Adaptive Control Of Magnetorheological Damper Semi-active Suspension System

With the development of the times,people pay more and more attention to the stability,comfort and safety of the car.The improvement of shock absorption performance of vehicle suspension system is the key to improve driving comfort and stability.A large number of research results show that the damping effect of semi-active suspension system with MR damper is better than that of conventional suspension system.In this paper,based on the Binghan model of the magnetorheological damper and the vehicle 1/4 suspension system,the magnetorheological damper semi-active suspension system model is established by deducing the physical formula and the system dynamics equation.The relationship between damping performance,driving comfort and generalized equivalent damping coefficient of Mr Damper is discussed by referring to the actual vehicle parameters.Aiming at the influence of modeling error of magnetorheological damper,nonlinear approximation error in the realization of control system,different vehicle parameters and other disturbances on the damping effect and driving comfort,a model reference adaptive control strategy and the overall hardware structure realization of the suspension system are proposed.The basic idea is to establish the transfer function between the sprung mass block and the road interference excitation and draw the block diagram of the control principle.A reference model is constructed based on the relative displacement relationship between the mass block below the spring and the mass block above the spring.According to the generalized error signal between the reference model and the actual system,the generalized equivalent damping coefficient of the magnetorheological damper is adjusted based on Popov superstability theory.In order to avoid the dependence of the adaptive law on the derivative of state variables,a state filter is introduced.After a thorough study of the adaptive control principle,the block diagram of the adaptive control principle of the magnetorheological damper semi-active suspension system is presented and its stability and control effect are verified by simulation.The results show that the adaptive control strategy proposed in this paper can effectively suppress the influence of the modeling error of the magnetorheological damper,the nonlinear approximation error in the realization of the control system,the parameters of the state filter,the parameters of the model reference adaptive control law and different vehicle parameters on the performance of the suspension system.The generalized equivalent damping coefficient of the magnetorheological damper can be automatically followed by the expected generalized equivalent damping coefficient to ensure the driving comfort and stability,and the control system is simple in structure and can be realized.Finally,the hardware schematic diagram including the minimum system,digital-to-analog conversion module,digital-to-analog conversion module and power supply module is designed for its realization.In the aspect of software,the program flow chart is drawn and the programming idea is expounded.