6.6 Auxiliary Point-Specified Circular Interpolation Control. Mitsubishi MOTION CONTROLLERS Q172DCPU

6 POSITIONING CONTROL

6.6 Auxiliary Point-Specified Circular Interpolation Control

Circular interpolation control by specification of the end point address and auxiliary point address (a point on the arc) for circular interpolation is executed.

Auxiliary point-specified circular uses ABS (Absolute data method) and INC

(Incremental data method) servo instructions.

Items set using MT Developer

Servo instruction

Positioning method

Number of control axes

Speed change

ABS

INC

[Control details]

Absolute

Incremental

2

Valid

: Must be set

: Set if required

Control using ABS (Absolute data method)

(1) Circular interpolation from the current stop address (address before positioning) based on the home position through the specified auxiliary point address to the end point address is executed.

(2) The center of the arc is the point of intersection of the perpendicular bisectors of the start point address (current stop address) to the auxiliary point address, and the auxiliary point address to the end point address.

Forward direction

Operation by circular interpolation

End point address (X

1

, Y

1

)

Auxiliary point address (X

2

, Y

2

)

Reverse direction

Start point address

(X

0 , Y

0

)

0

Arc central point

Reverse direction

Forward direction

(Note) : Indicates setting data

Fig.6.9 Circular interpolation control using absolute data method

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6 POSITIONING CONTROL

(3) The setting range of the end point address and auxiliary point address is (-2

31

) to

(2

31 -1).

(4) The maximum arc radius is 2

32

-1.

2 32 -1

Maximum arc

0

-2 31 2 31 -1

Radius R

Arc central point

Fig.6.10 Maximum arc

Control using INC (Incremental data method)

(1) Circular interpolation from the current stop address through the specified auxiliary point address to the end point address is executed.

(2) The center of the arc is the point of intersection of the perpendicular bisectors of the start point address (current stop address) to the auxiliary point address, and the auxiliary point address to the end point address.

Forward direction

Positioning speed

Y

1

End point

Travel value to end point

Travel value to auxiliary point

Y

2

Auxiliary point

X

1

Arc central point

X

2

Reverse direction

Start point Travel value to auxiliary point

Travel value to end point

Forward direction

Home position

(Note) : Indicates setting data

Fig.6.11 Circular interpolation control using incremental data method

(3) The setting range for the travel value to the end point address and auxiliary point address is 0 to (2 31 -1).

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6 POSITIONING CONTROL

(4) The maximum arc radius is 2

31

-1.

If the end point and auxiliary point are set more than a radius of 2

31 -1, an error occurs at the start and error code [107] is stored in the data register.

2 31 -1

Maximum arc

Arc central point

0

-2 31

Radius R

2 31 -1

Fig.6.12 Maximum arc

[Program]

Program for auxiliary point-specified circular interpolation control is shown as the following conditions.

(1) System configuration

Auxiliary point-specified circular interpolation control of Axis 1 and Axis 2.

Motion CPU control module

Q61P Q03UD

CPU

Q172D

CPU

QX41 QY41 Q172D

LX

Positioning start command (PX000)

AMP

Axis

1 M

AMP

Axis

2 M

AMP

Axis

3 M

AMP

Axis

4 M

(2) Positioning details

The positioning uses the Axis 1 and Axis 2 servomotors.

The positioning by the Axis 1 and Axis 2 servomotors is shown in the diagram below.

Axis 2 positioning direction

(Forward direction)

50000

Auxiliary point (40000, 50000)

Positioning using the servo program No.31

30000

20000

End point (80000, 30000)

0

Start point

(10000,

20000)

10000 40000

Arc central point

80000

Axis 1 positioning direction

(Forward direction)

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6 POSITIONING CONTROL

(3) Positioning conditions

(a) Positioning conditions are shown below.

Item

Positioning method

Positioning speed

Servo program No.

No.31

Absolute data method

1000

(b) Positioning start command ........ PX000 Leading edge (OFF ON)

(4) Operation timing

Operation timing for auxiliary point-specified circular interpolation control is shown below.

V

Servo program No.31

Vector speed t

PLC ready flag (M2000)

All axes servo ON command

(M2042)

All axes servo ON accept flag

(M2049)

Axis 1 servo ready (M2415)

Axis 2 servo ready (M2435)

Start command (PX000)

Servo program start

Axis 1 start accept flag

(M2001)

Axis 2 start accept flag

(M2002)

(5) Servo program

Servo program No.31 for auxiliary point-specified circular interpolation control is shown below.

<K 31>

ABS

Axis

Axis

Speed

Auxiliary

point

Auxiliary

point

1,

2,

1,

2,

80000

30000

1000

40000

50000

Auxiliary point-specified circular interpolation control

Axis used . . . . . . . . Axis 1, Axis 2

End point address

Axis 1 . . . . . . 80000

Axis 2 . . . . . . 30000

Positioning speed . . . . . . . . . . . . . . 1000

Auxiliary point address

Axis 1 . . . 40000

Axis 2 . . . 50000

(Note): Example of the Motion SFC program for positioning control is shown next page.

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6 POSITIONING CONTROL

(6) Motion SFC program

Motion SFC program for which executes the servo program is shown below.

Auxiliary point-specified circular interpolation control

Auxiliary point-specified circular interpolation control

[F10] SET M2042

[G10] PX000*M2415*M2435

[K10] ABS

Axis 1, 80000PLS

Axis 2, 30000PLS

Speed 1000PLS/s

Auxiliary 1, 40000PLS

point

Auxiliary 2, 50000PLS

point

[G20]

!PX000

Turn on all axes servo ON command.

Waits until PX000, Axis 1 servo ready and Axis 2 servo ready turn on.

Auxiliary point-specified circular interpolation control

Axis used. . . . . . . . . . . . . . . Axis 1, Axis 2

End point address

. . . . . . .

Axis 1 . . . 80000[PLS]

Axis 2 . . . 30000[PLS]

Positioning speed . . . . . . . . . . . . . . . . . . . . 1000[PLS/s]

Auxiliary point address . . . . .

Axis 1 . . . 40000[PLS]

Axis 2 . . . 50000[PLS]

Wait until PX000 turn off after circular interpolation completion.

END

(Note): Example of the above Motion SFC program is started using the automatic start or PLC program.

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