not allowing me use pid tunes

Hi

please help me

I have an tf i need PID contoller for it and I must use sisotool .

when i open PID tunnig in sisotool and click on update compensator it gives me an error i've never seen .

please help

[Raj]

Difficult to say anything unless you share your system model (transfer function).

[arash rad]

sent you my tf as a picture here

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency

Answer 1

[Raj]

Why don't you compute the closed-loop transfer function (with a PID controller) and then apply Routh's criterion. It will tell you whether you will be able to stabilize your system with a PID controller. In case, as the 'sisotool' tool error says, PID controller is not able to stabilize the system (no combination of Kp,Kd,Ki is making all the roots stable) then I would recommend switching to other control methods like LQR.