Near-time-optimal tracking controller design for an automotive electromechanical brake

A state-constrained, robust near-time-optimal clamp force tracking controller for an automotive electromechanical brake is presented. The proposed hybrid control structure consists of two switching control laws that handle tracking of rate-bounded references in the presence of state constraints. The responsive tracking utilizes an approximated time-optimal switching curve as a sliding manifold, while state constraints are handled by a linearizing–stabilizing feedback controller. The hybrid controller is proven to asymptotically track the reference in the presence of unknown but bounded time-varying disturbances and modelling errors. Implementation and validation of the proposed controller on a prototype electromechanical brake enables favourable performance comparisons with existing servo control architectures to be obtained.