Simulation And Control Method Research On Magnetorheological Vehicle's Front Energy Absorbing Structure

The ownership of the vehicle is growing with the rapid development of economy in our country.The vehicle has become modern main transport tool.While the vehicle brought in a convenient trip,it also has taken away many people's life because of frequent traffic accidents.When the vehicle front collision occurs,bumpers play an important role in enhancing vehicle's passive safety,reducing traffic accidents casualty rates and improving the ability of pedestrians protect themselves.Magnetorheological(MR)damper plays a significant role in improving vehicle's passive safety,which can be used in the vehicle front energy absorbing structure as a kind of auxiliary energy absorption devices,as well as an intelligent damping device.Therefore,for the vehicle's passive safety,the dynamic response and control effect of MR damper is studied when it is used in impact environment.The main content of this dissertation as follows:(1)The research significance and vehicle's passive safety technology were introduced.And based on the advantages of continuous adjustable damping force of MR damper and fast response,the important significance of MR damper which is used in the vehicle front energy absorbing structure was discussed.At last,the main application fields of MR technology and the development of control research on MR damper were summarized.(2)Multi-objective optimization was used to analyze the structure parameters of the MR damper based on the bingham plastic modified model(BPM).Meanwhile,the control model was established.The results showed that the optimized magnetic field distribution of MR damper was more reasonable.(3)Simplified the vehicle model,and established the frontal collision model with the aid of an explicit nonlinear dynamics analysis software LS-DYNA.Then the energy absorption characteristics of the front energy-absorbing components(such as bumper beams,crash box,front girder)were simulated,the results showed that most of the collision energy is absorbed by bumper beams and crash box when vehicle collision occurs at low speed.(4)The optimized MR damper was equivalent to different damping units which applied to the frontal energy-absorbing structure,carried out a comparative study for the influence of MR damper to vehicles' passive safety in the different front structure.(5)The control model of MR damper was established by using ADAMS and Matlab/Simulink software based on the joint simulation theory,and then confirmed the optimal control method by comparing the effect of different control strategies,provided animportant reference value for further designing controller hardware and how to apply MR damper to vehicle front energy absorbing structure.