and rotation and maximum PWM are stored as

FLASH parameters in your robot’s H8S microcontroller and may be changed. You also may temporarily update the PID values with the AROS client commands 84 through 87.

On-the-fly changes persist until you disconnect the client. The translation PID values apply to independent wheel-velocity mode.

The P term value Kp increases the overall gain of the system by amplifying the position error. Large gains will have a tendency to overshoot the velocity goal; small gains will limit the overshoot but cause the system to become sluggish. We’ve found that a fully loaded robot works best with a Kp setting of around 15 to 20, whereas a lightly loaded robot may work best with Kp in the range of 20 to 30.

The D term Kv provides a PID gain factor that is proportional to the output velocity. It has the greatest effect on system damping and minimizing oscillations within the drive system. The term usually is the first to be adjusted if you encounter unsatisfactory drive response. Typically, we find Kv to work best in the range of 600 to 800 for lightly to heavily loaded robots, respectively.

The I term Ki moderates any steady state errors thereby limiting velocity fluctuations during the course of a move. At rest, your robot will seek to “zero out” any command position error. Too large of a Ki factor will cause an excessive windup of the motor when the load changes, such as when climbing over a bump or accelerating to a new speed.

Consequently, we typically use a minimum value for Ki in the range of 0 to 10 for lightly to heavily loaded robots respectively.

Position Integration

ActivMedia robots, including your PowerBot, track their position and orientation based on dead-reckoning from wheel motion derived from encoder readings. The robot maintains its internal coordinate position in platform-dependent units, as reported in the standard SIP (Xpos, Ypos, and Thpos).

15 These are other client-resettable parameters persisted across client connections in AROS versions prior to v1.5.

40

ActivMedia Robotics

+90 +Y

0

+X

Front

+270

Be aware that with real robots, as well as with the simulator, registration between external and internal coordinates deteriorates rapidly with movement, due to gearbox play, wheel imbalance and slippage, and many other realworld factors. You can rely on the deadreckoning ability of the robot for just a short range—on the order of several meters and one or two revolutions, depending on the surface.

Carpets tend to be worse than hard floors.

Also, moving either too fast or too slow tends to exacerbate the absolute position errors.

+180

Figure 25. PowerBot’s internal coordinate system

Accordingly, consider the robot’s deadreckoning capability as a means of tying together sensor readings taken over a short period of time, not as a method of keeping the robot on course with respect to a global map.

The orientation commands HEAD and DHEAD turn the robot with respect to its internal dead-reckoned angle. On start-up, the robot is at the origin (0,0), pointing toward the positive X-axis at 0 degrees. Absolute angles vary between 0 and 359.

You may reset the internal coordinates to 0,0,0 with the SETO P2OS command.

S ONAR

When connected with and opened by the client, AROS automatically begins firing your robot’s sonar, one disc each simultaneously for each array, as initially sequenced and enabled in your robot’s FLASH parameters. The sonar servers also begin sending the sonar-ranging results to the client via the standard SIP.

Use the SONAR client command to enable or disable all or individual sonar arrays. Set

("1") bit zero of the SONAR argument to enable or reset it ("0") to disable the sonar pinging.

Set argument bits two through four to an individual array number one through four to enable or disable only that array. Array zero, the form of the P2OS command, affects all the arrays at once.

For example, an argument value of one enables all the sonar arrays, whereas an argument value of six silences array number three. Monitor the status of the sonar arrays in the Flags integer of the standard SIP.

Each array’s sonar fire one-at-a-time every 40 milliseconds (25 Hertz) in the sequence defined in your robot’s FLASH parameters. (Consult the next chapter on how to change the FLASH settings.) Use the sonar POLLING command to have your client change that firing sequence. The changes persist until you disconnect.

16

The POLLING command string argument consists of a sequence of sonar numbers one through 32. Sonar numbers one through eight get added to the polling sequence for sonar array number one; numbers nine through 16 get added to the sequence for sonar array number two; 17-24 specify the sequence for array three; and 25-32 are for array four. You may include up to 16 sonar numbers in the sequence for any single array. Only those arrays whose sonar numbers appear in the argument get re-sequenced. You may repeat a sonar number two or more times in a sequence. If a sonar number does not appear in an otherwise altered sequence, the disc will not fire.

16 Used to persist across client-server connection sessions in AROS versions prior to v1.5.

41

ActivMedia Robotics Operating System

Note that for compatibility with earlier ActivMedia robot operating systems, if the string is empty, all the sonar get disabled, but their polling sequences remain unaltered, just as if you had sent the SONAR command with an argument value of zero.

STALLS AND EMERGENCIES

With the robot equipped with forward and rear bumpers, AROS immediately stops the robot and notifies the client of a stall if any one or more of the front contact sensors get triggered and the robot is moving forward. Same for the rear bumpers when the robot is moving backwards. Send the BUMP_STALL command (#44) with a integer argument of zero to disable that bump-stall behavior. Give the argument value of one to re-enable

BUMP_STALL only when a forward bump sensor gets triggered; two for rear-only

BUMP_STALLs; or three for both rear and forward bump contact-activated stalls.

Change AROS’ bump-stall behavior default with the BumpStall FLASH parameter. In an emergency, your client may want the robot to stop quickly, not subject to normal deceleration. In that case, send the E_STOP command (#55).

With the robot equipped with ledge-sensing IRs, by default (LedgeIR FLASH parameter) it will slow to a forward-motion crawl if the far-sensing ones no longer see the ground, and stop altogether, throwing a stall, if the near-sensing IRs trigger.

17 Both behaviors are

overridden by the joystick button #1.

Send the LEDGE_RESP client command with integer argument to change those behaviors. Use an argument of zero to cancel the effects of the ledge-sensing IRs.

In an emergency, your client may want the robot to stop quickly, not subject to normal deceleration. In that case, send the E_STOP command (#55).

Like BUMP_STALL, AROS’ built-in E-STOP feature simulates a stall when someone presses either of your PowerBot’s E-STOP buttons. In addition, E-STOP disables the motors. An integrated switch in the E-

STOP button toggles a dedicated digital

I/O port (Port A, bit 3) on the microcontroller and thereby notifies

AROS of the emergency condition. AROS responds by disabling the motor servers in software. Another part of the E-STOP switch unconditionally disconnects the motors from their drive power and sets the brakes for as long as the button is depressed.

Table 7. The Flags bits in the standard SIP

BIT

1

2

3

4

5

6

7

8

CONDITION IF SET

Sonar array #1 enabled

Sonar array #2 enabled

Sonar array #3 enabled

Sonar array #4 enabled

Emergency STOP button pressed

Emergency stall engaged

Far ledge detected (IR)

Near ledge detected (IR)

9 Joystick button #1 pressed

10-15 Reserved

E_STALL affects the behavior of your PowerBot after the E-STOP condition is relieved. By default, the servers do not release the brakes nor re-enable the motors, such as after a stall, when you release the E-STOP button. Change that behavior with E_STALL by sending the AROS command (#56). With argument of zero, E_STALL gets disabled, so that AROS doesn’t register a stall nor disable the motors in software when E-STOP is depressed. Once the E-STOP is released, the brakes release and the motors get reenabled, possibly cause a motion rush as the platform accelerates to the speed and direction it was going before the E-STOP. An argument value of one re-enables

E_STALL.

17 Speed limit is not implemented if you are using VEL2 mode.

42

ActivMedia Robotics

Note that changing the AROS server responses to the various safety features through client commands persist until the controller gets reset. State reflection, however, continues, regardless of the behavior. Accordingly, the standard SIP FLAGS will record near and far ledge detections, even though the robot may not respond, and the various

I/O bits reflect the actual state of the hardware.

