On the Relationship between Time-Varying Component of Controller and Control Performance

Abstract

In this paper, we propose a new approach to design time-varying (TV) controllers for LTV plants by dealing with a performance inequality directly. The controller has a structure composed of a linear time-invariant (LTI) part and a TV one. We design the latter part to enhance l₂ induced norm performance of the closed loop. We also precisely show a relationship between the available information for the TV controllers and the improvement of the performances compared with LTI controllers. This result supports the well-known result by Poolla et al. on a performance limitation of TV controllers for a robust control problem as a special case.