Simulation and Code Generation Using Simulink Coder

This example shows how to simulate and generate real-time code for an MPC Controller block with Simulink® Coder™. Code can be generated in both single and double precisions.

Required Products

To run this example, Simulink and Simulink Coder are required.

if ~mpcchecktoolboxinstalled('simulink')
    disp('Simulink is required to run this example.')
    return
end
if ~mpcchecktoolboxinstalled('simulinkcoder')
    disp('Simulink Coder is required to run this example.');
    return
end

Configure Environment

You must have write-permission to generate the relevant files and the executable. Therefore, before starting simulation and code generation, change the current directory to a temporary directory.

cwd = pwd;
tmpdir = tempname;
mkdir(tmpdir);
cd(tmpdir);

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 Code in Double-Precision

By default, MPC Controller blocks use double-precision data for simulation and code generation.

Simulate the model in Simulink.

mdl1 = 'mpc_rtwdemo';
open_system(mdl1)
sim(mdl1)
-->Converting model to discrete time.
-->Assuming output disturbance added to measured output channel #1 is integrated white noise.
-->The "Model.Noise" property of the "mpc" object is empty. Assuming white noise on each measured output channel.

The controller effort and the plant output are saved into base workspace as variables u and y, respectively.

Build the model with the rtwbuild command.

disp('Generating C code... Please wait until it finishes.')
set_param(mdl1,'RTWVerbose','off')
rtwbuild(mdl1);
Generating C code... Please wait until it finishes.
### Starting build procedure for model: mpc_rtwdemo
### Successful completion of build procedure for model: mpc_rtwdemo

On a Windows® system, an executable file named mpc_rtwdemo.exe appears in the temporary directory after the build process finishes.

Run the executable.

if ispc
    disp('Running executable...')
    status = system(mdl1);
else
    disp('The example only runs the executable on Windows system.')
end
The example only runs the executable on Windows system.

After the executable completes successfully (status=0), a data file named mpc_rtwdemo.mat appears in the temporary directory.

Compare the responses from the generated code (rt_u and rt_y) with the responses from the previous simulation in Simulink (u and y).

The responses are numerically equal.

Simulate and Generate Code in Single-Precision

You can also configure the MPC block to use single-precision data in simulation and code generation.

mdl2 = 'mpc_rtwdemo_single';
open_system(mdl2)

To do so, set the Output data type property of the MPC Controller block to single.

Simulate the model in Simulink.

sim(mdl2)

The controller effort and the plant output are saved into base workspace as variables u1 and y1, respectively.

Build the model with the rtwbuild command.

disp('Generating C code... Please wait until it finishes.')
set_param(mdl2,'RTWVerbose','off')
rtwbuild(mdl2);
Generating C code... Please wait until it finishes.
### Starting build procedure for model: mpc_rtwdemo_single
### Successful completion of build procedure for model: mpc_rtwdemo_single

On a Windows system, an executable file named mpc_rtwdemo_single.exe appears in the temporary directory after the build process finishes

Run the executable.

if ispc
    disp('Running executable...')
    status = system(mdl2);
else
    disp('The example only runs the executable on Windows system.')
end
The example only runs the executable on Windows system.

After the executable completes successfully (status=0), a data file named mpc_rtwdemo_single.mat appears in the temporary directory.

Compare the responses from the generated code (rt_u1 and rt_y1) with the responses from the previous simulation in Simulink (u1 and y1).

The responses are numerically equal.

Close the Simulink models, and return to the original directory.

bdclose(mdl1)
bdclose(mdl2)
cd(cwd)

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