automatic pid tuning in matlab

To automatically tune a PID controller in Matlab, you can use the pidtune() function. This function provides several tuning methods to automatically tune a PID controller based on the desired system response. Here's a simple example for how to use pidtune() function to tune a PID controller for a plant model.

main.m
% Plant model
s = tf('s');
G = 1/(s*(s+1)*(s+2));

% PID controller
C = pid(1,1,1);

% Tune PID controller
opts = pidtuneOptions('DesignFocus','reference-tracking');
[C,info] = pidtune(G,C,opts);

% Display results
step(G/(1+G*C))
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In this example, we first define a plant model G which is a third-order transfer function. We then create a PID controller C with initial values of Kp=1, Ki=1, and Kd=1. Next, we use pidtune() function to tune this controller for the plant model G. We set the DesignFocus option to 'reference-tracking' to specify that we want to optimize the controller for reference-tracking performance. The pidtune() function returns the new tuned controller C and a structure info containing the tuning results.

Finally, we simulate the closed-loop system with the tuned controller and display the step response of the system. By using pidtune() function, we can easily tune a PID controller without manually adjusting the controller gains.