LQR Control for Semi-Active Quarter Vehicle Suspension with Magnetorhehological Damper and Bouc-Wen Model

This paper discuss the problem of controlling quarter-car semi-active suspension system. Presently, the suspension system involves a magnetorheological (MR) damper with a hysteretic behavior captured through the Bouc-Wen model. This device can be integrated in the electric or hybrid electric vehicle. The control objective is to regulate well the chassis vertical position despite the road irregularities. In addition to these irregularities, the difficulty of the control problem lies in the nonlinearity of the system model and the inaccessibility to measurements of the hysteresis internal state variable. The control design is performed using the LQR theory and Lyapunov control design tools; it includes an observer providing online estimates of the hysteresis internal state. The controller is formally shown to meet the desired control objectives. This theoretical result is confirmed by several simulations. The latter illustrate the performances of the LQR method and compare them with those of the passive suspension.