Run simulink model in for loop

Hi,

I would like to run a simulink model and save results as .mat files in a for loop. I do this with for loop and working fine. Now, I would like to use parfor function. But I could not figure it out how it can be done. I am describing a simple model to explain my problem.

Matlab verson is : R2020a 64 bit in Windows pc, I have license for parallel computing tool box also.

-Simulink model consist of a variable voltage source connected across a resistor.

-Resistance of the resistor (R) changes in each for loop.

-Variable voltage source block creates sinusoidal voltage. The frequency of the voltage changes in each loop.

-Resistance and input to variable voltage source are defined in matlab work space. Simulink reads these parameters during simulation. In every occurance of the for loop these parameters vary.

-During simulation a scope records voltage across the resistor. After simulation it logs data to workspace as an array named 'volt'.

-This array volt is saved in the current directory as a .mat file with different file names.

With for loop the simulation goes perfectly fine. Code for for loop is given below.

clc
clear all
close all

for k=1:1:10;
      
    f=k; %frequency of sine wave
    R=50*k; %value of resistor
    dt=1e-4; %time step  
    t=0:dt:10; %time vector    
    voltage=4e-4*sin(2*pi*f*t); %sinusoidal voltage
    wave = struct(); %input to simulink wave block
    wave.time = t';
    wave.signals.values = [voltage'];
    wave.signals.dimensions =1;
   
    
    sim('Test.slx');
    
    
    foldern=(['f',int2str(k)]);
    save(foldern,'volt'); %Output from simscape scope 'volt' is saved as mat file with different names
    Simulink.sdi.clear;
    
end

For using parfor, I tried different ways mentioned in the website. But I could not simulate. One of the try is given below. How can I modify my above code with for loop for using parfor?

clc
clear all
close all

% model = 'Test.slx';

myDictionaryObj = Simulink.data.dictionary.create('testdd2.sldd');
dd = 'testdd2.sldd';
spmd 
    Simulink.data.dictionary.setupWorkerCache
end

parfor k=1:1:10;
    
    dictObj = Simulink.data.dictionary.open(dd);
    sectObj = getSection(dictObj,'Design Data');
    entryObj = getEntry(sectObj,'MODE'); 
    temp = getValue(entryObj);
    temp.Value = CtrlValues(index);
    setValue(entryObj,temp);
%       
    f=k; %frequency of sine wave
    R=50*k; %value of resistor
    dt=1e-4; %time step  
    t=0:dt:10; %time vector    
    voltage=4e-4*sin(2*pi*f*t); %sinusoidal voltage
    wave = struct(); %input to simulink wave block
    wave.time = t';
    wave.signals.values = [voltage'];
    wave.signals.dimensions =1;
   
    
    [volt]=runsimulation;
    
    
    foldern=(['f',int2str(k)]);     
    save(foldern,'volt'); %Output from simscape scope 'volt' is saved as mat file with different names

    discardChanges(dictObj);
    close(dictObj);
    
    
end

spmd
    bdclose(model)
    Simulink.data.dictionary.cleanupWorkerCache
end

Please help me with this.

I am attaching .m file and .slx file of simulink model.

[Raymond Norris]

Hi Sreejith,

Could you provide more info about how the model could not simulate? Are you getting errors, warnings, incorrect results, etc.?

I'm not a Simulink user and can't provide an answer, but if you haven't already, you might consider looking at parsim

https://www.mathworks.com/help/simulink/slref/parsim.html

Raymond

[SREEJITH V S]

Hi Raymond,

Thank you for your suggestion. I have used parsim function and I could do the simulation by defining each variables using setVariable.

Now I have two more doubts remaining.

-I would like to bring a time series structure defined as 'wave' below in matlab workspace to simulink environment as I brought other variables using setVariables function. How can we do it?

-If I defined a constant 'A=10' in matlab workspace, is there any method other than setVariable to incorporate it in simulink variable list. I wanted to call A inside some simulink blocks. I am looking for some function which make all constants in the matlab workspace available to simulink during parsim simulation.

Thanks again.

Sreejith

model = 'Test';
load_system(model);
f=1:2:20;
numSims=length(f);
R=50*f; %value of resistor
dt=1e-4; %time step  
t=0:dt:10; %time vector    
for k=1:length(f)
    ff=f(k);
    voltage=4e-4*sin(2*pi*ff*t); %sinusoidal voltage
    wave = struct(); %input to simulink wave block
    wave.time = t';
    wave.signals.values = [voltage'];
    wave.signals.dimensions =1;
    st(k)=wave;
end
clear wave
simIn(1:10) = Simulink.SimulationInput(model);
for idx = 1:10
    simIn(idx) = setVariable(simIn(idx),'R',R(idx));
    simIn(idx) = setVariable(simIn(idx),'x_v',1e4);
    simIn(idx) = setVariable(simIn(idx),'ff',f(idx));
    simIn(idx) = setVariable(simIn(idx),'dt',1e-4);
end
simOut = parsim(simIn)

Answer 1

[Joel Van Sickel]

Hello Sreejith,

please use the parsim function for this type of application. If you want to use parfor, there are ways to do it, but they are more complicated.

https://www.mathworks.com/help/simulink/slref/parsim.html

If you want to use parfor, here is some example code. This code uses the controls toolbox to linearize a model: You will need to configure the pool and multiple directories for each one to run in.

https://www.mathworks.com/help/simulink/ug/not-recommended-using-sim-function-within-parfor.html

Regards,

Joel

[SREEJITH V S]

Hi Joel,

Thank you for your suggestion. I have used parsim function and I could do the simulation by defining each variables using setVariable.

Now I have two more doubts remaining.

-I would like to bring a time series structure defined as 'wave' below in matlab workspace to simulink environment as I brought other variables using setVariables function. How can we do it?

-If I defined a constant 'A=10' in matlab workspace, is there any method other than setVariable to incorporate it in simulink variable list. I wanted to call A inside some simulink blocks. I am looking for some function which make all constants in the matlab workspace available to simulink during parsim simulation.

Thanks again.

Sreejith

model = 'Test';
load_system(model);

f=1:2:20;
numSims=length(f);

R=50*f; %value of resistor
dt=1e-4; %time step  
t=0:dt:10; %time vector    
for k=1:length(f)
    ff=f(k);
    voltage=4e-4*sin(2*pi*ff*t); %sinusoidal voltage
    wave = struct(); %input to simulink wave block
    wave.time = t';
    wave.signals.values = [voltage'];
    wave.signals.dimensions =1;
    st(k)=wave;
end

clear wave
simIn(1:10) = Simulink.SimulationInput(model);

for idx = 1:10
    simIn(idx) = setVariable(simIn(idx),'R',R(idx));
    simIn(idx) = setVariable(simIn(idx),'x_v',1e4);
    simIn(idx) = setVariable(simIn(idx),'ff',f(idx));
    simIn(idx) = setVariable(simIn(idx),'dt',1e-4);
end


simOut = parsim(simIn)