Robust modelling and control of vehicle active suspension with MR damper

Abstract

This paper presents a robust modelling and control method for an active vehicle suspension fitted with a magneto-rheological (MR) damper, and evaluates the performance of the active suspension (AS) in a hardware-in-the-loop (HiL) platform. Firstly, mathematical models for a quarter vehicle including a nonlinear MR damper are given, and a linear piecewise function describing an inverse MR damper model is derived for an easy hardware implementation. Secondly, the uncertainty associated with the nonlinear MR damper and the HiL platform is recast into an input-type unstructured uncertainty, and the AS control problem is transformed into and solved by the H-infinity control method. Thirdly, the HiL platform is setup, where the vehicle is modelled in software, and the controller is implemented in a digital signal processor (DSP). Finally, the AS is assessed by MATLAB-based software simulations and DSP-based HiL ones.