The Research Of The Obstacle Detection Method For Trains

ABSTRACT:With the rapid development of China’s economy and accelerating urbanization, urban rail transit plays an increasingly important role in our public transport by its transportation capacity, short intervals and no environmental pollution. As sharp rise in passenger traffic, the requirements on urban rail transit operation safety are also increasing. Because of the hazard of track obstacles, obstacle detection and relevant research have become a hot topic in rail transportation. This thesis studies the domestic and international railway obstacle detection technology and a new contacted type of obstacle and derailment detection system for trains is designed according to the characteristics of urban rail transit.Firstly, the thesis explains the system structure and operating principle, detailing the selection and optimization of the mechanical detection sensor design; the main control chassis is designed with fail-safe principle using CPLD and ARM, containing a dual-parallel redundant electrical structure with fault recording unit and evaluates the reliability with FMEA and FTA.The design process can be divided into two parts, hardware and software. The former includes the power isolation conversion circuit design, the signal conditioning circuit design, the peripheral circuit design CPLD and ARM, the data storage circuit design, the RS-232communication interface circuit design and the relay driver circuit design. The latter includes program design of the logic control unit CPLD and fault recording unit ARM, and the simulation logic control section which preliminary validated the functionality of the program.In addition, an experiment of the obstacle and derailment detection systems was conducted in the thesis, which was divided into two parts, that one is static and the other is dynamic, to simulate the train derailed and collided with obstacles conditions to verify the basic functionality of the system. The results show that the design of the obstacle and derailment detection system meets the design requirements, operating stably and reliably and providing a benefit reference for the future obstacle detection program of urban rail transit.