Pole assignment in a disk for linear systems by static output feedback

A systematic approach for pole assignment in a disk for continuous or discrete-time linear systems using a static output control law is proposed. It is shown that if the open-loop system satisfies certain structural conditions, a static output feedback gain can be easily computed, using a formula that simply involves the original system matrices and the parameters that define the disk. Among the conditions the system has to satisfy, the key one relies on a minimum phase argument. Square and non-square, proper and non-proper systems are considered. The main results are derived invoking the limiting behaviour of the optimal linear quadratic regulator for discrete-time systems. Some other implications are also presented.