For vector or matrix-valued parameters, you can use the Free parameter to constrain the
structure of the parameter. For example, to restrict a matrix-valued parameter to be a
diagonal matrix, set the current values of the off-diagonal elements to 0, and set the
corresponding entries in Free to false.Custom Parameterization
When tuning a control system represented by a Simulink model or by a “Predefined
Feedback Architecture” on page 10-9, you can specify a custom parameterization for any
tuned block using a generalized state-space (genss) model. To do so, create and
configure a genss model in the MATLAB workspace that has the desired
parameterization, initial parameter values, and parameter properties. In the Change
parameterization dialog box, select Custom. In the Parameterization area, the
variable name of the genss model.For example, suppose you want to specify a tunable low-pass filter, F = a/(s +a), where a
is the tunable parameter. First, at the MATLAB command line, create a tunable genss
model that represents the low-pass filter structure.a = realp('a',1);
F = tf(a,[1 a]);F =
Generalized continuous-time state-space model with 1 outputs, 1 inputs,
1 states, and the following blocks:
a: Scalar parameter, 2 occurrences.
Type "ss(F)" to see the current value, "get(F)" to see all properties, and
"F.Blocks" to interact with the blocks.Then, in the Tuned Block Editor, enter F in the Parameterization area.10 Control System Tuning