MPC State Object

The mpcstate object type contains the state of an MPC controller. Create the MPC state object using mpcstate. Its properties are as follows.

Property

Description

Plant

Vector of state estimates for the controller's plant model. Values are in engineering units and are absolute, i.e., they include state offsets.

If the controller's plant model includes delays, the Plant field of the MPC state object includes states that model the delays. Therefore length(Plant) > order of undelayed controller plant model.

Default: controller's Model.Nominal.X property.

Disturbance

Vector of unmeasured disturbance model state estimates. This comprises the states of the input disturbance model followed by the states of the output disturbances model.

Disturbance models may be created by default. Use the getindistand getoutdistcommands to view the two disturbance model structures.

Default: zero, or empty if there are no disturbance model states.

Noise

Vector of output measurement noise model state estimates.

Default: zero, or empty if there are no noise model states.

LastMove

Vector of manipulated variables used in the previous control interval, u(k–1). Values are absolute, i.e., they include manipulated variable offsets.

Default: nominal values of the manipulated variables.

Covariance

n-by-n symmetrical covariance matrix for the controller state estimates, where n is the dimension of the extended controller state, i.e., the sum of the number states contained in the Plant, Disturbance, and Noise fields.

Default: If the controller is employing default state estimation the default is the steady-state covariance computed according to the assumptions in Controller State Estimation. See also the description of the P matrix in the Control System Toolbox kalmd command. If the controller is employing custom state estimation, this field is empty (not used).

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