A

CCESSORY

C

OMMANDS AND

P

ACKETS

Several types of alternative server information packets (SIPs) come with AROS to better support the ActivMedia Robotics community. On request from the client by a related

AROS command, the AROS server packages and sends one or a continuous stream of information packets to the client over the HOST serial communication line. Extended packets get sent immediately after the standard SIP that AROS sends to your client every

SIP milliseconds (typically 100).

18

The standard SIP takes priority and gets sent as soon as the communication port is free and the cycle timer expires. So you may have to adjust the communications baud rate to accommodate all data packets in the allotted cycle time, or some packets may never get sent.

Packet Processing

Identical with the standard SIP, all AROS server information packets get encapsulated with a header (0xFA, 0xFB), byte count, packet type byte, and trailing checksum. It is up to the client to parse the packets, sorted by type for content. Please consult the respective client application programming manuals for details.

ARIA, for example, comes with a framework for packet parsing and has an internal parser for the PSOS/P2OS/AROS packet type 0x3S (S=0-2; aka “standard” SIP), as well as for some of the extended packets we describe in this section.

CONFIGpac and CONFIG Command

Send the CONFIG command #18 without an argument to have AROS send back a

CONFIGpac SIP packet type 32 (0x20) server information packet containing the robot's operational parameters. Use the CONFIGpac to examine many of your robot’s default

FLASH_based settings or their working values, when appropriate, as changed by other client commands, such as SETV and ROTKV. A table nearby gives details about the configuration packet data.

Table 8. CONFIGpac contents

LABEL

HEADER

DATA DESCRIPTION int Common packet header = 0xfAFB

T YPE

B

YTE COUNT byte IDs ENCODERpac = 0x20 byte Number of following data bytes

R OBOT T YPE str “Pioneer”

S UBTYPE the ActivMedia robot model; powerbot, for example. str Serial number for the robot. S ERIALNUM

4M OTS

R OT V EL T OP

T RANS V EL T OP

R OT A CC T OP

T RANS A CC T OP

P WM M AX

Byte Antiquated (=1 if AT with P2OS) int Maximum rotational velocity; deg/sec int Maximum translation speed; mm/sec int Maximum rotation (de)acceleration; deg/sec 2 int Maximum translational (de)acceleration; mm/sec 2 int Maximum motor PWM (500=fully on).

N AME str Unique name given to your robot.

18 You may have to adjust the HOST serial baud rate to accommodate the additional communications traffic.

43

ActivMedia Robotics Operating System

SIP

H OST B AUD

A

S

S

UX

GRIPPER

FRONT SONAR

REAR SONAR

L

R

W

P2M

J

J

R

T

R

R

R

OW

EV

B

C

ATCH

TALL

TALL

OY

OY

OT

B AUD

ATTERY

OUNT

PACS

RANS

OT

OT

OT

V

RV

V

A

D

K

D

V

C

EL

EL

CC

OG

AL

OUNT

ECEL

P

V

EL

M

EL

AX

M AX byte Server information packet cycle time byte Baud rate for client-server HOST serial: 0=9.6k,

1=19.2k, 2=38.4k, 3=56.8k, 4=115.2k. byte Baud rate for AUX serial port 1; see HostBaud int 0 if no Gripper; else 1 int 1 if robot has front sonar array enabled, else 0

Byte 1 if robot has rear sonar enabled, else 0 int In 1/10 volts; alarm activated when battery charge falls below this value. int Current number of differential encoder ticks for a 360 degree revolution of the robot. int Ms time before robot automatically stops if it has not received a command from a client.

Restarts on restoration of connection. byte 1 enables alternative SIP. int Maximum PWM before stall. If > PwmMax, never. int Ms time after a stall for recovery. Motors not engaged during this time. int Joystick translation velocity setting, mm/sec int Joystick rotation velocity setting in deg/sec int Current max rotational speed; deg/sec. int Current max translational speed; mm/sec. int Current rotational acceleration; deg/sec 2 int Current rotational deceleration; deg/sec 2 int Current Proportional PID for rotation

R OT K V

R OT K I int Current Derivative PID for rotation int Current Integral PID for rotation

T RANS A CC

T RANS D ECEL int Current translational acceleration; mm/sec 2 int Current translational deceleration; mm/sec 2

T RANS K P

T RANS K V

T RANS K I int Current Integral PID for translation

ADDED IN AROS 1.6

F RONT B UMPS

R EAR B UMPS int Current Proportional PID for translation int Current Derivative PID for translation byte Number of front bumper segments byte Number of rear bumper segments

AUX port communications

AROS provides two-way communications through the HOST client-server communication port to and through two auxillary serial ports on the microcontroller, AUX1 and AUX2. Use the TTY2 command number 42 with a string argument to have that string sent out the

AUX1 port to the attached serial device, such as a robotic camera. Similarly, use the

TTY3 command number 66 to send a string argument to the AUX2 port.

AROS also maintains two circular buffers for incoming serial data from the AUX1 and

AUX2 ports. On request, AROS sends successive portions of the buffers to your client via the HOST port in the respective SERAUXpac (type = 176; 0xB0) and SERAUX2pac (type =

184; 0xB8) SIPs. Use the GETAUX command 43 for AUX1 or GETAUX2 command number 67 for AUX2. Use the integer argument value of zero to flush the contents of the respective buffer. Use an argument value of up to 253 bytes to have AROS wait to collect the requested number of incoming AUX-port serial bytes and them send them in the respective SERAUX or SERAUX2 SIP.

Encoder packets

Issue the ENCODER command 19 with an argument of one for a single, or with an argument value of two or more for a continuous stream of ENCODERpac (type 144; 0x90)

SIPs. Discontinue the packets with the ENCODER command 19 with an argument of zero.

44

ActivMedia Robotics

Table 9. ENCODERpac SIP contents

Byte Count byte

Left Encoder integer integer

Right Encoder integer integer

Number of data bytes + 2 (checksum)

Least significant, most significant portion of the current 4-byte raw encoder count from the left drive wheel

Least significant, most significant portion of the current 4-byte raw encoder count from the left drive wheel

Sounds

Unlike its ActivMedia robot cousins, the AmigoBot mobile robot has onboard sound reproduction hardware and software that includes a playlist of contents. To support the

ActivMedia Robotics Basic Suite that includes all ActivMedia’s robots, we’ve included the PLAYLISTpac (type = 208; 0xD0) and PLAYLIST request command 91 in AROS. We document the command and packet here for completeness, but they have no effect on the operation or performance of your ActivMedia mobile robot.

The AmigoBot sounds playlist consists of a series of one to 255 24-byte long sound references, followed by individual sound data. Sound references may be NULL or redundant.

Sound references consist of a 16-byte sound name followed by two long integers, which specify the sound data position and length in the playlist. Upon receipt of the PLAYLIST command 91 with any or no argument, AROS responds with a PLAYLISTpac SIP containing 25 NULL bytes, telling the client that your AROS-based robot does not have any onboard sounds.

Whereas the AmigoBot has a high-fidelity sound system, AROS- and P2OS-based robots have a piezo buzzer that aurally notifies you of system conditions, such as low battery or stalls. For stealthy operation, issue the SOUNTOG command number 92 with an argument of zero to mute the microcontroller’s buzzer; argument of one to re-enable it.

(See also the SOUNDTOG FLASH parameter in the next chapter to set its default state.)

