How can I get "simple PID closed-loop controller" code for Matlab function for applying in simulink ?

I want to build a modified PID closed loop controller, so I need a simple PID closed-loop code with only one feedback and one reference to applying in matlab function in simulink, I will aprriate your helps, Thanks ...

Answer 1

[Sam Chak]

@Rawaz Aziz, From the description of the problem, it seemed that you want a modified closed-loop controller like this:

% pid controller
Gc  = pid(1, 1, 1, 1)

Gc =
 
             1            s    
  Kp + Ki * --- + Kd * --------
             s          Tf*s+1 

  with Kp = 1, Ki = 1, Kd = 1, Tf = 1
 
Continuous-time PIDF controller in parallel form.

% modified pid closed-loop controller with 1 feedback
Gcl = feedback(Gc, 1)

Gcl =
 
  2 s^2 + 2 s + 1
  ---------------
  3 s^2 + 3 s + 1
 
Continuous-time transfer function.

% response
step(Gcl, 20), grid on