Explanation Of Tuning Gains; Proportional Gain; Derivative Gain (Dgain); Integral Gain (Igain) - Parker ACR7000 Series Programmer's Manual

APPENDIX C: SERVO PID TUNING

Explanation of Tuning Gains

Proportional Gain (PGAIN)
This command modifies the value used in the PID algorithm to control proportional gain. The default gain is
0.0024414 (10 volts at 4096 pulses) for all axes. Units are volt/pulse.

Derivative Gain (DGAIN)

This command modifies the value used in the PID algorithm to control derivative gain. The default gain is 0.0001
for all axes.

Integral Gain (IGAIN)

This command modifies the value used in the PID algorithm to control integral gain. Increase the integral gain to
counter any steady-state error after the commanded move is complete. The default gain is 0.0 for all axes. Units
are volts/second/pulse.
NOTE: If ILIMIT is zero the integral will remain off, even if the IGAIN value is set to something
other than zero.

Integral Limit (ILIMIT)

This command modifies the value used by the PID filter to limit the amount of integral term allowed to build up in
the loop. The default gain is 0.0 for all axes. Units are volts/second/pulse.

Integral Delay (IDELAY)

This command modifies the value used in the PID algorithm to control integral delay. The integral delay
determines the amount of time, after a move ends, before integration begins. If the value is set to zero, integration
is active all the time, even during moves. The default gain is 0.0 for all axes. Units are milliseconds.

Torque Limit (TLM)

This is the controller's analog max output in volts (max is 10 volts = 100%). Users can use this to limit motor
torque—1 volt would be a 10% limit. This would be a limit to the servo amplifier in torque mode. The amplifier
setting sets the motor current scaling for 10 volt input to the drive and can be used to correlate the motor torque
to DAC output voltage.
The IPA uses the standard ACR tuning gains (PGAIN, DGAIN, etc.), however with the IPA the feedback resolution
is normalized to 8000 counts per revolution. With other the ACR controllers the gains are feedback resolution-
dependent.
Thus, the IPAs gains will be similar for standard and high-resolution servos. An ACR's gains will be linearly lower
for higher resolution servos.

Tips and Tricks

Auto Scale is on by default for vertical scaling in PMM. Note the following error values as you are tuning; the
graph may appear larger but that may just be the Auto Scale adjusting based on the data spread.
The position values and following error are in encoder counts.
ACR Programmer's Guide 297