The SAY command number 15 lets you play your own sounds through the buzzer. The argument consists of a length-specified string of duration/frequency tone pair bytes. The duration is measured in 20 millisecond increments. Frequencies are half-tones, limited by the 8-bit timer. You’ll have to experiment with tones. Here is the sequence that generates the AROS tone when the robot stalls (in octal):

\012\001\012\000\012\010\012\000\012\001

Onboard PC

Communication between the onboard PC and the H8S microcontroller is RS232 serial through the respective COM1 (Windows) or /dev/ttyS0 (Linux) and internal HOST ports.

Set the HostBaud FLASH communication rate to match the PC client-software’s serial port rate.

Beginning with AROS version 1.6, the RI pin 9 on the HOST port initializes to low and goes high when the batteries discharge to below 11 VDC. We use the genpowerd software under Linux to detect that low-power signal and automatically shut down the PC.

Windows PCs are a bit more problematic.

45

ActivMedia Robotics Operating System

The Windows genpowerd-like ups.exe program requires a dedicated serial port and prefers to use the CTS line to indicate low power. Accordingly, we jumper the RI signal of

HOST COM1 to the CTS signal pin 8 of the adjacent 9-pin COM3 port of the onboard PC for the feature.

Once the port is wired, start up Windows and, as Administrator, go to the

Start:Settings:Control Panel:Power Options dialog and select the UPS tab.

Click Select and in the UPS Selection dialog, select COM2 (or other) port, Generic manufacturer, and Custom model. Then click Next.

In the UPS Interface Configuration On: COM2 dialog, check the Power Fail/On

Battery and its related Position options. Uncheck to disable the Low Battery and UPS

Shutdown options. Then click Finish to save the settings and close the dialog. Click OK or

Apply to enable the UPS shutdown programs.

Change a registry value so that the PC shuts down one minute instead of two inutes after low-power notification by the controller: Use regedit and navigate to

[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\UPS\Config. Change the

ShutdownOnBatteryWait dword value to 1 (from 2).

Use the AROS client maintenance command #250 to test your genpowerd or ups.exe setup. Send the COMshutdown command #250 with an integer argument of 1 to simulate the low battery condition, in which AROS issues warnings first, then disconnects from the client after about a minute and sets the PC-shutdown signal on RI. An argument of 2 forces the computer shutdown signal (RI high); 0 cancels the shutdown/test. Resetting the controller cancels shutdown, too, unless battery power really is very low.

Put the controller into maintenance mode and fix your onboard PC settings if the computer falsely engages genpowerd or ups.exe.

TCM2

The TCM2 accessory is an integrated inclinometer, magnetometer, thermometer, and compass that attaches to one of the AUX serial ports of the AROS microcontroller. When attached and enabled, special TCM2 compass servers read and report the heading as the compass byte in the standard SIP. Use the TCM2 command 45 to request additional information from the device in the form of the TCM2pac. See the TCM2 Manual and supporting software that accompanies the device for details.

I NPUT O UTPUT (I/O)

Your PowerBot comes with a number of I/O ports that you may use for sensor and other custom accessories and attachments. See Appendix B for port locations and specifications. Some I/O states and readings appear in the standard SIP and may be manipulated with AROS client commands. There also is an IOpac SIP for convenient access to all your robot’s I/O.

User I/O

The User I/O connector on the H8S microcontroller contains sixteen total digital input/output ports, as well as an analog-to-digital (A/D) port. Four of the output ports and six input ports are used by the Gripper accessory of the PowerBot. See below.

The bit-mapped states of the sixteen digital ports and analog port automatically and continuously appear in the standard SIP, in their respective DIGIN, DIGOUT, ANALOG bytes.

When not physically connected, the digital input and A/D port values may vary and change without warning.

46

ActivMedia Robotics

Use the AROS client command number 30 to set one or more of the eight DIGOUT ports on the AROS microcontroller. Electrically, the ports are digital high (1) at ~5 VDC (V cc

) and low (0) at ~0 VDC (GND). DIGOUT uses a two-byte (unsigned integer) argument. The first byte is a mask whose bit pattern selects (1) or ignores (0) the state of the corresponding bit in the second byte to set (1) or unset (0) the digital output port.

For example, here’s the AROS client command to set digital output ports one and three

(OD1 and OD3), reset port four (OD4), and leave all the rest alone (hexadecimal notation):

0xFA, 0xFB, 0x06, 0x1E, 0x1B, 0x19, 0x09, 0x37, 0x24

Bumper and IR I/O

Two 10-position latching IDC connectors on the H8S microcontroller provide 16 digital input ports. See Appendix B for connector details. Twelve of the inputs are used for front and rear bumper inputs of the PowerBot.

Similarly, the PowerBot’s Motor-Power board contains four inputs with required power for the four fixed-range, ledge-sensing IR sensors, whose states are digitally mapped. See

Appendix C for connector details.

Normally low (digital 0), the bumper switches go high (digital 1) when the respective sensor gets triggered. Bumper inputs also appear with the stall bits in the standard SIP, but unlike in the IOpac, are modified by the InvertBumps mask. All the bumper and IR data bits appear in the IOpac packet.

The IR switches act in the reverse. Normally high, they go low when the respective device is triggered.

Bumper inputs also appear with the stall bits in the standard SIP. All the bumper and IR data bits appear in the IOpac packet, too.

Expansion I/O

Four alternative A/D ports appear at the 40-position Expansion I/O connector of the H8S microcontroller.

19 Use the ADSEL client command number 35 to select and subsequently

have the A/D value from one of the alternative ports AN2-5 appear in the standard SIP.

The default port is AN0 (ADSEL argument value of zero), the A/D port also on the User I/O connector.

IO packets

Not all analog and digital I/O appears in the standard SIP. Accordingly, your client software may request the IOpac SIP (type = 240; 0xF0), which contains all common I/O associated with the H8S microcontroller and which appear on the various connectors, including User IO, General IO, Bumpers, and IRs.

Table 10. IOpac packet contents

LABEL

HEADER

B YTE COUNT

BYTES

2

1

CURRENT VALUE DESCRIPTION

0xFA, 0xFB Common header

22

TYPE 1

Number of data bytes + 2

N DIGIN

DIGIN

FRONTBUMP

REARBUMP

IR

*

*

1

1

1

1

1

4 varies 0-255 varies 0-255 varies 0-255 varies 0-255

Number of digital input bytes

ID0-8 bits mapped

Front bumper bits

Rear bumpers bits

Top-left IR bit 0; lower-left bit 1;

19 Many other ports also appear at that connector, but are not yet supported in AROS.

47

ActivMedia Robotics Operating System

N DIGOUT

DIGOUT

1

1

1 top-right bit 2; lower-right bit 3

Number of digital output bytes varies 0-255 Digital output byte(s)

AN 1

A/D 10

5 varying 0-2047

Number of A/D values integers resolution = 0-5 VDC

CHECKSUM 2 varies

* Actual bits, not affected by InvertBumps since bumper bits may be used for other digital input besides bumpers.

Use the AROS client IOREQUEST command number 40 with an argument value of zero, one, or two. The argument value one requests a single packet to be sent by the next client-server communications cycle. The request argument value of two tells AROS to send IOpac packets continuously, at approximately one per cycle depending on serial port speed and other pending SIPs. Use the IOREQUEST argument value zero to stop continuous IOpac packets.

48

ActivMedia Robotics

Chapter 7

Updating & Reconfiguring AROS

The AROS software and a set of operating parameters for your PowerBot get stored in the

H8S microcontroller's FLASH ROM. With special upload and configuration software tools, you change and update the FLASH memory image. No hardware modifications are required.

