Simulink model 'to workspace' output

I am trying to control motor torque and am using a workspace variable in Simulink and want to output similar variable to workspace.

I have size(T_u)=[3, 91] whereas the output I am getting from the simulation has size [101, 90]

I am unable to understand why this is so.

Code that I am using:

load('Motor_Param.mat')

t = 1:0.1:10;
T_o = [0.05*(10-t);0.04*(10-t);0.03*(10-t)];
T_d = zeros(size(T_o));
T_e = (T_d - T_o);
C_PD = pid(100,0,10,100);
T_u = zeros(size(T_e));
for k=1:size(T_e,1)
    T_u(k,:) = lsim(C_PD,T_e(k,:),t);
    T_l = zeros(size(T_u));
    C_PI = pid(10,1000,0);

    a = sim('Motor_Control','SimulationMode','normal');
    out = a.get('T_l')
end

.mat and .slx files are attached.

Answer 1

[Jesús Zambrano]

Hi Mohsina,

I see T_u matrix is loaded in you model using the From Workspace block. In this case each row of the matrix has time stamp in the first column, and the data in the rest of columns. In this particular example the data takes 90 columns. Then, the simulation runs using a variable step solver, it means that the step size varies from step to step, and it will depend on the model dynamics. You can see this variation when plotting

plot(out.Time(2:end),diff(out.Time));

Hope this answers your question.

Best,

Jesús