Tuning PI, PD, PID controller

Hi guys,

I'm using pidtune and pidtool for tuning the controllers, but even if I put all three constants (Kd, Ki, Kp) it tunes the controller as if it's a p controller. Will post the code bellow, also the return message as a pic. Please help <3.

Kp=290;

Ki=500;

Kd=46;

num1=[Kd Kp Ki];

den1=[1 0];

W=tf(num1,den1);

num2=[1];

den2=[1 10 20];

G=tf(num2,den2);

A=series(W,G);

sys=feedback(A,1);

t=0:0.01:2;

y=step(sys,t);

plot(t,y);

grid on;

pidtune(G,'pi')

pidtool(G,'pid');

Answer 1

[Sam Chak]

Not sure what happened. But it works for both auto and manual tuning.

% Plant
Gp   = tf(1, [1 10 20])

Gp =
 
         1
  ---------------
  s^2 + 10 s + 20
 
Continuous-time transfer function.

% PID (Auto)
Gc1  = pidtune(Gp, 'PID')

Gc1 =
 
             1          
  Kp + Ki * --- + Kd * s
             s          

  with Kp = 39.3, Ki = 116, Kd = 3.33
 
Continuous-time PID controller in parallel form.

Gcl1 = feedback(Gc1*Gp, 1);

% PIDF (Manual)
kp  = 32.94;
ki  = 86.88;
kd  = 0.3632;
Tf  = 0.1208;
Gc  = pid(kp, ki, kd, Tf)

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

  with Kp = 32.9, Ki = 86.9, Kd = 0.363, Tf = 0.121
 
Continuous-time PIDF controller in parallel form.

Gcl2= feedback(Gc*Gp, 1);

% Step responses
step(Gcl1, 2), hold on
step(Gcl2, 2), grid on
legend('PID', 'PIDF')