W HERE TO G ET AROS S OFTWARE

Your robot comes preinstalled with the latest version of AROS. And the various AROS configuration and update tools come with the robot on CD-ROM. Thereafter, stay tuned to the pioneer-users newsgroup or periodically visit our support website to obtain the latest AROS software and related documentation: http://robots.activmedia.com

AROS tools come in two flavors: One (dl_AROSV_v) simply updates the AROS servers in

FLASH. The other utility, AROScf, is a multi-functional application for both uploading new

AROS versions as well as modifying your robot’s onboard FLASH-based parameters.

AROS M AINTENANCE M ODE

To connect with and update your robot’s AROS servers and its FLASH-based operating parameters, you need to first connect a serial port on the PC from which you will run the

AROS tool(s) to the HOST port of your robot’s microcontroller:

If you are running from the onboard PC, the computer-to-HOST connection already is made.

If you have an onboard PC, but prefer to use an external computer for maintenance, simply power down the onboard computer.

When connecting from an external PC, directly tether its serial port to the 9-pin

DSUB serial connector on the User Control Panel.

Now start up your robot and put its microcontroller into the special Maintenance Mode:

1. Press and hold the white MOTORS button on the User Control Panel

2. Press and release the adjacent red RESET button

The STATUS LED on the User Control Panel should flash twice the rate than when in server

(“wait”) mode and the BATTERY LED should shine bright red.

S

IMPLE

AROS U

PDATES

The simple AROS update application is just that: a standalone program that, when run, updates the AROS servers to the indicated version V_v (1_0, for example) in your robot’s microcontroller. Although it may add parameters to your current FLASH values, the dl_AROSV_v application never changes your current parameters, but may add new ones.

To use this convenient utility, simply download the “dl_”-prefixed executable for your PC’s operating system (“.lin” filename suffix for Linux or “.exe” for Windows). Connect the

PC to your robot’s HOST serial port and put its microcontroller into Maintenance Mode

(see section above). Then run the dl_… program.

49

Updating and Reconfiguring AROS

Text prompts will help you get connected with your ActivMedia robot’s H8S-based microcontroller and update its AROS servers. No fuss. No muss.

AROS

CF

The AROS update and configuration program, AROScf, is part of a collection of utilities and files for comprehensive management of your ActivMedia robot’s onboard servers and FLASH-based operating parameters. The distribution archive for the software is simply named AROSV_v (V and v are the version major and minor numbers, such as 1_0), with a “.tgz” suffix for Linux-based PCs or “.exe” for Windows computers.

Install the utilities and files on the PC you plan to use for maintaining your robot’s operating system and parameters (if not the your PowerBot’s onboard PC) by doubleclicking the distribution software’s onscreen icon or otherwise executing the selfextracting, self-installing package. For Linux, uncompress and untar the files:

% tar –zxvf AROS1_0.tgz

The expanded archive creates an AROS/ directory in the selected Windows or current

Linux path and stores the AROS software within.

S TARTING AROS CF

AROScf is a text-based console application, as opposed to a graphical-user one. It runs in two stages: Startup Mode followed by Interactive Mode. When invoked, you may start AROScf with various command-line options. With an X-terminal under Linux, for example, navigate to the AROS directory and invoke the program:

% cd /usr/local/AROS

% ./AROScf <options>

With Windows PCs, you may double-click the AROScf icon to automatically open a console window and start the program without any options. To start up with commandline options, Run the program from the Start menu, or run Command from the Start menu, then navigate to the AROS directory and start AROScf with options.

For example (after invoking the MSDOS-like command window):

C:\> cd AROS

C:AROS\> AROScf <options>

Normally (without any command-line arguments), AROScf starts up expecting to connect your PC’s COM1 or /dev/ttyS0 serial port with your robot’s microcontroller which you’ve put into Maintenance Mode. If successfully connected, the program automatically retrieves your robot’s FLASH-stored operating parameters and enters interactive mode.

If the initial connection fails, AROScf still starts up into its Interactive Mode, but with empty, and thereby useless parameter values. You may still operate many of AROScf’s interactive features without a connection, such as maintain disk-based copies of your robot’s operating parameters. And there is an interactive connect command that lets you establish a maintenance connection with your robot. See the next section for

AROScf commands and operating features.

Include each of the selected AROScf’s startup-mode options as a key letter with a dash

(“-“) prefix, followed by any required arguments, separated by spaces. For example, to start up AROScf and make a connection with a serial port other than the default COM1 or ttyS0:

C:\AROS> AROScf –p COM3

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ActivMedia Robotics

Similarly, this Linux xterm command uploads a fresh copy of AROS to your robot’s H8Sbased microcontroller and then exits, much like the simple dl_AROS1_0 program:

% ./AROScf –d AROS1_0.hex –n -b

Table 11. AROScf startup options

KEY ARGUMENT DESCRIPTION

-b command arguments

-d hexfile

Batch mode executes list of AROScf

Interactive mode commands with arguments

Automatically upload AROS hex image file after connecting with the microcontroller

Print help message and exit -h none

-l paramsfile Load the disk-stored parameter file instead of the robot’s copy

-n none Don’t automatically connect with microcontroller

-p serialdevice

Uses specified serial port for connection

-s paramsfile

On exit from AROScf, automatically save the current parameter values to the named paramsfile

C ONFIGURING AROS O PERATING P ARAMETERS

Your ActivMedia robot has several parameters stored in FLASH that AROS uses to configure its servers and auxiliary attachments and to uniquely identify your robot. For instance, the default maximum translational velocity is stored in the TransVelMax parameter. Its value takes effect when starting your robot or after resetting the microcontroller, and may be changed temporarily by a client command. Use AROScf’s

Interactive Mode to modify these operating parameters, and hence your robot’s default operating characteristics.

Start up AROScf as described in the previous section. As discussed earlier, AROScf normally downloads the set of operating parameters from your robot’s FLASH for your review and modification. Or you may load a disk-stored version of those parameters.

Some of the parameters, "Constants", are not to be changed. The others, "Variables", are the identifying and operating parameters that you may edit.

Interactive Commands

To operate AROScf in interactive mode, simply type a keyword at the command line.

Some keywords affect the operation of AROScf, the status of the parameters file as a whole, or the connection between AROScf and your robot’s microcontroller. For instance, to review the list of current AROS constants or variables, type 'c' or 'v', respectively, followed by a return (Enter). Similarly, type '?' or 'help' to see a list of

AROScf interactive commands.

Changing Parameters

Other keywords refer to the operating parameters themselves. Alone, a parameter’s keyword simply asks AROScf to display the parameter’s value. Provide an argument with the parameter keyword separated by a space to change its value. That value may be a string (no quotes or spaces) or a decimal or hexadecimal ("0xN") number. For example, to change the watchdog timeout to four seconds, type:

> watchdog 4000 or

51

Updating and Reconfiguring AROS

> watchdog 0xfa0

See the respective control command and parameter Tables nearby for a full description of AROScf operation.

Table 12. AROScf control commands

COMMAND DESCRIPTION

KEYWORD <value>

c or constants

Alone, a keyword displays current, edited value. Add argument to change current value.

Display all constant parameters. You cannot edit these.

v or variables Display all variable parameter values which you may edit and eventually save to your robot’s

FLASH.

r or restore

<paramsfile>

Restores variables to values currently stored in FLASH or from a paramsfile on disk

save <paramsfile> Saves current edited values to FLASH or saves current edited values to pathname on disk for later reference.

q or quit disconnect

Exits AROScf.

connect <portname> Connects AROScf with microcontroller through serial port (COM1 or /dev/ttyS0 default)

Disconnects AROScf from your robot’s microcontroller

? or help Displays these commands and descriptions.

S

AVE

Y

OUR

W

ORK

While changing parameter values in AROScf Interactive Mode, you are editing a temporary copy; your changes are not put into effect in your robot’s FLASH until you explicitly "save" them to the microcontroller.

