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Simulation and Structured Text Generation for MPC Controller Block

This example uses:

Open Script

This example shows how to simulate and generate structured text for an MPC Controller block by using Simulink® PLC Coder™ software. The generated code uses single-precision data.

Required Products

To run this example, Model Predictive Control Toolbox™, Simulink®, and Simulink PLC Coder™ are required.

if ~mpcchecktoolboxinstalled('simulink')
    disp('Simulink is required to run this example.')
    return
end
if ~mpcchecktoolboxinstalled('plccoder')
    disp('Simulink PLC Coder is required to run this example.');
    return
end
if ~mpcchecktoolboxinstalled('mpc')
    disp('MPC Toolbox is required to run this example.');
    return
end

Define Plant Model and MPC Controller

Define a SISO plant.

plant = ss(tf([3 1],[1 0.6 1]));

Define the MPC controller for the plant.

Ts = 0.1;   %Sample time
p = 10;     %Prediction horizon
m = 2;      %Control horizon
Weights = struct('MV',0,'MVRate',0.01,'OV',1); % Weights
MV = struct('Min',-Inf,'Max',Inf,'RateMin',-100,'RateMax',100); % Input constraints
OV = struct('Min',-2,'Max',2); % Output constraints
mpcobj = mpc(plant,Ts,p,m,Weights,MV,OV);

Simulate and Generate Structured Text

Open the Simulink model.

mdl = 'mpc_plcdemo';
open_system(mdl)

To generate structured text for the MPC Controller block, put the MPC block inside a subsystem block and treat the subsystem block as an atomic unit. Select the Treat as atomic unit property of the subsystem block.

Simulate the model in Simulink.

close_system([mdl '/Control System/MPC Controller'])
open_system([mdl '/Outputs//References'])
open_system([mdl '/Inputs'])
sim(mdl)

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

To generate code by using the Simulink PLC Coder, use the plcgeneratecode command.

disp('Generating PLC structure text... Please wait until it finishes.')
%
%   plcgeneratecode([mdl '/Control System']);

Generating PLC structure text... Please wait until it finishes.

The Message Viewer dialog box shows that PLC code generation was successful.

Close the Simulink model and return to the original directory.

bdclose(mdl)