Backlash Compensation - YASKAWA SGD7S-xxxDA0 series Product Manual

9.12 Additional Adjustment Functions

9.12.8 Backlash Compensation

9.12.8 Backlash Compensation

Outline
If you drive a machine that has backlash, there will be 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 to add the backlash compensation value to the
position reference and use the result to drive the Servomotor. This will ensure that the travel
distance of the actual machine will be the same as the travel distance in the host controller.
Note: 1. Backlash compensation can be used only with a Rotary Servomotor.
2. Backlash compensation can be used only for position control.
Backlash compensation value
Related Parameters
Set the following parameters to use backlash compensation.
 Backlash Compensation Direction
Set the direction in which to apply backlash compensation.
Pn230
(2230h)
 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
Pn231
(2231h)
9-72
Reference travel distance
Machine shaft
Reference travel
Motor shaft
Motor shaft
Backlash (play due to mechanical tolerance)
Parameter

n. 0
Compensate forward references.
(default setting)

n. 1 Compensate reverse references.
When Pn231 = 6553.6 [reference units] and position reference unit (Numerator/Denominator)
= 1/1:
6,553.6 × 1 = 6,553.6 [pulses]
 The backlash compensation will be 6,553 encoder pulses.
Backlash Compensation
Setting Range
-500,000 to 500,000
distance
Forward reference direction
Machine axis (e.g., table)
Meaning
Setting Unit Default Setting
0.1 reference
0
units
When Enabled Classification
After restart Setup
Position
When Enabled Classification
Immediately Setup