Also use the AROScf save command to to save a copy of the parameters to a disk file for later upload. We strongly recommend that you save each version of your robot’s parameter values to disk for later retrieval should your microcontroller get damaged or its

FLASH inadvertently erased. Default parameter files come with each AROS distribution, but it is tedious to reconstruct an individual robot’s unique configuration.

PID P

ARAMETERS

The AROS configuration parameters include settings for the PID motors controls for translation and rotation of the robot. The translation values also are used for independent-wheel mode. The default values are for a moderately loaded robot.

Experiment with different values to improve the performance of your robot in its current environment.

52

ActivMedia Robotics

Table 13. AROS FLASH configuration parameters with values for PowerBot.

KEYWORD

CONSTANTS

T YPE

S UBTYPE

S ERIAL

R OT V EL T OP

T RANS V EL T OP

R OT A CC T OP

T RANS A CC T OP

T ICKSMM

B

N

P

H

A

A

S

S ONAR 2

S ONAR 3

S

L

W

R

G

L

B

I

F

R

R

T

R

R

R

R

R

ATT

AME

SIP

WM

OST

UX

UX

ONAR

ONAR

OW

TCM

B

C ONV

VARIABLES

ATTERY

ATCH

EV

M

B

B

C

UMP

AX

B

4

OUNT

RIPPER

2

EDGE

S TALL

NVERT

RONT

B

RANS

AUD

AUD

AUD

1

D

S

CC

B

1

2

OG

S OUND T OG

P2M PACS

S

S

TALL

TALL

EAR

OT

OT

OT

OT

OT

OT

V

A

D

K

K

K

EL

ENSE

UMP

ECEL

P

V

I

V

C

B

V

AL

M AX

EL

OUNT

UMPS

UMPS

M AX str str str int byte byte int int byte byte int int int int int int int

Type Default Description

Should not be changed str Pioneer Identifies the robot type. str PowerBot Identifies str int int int int int byte factory Serial number for the robot.

360 Maximum rotational velocity; deg/sec

2200 Maximum translation speed; mm/sec

360 Maximum rotation (de)acceleration; deg/sec 2

2000 Maximum translational (de)acceleration; mm/sec 2

110 Encoder ticks/mm: (ticks/rev x gear-ratio)

(wheel_diameter x PI)

1 0 if a 12V system; 1 if 24V str byte int byte byte byte str int int int byte int byte byte

Parameters that you may change not_set Unique name for your robot.

Maximum of 20 characters, no spaces.

100 Server information packet cycle time in 1 ms increments. Default is classic 100 ms.

500 Maximum motor PWM (500=fully on).

0 Baud rate for client-server HOST serial:

0=9.6k, 1=19.2k, 2=38.4k, 3=56.8k, 4=115.2k.

0 Baud rate for AUX serial port 1; see HostBaud

0 Baud rate for AUX serial port 2; see HostBaud

1234567 Ping sequence for sonar array #1. Up to 16 number characters 1-8; 0 alone to disable the array

1234567 Ping sequence for array #2. See sonar1 above

1234567 Ping sequence for array #3. See sonar1 above

1234567 Ping sequence for array #4. See sonar1 above

230 In 1/10 volts; microcontroller alarm activated when battery charge falls below this value.

2000 Ms time before robot automatically stops if it has not received a command from a client.

Restarts on restoration of connection.

50800 The number of differential encoder ticks for a

360 degree revolution of the robot.

1 0 disables the buzzer

0 1 enables alternative SIP.

400 Maximum PWM before stall. If > PwmMax, never.

100 Ms time after a stall for recovery. Motors not engaged during this time.

0 Set to 1 if P2 Gripper; 2 if Gripper on

PowerBot

0 TCM2 module connected to 1=AUX1 or 2=AUX2

0 0=disable; 1=stop/stall if near-IR ledge sensor triggered; 2=limit speed (<150mm/sec) if far-IR ledge sensor triggered; 3=both behaviors

3 0=disable bump stall; 1=enable rear; 2=enable front; 3=enable both front and rear bump stalls

0 0=none; 1=front; 2=rear; 3=invert both front and rear bumper signals

7 Number of front bumper segments

5 Number of rear bumper segments

60 Max rotational speed; deg/sec.

1000 Max translational speed; mm/sec.

40 Rotational acceleration; deg/sec 2

50 Rotational deceleration; deg/sec 2

30 Proportional PID for rotation

200 Differential PID for rotation

0 Integral PID for rotation

53

Updating and Reconfiguring AROS

T RANS A CC

T RANS D ECEL

T RANS K P

T RANS K V

T RANS K I

J OY V EL M AX

J OY RV EL M AX int int int int int int int

100 Translational acceleration; mm/sec 2

300 Translational deceleration; mm/sec 2

15 Proportional PID for translation

400 Differential PID for translation

4 Integral PID for translation

500 Joydrive maximum translation velocity

50 Joydrive maximum rotational velocity

The Proportional PID (Kp) values control the responsiveness of your robot. Lower values make for a slower system; higher values make the robot "zippier", but can lead to overshoot and oscillation.

The Derivative PID (Kv) dampens oscillation and overshoot. Increasing values gives better control of oscillation and overshoot, but they also make the robot’s movements more sluggish.

The Integral PID (Ki) adjusts residual error in turning and velocity. Higher values make the robot correct increasingly smaller errors between its desired and actual angular position and speed.

T ICKSMM AND R EVCOUNT

AROS uses the ticksmm and revcount parameters to convert your platformindependent speed and rotation commands—typically expressed in millimeters or degrees per second, respectively—into platform-dependent units.

The ticksmm value is the number of encoder pulses (“ticks”) per millimeter of wheel rotation. The value is, of course, dependent upon the wheel encoder’s resolution, the motor-to-wheel gear ratio, and the wheel’s diameter. These don’t normally change, and so are considered constants and not editable for your robot.

The revcount value is the number of encoder ticks for one full revolution of the robot. It depends on a number of factors, principally the length of the wheel base, which may change due to payload, tire wear, operating surface, and so on.

S TALL V AL AND S TALL C OUNT

An AROS stall monitor maintains a running average of PWM values for each wheel over a

500 millisecond integration period. PWM values get added to the sum if the wheel speed is below 100 mm/sec. The average is then compared with the stallval FLASH value. If it exceeds that value, in other words the motors are being given lots of power but are barely moving if at all, then a stall happens. Once stalled, power is removed and the motors relax for the stallwait period, after which power gets reapplied.

B UMPERS

Introduced in AROS version 1.6, use the BumpStall FLASH parameter to set the default for your PowerBot’s behavior when its front and/or rear bumper gets triggered. Normally,

BumpStall is engaged for both front and rear (default value of 0) bumpers. Reset it to 3 to disengage bump stalls altogether; 1 to trigger stalls only when the rear bumpers engage; or 2 for front bumps only.

You may over-ride the BumpStall FLASH default with the bump_stall client command number 44, although the command arguments are the reverse: enabling versus disabling the various bumper-stall combinations.

Your robot’s BumpStall behavior reverts to the FLASH default on reset and up disconnection from the client.

54

ActivMedia Robotics

Next-generation client-side software will need to know if you have bumpers or not and how they are configured. And new bumper hardware may invert PowerBot’s bumper signal bits which will confuse the client-server software. Moreover, different AROSenabled robots have different numbers of bumper segments, front and rear.

Accordingly, the new AROS v1.6 implements three new FLASH parameters that specify states (invert or not) and numbers of front and rear bumper segments. Unfortunately, we have no way of knowing automatically what bumpers your robot may have, if any, so we are forced to assume you DON'T have bumpers or that you have the old-style (noninverting) bumpers.

