Comparison on Hysteresis Models of Controllable Magneto-rheological Damper

Magneto-rheological damper(MRD) has wide application prospect in the field of structure semi-active vibration control,while the analysis and synthesis of semi-active controller require an accurate,concise and generalized hysteretic force-velocity(F-v) model.A candidate MRD is tested under several different groups of control current and harmonic excitation conditions(frequency and stroke).It is found that the damping force of MRD has strong nonlinear hysteresis and property of decoupling control current and hysteron under variations of control current and excitation nature.Considering the advantages and disadvantages of nonlinear hysteresis bi-viscous model,phenomenon model,S-type hysteresis model and generalized hysteresis model based on sigmoid function,a generalized F-v model of MRD is thus proposed.The generalized model decouples the current control function and the hysteron,and can easily derive the inverse model and benefit the synthesis of sophisticated controller.The proposed typical models are further modified by applying the proposed current control function based on sigmoid function,so as to accurately adapt variations of the control current.The parameters of typical models are identified by employing the least square method and the tested data,and then different model calculation results are compared with those obtained from the tested data,under different control currents and excitation nature.The results show that the modified typical models all have high accuracy.