LAUSR

This brief is to present a controller design for magnetorheological (MR) semiactive vehicle suspensions. The goal is to develop a method to optimize suspension performance while ensuring that the magnitude of the force generated by the control law satisfies the physical constraints of the MR damper. A piecewise controller is designed where an $H_\infty $ performance is used to ensure the suspension performance, and nonlinear constraints of the MR damper are approximated by piecewise constant constraints. By designing a piecewise controller under the framework of linear matrix inequality optimization, the constraints are captured using the concept of invariant ellipsoid. Simulation and experimental results under classical “clipped” schema show significant improvement of the proposed approach on ride comfort and road handling while guaranteeing the performance under the constraints.