Study On Mine Gas Monitoring System Based On ARM9 CPU And Industrial Ethernet

The advanced gas safety monitoring and control systems of domestic manufacturers have widely used industrial Ethernet as communication backbone. However, underground sub-station, the core equipment in gas safety monitoring and control system, does not provide the Ethernet interface, and only provides a RS485 interface or CAN bus interface. The maximum transmission rate of these two interfaces is only 5 000bps, and has huge gap between industrial Ethernet whose rate is 100Mbps. In addition, communication protocol of these systems is not standardized, various manufacturers'equipment is not compatible with each other, and man-machine interface of monitor sub-station is poor. Therefore, it is necessary to develop the underground monitoring sub-stations based ARM9 embedded CPU, which are equipped with a large color LCD screen and the Industrial Ethernet interface, and compatible with other manufacturer's products. It is also necessary to develop the gas monitoring system based entirely on industrial Ethernet, with the underground sub-station being its core. The main contents of this paper are as follows:(1)It proposed gas prediction algorithm based on wavelet analysis and neural networks. The algorithm has powerful noise filtering ability. It can process the time series data from gas field. Taking advantage of neural networks in predicting and valuating, we can train the BP neural network by using the post noise filtering data. And then the neural network will output the result of prediction after it is trained to predict according to the latest data put into it.(2)It designed the underground gas monitoring and control station hardware system Based on the ARM9 core of Samsung S3C2410 embedded chips. The system emphasizes on the CPU and memory modules, LCD display module, I/O Input output module, Ethernet interface module, USB interface module and serial module, gives the corresponding circuit diagram, and analyses the intrinsically safe explosion-proof of the circuit. Based on embedded operating system Win CE 5.0 as the core, the research also designed underground gas monitoring and control sub-station software system. Data acquisition software is written by Control Software "KingView Embedded Edition", the face gas prediction software in underground monitoring sub-station is compiled by Microsoft Embedded Visual C++(EVC). The face gas prediction software runs in the background, and gets the field gas concentration value of each channel through DDE from data collection software. After filtering the noise by wavelet analysis and forecasts of BP neural network algorithm, it sends face predicted gas concentration value back to the data acquisition software, and displays it on the screen.(3)It designed a completely Ethernet-based industrial gas monitoring and prediction system hardware programs and software programs. With the underground gas monitoring sub-station industrial Ethernet hardware being its core, the hardware connects all communication lines by Industrial Ethernet bus based on tree topology. Thus communication rate of gas monitoring system is improved to 100Mbps or more. The data of each underground field monitoring sub-station is collected by the KingOPCServer software with dual-redundant way into KingHistorian that is real-time/historical industrial database. Other related software all read data from the KingHistorian database to achieve their display, processing, control, printing and other functions. Monitoring software running on the upper monitoring computer is written by configuration software "KingView6.53", Gas prediction software is written by the MatLab7.0 software, transmission of data of both between them is carried out by the ways of OPC.(4)Finally, it analyses the cause of accident of gas monitoring system through an innovative use of Fuzzy-FTA. And the appropriate management measures were proposed. Mine gas monitoring system based on ARM9 CPU and Industrial Ethernet are capable of gas concentration prediction, so it can provide a longer warning time to gas concentration overrun. Because communication speed of monitoring system has been raised to100Mbps, inspection speed and size of the system are greatly improved. Just replacing the underground sub-station and part of communication lines, other gas monitoring system can be upgraded quickly. Therefore, the system has a wide range of applications.