MTS Series 793 User Manual
Page 50
MTS Series 793 Tuning and Calibration
When to Tune
Tuning Procedures
50
For example, a new system or a system under complete recalibration requires all
of the following to be completed. If you are performing periodic or fine-tuning,
review the following and determine which tasks you need to complete.
•
Connect an oscilloscope to your system or use the controller scope. You
need to monitor the sensor signal or error signal for the control mode you
intend to tune. See
“Monitoring Waveforms While Tuning”
help.
•
Balance the servovalve. The electrical valve balance adjustment
compensates for minor mechanical imbalance—it is an intermediate
adjustment. See
“How to Balance the Servovalve”
on page 60 for help.
•
Calibrate each sensor used for a control mode or data acquisition. Perform
the appropriate calibration procedure.
•
If your sensor calibration schedule does not require calibration at this time,
perform a shunt calibration check to determine if your DC sensor/DC
conditioner is within tolerance. See
help.
•
If you have a three-stage (Series 256 or 257) servovalve, tune the inner loop
(gain and rate) before tuning the outer loop. The rules for inner loop tuning
are similar to those of the outer loop. See
Tuning controls review
The following is a brief review of the most prominent tuning controls:
•
Proportional gain (P Gain) increases system response.
•
Integral gain (I Gain) increases system accuracy during static or low-
frequency operation and maintains the mean level at high frequency
operation.
•
Derivative gain (D Gain) improves the dynamic stability when high
proportional gain is applied.
•
Feed forward gain (F Gain) increases system accuracy during high-
frequency operation.
•
Forward loop filter (FL Filter) adjustments establish a frequency bandwidth
for the servoloop command signal.