Research Of Automatic Track System Based On PLC

For a long time, the process of traffic control automation is not fast because of the trainspeed in locomotive depot slower than in trunk railway and the influence of money, So far,there are still many locomotive depot used artificial throw switch, switchman to hand signaldriving way. This will inevitably affect running safety and production efficiency, and bringinconvenience to locomotive depot information management. As the railway passenger trafficvolume increasing, the locomotive servicing work also will increase. This is also increase theneed for switch centralized control system. So, it is urgent to design of locomotive depotautomatic track system.Automatic track system for locomotive depot is composed of three sections, switchcentralized control system, isolating switch microcomputer control system and imagemonitoring system. The paper base on an actual project as the background, combined with theactual demand, adopt the PLC technology complete switch centralized control systemdevelopment for locomotive depot. PLC is a kind of high reliability industrial controlcomputer which has many computerized functions; it can not only realize logic control, butalso with functions of data processing, communication, network, etc.The paper firstly designs the overall scheme of the automatic track system, focus onstudy switch centralized control system, and the three big outdoor equipments of options andcomparison are analyzed.Then design of switch centralized control system software, the keydesign is PLC interlock operation software. In this paper, the interlocking computing softwarewith Siemens S7-300series of modular programming language STEP7as development toolsfor the conditions of computer interlocking technology design basis, PLC ladder diagramprogramming to realize interlock function. When the design according to the route controlprocess could be divided interlocking computing software by function module, convenient todevelopment debugging and late function increase or decrease, it is also conducive to thestandardization and modularization of the program. The development cycle of the wholesystem based on PLC is shorter, the cost is lower. In the field use for more than a year,running stabilityAt last, the paper making use of the reliability theory to analyze the reliability of system.based on the system route control process to establish the relevant task profile, make itsrelevant subsystem reliability block diagram, and block diagram of each subsystem is tofurther divided into replaceable components level, through the analysis, the mathematicalmodel is established. System reliability is analyzed through establishing the mathematicalmodel of quantitative analysis and simulation, the results show the system comply withrelevant design specifications. So the completion of this topic, for the application of PLC in the computer interlocking system provides an important theoretical basis.