Research On Virtual Rail Train And Its Key Technologies

As the number of domestic vehicles increases year by year,urban traffic congestion is becoming more and more serious,affecting the normal work and life of urban residents.There is a growing demand for transportation tools with low cost,high speed,large passenger capacity and flexible operation.Therefore,this paper studies the new architecture of transportation vehicle and its key technologies,and mainly carries out the following work.1.Analysis of the current situation of urban public transport system and the demand for new vehicles.On the basis of comprehensive analysis of the advantages and structural characteristics of rail vehicles and ordinary road vehicles,and according to the relevant standards of urban construction and vehicle designing,the concept of ground virtual rail trains that can be flexibly operated in narrow urban space and flexibly grouped was firstly proposed.2.The basic design of the main structure and the dynamic performance of the virtual railvehicle.According to the requirements on the flexibility of the virtualrailvehicle,the key parameters of the body and the hinge mechanism of the virtual rail vehicle were designed.According to the dynamic requirements of the virtualrailvehicle,the dynamic parameters of the virtualrailvehiclewere designed,and then the prototype of the virtual rail vehicle was built.The PID control methodwas used to test its tracking function,the feasibility and motion controllability of the virtual rail train structure were verified.3.Study on independent tracking control andcoordinated tracking control methodfor the modules among carriages of virtual rail train.The ground virtual rail vehicle belongs to multi-input and multi-output system,the traditional PID control method can't realize the virtualrailtrackingwell.Therefore,the virtualrailvehicle's kinematic model was established according to the motion relationship between the virtualrailvehiclecomponents.The independent tracking control method of virtualrailvehiclesatisfies the flexible grouping requirements of the virtual rail vehicle,and has no limit on the number of carriages of the virtual rail vehicle.Therefore,based on the D'Alembert principle,the virtual displacement principle and the principle of energy conservation,the appropriate generalized coordinate system is selected to establish the dynamic model of the virtual rail train running at high speed.The high-speed driving tracking method for the virtual railvehicle is built based on its dynamic model and realize the virtual rail tracking of the virtual rail vehicle at high speed.4.Study on the vertical motion characteristics of the virtual railtrain.In order to improve the ride performance and comfort of the virtualrailvehicle,based on the characteristics of the virtualrailvehicle,the simplified vertical dynamic model and the related motion equations of the virtual railvehiclewere established.Based on the vertical dynamic model of virtualrailvehicle,the vibration characteristic of virtualrailvehiclewas studied.The amplitude and frequency characteristics of the displacement,the velocity and the acceleration of the vitural rail vehicle versus the inputs from road were used to analyze the compliance of the vehicle model.Then the ride performance characteristics of the virtual rail train wereobtained.5.Analysis of influencing factors on ride performance of the virtual railtrain.Multi-axle road excitation model of virtual rail train was built,and the ride performance simulation under typical road grade and different running speed were carried out in Simulink,the influence of road grade and running speed on train ride performancewere obtained.Through the simulation and analysis of the influence of suspension parameters such as different natural frequencies,damping ratio and mass ratio of train,the influence of suspension parameters on train ride performancewere given.