Documentation

getoutdist

Unmeasured output disturbance model

Syntax

outdist = getoutdist(MPCobj)
[outdist,channels] = getoutdist(MPCobj)

Description

outdist = getoutdist(MPCobj) returns the output disturbance model, outdist, used by the model predictive controller object, MPCobj. This model, in combination with the input disturbance model (if any), governs how well the controller compensates for unmeasured disturbances and prediction errors. The output disturbance model:

  • Is a discrete-time, delay-free, state-space (ss) object.

  • Has unit-variance white noise input signals. By default, the number of inputs depends upon the number of measured outputs and the need to maintain controller state observability. For custom output disturbance models, the number of inputs is your choice.

  • Has ny outputs, where ny is the number of plant outputs defined in MPCobj.Model.Plant. Each model output is added to the corresponding plant output.

Use this command to review the current default or custom output disturbance model. You can override the controller default behavior using the setoutdist command.

For details on the role of disturbance modeling in model predictive control and about the model used in the algorithm for state estimation, see Controller State Estimation.

[outdist,channels] = getoutdist(MPCobj) also returns the output channels to which integrated white noise has been added by default. If you specified a custom output disturbance model using setoutdist, channels is empty.

Introduced before R2006a

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