Dynamic Analysis Of Medium And Low Speed Maglev Vehicle-turnout Coupling System Considering Spatial Dynamic Magnetic Rail Relationship

With the continuous development of China’s urbanization,the urban population has grown significantly,and the demand for transportation within the city is increasing,and strict requirements have been put forward for urban rail transportation.The vibration and noise problems brought by traditional wheeled rail trains are becoming more and more prominent,which have a certain impact on the normal life and living of the residents along the line.With its stronger climbing ability,lower noise,more environmental protection,comfortable ride,and low terrain requirements,low-speed magnetic levitation rail transit has emerged as a good prospect for future urban short-distance transportation.In order to study the dynamical response analysis of the coupled vehicle-turnout system of low and medium speed magnetic levitation,four main aspects are studied: spatial dynamic magnetic rail relationship,levitation control system,vehicle-turnout coupling vibration and levitation failure.The main research works are as follows:(1)Considering that the difficulty in the calculation of the theoretical formula of the magnetic track relationship is actually the difficulty of integration in the elliptic domain,which makes the expression difficult to be simplified and cannot be obtained precisely and simply analytically,a refined dynamic magnetic track relationship model is established based on the consideration of the magnetic saturation effect,because the magnitude of the electromagnetic force of the levitating electromagnet is not only related to the levitation gap,but also influenced by the four degrees of freedom of the electromagnet traverse,rocking head,side-rolling and pitching In principle,all five degrees of freedom should be taken into account when calculating the electromagnetic force,due to the role of levitation control,only four degrees of freedom are considered in the calculation of the six-degree-of-freedom spatial dynamic magnetic rail model,and the proposed model of electromagnetic force is established by numerical simulation method instead of the theoretical formula;the characteristics of the levitation system are analyzed by the mathematical model of the levitation control system,and the PID levitation control model is established to adjust the PID control parameters to determine the optimal parameters.Based on the coupled vehicle-track dynamics theory of low and medium-speed magnetic levitation,the vehicle-track coupling system dynamics model is established by using multi-body dynamics software according to the main structure of the vehicle and the working principle of the turnout.(2)The lateral passing speed of straight-moving turnout and three-point centering is25km/h,while the lateral passing speed of chain turnout and deflectable turnout is obviously higher than the first two.Considering the different lateral passing speeds of different turnouts,the lateral passing speed of 25km/h is selected to pass the above turnouts,and the vibration response of vehicle system dynamics and vehicle-turnout coupling system are analyzed under the speed of 25km/h and limit speed.(3)In the normal operation of the vehicle,it is inevitable that the vehicle will fall during operation and the electromagnet will die due to the suspension fault,which will have an impact on the operation performance of the vehicle.Considering the impact of suspension failure on vehicle operation,the suspension force,air spring force,and vehicle body vibration characteristics are analyzed for the vehicle operator when the vehicle falls and the solenoid suction dies.