The Development And Research Of High Performance Metro Stray Current Monitoring System Based On ZYNQ

The post protective measures of metro stray current mainly depend on monitoring system.The high performance monitoring system not only needs to be able to monitor the field data in real time,but also must implement the analysis of the characteristics of metro stray current signal to provide favorable data support for further harness.Due to the weakness and intermittently of metro stray current signal,and the low sampling rate,the interference of high noise and small signal volume in existing indirect measurement methods,make it hard to be detected exactly and accurately.With the rapid development of electronic technology,communication technology and signal processing technology,it has laid a foundation for the development and research of high performance stray current intelligent monitoring system.The main task of this paper is to design a set of high performance metro stray current monitoring model system.Firstly,the corrosion principle,damage and protective measures of the stray current are illustrated.According to the characteristics of stray current and the overall resolution of the high performance metro stray current monitoring system has been analyzed,which is based on ZYNQ.ZYNQ,which integrated ARM Cortex-A series hard core part and Xilinx 7 series FPGA part,is an all programmable chip that can effectively speed up the design of embedded system.The high performance metro stray current monitoring system based on ZYNQ mainly consists of intelligent sensor unit and the main control unit of station,which is a multi-functional electrical equipment for urban rail transit system.This paper focuses on the hardware and software design of intelligent sensor unit and the main control unit of station based on ZYNQ.The intelligent sensor unit of stray current based on ZYNQ is charge of sampling field data,which uses the RS485 interface to communicate with the main control unit of station.When receiving the call message from the main control unit of station,it will upload the related data quickly.Meanwhile,the low noise multi-resolution acquisition system can provide low-resolution data stream for field monitoring and supply high-resolution data stream for the analysis of characteristics.Furthermore,the hardware collection,transmission and analysis of XADC data stream are completed based on FPGA part.And,the management and control of data is done by ARM part.The main control unit of station based on ZYNQ adopt embedded Linux system to implement multitask management,which achieves data from field sensor nodes via RS485 interface and communicates with the dispatch center through network interface that means receiving command and reporting messages from/to the dispatch center.At the same time,the GUI interfaces is designed to query and display historical data.Finally,using Disovery 2 to simulate the field data and the PC to substitute for the dispatch center have accomplished the evaluation of the functions of the intelligent sensor unit and the main control unit of station.The experimental results show that the monitoring system of stray current based on ZYNQ not only can detect the field data by low-resolution data stream in real time,but also be able to analyze the characteristics of stray current signal through high-resolution data stream.In addition,it can complete transmission,display and query of field data and communicate the dispatch center by network.