Application Of Virtual Reality-based Testing In The CBTC System

With the development of computer graphics, simulation, and network, virtual reality, which is an integrated information technology combined by all of these subjects, is widely used in the research and development of urban railway transportation. But the application of virtual reality still stays in simulation, and emphasizes the immersion. What's more, the interaction and imagination of virtual reality are ignored. In this paper, virtual reality and testing are combined based on scene simulation. Focusing on the participation and creativity of human, the VR-based testing system is developed, which incarnates the interaction imagination between human and system. Meanwhile, the study on the application of virtual reality in urban railway transportation is brought to a new theoretical level.Based on the virtual testing theory, this paper introduces virtual reality, simulation technology, testing technology and object-oriented modeling in the theoretic perspective. A VR-based testing theoretic model as well as the method to realize this system is proposed. The particular characteristics of virtual testing system are analyzed. The method to realize this system and the developing flow to design and estimate the whole system parallel are proposed. In addition, the feasibility of this system is demonstrated. This paper mainly focuses on the key technology to realize the VR-based testing system, including geometric modeling, dynamic modeling, DOF, switch node, model optimization and communication technology, etc. Considering these key technologies together with the development of CBTC virtual testing system, the virtual testing system's design method and process are discussed particularly in several ways, such as CBTC static scene modeling and optimization, study on the dynamic behavior method of mobile objects, the design and application of MMI, the connectivity between virtual reality hosts, etc.Finally, the applications of virtual testing system in CBTC system are mentioned and a series of basic functions are tested, mainly including the running mode of the train, CBTC login process, tracing process of the train and computer interlocking. Virtual testing has not only special graphical testing method, but also other advantages compared with the traditional testing method. All of these are demonstrated to play a vital and non-substitute role in the research and development of CBTC system. And the virtual testing system has made great contributions to the security and economy of CBTC system's testing.