Research And Implementation Of Switch Control System Based On Tram

The tram has become one of the main research directions of modern urban traffic under the situation of shortage of resources and traffic congestion caused by automobile-led urban traffic mode. At present, in the method of 6502 electrical centralized control turnout method based on tram, the control process is complex.Therefore, a safe and reliable and easaily maintenanced turnout control system is valuable.In this paper, a turnout controller for trams is designed by combining computer technology, embedded technology, wireless communication technology, automatic control method and decentralized control. The controller is divided into three parts: the data command receiving processing layer, the logical voting structure layer and the turnout action execution layer. Data command receiving layer use STM32 based on Cortex-M3 architecture as a processor, through a dedicated wireless communication network to receive the data,communication calibration package and the closing message. The data is stored in the serial Flash chip according to the tram number. Verify the reliability of the communication with the controller's own calculation results. Closing message resolved by the processor is compared with prepare data which is received from high-speed hardware SPI interface, if they are matched, the system export the control command. The logic voting structure layer uses the logic function of the programmable logic gate array FPGA and combines the STM32 dual communication function to design the Double 2-vote-2 mechanism. A total of two sets of controllers make up of the system, each group of the set have two control chip. In the group t two outputs have an and logic operation, the output of the group have a or logic operation. The turnout action layer receives the safety signal output from the logic structure and drives the push rod stepper motor to drive the turnout action. The different positions of the motor can drive a different turnout position and the turnout state is returned to the processor. Through the module test, function simulation and joint test, the system realizes the function of controlling turnout by the information of tram route, and its stability and safety meet the design performance requirements.The design combined with the characteristics of trams to achieve the purpose of turnout decentralized control. The method improve the tram turnout control flexibility and reliability,and overcomes problem that the original equipment is inefficient in the high-density running of the tram, completes the design demand and provides a realization method for the turnout control part of the tram signal system.