User Manual Of EL7-EC** AC Servo
225
Range
0~6400 Unit 0.01ms Default
50
Index
2111h
Activation
Immediate
Set velocity feed forward low pass filter to eliminate high or abnormal frequencies in velocity feed
forward command. Often used when position command with low resolution or high electronic gear
ration to smoothen velocity feed forward.
Position deviation under constant velocity can be lowered with higher velocity feed forward gain.
Please to refer to the equation below.
Position deviation[Uint]=
6.6.2 Velocity feedforward application
Set Pr1.11 to around 50 (0.5ms), then tune Pr1.10 from 0 to bigger values until the velocity
feedforward achieves better performance. Under constant velocity, the position
deviation in a motion will decrease as the velocity feedforward gain increase.
Steps to tuning:
1.
Increase Pr1.10 to increase responsiveness but velocity overshoot might occur
during acc-/deceleration.
2.
By reducing Pr1.11, velocity feedforward would be more effective and vice versa.
Pr1.10 and Pr1.11 need to be tuned to a balance.
3.
If mechanical noise exists under normal working conditions, please increase Pr1.11
or use position command filter (1 time delay/ FIR smoothing filter)
6.6.3 Torque feedforward
Position control mode:
Torque feedforward can increase the responsiveness of torque command, decrease
position deviation during constant acc-/deceleration.
Velocity control mode:
Torque feedforward can increase the responsiveness of torque command, decrease
velocity deviation during constant velocity.
Pr1.12
Name
Torque feed forward
gain
Mode
PP PV HM
CS
P
CS
V
