Study And Design Of Security Access System On Subway Steel Structure Work Platform

With the development of rail transportation, the demands of urban rail transitmaintenance equipment have grown rapidly. Subway steel structure work platform as akey equipment in vehicle maintenance library, is mainly used to inspect, repair, replacethe bodywork of subway and the equipment on the roof of the vehicle. As the topplatform closes to subway high-voltage grid, the platform has the security risks ofelectric shock. Therefore, the security and protection system is used for subway steelplatform. This system is mainly used to monitor and warning the platform, control thestaffs access and the maintenance workflow. It can effectively protect the safety of staffand ensure production safety.In this thesis, through analyzing the working conditions and control flow of thesubway steel platform, the author learned structure and function of the platform,determined the necessity of installing the security and protection system. Based on theanalysis of modern security system technology, aim at the particularity of the platform,the author research and design a SPS suitable for subway steel structure work platform.This the security and protection system is composed by detecting alarm, videosupervisory system and controlling passageway, PLC control system and etc. Thesesubsystems,through a combination or integrated into a unified security system, canachieve the corresponding linkage function. The SPS can achieve order control of workprocess and monitor the entire operating platform, ensure safety in productioneffectively.Analysis of the maintenance processes, PLC control system was adopted to controlthe process of maintenance. By using of master and slave communication, PLC canachieve the control for multiple platforms. Due to the particularity of steel platform, theoperating process hops are not allowed jump or unauthorized operation, Adopt PLCsequential control program for controlling processes. Through experimental modelvalidation, the control method is safe and reliable.The security system uses upper and lower machine communication, achieved thecommunication between PLC and PC. By using OPC technology, date exchange can beachieved and it can improve the capacity of data transmission. This paper useMTGW-bus converter module, RS-485bus and CAN bus are integrated application.RS-485bus as a lower bus, CAN bus as an upper bus, it can easily achieve each subsystem integration, enhanced control and communication capabilities of controlcenter.