Simulink Control Design™ - MathWorks

output of the controller at steady-state is 0.5. To remain within these limits, specify a sine

amplitude of 0.1. Specifying a scalar value uses the same amplitude at all four

frequencies.

For an asymptotically stable plant, the tuner also injects a step signal to estimate the

plant DC gain. Choose an amplitude for this step signal based on the same considerations

you used to choose the sine amplitudes. For this example, enter 0.1 in the Step

Amplitude field as well.

Specify Design Goals

Finally, specify the target bandwidth for tuning. As noted previously, the target bandwidth

is 8000 radians per second. Enter 8000 in the Bandwidth field. The default target phase

margin, 60 degrees, corresponds to an overshoot of about 10% or better.

Tune the PID Controller and Validate the Results

Click Tune to begin the two simulations of the buck converter and tune the PID

Controller.

At the conclusion of the tuning procedure the tuned gains, estimated phase margin and

nominal plant input are displayed in Frequency Response Based PID Tuner dialog in

the Tuning Results section. Check the estimated phase margin to ensure that it is close

to the Target phase margin.

7 PID Controller Tuning