De-tuning using the Workbench Performance Servo Tuner

How to use the Performance Servo Tuner to de-tune the AKD

The Performance Servo Tuner (or Autotuner) can be used even when the best tuning is not desired.  When tuning to a lower than optimal performance level, we call it "de-tuning".  The Autotuner in Workbench can be used to de-tune a system very easily.  Just increase the values of Phase Margin and Gain Margin.  The optimal tuning is based on a phase margin of 45 degrees and a gain margin of 8 dB.  If these values are increased to 55 degrees and 12 dB, the system will be tuned to a lower performance level.  Further increasing these values gives an even milder tuning.

Here are some good combinations to use:

Phase Margin = 45, Gain Margin = 8, stiff

Phase Margin = 55, Gain Margin = 12, less stiff

Phase Margin = 60, Gain Margin = 20, medium

Phase Margin = 65, Gain Margin = 35, weak

Phase Margin = 70, Gain Margin = 40, very weak, unstable, oscillation/run-away.