In this paper, analytical characterisation of the magneto–rheological (MR) damper is done using a new modified algebraic model. This model along with the obtained model parameters is used as a semi–active suspension device in a quarter car model and the stationary response of the vehicle traversing on a rough road is obtained. The control part consists of two nested controllers. For the system controller a model reference skyhook sliding mode controller (SMC) is used and for the damper controller a continuous state algorithm is built to determine the input voltage so as to gain the desired damping force. The analytical model is subsequently used in the quarter car vehicle model and the vehicular responses are studied for constant input voltages to the MR dampers. Results show that the semi–active controller can achieve compatible performance as that of active suspension controller except for a little deterioration.
Keywords: semi–active suspension, skyhook SMC, sliding mode control, continuous–state damper control, controller design, quarter–car suspension models, modelling, magneto–rheological damper, rough roads, model reference control, damping force, vehicle vibration, vehicle suspension