I have a transfer function with a RHP zero in $s=+1$, and I am trying to show in Matlab thath this limitation is present. In particular, initially I had a MIMO system, which I decoupled and then I started doing this analysis on the two separate SISO system that came out of the decoupling.
My code is the following:
s = tf('s'); G = [2/(s+1) 3/(s+2);1/(s+1) 1/(s+1)]; d_12 = -(G(1,2)/G(1,1)); d_21 = -(G(2,1)/G(2,2)); D_simp = [1 d_12;d_21 1]; %decoupler F1 = G*D_simp; k1 = 5; k2 = 2; k3 = 50; loop1 = loopsens(F1(1,1),k1/s); loop2 = loopsens(F1(1,1),k2/s); loop3 = loopsens(F1(1,1),k3/s); figure; bodemag(loop1.Ti,'r',loop2.Ti,'b',loop3.Ti,'g'),grid figure; bodemag(loop1.Si,'r',loop2.Si,'b',loop3.Si,'g'),grid
where I am trying to increase the bandwidth of the system by increasing the gain.
The expected result is that if I increase the bandwidth , I should have worse performances as the bandwidth increases, but what happen is exaclty the opposite:
can somebody please help me solve this problem?