Passivity-based design of switching controllers for nonlinear systems

When conflicting performance requirements are present, appropriately switching between differently tuned controllers can considerably enhance the closed-loop performance compared to a single control law. However, it is a well known fact that such a control strategy can result in unbounded state trajectories, even if each controller individually stabilizes the plant. In this paper, a new passivity-based approach is proposed for the design of a family of controllers for a nonlinear control affine system, which guarantees by construction that the overall switched system is (asymptotically) stable under arbitrary switching. A systematic procedure for the controller synthesis is presented and applied to an example system of technical relevance: A set of controllers is designed for an active vehicle suspension system such that the conflict between the requirements passenger comfort and ride safety can be eased by appropriately switching between them.