Use AROScf to indicate the type and number of bumper segments. Set the new

InvertBump FLASH parameter's value to 1 if you have new bumpers in front, which signals need to be inverted; 2 if in the rear; or 3 if both front and rear bumper signals need inverting. Set to the default 0 if your robot has no bumpers or has the original style

(non-inverting) bumpers.

Set the FrontBump and RearBump parameters to the number of bumper segments for the front and rear bumpers, repectively; or to 0 if you don't have a particular bumper. For pre-AROS 1.6 robots, you don't need to set these values to have them work with AROS

1.6. The number of segments are used to isolate the bumper bits, if any, and to apply

InvertBump as needed, so that a triggered bumper is reported as digital 1 regardless of the hardware, and is reported as such in the standard SIP. IOpac, on the other hand, simply reports the bit-mapped states of the input bytes associated with the bumpers, regardless of hardware.

The FrontBump and RearBump byte values also are reported at the end of the new

CONFIGpac for AROS 1.6.

If for any reason you remove a new-style bumper from your robot, you MUST reset the

InvertBump FLASH value or disable BumpStall for that bumper. Otherwise, the robot will stall incessantly.

55

Maintenance and Repair

Chapter 8

Maintenance & Repair

Your PowerBot is built to last a lifetime and requires little maintenance.

T IRE I NFLATION

Maintain even tire inflation for proper navigation of your PowerBot. We ship with each pneumatic tire inflated to 60 psi. If you change the inflation, remember to adjust the ticksmm and revcount FLASH values.

D

RIVE

L

UBRICATION

The PowerBot’s motors and gearboxes are sealed and self-lubricating, so you need not fuss with grease or oil. An occasional drop or two of oil on the axle bushings between the wheels and the case won’t hurt. And keep the axles clear of carpet or other strings that may wrap around and bind up your robot’s drive.

B

ATTERIES

Lead-acid batteries like those in your PowerBot last longest when kept fully charged. In fact, severe discharge is harmful to the battery, so be careful not to operate the robot if the battery voltage falls below 21 VDC.

Charging

The battery charge port is a two position, red and black connector inside the Power

Control Panel. A mating connector comes on the PowerBot charger. Simply plug the charger into a power source and into the robot.

While charging, a yellow indicator lights during the bulk (high-current) charge cycle. A green indicator flashes when the batteries have charged to 80% capacity; the green indicator stops flashing, but remains lit, when the batteries are fully charged. The red light indicates a fault, such as a short.

Allow roughly two to three hours per volt recharge time. You may continue using the onboard systems, although systems activity will elongate charging times.

Changing Batteries

1. Access the battery tray by releasing the rear door latches sliding the tray out.

Careful, the tray acts as a strong lever in this position so that you will tip the robot down in the back and raise its front and wheels off the ground with little effort.

2. Remove the retaining bolt (7/16”) and wire from the top (negative) terminal of the upright battery.

3. Remove the retaining bolt and wire from the outermost (negative) terminal of the lower battery.

4. Lift the upright battery out of the tray and set aside.

5. Remove the 25 centimeter (10-inch) power-jumper cable from the positive terminal of the removed battery.

6. Slide the remaining battery to the back of the tray.

7. Remove the remaining retaining bolt and wire from the battery; lift it out and set aside.

8. Place a fresh battery into the battery tray with the terminals facing up, positive terminal forward.

56

ActivMedia Robotics

9. Remove the bolt from the positive terminal of the battery and slide the red power cable onto the lug. Position the cable so that it runs down the center of the battery, then secure the connection with the bolt.

10. Push the battery all the way forward in the tray.

11. Similarly attach the red-tipped end of the 25 centimeter (10-inch) power-jumper cable to the second battery. The wire should point toward the center of the battery, too.

12. Place the second battery into the tray up on end so that the terminal with the attached jumper cable is on the bottom.

13. Connect the black tipped end of the power-jumper to the negative (-) terminal of the first battery.

14. Connect the remaining black power cable in the robot to the negative (-) terminal of the second battery. Run the wire so that it points down.

15. Carefully slide the battery tray into the robot and secure the rear door latches.

P LATFORM T ILT

To adjust the height of the front of the robot, locate the tilt-adjusment bolts on both sides of the robot beneath the suspension springs for the drive wheels.

Simply tighten the bolt with a 9/16" wrench to lower, or loosen the bolt to raise the front end of the robot. Adjust both sides of the robot for level tilt. Figure 26. Tilt-adusting bolt for left side of

PowerBot

Open the robot AT YOUR OWN RISK, unless explicitly authorized by the factory.

G ETTING I NSIDE

We normally discourage you from opening up your robot.

However, on occasion, you may need to get inside, for instance to access the user power connections on the

Motor-Power board and attach your custom electronics. Or you may need to get to your onboard computer and its accessories.

Opening the Deck

PowerBot’s deck is in two hinged parts. Most electronics, including the onboard PC, can be accessed from the rear panel of the deck.

Figure 27. Remove indicated screws to open or remove the deck of PowerBot.

57

Maintenance and Repair

Remove the respective RM2 or RM4 hex screws to release the front or back as shown in the figure nearby. Remove the PowerBot Arm accessory before opening the front panel of the deck.

F ACTORY R EPAIRS

If, after reading this manual, you’re having hardware problems with your ActivMedia robot and you’re satisfied that it needs repair, contact us:

[email protected]

(603) 924-2184 (fax)

(603) 924-9100 (voice)

In the body of your email or fax message, describe the problem in as much detail as possible. Also, include your name, email and mail addresses, as well as phone and fax numbers. Tell us when and how we can best contact you (we will assume email is the best manner, unless otherwise notified).

We will try to resolve the problem through communication. If the robot must be returned to the factory for repair, obtain a shipping and repair authorization code and shipping details from us first.

We are not responsible for shipping damage or loss.

58

Appendix A

S

YSTEMS AND

P

OWER

D

IAGRAM

ActivMedia Robotics

59

Appendix A: Systems and Power Diagram

60

ActivMedia Robotics

Appendix B

H8S P

ORTS

& C

ONNECTIONS

This Appendix contains pinout and electrical specifications for the external and internal ports and connectors on the H8S microcontroller, motor-power interface, and User Control boards.

Note that layered connectors are numbered differently, depending on the socket type. IDC ones are odd and even layers; mini- and micro-fit connectors use successive-position numbering.

See the Figures nearby for examples.

Figure 28. Mini- and micro-fit style connector numbering

H8S Microcontroller Figure 29. IDC-type connector b i

Figure 30. ActivMedia Robotic’s H8S-based microcontroller

Power Connector

The power connector is a 3-pin microfit socket that delivers 12VDC to the microcontroller circuitry and separate, conditioned 5 VDC to the sonar, including power grounds.

Table 14. H8S Controller Power Connector

PIN DESCRIPTION

2 GND

61

Appendix A: Systems and Power Diagram

Serial Ports

Two DSUB-9 and two 5-pin microfit sockets provide the HOST and AUX1/AUX2 auxiliary serial ports for the H8S controller. All are RS-232 compatible. The HOST port is shared on the User Control Panel and the H8S controller board and is for AROS client-server and maintenance connections.

20 The internal HOST serial connector also has signal lines for

detecting an attached device (DTR pin 4) and for notifying the attached PC of lowpower condition (HRNG pin 9). The HOST serial connectors are wired DCE for direct connection (straight-through cable, not NULL-modem) to a standard PC serial port. See the nearby Tables for details.

