Robust Controller Design for Linear, Time-Varying Systems

摘要

This paper examines the design of controllers .for linear, time-varying systems. A design procedure is presented that incorporates performance and robust- ness objectives into existing H optimal control methods for time-varying systems. Design guidelines are derived for several basic performance and robustness objectives using a description of the frequency domain behaviour of a time-varying sys- tem. The frequency response is dependent on time as well as frequency. These guidelines refiect the frequency domain intuition gained from the time- invariant case as well as the time dependence of the frequency domain behaviour of a time-varying system. Performance specifications are incorporated through the selection of time-varying weighting fil- ters. Time-varying realisations for the weighting filters are obtained by interpolating between time- invariant realisations. Results on the localised-in- time behaviour of these realisations are derived to permit localised-in-time performance specifications. This procedure is analogous to the loop-shaping design procedure of McFarlane and Gioverfor time- invariant svstems.