Estun Summa Series - Load Torque Compensation

Summa Series Servodrive Product Manual
Tuning
Document Version: V1.01
(Dec, 2019)
© 2019 ESTUN Automation Co., Ltd. All right reserved.
9-34
The friction compensation function is that the Drive compensates the load friction by using the relevant
parameter settings, which can be used for applications with frequently forward and reverse motion, and
high speed-stability requirements.
Friction compensation is used to compensate for viscous friction fluctuations and coulomb friction
fluctuations.
You can set Coulomb Friction Compensation (Pn130) manually, and its direction is consistent with the
direction of rotation speed. In addition, it is necessary to set Speed Dead Band for Coulomb Friction
Compensation (Pn131) to avoid the Motor changing the compensation direction frequently near zero
speed, in this case, the Friction Compensation in the Dead Band is 0, as is shown in Figure 9-15.
Figure 9-15 Friction compensation diagram
Torque
compensation
Speed
(Positive) Cou lomb Friction
Compensation [Pn130]
Speed Dead Band for Cou lomb
Friction Compensat ion [Pn131]
0
(Negative) Coulomb Fric tion
Compensation [Pn130]
Cou lomb Fric tion
Compensation is 0
The viscous friction compensation is a linear relationship with the Motor speed, as is shown in Figure 9-
16. You can set the Viscous Friction Compensation by Pn132.
Figure 9-16 Relationship between viscous friction and speed
Torque compens at ion
Speed
Vi scous Friction
Compensation [Pn132]
0
Parameter
Setting
Meaning
When Enabled
Classification
Pn130
－
Coulomb Friction Compensation
Immediately
Adjustment
Pn131
－
Speed Dead Band for Coulomb
Friction Compensation
Immediately
Adjustment
Pn132
－
Viscous Friction Compensation
Immediately
Adjustment
9.5.5 Load Torque Compensation
If there is a sudden load torque during the operation of the Motor, the speed will decrease or the position
will move. The continuously changing load torque will also cause the speed fluctuation or position jitter.
In this case, it is generally necessary to improve the anti-load disturbance performance of the servo by
tuning.
In the tuning process, the load torque compensation function can be used to improve the anti-load
disturbance performance, considering that the reference response performance and the load disturbance
resistance cannot be balanced.
As shown in the figure below, the speed drop is caused by a sudden load torque, and the load torque
compensation function can be used to reduce the drop of the speed.