Find a PID Controller

Hi

I want to find a PID Controller for the following process:

Hp(s) = 1 / (s^2 + 1)

or Hp = tf (1, [1 0 1] );

Performance requirements: overshoot < 5%, settling time < 3 sec, steady-state error = 0.

I tried to use pidtool(H) and none of the available pid types meet the performance requirements.

Do you have any suggestion on how to find the optimal controller using Matlab / Simulink ?

Thanks

Answer 1

[Azzi Abdelmalek]

Hp=tf (1, [1 0 1] );
[kpid,info] = pidtune(Hp,'pid')

Then simulate your system using tune (in PID block) to find the desired values of kp ki and kd

you will find approximately

kp=83 
ki=19
kd=32

[River Rock]

Is it possible to set the overshoot to a fixed value and adjust only the settling time? It seems that I cannot lower the overshoot under 10% using pidtool; the manual tuning works though.

[Azzi Abdelmalek]

You have to do it manualy, adjust the time (lower then expected) then decrease the kp to reduce the overshoot

Answer 2

[mano]

tranfer function using pid controller

c(s)/r(s)=1/s*2+10s+20