Abstract: A hysteretic force-velocity (f-v) model based on the symmetric and asymmetric sigmoid functions is proposed to characterize the semi-actively controllable magneto-rheological (MR) fluids damper. The model accurately describes the damping characteristics of the damper, involving nonlinearly saturated direct-current control, hysteretic saturation, and the strong dependence on excitation frequency and amplitude. The model has attractive features of high precision and decoupling the current control gain function and the hysteron function. By analyzing the quarter-vehicle suspension dynamic system with a MR damper, the simulation results show that the MR-damper has significant potential for achieving the new intelligent vehicle suspension design with MR dampers, and the proposed model will play an important role in improving the advanced controller synthesis for vibration attenuation.

Key words: Hysteretic F-v model, Magneto-rheological (MR) fluids damper, Vehicle suspension, Vibration attenuation