Vibration control in quarter-car model with magnetorheological dampers using FxLMS algorithm with preview

The paper presents a novel approach to the adaptive control of a semi-active vehicle suspension with magnetorheological (MR) dampers. Research was carried out for a quarter-car model with two degrees of freedom and the Bouc-Wen model of the MR damper behavior. To apply vibration control the inverse model of the damper is needed to determine the current controlling the MR damper. Thus, the Bouc-Wen model was approximated by the model based on tanh function with hysteresis included, which can be easy inverted. This approach resembles the real situation, where the model used for control does not correspond perfectly to the real device. The dissipative domain of this model can be modified by subtracting a nonlinear average velocity-force characteristics from the original one. After such modification, the real semi-active element can be treated as a fictitious active actuator which generates force limited by the nonlinear boundaries dependent on the relative piston velocity. Hereby, the FxLMS adaptive algorithm can be applied for vibration control in the semi-active suspension assuming preview about the road excitation is available as the reference signal. Simulation experiments indicated the high performance of the proposed approach and its advantage over the classical Skyhook algorithm in vibration control of the suspension. Adaptability of vibration control based on the FxLMS makes the presented algorithm scalable.