Simulink Control Design™ - MathWorks

Minimum and Maximum Loop Gain

Instead of TuningGoal.LoopShape, you can use TuningGoal.MinLoopGain and

TuningGoal.MaxLoopGain to specify minimum or maximum values for the loop gain in

a particular frequency band. This is useful when the actual loop shape near crossover is

best left to the tuning algorithm to figure out. For example, the following requirements

specify the minimum loop gain inside the bandwidth and the roll-off characteristics

outside the bandwidth, but do not specify the actual crossover frequency nor the loop

shape near crossover.

MinLG = TuningGoal.MinLoopGain('u',5/s); % integral action

MinLG.Focus = [0 0.2];

MaxLG = TuningGoal.MaxLoopGain('u',1/s^2); % -40dB/decade roll off

13 Control System Tuning Examples