Hi Kashish,
If you don't have the Robust Control Toolbox for hinfnorm(), you can probably use sigma() from the Control Systems Toolbox
Example from the Question:
theta=0;
kp=0.2;
kd=0.7;
tau=0.1;
h=0.5;
s=tf('s');
Gamma=(exp(-theta*s)*s^2*((0.6*s)+1)+(kd*s)+kp)/((h*s+1)*(s^2*((0.1*s)+1)+(kd*s)+kp));
ninf=hinfnorm(Gamma)
sv = sigma(Gamma);
max(sv(1,:))
MIMO example from doc page for hinfnorm()
G = [0 tf([3 0],[1 1 10]);tf([1 1],[1 5]),tf(2,[1 6])];
ninf = hinfnorm(G)
sv = sigma(G);
max(sv(1,:))
See the doc page for sigma() for more info to see if it will suit your needs.
Note that, unilke hinfnorm(),sigma() doesn't check for stability of the system.
