Handout 2: Gain and Phase margins Eric Feron Feb6,2004 Nyquist plots and Cauchy's principle Let H(s) be a transfer function. eg H(s)= s2+s+1 (s+1)(s+3) Evaluate H on a contour in the s-plane. (your plots here)
Model Uncertain Prior analysis assumed a perfect model. What if the model is in correct= actual system dynamics GA(s)are in one of the sets Multiplicative model G,(s=GN(s(1+E(s)) Additive model Gp(S)=GN(S)+E(s) where