Flexible System Parameters - Omron XTRADRIVE User Manual

XtraDrive User Manual
• Second Order Torque Filter (Pn1A5), Range 0-1000 [0.1%],
Default 0:
This parameter is a part of the second order torque filter. It has good
influence in many cases, even if the first order torque filter is not
active.
After tuning Pn1A4, raise this parameter progressively until
vibrations occur. In many systems, values for this parameter will be
in the 500—700 (0.1%).
• Command Smoothing (Pn216), Range 0-65536 [0.1ms],
Default 0: (See 6.1.2)
In case of a flexible system, if command acceleration is not applied
progressively, the system will oscillate around the command
position after every discontinuity of the command acceleration (even
if the oscillation is not seen). The command-smoothing smoothes
the command acceleration to avoid these oscillations.
Using a command filter will delay the arrival of the command to the
final target position. The value of this filter should be set higher than
the period of self-oscillations, but not too high to keep good settling
time.
6.3.7.

Flexible System Parameters

• K
ff
This parameter compensates the position error during the
acceleration and deceleration phase and the overshoot observed
when stopping at the end of a deceleration phase. Typically, this
overshoot is caused by the elasticity of the system; a wind up occurs
during the deceleration phase and relaxes after stop. The K
parameter compensates for that wind up.
The frequency of this parameter relates to the self-oscillation
frequency of the system. It can be adjusted to avoid overshoot and
minimize settling time.
Default value is 2000 Hertz. This value is well beyond the frequency
response of usual systems, so that it has no influence.
To adjust, decrease this value progressively, while monitoring the
position error, until overshoot is canceled or position error in the
acceleration and deceleration phase are minimized.
• KfbSpring (Pn1BD) range 10-2000 [Hz] default 2000:
This parameter compensates the vibrations of the motor, it smoothes
the control in case of a flexible system. Usually it should be tuned to
the low resonance of the system.
You can tune this parameter by progressively decreasing its value
until vibrations occur. Then use a higher value for setting (~20%).
Spring (Pn1BB) range 10-2000 [Hz] default 2000:
6-18
Chapter 6: Servo Adjustment
Spring
ff