Research On The Simulation System Of Metro Vehicle And Ground Information Transmission

Communication based train control system(CBTC, Communication Based Train Control) differs from other train control system at the fact that radio channel is established between the ground and the train real-time transmission, which makes the on-board equipment and ground control equipment be closely linked, and transfers large capacity, fast rate and high reliability real time data to ground and train, and occupies a crucial position in the train control system. However, the radio transmission’ environment between vehicles and ground is very complex and changeable. Researching and testing in real environment is very time consuming and laborious.In this paper, based on vehicles and ground wireless communication technology of today’s mainstream urban rail transit to simulate the actual situation of the laboratory. Its main purpose was: building a train to ground wireless transmission model, realizing time date transmission of train and ground equipment, which makes the train no longer be limited by the track circuit, achieves moving block, and provides simulation platform for teaching and research of CBTC system in our school.The main work and content of this article: the application status of wireless transmission system of metro at home and abroad was briefly introduced. By analyzing and comparing the current characteristics of several commonly used wireless communication technology, the superiority of ZigBee wireless technology, according the characteristics of the ZigBee network to design topological structure stands out, protocol stack and routing algorithm for wireless transmission network of vehicle and ground. In the aspect of hardware, according to the requirement of communication system using CC2530 chip to design the hardware of ZigBee coordinator module and vehicle mounted wireless communication module, and according to the requirements of STM32F103 communication to control interface for the core control chip of vehicle controller to design transponder module in train positioning, correct vehicle orientating system, which improves the positioning accuracy of the whole train. In the aspect of software, using C sharp language to design zone controller(ZC) interface and vehicle interface. Then, the corresponding algorithm was made for the generation of mobile license(MA). And this paper designed corresponding zone controller to send and receive message, introduced an algorithm for generating one-step braking curve, and combined with this method to generate one-step braking curve in the vehicle interface. At last, based on the combination of distance, position and current speed, the mobile license is sent to the train in real time to realize moving block. Through hardware and software debugging, the real-time monitoring and management of train operation information, and the generation and transmission of the train mobile license all got satisfactory results. Its communication basically achieve the requirement of being real-time, fast and stable.