vrfttuneOptions

Create options for virtual reference feedback tuning

Since R2026a

Syntax

opt = vrfttuneOptions(ControllerStructure)

Description

opt = vrfttuneOptions(ControllerStructure) returns an options object based on the controller structure for virtual reference feedback tuning.

Examples

Create Option Set for VRFT

Create option set for vrttune to specify the controller structure for tuning.

By default, vrfttuneOptions returns options for parallel-form PID controller.

options = vrfttuneOptions

options = 
  ParallelPID with properties:

                 PIDType: 'PI'
        IntegratorMethod: 'ForwardEuler'
    DiscretizationMethod: 'tustin'

To set the values of options, use dot notation.

options.PIDType = "PID"

options = 
  ParallelPID with properties:

                 PIDType: 'PID'
        IntegratorMethod: 'ForwardEuler'
    DiscretizationMethod: 'tustin'

Similarly, you can create options for other controller structures such as FIR filter, LTI combination, and tunable LTI.

options = vrfttuneOptions("fir-filter")

options = 
  FIRFilter with properties:

             FilterOrder: 5
    DiscretizationMethod: 'tustin'

options = vrfttuneOptions("lti-combination")

options = 
  LTICombination with properties:

      LinearControlBasis: {2×1 cell}
    DiscretizationMethod: 'tustin'

options = vrfttuneOptions("tunable-lti")

options = 
  TunableLTI with properties:

       TunableController: [1×1 tunablePID]
     OptimizationOptions: [1×1 optim.options.Fmincon]
    DiscretizationMethod: 'tustin'

Input Arguments

ControllerStructure — Controller structure

"parallel-pid" (default) | "fir-filter" | "lti-combination" | "tunable-lti"

Controller structure, specified as a string scalar with one of the following values.

• "parallel-pid" — Parallel-form PID controllers

  $$\begin{array}{l}C\left(z,\theta \right)=P+I\alpha (z)+D\frac{1}{T_s}\frac{z-1}{z}\\ \begin{array}{ccc}{\theta }_1=P& {\theta }_2=I& {\theta }_3=D\end{array}\end{array}$$

• "fir-filter" — FIR filters

  $$\begin{array}{l}C(z,\theta )=b_0+\frac{b_1}{z}+\dots +\frac{b_n}{z^n}\\ \begin{array}{cccc}{\theta }_1=b_0,& {\theta }_2=b_1,& \mathrm{...}& {\theta }_{n+1}=b_n\end{array}\end{array}$$

• "lti-combination" — Linear combination of LTI systems

  $$C(z,\theta )={\theta }_1{C}_1(z)+{\theta }_2{C}_2(z)+\dots +{\theta }_n{C}_n(z)$$

• "tunable-lti" — Tunable LTI objects such as tunableTF or tunablePID.

Output Arguments

opt — Options

vrfttune.options.ParallelPID object | vrfttune.options.FIRFilter object | vrfttune.options.LTICombination object | vrfttune.options.TunableLTI object

Option set, returned as one of the following objects.

Options Object	Properties	Values
vrfttune.options.ParallelPID	PIDType	Specify the PID controller type. "P" "I" "PI" "PD" "PID"
	IntegratorMethod	Specify the PID integrator method α(z). "ForwardEuler" "BackwardEuler" "Trapezoidal"
	DiscretizationMethod	Specify the discretization method. "tustin" "zoh" "foh" "impulse" "matched" "least-squares" "damped"
vrfttune.options.FIRFilter	FilterOrder	Specify a positive integer between 2 and 10.
	DiscretizationMethod	Specify the discretization method. "tustin" "zoh" "foh" "impulse" "matched" "least-squares" "damped"
vrfttune.options.LTICombination	LinearControlBasis	Linear systems Ci(z) in the generic-form control structure, specified as a cell array of LTI objects (ss, tf, zpk) or an LTI model array. $$C(z,\theta )={\theta }_1{C}_1(z)+{\theta }_2{C}_2(z)+\dots +{\theta }_n{C}_n(z)$$ Specify this parameter such that the value matches the form of the controller to tune. This can also represent a combination of linearly parameterized controllers. Here, the controller parameters θi are ordered corresponding to the index of LTI objects provided in the array. For example, the default value of this parameter represents a discrete-time parallel-form PID controller, with θ1 as the proportional gain and θ2 as the integral gain.
	DiscretizationMethod	Specify the discretization method. "tustin" "zoh" "foh" "impulse" "matched" "least-squares" "damped"
vrfttune.options.TunableLTI	TunableController	Specify a tunable LTI object. You can provide the following tunable LTI objects: tunablePID tunablePID2 tunableGain tunableTF tunableSS
	OptimizationOptions	Specify fmincon options created using optimoptions.
	DiscretizationMethod	Specify the discretization method. "tustin" "zoh" "foh" "impulse" "matched" "least-squares" "damped"

Version History

Introduced in R2026a