Research On Control Of Magnetorheological Damper For High Speed Vehicles

With the speed of the continuous improvement of our trains,higher requirements on the dynamic performance such as the stationarity,stability and safety in train operation are needed.The suspension system of rail vehicles plays a role in mitigating the impact and vibration of the vehicle body in all directions caused by external factors such as line unsmoothness.However,the train running at high speed will be s`ubject to greater impact and vibration,which will affect the dynamic performance of the train.Therefore,through the comparison of various suspension systems,this thesis attempts to study the suspension system with more obvious vibration reduction effect under the premise of economy and practicality.This thesis takes CRH3 high-speed vehicle as the research object.Based on the vehicle system dynamics and the rigid-flexible coupling dynamics theory,the multi-body dynamics software UM and finite element software ANSYS are used to establish the Multi-body rigid coupling model of high-speed vehicle and the rigid-flexible coupling models of flexible wheelset.A Bouc-wen model of the MR damper was established by using the numerical calculation software Matlab/Simulink,and the model was embedded as a subsystem in the semi-active suspension control system to study the dynamic impact of the controlled MR damper on the vehicle system.Moreover,the model of Skyhook damping and fuzzy control algorithm was built in Simulink environment,and thus the fuzzy control rules and corresponding quantization factor,scale factor and membership function were determined.The constructed control block diagram was used to generate dynamic data link library(DLL).UM Simulation was imported into DLL for joint Simulation,and the Simulation results under the two control strategies were compared.Under the control of Skyhook damping,the dynamic response of the multi-rigid body and rigid-flexible coupling dynamics simulation model under the massless rails model is studied,and the dynamic performance differences of the eight operating conditions under the two suspension modes are compared and analyzed.The influence of the fuzzy control MR damper on the safety,stability and curve passability of the vehicle system was explored.The results show that the use of a semi-active suspension control strategy for high-speed vehicles can effectively reduce the lateral vibration of the vehicle body and improve the ride comfort of the vehicle.The Skyhook damping can improve the transverse vibration acceleration and the transverse force of wheel and rail of the multi-rigid body and rigid flexible coupling model.After replacing the two-series transverse shock absorbers with MR damper controlled by fuzzy control,the safety,stability and curve passing of high-speed vehicles under movingmass rails and massless rails are improved,and the control effect of fuzzy control strategy is better than that of Skyhook damping.