An algorithm for robust control system design

The robust output feedback control of linear systems with cone-bounded nonlinear perturbations is considered. By using the Lyapunov approach, a sufficient robust stability condition for the closed-loop system is obtained, which is expressed in terms of closed-loop eigenvalues and eigenvectors. Based on this condition and a parametric eigenstructure assignment result, an algorithm for robust output feedback controller synthesis is presented, which ensures not only the robust stability, but also the robust performance to a certain degree. The approach has the advantage of allowing the nominal closed-loop eigenvalues to be optimized within any desired region, and the closed-loop eigenvalues so determined are naturally insensitive to small parameter perturbations in the open-loop system coefficient matrices