5 Adjustments
5.8.6 Backlash Compensation Function
5-64
5.8.6
Backlash Compensation Function
(1) Overview
When driving a machine with backlash, there will be a deviation between the travel distance in the position
reference that is managed by the host controller and the travel distance of the actual machine. Use backlash
compensation function to add the backlash compensation value to the position reference and use the result to
drive the servomotor. This means that the travel distance of the actual machine will be the same as the travel
distance in the host controller.
Note 1. This function is supported only for position control.
2. Software version 0023 or higher is required to use this function. You can confirm the software version in Fn012.
For details, refer to
6.14 Software Version Display (Fn012)
.
(2) Related Parameter
Set the following parameter to use backlash compensation.
Backlash Compensation Direction
Set the direction in which to apply backlash compensation.
Backlash Compensation Value
Set the amount of backlash compensation to add to the position reference.
The amount is set in increments of 0.1 reference unit. However, when the amount is converted to encoder
pulses, it is rounded off at the decimal point.
Example: If Pn231 is set to 6,553.6 [reference unit] and the electronic gear ratio (Pn20E/Pn210) is set to 4/1,
then the pulse equivalent is 6,553.6
×
4 = 26,214.4 [pulses].
The backlash compensation value will be 26,214 encoder pulses.
Backlash (play due to mechanical precision)
Backlash compensation value
Reference forward
rotational direction
Machine axis
Motor axis
Motor axis
Machine axis (e.g. table)
Travel distance by
position reference
Travel distance
by position reference
Parameter
Function
When Enabled
Classification
Pn230
n.
0
[Factory
setting]
Compensates with a reference in the forward direc-
tion.
After restart
Setup
n.
1
Compensates with a reference in the reverse direc-
tion.
Pn231
Backlash compensation value
Classification
Setting Range
Setting Unit
Factory Setting
When Enabled
-500000 to 500000
0.1 reference
unit
0
Immediately
Setup
Position