getCodeGenerationData

Create data structures for mpcmoveCodeGeneration

Syntax

[configData,stateData,onlineData] = getCodeGenerationData(mpcobj)

[___] = getCodeGenerationData(___,Name,Value)

Description

Use this function to create data structures for the mpcmoveCodeGeneration function, which computes optimal control moves for implicit and explicit linear MPC controllers.

For information on generating data structures for nlmpcmoveCodeGeneration, see getCodeGenerationData.

[configData,stateData,onlineData] = getCodeGenerationData(mpcobj) creates data structures for use with mpcmoveCodeGeneration.

[___] = getCodeGenerationData(___,Name,Value) specifies additional options using one or more Name,Value pair arguments.

Examples

Create MPC Code Generation Data Structures

Create a plant model, and define the MPC signal types.

plant = rss(3,2,2);
plant.D = 0;
plant = setmpcsignals(plant,'mv',1,'ud',2,'mo',1,'uo',2);

Create an MPC controller.

mpcObj = mpc(plant,0.1);

-->"PredictionHorizon" is empty. Assuming default 10.
-->"ControlHorizon" is empty. Assuming default 2.
-->"Weights.ManipulatedVariables" is empty. Assuming default 0.00000.
-->"Weights.ManipulatedVariablesRate" is empty. Assuming default 0.10000.
-->"Weights.OutputVariables" is empty. Assuming default 1.00000.
   for output(s) y1 and zero weight for output(s) y2 

Configure your controller parameters. For example, define bounds for the manipulated variable.

mpcObj.ManipulatedVariables.Min = -1;
mpcObj.ManipulatedVariables.Max = 1;

Create code generation data structures.

[configData,stateData,onlineData] = getCodeGenerationData(mpcObj);

-->Converting model to discrete time.
-->The "Model.Disturbance" property is empty:
   Assuming unmeasured input disturbance #2 is integrated white noise.
   Assuming no disturbance added to measured output #1.
-->"Model.Noise" is empty. Assuming white noise on each measured output.
-->Converting model to discrete time.
-->The "Model.Disturbance" property is empty:
   Assuming unmeasured input disturbance #2 is integrated white noise.
   Assuming no disturbance added to measured output #1.
-->"Model.Noise" is empty. Assuming white noise on each measured output.

Specify Options for Creating MPC Code Generation Structures

Create a plant model, and define the MPC signal types.

plant = rss(3,2,2);
plant.D = 0;

Create an MPC controller.

mpcobj = mpc(plant,0.1);

-->"PredictionHorizon" is empty. Assuming default 10.
-->"ControlHorizon" is empty. Assuming default 2.
-->"Weights.ManipulatedVariables" is empty. Assuming default 0.00000.
-->"Weights.ManipulatedVariablesRate" is empty. Assuming default 0.10000.
-->"Weights.OutputVariables" is empty. Assuming default 1.00000.

Create code generation data structures. Configure options to:

• Use single-precision floating-point values in the generated code.

• Improve computational efficiency by not computing optimal sequence data.

• Run your MPC controller in adaptive mode.

[configData,stateData,onlineData] = getCodeGenerationData(mpcobj,...
    'DataType','single',OnlyComputeCost=true,IsAdaptive=true);

-->Converting model to discrete time.
-->Assuming output disturbance added to measured output #1 is integrated white noise.
-->Assuming output disturbance added to measured output #2 is integrated white noise.
-->"Model.Noise" is empty. Assuming white noise on each measured output.
-->Converting model to discrete time.
-->Assuming output disturbance added to measured output #1 is integrated white noise.
-->Assuming output disturbance added to measured output #2 is integrated white noise.
-->"Model.Noise" is empty. Assuming white noise on each measured output.

Input Arguments

mpcobj — Model predictive controller

mpc object | explicitMPC object

Model predictive controller, specified as one of the following:

• mpc object — MPC controller

• explicitMPC object — Explicit MPC controller created using generateExplicitMPC.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'DataType','single' specifies that the generated code uses single-precision floating point values.

InitialState — Initial controller state

mpcstate object

Initial controller state when using mpcmoveCodeGeneration, specified as the comma-separated pair consisting of 'InitialState' and an mpcstate object. This state is used in place of the default state information from mpcobj.

DataType — Data type used in generated code

'double' (default) | 'single'

Data type used in generated code when using mpcmoveCodeGeneration, specified as specified as the comma-separated pair consisting of 'DataType' and one of the following:

• 'double' — Use double-precision floating point values.

• 'single' — Use single-precision floating point values.

OnlyComputeCost — Toggle for computing only optimal cost

false (default) | true

Toggle for computing only optimal cost during simulation when using mpcmoveCodeGeneration, specified as specified as the comma-separated pair consisting of 'OnlyComputeCost' and either true or false. To reduce computational load by not calculating optimal sequence data, set OnlyComputeCost to true.

