Railway Vehicle Running Stability Of Virtual Test Technology Research

The running stability of railway vehicles has great influence on the safety of rail transportation. The traditional evaluating manner of the vehicle stability is to carry out complicated manual calculation in the design stage and reduplicate vehicle running tests in the trial phase, and makes the necessary design improvements. The manner has to takes a lot of manpower and material resources, and lead to long cycle and low efficiency. The virtual test technology, which combines with virtual prototyping and virtual reality technology, can provide a new approach to evaluate the running stability of railway vehicles in early stage.The paper studies virtual test technology and a prototype system on running stability of railway vehicles by numerical simulation and virtual reality technology, and the goal is to make more accurate evaluation of the vehicle running stability in the design stage so as to reduce the development cycle and cost, and to ensure the running safety.The research category of the running stability for railway vehicles are discussed, and current situation of virtual test technology of vehicle research at home and abroad are analyzed in the paper. The problems to solve and the major work to finish are raised in this paper.The various theory models are studied and compared on anti-overturning stability, the anti-derailment stability, snaking motion stability, and a set of formulas on running stability of railway vehicles are summed up, which are more comprehensive and easy to program. These formulas provide the theoretical foundation for the virtual test of the vehicle running stability.In order to simulate accurately the actual running condition of railway vehicles, the paper carries out the research work on the acquisition of dynamics parameters and the running condition interactive definition on railway vehicle system. A method which can extract the vehicle structure and kinetic parameters from the vehicle three-dimensional CAD models is developed. The definition style of vehicle running parameters and track geometry parameters and storage methods are explained.The module components for analysis of the anti-overturning stability, anti-derailment stability and the snake-running movement stability are developed by Matlab tool which have powerful scientific computation and numerical simulation. These module components can automatically calculate the anti-overturning coefficient, anti-derailment coefficient, load rate and critical speed of snake-running movement, and automatically generate the relevant charts, and forecast running stability of vehicles.The virtual model of railway vehicle and the test scene model are built by Virtual Reality Modeling Language VRML. The control data of vehicle movement simulation is solved by a locus function of railway track. The motion control of virtual vehicle model is achieved by a SIMULINK element. The test results of railway vehicle running stability are shown interactively and visually by Matlab Virtual Reality Toolbox and S-Function Module.