Simulink Control Design™ - MathWorks

• Typically, the estimated phase margin is near the target phase margin. In general, the
  larger the value, the more robust is the tuned system, and the less overshoot there is.


• A negative phase margin indicates that the closed-loop system might be unstable.

Dependencies

To enable this port, in the Tuning tab, select Output estimated phase margin achieved

by tuned controller.

frd — Estimated frequency response

vector

This port outputs the frequency-response data estimated by the experiment. Initially, the

value at frd is [0, 0, 0, 0, 0]. During the experiment, the block injects signals at

frequencies [1/10, 1/3, 1, 3, 10]ωc, where ωc is the target bandwidth. At each sample time

during the experiment, the block updates frd with a vector containing the complex

frequency response at each of these frequencies, respectively. You can use the progress of

the response as an alternative to % conv to examine the convergence of the estimation.

When the experiment stops, the block updates frd with the final estimated frequency

response used for computing the PID gains.

Dependencies

To enable this port, in the Experiment tab, select Plant frequency responses near

bandwidth.

nominal — Plant input and output at nominal operating point

vector

This port outputs a vector containing the plant input (u+Δu) and plant output (y) when

the experiment begins. These values are the plant input and output at the nominal

operating point at which the block performs the experiment.

Dependencies

To enable this port, in the Experiment tab, select Plant nominal input and output.

16 Blocks — Alphabetical List