Speed Detection Method Selection; Speed Feedback Filter; Backlash Compensation - YASKAWA SGD7S Product Manual

8.12.5

Speed Detection Method Selection

You can use the speed detection method selection to ensure smooth Servomotor speed
changes during operation. To ensure smooth motor speed changes during operation, set
Pn009 to n.1 (Use speed detection 2).
With a Linear Servomotor, you can reduce the noise level of the running motor when the linear
encoder scale pitch is large.
Parameter

n. 0
(default setting)
Pn009

n. 1
If the speed detection method is changed, the response characteristic of the speed loop will also
change. Servo tuning must therefore be performed again.
Important
8.12.6

Speed Feedback Filter

You can set a first order lag filter for the speed feedback in the speed loop. This ensures
smooth changes in the feedback speed to reduce vibration. If a large value is set, it will
increase the delay and make response slower.
Speed Feedback Filter Time Constant
Setting Range
Pn308
(0.00 ms to 655.35 ms)
8.12.7

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.
Machine shaft
Backlash compensation value
Motor shaft
Motor shaft

Use speed detection 1.

Use speed detection 2.
Setting Unit
0 to 65,535
0.01 ms
Reference travel distance
Reference travel
distance
Backlash (play due to mechanical tolerance)
8.12 Additional Adjustment Functions

8.12.5 Speed Detection Method Selection

Meaning
Default Setting
0
(0.00 ms)
Forward reference direction
Machine axis (e.g., table)
When Enabled Classification
After restart Tuning
Speed Position
When Enabled Classification
Immediately Setup
8
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