The AUX1 and AUX2 serial ports are for RS232-compatible serial device connections, such as for the TCM2 Modules or any of several pan-tilt-zoom robotic systems.

AROS operates the serial ports at any of the FLASH-configured common data rates:

9,600, 19,200, 38,400, 57,800, or 115,200 bits per second; and at eight data bits, one stop bit, no parity or hardware handshaking.

Table 15. HOST serial ports on H8S board and on User Control (*) (DSUB-9 socket)

PIN SIGNAL

1 nc

DESCRIPTION

3 *RCV Input

PIN SIGNAL DESCRIPTION

2 *TXD output

4 DTR Input detects attached device and switches TxD and RxD into the uC

5 *GND Common 6 *DSR Output when controller powered

7 nc May be jumpered to pin 6

8 nc

9 † HRNG Output lowered to signal PC shutdown

† Shared on Motors interface

Table 16. AUX1 and AUX2 serial ports (5-pos microfit sockets)

PIN SIGNAL DESCRIPTION PIN SIGNAL DESCRIPTION

1 DTR Input 2 TXD output

3 RCV Input 4 DSR output

5 GND common

User I/O-Gripper Port

A 20-pin latching IDC socket on the H8S microcontroller provides the digital, analog, and power ports for user connections and for the Gripper accessory. Indicated ports (*) are shared on other connectors. Digital inputs are buffered and pulled high (digital 1); outputs are buffered and normally low (digital 0).

20 Unlike with earlier P2 controllers, HOST does not interfere with the User Control Panel serial connections if its attached device—PC or radio modem—is OFF.

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ActivMedia Robotics

Table 17. User I/O – Gripper (20-pos latching IDC)

PIN

SIGN

AL

DESCRIPTION PIN SIGNAL DESCRIPTION

1

3

5

7

9

OD0

OD1

OD2

OD3

ID4

DIGOUT bit 0;

Gripper enable

DIGOUT bit 1;

Gripper direction

DIGOUT bit 2;

Lift enable

DIGOUT bit 3;

Lift direction

DIGIN bit 4;

Left paddle contact

2

4

6

8

10

ID0

ID1

ID2

ID3

OD4

DIGIN bit 0;

Paddles open limit

DIGIN bit 1;

Lift limit

DIGIN bit 2;

Outer breakbeam IR

DIGIN bit 3;

Inner breakbeam IR

DIGOUT bit 4;

Not used by Gripper

11

13

15

ID5

ID6

ID7

DIGIN bit 5;

Right paddle contact

DIGIN bit 6;

Not used by Gripper

DIGIN bit 7;

Not used by Gripper

17 *AN0 A/D port 0 (default)

12

14

16

OD5

OD6

OD7

18 Vcc

DIGOUT bit 5;

Not used by Gripper

DIGOUT bit 6;

Not used by Gripper

DIGOUT bit 7;

Not used by Gripper

5VDC < 1A

(0-5VDC = 0-255)

19 Vpp Battery 12VDC < 1A 20 Gnd Signal/power

The Expansion I/O Bus

A 40-pin high-density IDC socket on the H8S microcontroller provides a general-purpose connector for future I/O expansion. Digital lines, including 8-bit bus address, data, read/write, and other general-purpose ones, are buffered with inputs pulled high.

Indicated ports (*) appear on other connectors.

Table 18. General-purpose I/O and data bus (40-pos high-density IDC)

PIN

SIGN

AL

DESCRIPTION PIN SIGNAL DESCRIPTION

1 AD0 Address bit 0 2 D7 Data bit 7

3 AD1 Address bit 1 4 D6 Data bit 6

5 AD2 Address bit 2 6 D5 Data bit 5

7 AD3 Address bit 3 8 D4 Data bit 4

9 AD4 Address bit 4 10 D3 Data bit 3

11 AD5 Address bit 5 12 D2 Data bit 2

13 ID6 Address bit 6 14 D1 Data bit 1

15 ID7 Address bit 7 16 D0 Data bit 0

17 DAC1 D/A port 1 18 CS4 Chip select 4

19 DAC0 D/A port 0

21 *AN4 A/D port 4;

Joystick Y

23 *AN3 A/D port 3;

20 CS3 Chip select 3

22 CS2 Chip select 2

24 WR Data

Joystick X

25 AN2 A/D port 2 26 RD Data

27 AN1 A/D port 1

29 *AN0 A/D port 0

28 CS6 Chip select 6 or digital I/O

30 CS7 Chip select 6 or digital I/O

31 GND Signal 32 reset

33 GND Signal I/O

35 GND Signal 36 Vcc Controller 5VDC (<200ma)

63

Appendix A: Systems and Power Diagram

37 GND Signal 38 Vcc Controller 5VDC (<200ma)

39 GND Signal 40 Vpp Battery 12VDC (<0.5A)

Bumper Ports

Two 10-position latching IDC connectors provide general-purpose digital inputs, typically used for the robot’s bumpers. All inputs are buffered and pulled high (digital 1).

Table 19. Bumper ports (10-pos latching IDC)

PIN

SIGN

AL

DESCRIPTION PIN SIGNAL DESCRIPTION

1 BP0

3 BP2

5 BP4

7 BP6

Bumper bit 0

Bumper bit 2

Bumper bit 4

Bumper bit 6

2

4

6

8

BP1

BP3

BP5

BP7

Bumper bit 1

Bumper bit 3

Bumper bit 5

Bumper bit 7

9 Gnd Common 10 Gnd Common

Motors, Encoders, and IR Sensors

A 26-position latching IDC connector on the H8S microcontroller provides interface to the

General Power and Signal Distribution Board (Appendix C). Line descriptions also can be found in the following Motor-Power Interface section.

Table 20. Motors, encoders, and IRs interface (26-pos latching IDC)

PIN

SIGNAL

DESCRIPTION PIN SIGNAL DESCRIPTION

1 LPWM

3 RPWM

Left motors PWM 2 LDIR Left motors direction

Right motors PWM 4 RDIR Right motors direction

5 enable 6 LEA Left encoder channel A

7 E-STOP E-Stop detect input 8 REA Right encoder channel A

9 RPWR Aux1 power enable 10 LEB Left encoder channel B

11 APWR Aux2 power enable 12 REB Right encoder channel B

13 CHRG Charge port detect 14 IR6 IR input bit 6

15 IR7

17 IR5

IR input bit 7

IR input bit 5

16 IR4

18 IR2

IR input bit 4

IR input bit 2

19 IR3

21 IR1

IR input bit 3

IR input bit 1

20 IR0 IR input bit 0

22 BAT Battery voltage detect

23 Gnd Signal 24 *HRNG RS232-level PC shutdown

25 Gnd Signal 26 Gnd Signal

User Control Interface

A 16-position latching IDC connector provides interface with the User Control Panel board and functions. See description in a following section.

Table 21. User Control Panel interface

PIN

1

3

SIGNAL

Vcc

DESCRIPTION

5 VDC power

PIN SIGNAL

2 Vcc

DESCRIPTION

5 VDC power button 4 button

64

ActivMedia Robotics

5 RPWR Aux1 power switch 6 APWR Aux2 power switch

7 CHRG Charging 8 BZR Buzzer

9 PLED Main 10 SLED Status

11 Vpp Battery 12 VDC 12 Gnd Signal/power

13 Gnd Signal/power 14 HTXD

15 HDSR HOST serial enabled 16 HRCV

HOST serial transmit

HOST serial receive

Joystick Port

An 8-position microfit socket provides signal lines for connection to an analog joystick.

Indicated lines (*) are shared on other connectors.

