Robust Active Suspension Design Subject to Vehicle Inertial Parameter Variations

This paper presents an approach in designing a robust controller for vehicle suspensions considering changes in vehicle inertial properties.A four-degree-of-freedom half-car model with active suspension is studied in this paper,and three main performance requirements are considered.Among these requirements,the ride comfort performance is optimized by minimizing the H norm of the transfer function from the road disturbance to the sprung mass acceleration,while the road holding performance and the suspension deflection limitation are guaranteed by constraining the generalized H2 (GH2) norms of the transfer functions from the road disturbance to the dynamic tyre load and the suspension deflection to be less than their hard limits,respectively.At the same time,the controller saturation problem is considered by constraining its peak response output to be less than a given limit using the GH2 norm as well.By solving the finite number of linear matrix inequalities (LMIs) with the minimization optimization procedure,the controller gains,which are dependent on the time-varying inertial parameters,can be obtained.Numerical simulations on both frequency and bump responses show that the designed parameter-dependent controller can achieve better active suspension performance compared with the passive suspension in spite of the variations of inertial parameters.