Study On Dynamic Simulation And Control System Of Automotive Magnetorheological Semi-active Seat Suspension

With the rapid growth of car ownership and the improvement of automobile manufacturing level in China,the ride comfort of vehicles has gradually become an important indicator for consumers to consider,and automobile manufacturers have also increased research and development investment in this area.Working conditions in commercial vehicles are harsher than in passenger vehicles,and professional drivers are two to four times more likely to suffer from low back pain than the general population.The driver’s body is connected to the vehicle through the seat,and all vibrations are transmitted to the driver’s body through the seat.The car seat must isolate the vehicle vibration and shock transmitted to the driver,providing a good ride for a long time for drivers of all sizes.Compared with passive suspension,semi-active seat suspension based on magnetorheological damper can adapt to different working conditions of the vehicle and effectively control the vibration transmitted to the human body.In this paper,the magnetorheological semi-active seat suspension system is taken as the research object.Based on the school-enterprise cooperation project（No.3R119D592415）,the dynamics simulation and experimental study of the system are carried out,mainly including the following aspects:Firstly,the semi-vehicle model of commercial vehicle was established,and its response was simulated under sinusoidal excitation,pulse excitation and random excitation respectively,and the response was taken as the external input of the seat assembly.The seat dynamics model was established,and the influence of the stiffness and damping of the seat suspension on different frequency bands of suspension vibration was understood by analyzing the frequency characteristics of its transfer function.Secondly,the dynamic model of MR Damper is established.The dynamic characteristics of magnetorheological damper were studied by bench test.The characteristics of Bingham model,hyperbolic tangent model and ANFIS model of magnetorheological damper were studied,and the parameters of the damper model were identified by using the data collected from the bench experiment.For parameter identification,a method combining genetic algorithm and pattern search algorithm is adopted to obtain the optimal solution and improve the repeatability of identification results.The parameters of hyperbolic tangent model are extended to establish the relationship between each parameter and input current and excitation velocity amplitude.By comparing the predicted data with the experimental data,the accuracy of the established damper model in describing the dynamic characteristics of the damper is verified.At the same time,ANFIS inverse model is established and compared with hyperbolic tangent model in the difficulty of modeling and accuracy of prediction.Thirdly,research on control strategy of semi-active seat Suspension.By analyzing the frequency characteristics of three different control strategies,namely Skyhook algorithms,ADD algorithms and mixed Skyhook and ADD algorithms,the suitable working conditions are understood.The control strategies were simulated under three different road inputs of sweep excitation,pulse excitation and random excitation respectively,and the damping effects of various control strategies were compared and analyzed.Finally,experimental study on Magnetorheological Semi-active Seat Suspension System.The seat suspension controller and current drive circuit are designed and developed,and the experimental platform is built and the seat bench test is carried out.In the safety range of hydraulic vibration excitation table,the vibration control effect of Skyhook algorithms and passive suspension is compared by inputting frequency sweep excitation and single point sinusoidal excitation to the seat suspension system.Through this experiment,the feasibility of semi-active seat suspension control is verified,and the experimental platform also provides an effective validation tool for the research and development of semi-active seat suspension control system.