How to find this parameters..?

 [k,ku,pu]=znpidtuning(G,2) 
T=1;
G=tf(3.24,[15.23*T 1]);
k=znpidtuning(G,2); 
C=k.kc*(1+tf(1,[k.ti 0]));  % the PI-controller
H=minreal(feedback(ss(G*C),1)); % the closed loop transfer function
[Gm,Pm,Wcg]=margin(G);
ku=Gm;
pu=2*pi/Wcg;
        k.kc=ku/1.7;
        k.ti=pu/2;
        k.td=pu/8;

Hi i have made this as a finction znpidtuning But it shows undefined.. So how to solve it..? please help..

Answer 1

[Azzi Abdelmalek]

Check if your function is in the current folder

dir znpidtuning.m

[pankajkumar]

Ok.. It shows in folder..

When i am running code then The error is

 Error in ==> znpidtuning at 
 k=znpidtuning(G,2);

I am using function as function

 [k,ku,pu]=znpidtuning(G,2)

and my G is

 G=tf(3.24,[15.23*T 1])

[Azzi Abdelmalek]

Ok, znpidtuning is a FEX function. Then why are you writing

function [k,ku,pu]=znpidtuning(G,2)

You should write

[k,ku,pu]=znpidtuning(G,2)

[Azzi Abdelmalek]

But it seems that this function is not working well

[pankajkumar]

 ??? Attempt to execute SCRIPT znpidtuning as a function:
C:\Users\admin\Documents\MATLAB\code\znpidtuning.m

I change my script as your saying, but when i type

 [k,ku,pu]=znpidtuning(G,2)

in command window it shows error as above..

[Azzi Abdelmalek]

If you have a Control System Toolbox, use the pidtool

[pankajkumar]

No, i am using older version of matlab but i want to do tuning using my own code.. Thats why i require correction..

[Azzi Abdelmalek]

But znpidtuning is not your own code