Queries regarding PID Tuner app?

I have two queries regarding PID Tuner app

1)What is the purpose of highlighted controls in PID Tuner app?

2)Can't we change single or independently,the values of kp,ki and kd because here in PID Tuner app,when we play with the seek bar of response time or transient behavior, almost every parmeter(kp,ki and kd) changes,Isn't there any scenario,where we can change only one parameter of intersest ,let say kp or ki?

Answer 1

[Sam Chak]

Hi @ABTJ

The PID Tuner app assists designers in automatically tuning the PID control gains for a SISO plant to achieve a balance between the desired performance and disturbance rejection in the default settings.

The top value in the highlighted fields represents the Response Time parameter, while the bottom value represents the Transient Behavior parameter. These values are adjusted using the Response Time and Transient Behavior sliders. Increasing the Response Time parameter will result in a faster closed-loop response, while decreasing it will slow down the response. The Transient Behavior slider affects how the controller responds to disturbances or plant uncertainties.

The PID Tuner app is available to help both experts and beginners with their work, eliminating the need for manual calculations. If you wish to study the effects of manually tuning one control gain at a time, you can utilize the 'pid()' command.

% Plant
Gp  = tf(1, [1 1 1])

Gp =
 
       1
  -----------
  s^2 + s + 1
 
Continuous-time transfer function.

% Control parameters
Kp  = [0.5 1.0 2.0];    % <-- test different values of Kp
Ki  = 1;                % <-- Ki unchanged
Kd  = 1;                % <-- Kd unchanged
Tf  = 1;                % <-- Tf unchanged

for j = 1:numel(Kp)
    % PID Controller
    Gc   = pid(Kp(j), Ki, Kd, Tf);
    Gcl  = feedback(series(Gc, Gp), 1);
    step(Gcl), hold on
end

hold off, grid on
legend('Kp = 0.5', 'Kp = 1.0', 'Kp = 2.0', 'location', 'East')