Programatically changing block parameter during simulation.

I am automatically changing the amplitude value of my sin wave block in my model. But the problem is that my program runs the simulation multiple times and do not change the values of amplitude during one simulation. this is the code:

amplitude_vec=(0.5:0.2:2.3);
for i=1:10
    amplitude=amplitude_vec(i);
    sim('Amplifier.mdl');
end;

How do i write a program that will change the values of amplitude of my sin wave block in one simulation run ?

Thanks for your help,

Janez

[TAB]

"my program runs the simulation multiple times and do not change the values of amplitude during one simulation"...??? Confusing line.

You have never changed any block parameter value in existing code.

[Janez]

yes i did.

Here : amplitude=amplitude_vec(i);

This changes the amplitude parameter of the sine wave. I placed variable 'amplitude' in that block.

This changes the amplitude of the sine wave for every simulation. Which means that my program runs ten simulation each with different sine wave amplitude. Believe me, i have run it.

But i want it to happen in one simulation for different time intervals in that simulation.

Answer 1

[Azzi Abdelmalek]

 amplitude_vec=(0.5:0.2:2.3);
 for k=1:10
    amplitude=amplitude_vec(k);
    set_param('Amplifier/Sine Wave','Amplitude',num2str(amplitude))
    %check if "Sine Wave" is the name of your sine block, if not, replace it
    sim('Amplifier');
 end;

or you can use (you don't need to pause simulation)

1. the below code allows to create a signal with multiple amplitude saved in "file.mat"
2. you set sine amplitude to 1

   amplitude_vec=(0.5:0.2:2.3);
 t0=0;tf=5;te=0.1;
 tf1=tf;t=[];amp=[];
 for k=1:length(amplitude_vec)
    t1=t0:te:tf;
    t=[t t1 ];
    amp=[ amp amplitude_vec(k)*ones(1,length(t1))];
    t0=tf+te;tf=t0+tf1
 end
 close;plot(t,amp);
 ty=[t;amp];
 save file ty

[Azzi Abdelmalek]

you can use the "assertion" block to pause your simulation

[Janez]

Hey

This last part works like a charm. Thank you.

Best regards.

Answer 2

[Mariano Lizarraga]

I might be misunderstanding your problem statement but if you only want to change the amplitude base on the time of the simualtion then you could do an embedded matlab function as follows:

function y = timeDependentSine(t, amplitude, freq, phase, bias)

   y = amplitude*sin(freq*t + phase) + bias;

and now all the parameters for the sine function can be time varying if you so desire. You can implement all in Simulink as shown here: http://skit.ch/nwn1