On finding stabilizing state feedback gains for a discrete-time periodic system

Presents an algorithm for stabilising a linear periodic discrete time system using periodic state feedback. The algorithm is very simple and mainly involves the solution of a periodic Lyapunov equation. It gives a number 0</spl alpha/<1 such that all closed loop poles have magnitude less than /spl alpha/. Moreover, it works only with that sub-system whose poles need to be shifted, and is cheaper than an explicit pole placement routine. Thus it is attractive for stabilisation problems where the exact location of closed loop poles is unimportant.