National Instruments NI-Motion - Manual (Page 29)

© National Instruments Corporation 3-1 NI-Motion User Manual
3
Tuning Servo Systems
When your motion control system includes a servo motor, you must tune
and calibrate the system to ensure proper performance. This chapter covers
general information about tuning and calibrating your servo system using
control loop parameters. Refer to Measurement & Automation Explorer
Help for Motion for more information about and instructions for tuning
servo motors in Measurement & Automation Explorer (MAX).
NI SoftMotion Controller Considerations
This section includes information you need if you are using the
NI SoftMotion Controller.
NI SoftMotion Controller for CANopen
This chapter does not apply if you are using the
NI SoftMotion Controller for CANopen because the control loop is
implemented on the drive. Refer to the drive documentation for
information about tuning the servo motors you are using with the CANopen
drive.
NI SoftMotion Controller for Ormec
If you are using the NI SoftMotion Controller for Ormec with an Ormec
ServoWire drive in position mode, you must tune the control loop using the
drive configuration utility provided by Ormec.
Using Control Loops to Tune Servo Motors
Tuning maximizes the performance of your servo motors. A servo system
uses feedback to compensate for errors in position and velocity.
For example, when the servo motor reaches the desired position, it cannot
stop instantaneously. There is a normal overshoot that must be corrected.
The controller turns the motor in the opposite direction for the amount of
distance equal to the detected overshoot. However, this corrective move
also exhibits a small overshoot, which must also be corrected in the same
manner as the first overshoot.