Simulink Control Design™ - MathWorks

• Adjust for signal amplitude

When this option is set to No, the closed-loop transfer function being constrained is

not scaled for relative signal amplitudes. When the choice of units results in a mix of

small and large signals, using an unscaled transfer function can lead to poor tuning

results. Set the option to Yes to provide the relative amplitudes of the input signals

and output signals of your transfer function.

For example, suppose the tuning goal constrains a 2-input, 2-output transfer function.

Suppose further that second input signal to the transfer function tends to be about

100 times greater than the first signal. In that case, select Yes and enter [1,100] in

the Amplitude of input signals text box.

Adjusting signal amplitude causes the tuning goal to be evaluated on the scaled

transfer function Do–1T(s)Di, where T(s) is the unscaled transfer function. Do and Di are

diagonal matrices with the Amplitude of output signals and Amplitude of input

signals values on the diagonal, respectively.

• Apply goal to

Use this option when tuning multiple models at once, such as an array of models

obtained by linearizing a Simulink model at different operating points or block-

parameter values. By default, active tuning goals are enforced for all models. To

enforce a tuning requirement for a subset of models in an array, select Only Models.

Then, enter the array indices of the models for which the goal is enforced. For

example, suppose you want to apply the tuning goal to the second, third, and fourth

models in a model array. To restrict enforcement of the requirement, enter 2:4 in the

Only Models text box.

For more information about tuning for multiple models, see “Robust Tuning

Approaches” (Robust Control Toolbox).

Tips

• When you use this requirement to tune a control system, Control System Tuner
  attempts to enforce zero feedthrough (D = 0) on the transfer that the requirement
  constrains. Zero feedthrough is imposed because the H 2 norm, and therefore the value
  of the tuning goal (see “Algorithms” on page 10-94), is infinite for continuous-time
  systems with nonzero feedthrough.

Control System Tuner enforces zero feedthrough by fixing to zero all tunable

parameters that contribute to the feedthrough term. Control System Tuner returns an

Variance Goal