Study On An Inverse Model Of Magnetorheological Damper For Automobiles And Its Current Driver

Magnetorheological fluid (MRF) is a kind of smart material, and the rheological properties of MRF can be continuously and rapidly turned between Newtonian fluid and semisolid state under the external magnetic fields. Magnetorheological damper (MRD) is a typical application of MRF, which works as semi-active actuators to establish an interface between mechanical structure and electric control. As a semi-active actuator, MRD has great theoretical value and application potential in vehicle semi-active suspension control systems. However, due to its intrinsic strong nonlinear hysteresis behaviors, it is difficult to establish its inverse model, and the precise, fast and effective control of MRD in engineer applications cannot be realized in turn. This paper presents an inverse model for MRD based on a restructured phenomenological model with incorporation of the "normalization" concept. At first, the parameters of restructured phenomenon are identified by the multi-island genetic algorithm, and the value of model parameters is obtained under different field currents. The relation between the parameters of restructured phenomenon model and field current in the coil is established by data fitting method. The numerical simulation of the accuracy of the inverse model of MRD is carried out. The simulation results show that the proposed inverse model can effectively predict the required field current according to the state of motion and desired output damping force of MRD. Then the desired output damping force is output and the optimal vibration control is achieved correspondingly. A current driver of MRD is designed and investigated. The performance of current driver is proposed according to the requirements of MRD. The relevant parts of current driver are designed and the circuit parameters are calculated. The simulation model of circuit and experimental test system are established respectively in order to analyze and validate the circuit. The simulation and experiment results show that the current driver exhibits good linearity, small ripple and short response time of the output current. The various indexes of performance meet the requirement of MRD, and the design goal of current driver is satisfied.