Table 22. Joystick connector (8-pos microfit)

PIN SIGNAL DESCRIPTION PIN SIGNAL DESCRIPTION

2 FB0 Fire button 0

3 *AN4 A/D port 4;

Y-axis

5 *AN3 A/D port 3;

X-axis

7 nc

6 FB1 Fire button 1

8 nc

65

Appendix C: Motor-Power Board Connectors

Appendix C

P

OWER

D

ISTRIBUTION

Your PowerBot has two power-distribution boards; a high-current, main power one for motors, onboard PC, and PowerBot Arm power, under E-STOP and main power-switch control, and one for general power conditioning and distribution for onboard systems and accessories. Consult Appendix B for H8S-controller and User Control Panel interface details.

Figure 31. General Power and Signal Distribution Board

G

ENERAL

P

OWER AND

S

IGNAL

D

ISTRIBUTION

B

OARD

The low-current, general power distribution board provides conditioned 5 and 12 VDC power to the onboard systems except for the motor drives and PowerBot Arm, and distributes several of the H8S microcontroller’s control signals, such as to the drive motors and fixed-range IRs.

The general power and signal distribution circuitry is isolated from main battery power (24

VDC) by the high-current relay board, except for power to the brakes. There is a manual brake release button that triggers the brake relay which connected to unswitched battery power, consequently releasing the motor brakes regardless of main power state, so that you can push the robot around.

Power Distribution and User Power

Distinct connectors provide power for many common onboard systems, including the

H8S controller, the laser range finder, fixed-range IRs, and the motors brake release. Two other types of connectors—Aux1 and Aux2 power switched and un-switched—provide general 5, 12 and 24 VDC power for attached accessories, including user-added options.

66

Table 23. Switched User Power Screw-Down Terminals (12-pos)

T ERMINAL SIGNAL DESCRIPTION

1

2

3

A1Vcc Aux1-switched battery 5 VDC

A1Vpp Aux1-switched 12 VDC

A1Vbat Aux1-switched 24 VDC (battery)

10 A2Vcc Aux2-switched 5 VDC

11 A2Vpp Aux2-switched 12 VDC

12 A2Vbat Aux2-switched 24 VDC

Table 24. Aux1- and Aux2-Switched Power Connectors (6-pos microfits)

PIN SIGNAL DESCRIPTION

1-3 GND Commons

4 Vbat Aux switched 24 VDC

5 Vpp Aux switched 12 VDC

6 Vcc Aux switched 5 VDC

Table 25. AUX Power unswitched (12-pos minifit)

PIN SIGNA

L

DESCRIPTION

1-2 Vbat 24 VDC unswitched

3-4 Vpp 12 VDC unswitched

5-6 Vcc 5 VDC unswitched

7-12 GND Commons

Table 26. IR Power and Signal Connectors (3-pos microfits)

PIN SIGNAL DESCRIPTION

ActivMedia Robotics

2 IRn IR switching signal

67

Appendix C: Motor-Power Board Connectors

M AIN P OWER D ISTRIBUTION B OARD

Main power from the batteries goes through the maintenance breaker to the Main

Power Distribution board, found just beneath the rear deck on the left side of the robot.

Figure 32. Main Power Distribution Board

A set of redundant relays, triggered by the main power switch deliver power to the motors, PC power supply, the PowerBot Arm, and to the General Power Distribution board via the Main Power Out terminal. A separate Brakes Power connector delivers unswitched battery power to the General Power Distribution board which switches allow for manual release of the brakes even when main power is off on the robot.

The motors and arm relays and subsequent power also are switched through the E-STOP buttons for failsafe removal of power; onboard PC and general systems power remains on through E-STOP.

User-replaceable fuses are automotive spade-type, whose values are given in the Figure.

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ActivMedia Robotics

Appendix D

ARIA/S

APHIRA

P

ARAMETERS

F

ILE

;;

;; Parameters for the PowerBot

;;

[General]

Class Pioneer

Subclass PowerBot

RobotRadius 550.0 ; radius in mm

RobotDiagonal 400.0 ; half-height to diagonal of octagon

Holonomic 1 ; turns in own radius

MaxRVelocity 360.0 ; degrees per second

MaxVelocity 2000.0 ; mm per second

HasMoveCommand 1 ; has built in move command

[ConvFactors]

AngleConvFactor 0.001534 ; radians per angular unit (2PI/4096)

DistConvFactor 0.5813 ; mm returned

VelConvFactor 1.0 ; mm/sec returned

RangeConvFactor 1.0 ; sonar range returned in mm

DiffConvFactor 0.003728 ; ratio of angular to wheel velocity

Vel2Divisor 20.000000 ; divisor for VEL2 commands

[Accessories]

TableSensingIR false ; if the robot has upwards facing table sensing IR

FrontBumpers true ; if the robot has a front bump ring

RearBumpers true ; if the robot has a rear bump ring

[Sonar]

;; These are for the 14 front and 14 rear sonar

;;

;; Sonar parameters

;; SonarNum N is number of sonars

;; SonarUnit I X Y TH is unit I (0 to N-1) description

;; X, Y are position of sonar in mm, TH is bearing in degrees

;;

SonarNum 31 ; 7 in each of 4 banks of 8 total sonar

@start ;start from leftmost front sonar and go CW

SonarUnit 0 152 278 90 ; FRONT LEFT

SonarUnit 1 200 267 65

SonarUnit 2 241 238 45

SonarUnit 3 274 200 35

SonarUnit 4 300 153 25

SonarUnit 5 320 96 15

SonarUnit 6 332 33 5

SonarUnit 7 0 0 0 ; phantom 8 th sonar in array

SonarUnit 8 332 -33 -5

SonarUnit 9 320 -96 -15

SonarUnit 10 300 -153 -25

SonarUnit 11 274 -200 -35

69

Appendix D: ARIA/Saphira Parameters File

SonarUnit 12 241 -238 -45

SonarUnit 13 200 -267 -65

SonarUnit 14 152 -278 -90 ;FRONT Right

SonarUnit 15 0 0 0

SonarUnit 16 -298 -278 -90 ;REAR Right

SonarUnit 17 -347 -267 -115

SonarUnit 18 -388 -238 -135

SonarUnit 19 -420 -200 -145

SonarUnit 20 -447 -153 -155

SonarUnit 21 -467 -96 -165

SonarUnit 22 -478 -33 -175

SonarUnit 23 0 0 0

SonarUnit 24 -478 33 175

SonarUnit 25 -467 96 165

SonarUnit 26 -447 153 155

SonarUnit 27 -420 200 145

SonarUnit 28 -388 238 135

SonarUnit 29 -347 267 115

SonarUnit 30 -298 278 90 ;REAR Left

@end

70

Warranty & Liabilities

Your PowerBot is fully warranted against defective parts or assembly for one year after it is shipped to you from the factory. Accessories are warranted for 90 days. This warranty explicitly does not include damage from shipping or from abuse or inappropriate operation, such as if the robot is allowed to tumble or fall off a ledge, or if it is overloaded with heavy objects.

The developers, marketers, and manufacturers of ActivMedia Robotics products shall bear no liabilities for operation and use of the robot or any accompanying software except that covered by the warranty and period. The developers, marketers, or manufacturers shall not be held responsible for any injury to persons or property involving

ActivMedia Robotics products in any way. They shall bear no responsibilities or liabilities for any operation or application of the robot, or for support of any of those activities.

And under no circumstances will the developers, marketers, or manufacturers of

ActivMedia Robotics product take responsibility for support of any special or custom modification to ActivMedia robots or their software.

44 Concord Street

Peterborough, NH 03458

(603) 924-9100

(603) 924-2184 fax http://www.activrobots.com

72

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