Rockwell Automation 2098-UWCPRG Ultraware Software User Manual - Manual (Page 259)

Rockwell Automation Publication 2098-UM001G-EN-P - February 2011 261
Configuring the Kinetix 3 Drive Chapter 5
The following display is the default status for a Kinetix 3 drive in
Kp Proportional gain for the position loop. The Kp gain generates a
control signal proportional to the position error. The range is 0…32
in/min/mil.
Note: Increasing the P gain improves response time and increases
the stiffness of the system. Too high a P gain value causes
instability; too low a P gain value results in loose or sloppy system
dynamics.
Kd Derivative gain for the position loop. The Kd gain generates a
control signal proportional to measured velocity. The range is
0…32.
Note: Kd gain provides damping to the position loop, that can
reduce overshoot.
Kff Feedforward gain for the position loop. The Kff gain generates a
feed forward signal proportional to the commanded speed. The
range is 0…200.
Note: Kff gain reduces position following error. However high
values can cause position overshoot.
Ki Integral gain for the position loop. Ki gain generates a control
signal proportional to the integral of the velocity error. The range is
0…32.
Note: Ki gain improves the steady-state positioning performance of
the system and virtually eliminates steady-state positioning errors.
It affects the ability to reject load disturbances. Increasing the
integral gain generally increases the ultimate positioning accuracy
of the system. However excessive integral gain results in system
instability.
Ki Zone The region, in counts, around the commanded position where
integral gain is active. If the position error is greater than Ki Zone,
the integrator is reset. The range is 0…32,767 counts.
Velocity Regulator Gains
P Proportional gain for the velocity loop. The P gain generates a
control signal proportional to the velocity error. The range is
0…4000.
Note: Increasing the P gain improves response time and increases
the stiffness of the system. Too high a P gain value causes
instability; too low a P gain value results in loose or sloppy system
dynamics.
I Integral gain for the velocity loop. The I gain generates a control
signal proportional to the integral of the velocity error. The range is
0…4000.
Note: I gain improves the steady-state velocity performance of the
system. Increasing the integral gain generally increases the
ultimate positioning accuracy of the system. However excessive
integral gain results in system instability.
D Derivative gain value for the velocity loop. The D gain generates a
control signal proportional to measured acceleration. The range is
is -1000…1000.
Note: Positive D gain reduces velocity overshoot, and negative D
gain should be used only in systems that exhibit mechanical
resonance.
Parameter Description