Unmeasured input disturbance model


indist = getindist(MPCobj)
[indist,channels] = getindist(MPCobj)


indist = getindist(MPCobj) returns the unmeasured input disturbance model, indist, used by model predictive controller object, MPCobj. This model, in combination with the output disturbance model (if any), governs how well the controller compensates for unmeasured disturbances and prediction errors. The input 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 unmeasured input disturbances and the need to maintain controller state observability. For custom input disturbance models, the number of inputs is your choice.

  • Has nd outputs, where nd is the number of unmeasured disturbance inputs defined in MPCobj.Model.Plant. Each output channel is sent to the corresponding plant unmeasured disturbance input.

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

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

Introduced before R2006a

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