Backlash Compensation Function - Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual

7.2

Backlash Compensation Function

This function compensates for the backlash amount in the machine system.
When the backlash compensation amount is set, extra feed pulses equivalent to the backlash compensation amount set up
whenever the travel direction is generated at the positioning control, JOG operation or manual pulse generator operation.
Backlash compensation amount
Setting of the backlash compensation amount
The backlash compensation amount is one of the fixed parameters, and is set for each axis using MT Developer2.
The setting range differs according to whether [mm], [inch], [degree] or [pulse] units are used as shown below.
Units
mm
inch
degree
pulse
A servo error (AL.35 etc.) may occur depending on the type of the servo amplifier (servo motor) or operation cycle even if the
backlash compensation amount fulfils the above condition. Set the backlash compensation amount within the following range
to avoid an error occurrence.
Maximum motor speed [r/min]×1.2×Encoder resolution [Pulse]×Operation cycle [ms]
A ≤
Backlash compensation processing
Details of backlash compensation processing are shown below.
Condition
First start after power on
JOG operation start
Positioning start
Manual pulse generator operation
Home position return completion
Absolute position system
• When backlash compensation amount has been set, feed pulses of the backlash compensation amount are
added to the position command value but are not added to feed current value.
• When the backlash compensation amount is changed, the home position return is required. When the home
position return is not executed, the original backlash compensation amount is not changed.
Feed screw
Workpiece
Setting range
-1
0 to 65535 (10 [m])
-5
0 to 65535 (10 [inch])
-5
0 to 65535 (10 [degree])
0 to 65535 [pulse]
60 [s]×1000 [ms]
Processing
• If travel direction is equal to home position return direction, the backlash compensation is not executed.
• If travel direction is not equal to home position return direction, the backlash compensation is executed.
If travel direction is changed at the JOG operation start, the backlash compensation is executed.
If travel direction is changed, the backlash compensation is executed.
If travel direction is changed, the backlash compensation is executed.
The backlash compensation is executed after home position return completion.
Status stored at power off and applied to absolute position system.
[pulse]
7 AUXILIARY AND APPLIED FUNCTIONS
7.2 Backlash Compensation Function
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