The Inverted Pendulum
Quentin Corich, Austin Hutchison
What is an Inverted pendulum?
● Normal pendulum
o Weight is below the pivot
point
o The weight swings back
and forth about its pivot
point, and oscillates
around its equilibrium
position directly below (in
the direction of gravity)
the pivot point.
Image from wikipedia
What is an Inverted pendulum?
● Inverted pendulum
o Weight is above the pivot point
o The weight is connected to a rigid
pole with a pivot point on a moving
platform
o The platform oscillates back and
forth to balance the mass directly
above the pivot point.
Image from wikipedia
Our Inverted Pendulum
Starts life as an
actobotics channel
slider kit from
servocity.
Image from servocity
Our Inverted Pendulum
The pivot platform is
mainly built with
Actobotic parts from
servocity.
Our Inverted Pendulum
● Supported by two ball
bearings
● Potentiometer is
connected to the
rotating assembly
with a shaft coupler
o And fixed to main
chassis with a tube
clamp (not shown)
Our Inverted Pendulum
● Supported by two ball
bearings
● Potentiometer is
connected to the
rotating assembly
with a shaft coupler
o And fixed to main
chassis with a tube
clamp
Our Inverted Pendulum
Controlling the Pendulum
● Must be able to balance the arm if it is
pushed off center
● Must be able to be started with the arm out
of balance
Initialization
PI System
● Stands for Proportional Integral control
y = P * e + Ti * ∫ e dt
PI System Cont.
Main Loop
PI code
Timing Diagram
Important Code
Questions
">