IsAdaptive — Adaptive MPC indicator

false (default) | true

Adaptive MPC indicator when using mpcmoveCodeGeneration, specified as specified as the comma-separated pair consisting of 'IsAdaptive' and either true or false. Set IsAdaptive to true if your controller is running in adaptive mode.

For more information on adaptive MPC, see Adaptive MPC.

Note

IsAdaptive and IsLTV cannot be true at the same time.

IsLTV — Time-varying MPC indicator

false (default) | true

Time-varying MPC indicator when using mpcmoveCodeGeneration, specified as the comma-separated pair consisting of 'IsLTV' and either true or false. Set IsLTV to true if your controller is running in time-varying mode.

For more information on time-varying MPC, see Time-Varying MPC.

Note

IsAdaptive and IsLTV cannot be true at the same time.

UseVariableHorizon — Variable horizon indicator

false (default) | true

Variable horizon indicator when using mpcmoveCodeGeneration, specified as the comma-separated pair consisting of 'UseVariableHorizon' and either true or false. To vary your prediction and control horizons at run time, set UseVariableHorizons to true.

When you use variable horizons, mpcmoveCodeGeneration ignores the horizons specified in configData and instead uses the prediction and control horizon specified in onlineData.horizons.

For more information, see Adjust Horizons at Run Time.

Output Arguments

configData — MPC configuration parameters

structure

MPC configuration parameters that are constant at run time, returned as a structure. These parameters are derived from the controller settings in mpcobj. When simulating your controller, pass configData to mpcmoveCodeGeneration without changing any parameters.

For more information on how generated MPC code uses constant matrices in configData to solve the QP problem, see QP Problem Construction for Generated C Code.

stateData — Initial controller states

structure

Initial controller states, returned as a structure. To initialize your simulation with the initial states defined in mpcobj, pass stateData to mpcmoveCodeGeneration. To use different initial conditions, modify stateData. You can specify nondefault controller states using InitialState.

For more information on the stateData fields, see mpcmoveCodeGeneration.

stateData has the following fields.

Field	Description
Plant	Plant model state estimates
Disturbance	Unmeasured disturbance model state estimates
Noise	Output measurement noise model state estimates
LastMove	Manipulated variable control moves from previous control interval
Covariance	Covariance matrix for controller state estimates
iA	Active inequality constraints

onlineData — Online MPC controller data

structure

Online MPC controller data that you must update at each control interval, returned as a structure with the following fields.

Field	Description
signals	Input and output signals, returned as a structure with the following fields. Field Description ym Measured outputs ref Output references md Measured disturbances mvTarget Targets for manipulated variables externalMV Manipulated variables externally applied to the plant
limits	Input and output constraints, returned as a structure with the following fields: Field Description ymin Lower bounds on output signals ymax Upper bounds on output signals umin Lower bounds on input signals umax Upper bounds on input signals When mpcobj is an explicit MPC controller, mpcmoveCodeGeneration ignores the limits field.
weights	Updated QP optimization weights, returned as a structure with the following fields: Field Description ywt Output weights uwt Manipulated variable weights duwt Manipulated variable rate weights ecr Weight on slack variable used for constraint softening When mpcobj is an explicit MPC controller, mpcmoveCodeGeneration ignores the weights field.
customconstraints	Updated custom mixed input/output constraints, returned as a structure with the following fields: Field Description E Manipulated variable constraint constant F Controlled output constraint constant G Mixed input/output constraint constant S Measured disturbance constraint constant When mpcobj is an explicit MPC controller, mpcmoveCodeGeneration ignores the customconstraints field.
horizons	Updated controller horizon values, returned as a structure with the following fields: Field Description p Prediction horizon m Control horizon The horizons field is returned only when the UseVariableHorizon name-value pair is true. When mpcobj is an explicit MPC controller, mpcmoveCodeGeneration ignores the horizons field.
model	Updated plant and nominal values for adaptive MPC and time-varying MPC, returned as a structure with the following fields: Field Description A, B, C, D State-space matrices of discrete-time state-space model. X Nominal plant states U Nominal plant inputs Y Nominal plant outputs DX Nominal plant state derivatives The model field is returned only when either the IsAdaptive or IsLTV name-value pair is true.

getCodeGenerationData returns onlineData with empty matrices for all structure fields, except signals.ref, signals.ym, and signals.md. These fields contain the corresponding nominal signal values from mpcobj. If your controller does not have measured disturbances, signals.md is returned as an empty matrix.

For more information on configuring onlineData fields, see mpcmoveCodeGeneration.

Version History

Introduced in R2016a