Instantaneous Speed Observer - Omron OMNUC G Series User Manual

5-24 Instantaneous Speed Observer

Function
The instantaneous speed observer improves speed detection accuracy, increases responsiveness,
and reduces vibration at stopping by estimating the speed of the Servomotor using a load model
(load inertia).
This function does not work for machines with resonance or insufficient rigidity.
This function can be used in the position and speed control modes.
This function is available for Servomotors with only a high speed resolution absolute encoder.
Speed Command
Position Command
Position
Parameters Requiring Settings
Parameter
Parameter name
No.
Pn020 Inertia Ratio
Instantaneous
Pn027 Speed Observer
Setting
Positioning
Pn060 Completion
Range 1
Precautions
for Correct Use
Control Mode
Resonating load
status
Load status
Encoder
Control
Control
Instantaneous
Speed Observer
Estimated
Load Model
Speed
Setting
Sets the load inertia ratio as accurately as possible.
0 Instantaneous Speed Observer disabled
1 Instantaneous Speed Observer enabled
Set this parameter when using an absolute encoder.
 The instantaneous speed observer may not function properly or may not
be effective under the following conditions.
Conditions under which the instantaneous speed observer
 In Torque Control Mode. (Operates in position and speed control modes)
 If there's a large resonance point at the frequency of 300 Hz or lower.
 If there are multiple resonance frequencies.
 If the resonance peak or control gain is low, and the Servomotor speed is not
affected by it.
 If the Servomotor speed with high-frequency components changes due to
backlash or other non-linear elements (play).
 If a large disturbance torque with high-frequency components is applied.
 If the load inertia changes.
 If a 2,500-p/r incremental encoder is used.

5-24 Instantaneous Speed Observer

Torque
Current Loop
Command
Speed
Control
Speed Feedback
Explanation
does not function properly
5
SM
Load
RE
Reference page
5-68
5-71
5-75
5-48