Design And Implementation Of Subway LCU Software Based On IEC61131

With the continuous development of networking,AI detection and other technologies,subway trains require higher and higher reliability and safety of on-board equipment.LCU plays a vital role in the smooth operation of subway vehicles.At present,that traditional relay control mode has been use in China,The traditional control mode has two shortcomings: On the one hand,most of the traditional subway control circuits use mechanical relays with contacts,which are used in harsh underground environments such as humidity and high temperature for a long time,and are prone to mechanical failures,thus causing the failure of the whole control circuit and seriously affecting the operation safety of subway trains.On the other hand,the subway train computer control system adopts electronic analog control circuit,which requires the traditional wiring logic to be used for relay and contactor control circuits,complicated wiring,the reliability is poor and the later maintenance is difficult.Aiming at the problem that relays on subway are vulnerable to failure caused by adverse environmental effects,this paper proposes a programmable logic control unit to replace some relay circuits in subway.Firstly,the working principle and hardware platform of LCU controller are briefly introduced,and the related technologies of software design are introduced.According to the requirements put forward by customers,the overall architecture of the software is designed and the functions of each module are divided.Then it introduces the concrete realization of the corresponding modules,including the system initialization and self-checking function,communication function,logic management,fault self-diagnosis and reporting,hot standby redundancy,and each module of the upper computer development system.Finally,LCU software is tested according to specific requirements.The LCU controller finally realized supports the realization of hardware functions with software logic,and completes logic control through program writing and pouring.FPGA is used to realize hardware acceleration,and the serial calculation of the controller is changed to parallel calculation to improve the input and output response time.Support fault self-diagnosis and reporting functions,with stronger information processing capability and easier fault finding;Redundancy and automatic switching functions are supported.When any group of LCU fails,it can seamlessly switch to another group to work without affecting the normal operation of the train and significantly improving the reliability.LCU is a new generation of intelligent electronic equipment specially used for rail transit.