how to apply stepinfo command correctly

i have a curve based on a step input using simulink the step starts at t=1 second and before this time there a intial values

i save the data given from simulink as an array

my question is how to apply stepinfo correctly to measur settling time ,overshoot,rise time or there another accurate method

thanks in advance

Answer 1

[Shlok]

Hi Shymaa,

To apply the “stepinfo” function correctly using your Simulink array data, you can extract the time and output data from the simulation, then adjust for any initial conditions before the step input (starting at 1 second in your case).

After cropping the data from the point where the step input begins, you can use “stepinfo” to measure key parameters like settling time, overshoot, and rise time. Here’s a small code snippet for the same:

% Assuming out stores Simulink data 
time = out.tout;  % Time array 
output = out.sim_output;  % Response array 

% Crop the data starting from the step input time 
step_start_time = 1; 
cropped_time = time(time >= step_start_time); 
cropped_output = output(time >= step_start_time); 

S = stepinfo(cropped_output, cropped_time); 
fprintf('Rise Time: %.2f seconds\n', S.RiseTime); 
fprintf('Settling Time: %.2f seconds\n', S.SettlingTime); 
fprintf('Overshoot: %.2f%%\n', S.Overshoot); 
fprintf('Peak Time: %.2f seconds\n', S.PeakTime); 

To know more about “stepinfo” function, you can refer to the following documentation link:

https://www.mathworks.com/help/control/ref/dynamicsystem.stepinfo.html