The bounded real lemma for discrete time-varying systems with application to robust output feedback

Develops a solution to the discrete-time robust output feedback control problem for linear time-varying (LTV) systems. The solution is developed along the strategy set up in Doyle et al. (1989) and the main ingredient in its derivation is the extension of the well-known bounded real lemma in a (discrete) time-varying context, developed in van der Veen and Verhaegen (1993). This approach contributes to the conceptual simplicity, and hence to the accessibility, of the solution. Apart from that, the authors treat the ∞-horizon case for LTV systems of non-uniform state dimension, and varying input and output dimension. Both situations can easily occur in practice, e.g. in multirate sampled data control systems