The Design And Development Of The Coal Gas Warning And Monitoring System

Nowadays along with the people’s environmental protection consciousnessenhanced. Clean energy has attracted more attention and development. In a lot ofclean energy，Gas get people more attention for its unique advantages. As a cleanenergy gas will not only satisfy people’s demand for environmental protection but alsoprovide efficient energy. And then it is also an important raw materials of chemicalindustry. A lot of additional product is gas industry. With the development of gasindustry，The importance of gas safety is increasingly facing the people. The coal gasleakage and the gas explosion accidents also remind us that gas brings us convenientalso comes with hidden danger. The safety accidents not only influence economicdevelopment but also affect the stability of the society. Gas warning system today allhas a widespread problem of aging.Based on this situation, we learn more about enterprise needs and refer to therelated project information. Make full use of existing resources. We researched anddesigned our system. Make our system meets the needs of the enterprisesscientifically and accurately. The main content is as follows:Firstly it compares the commonly used several kinds of wireless communicationtechnology such as infrared, bluetooth and so on. And their advantages anddisadvantages are illustrated and compared. After we decided to use ZigBee wirelesstransmission, we introduce the characteristics of the ZigBee protocol and networktopology. After the introduction we have explained the ZigBee protocol standard.According to the different part, we have carried on the detailed introduction. There isPHY、MAC、NWK and APS.Secondly it introduces the characteristics of the ZigBee protocol in detail. Then itputs forward the overall structure of the system and introduces the design principle ofthis system and the function to realize and indicators. Then this paper introduces thebasic process of the node hardware design. The ZigBee chips of differentmanufacturers at home and abroad are made introduction and performancecomparison. Finally CC2530of TI was chosen. ZigBee node is designed inhardware based on main chip CC2530. We choose MQ-7as the sensor part andanalyses its working principle and performance. The according to the situation wedesign different regulated power supply and make a simple introduction of its circuitdesign. We also briefly explain the other part of the hardware design.After that we introduce the development of the whole system software environment.We use IAR-Embedded Workbench. Then Z-Stack is introduced as the best protocolstack of this field. We introduced the layered software structure of Z-Stack and the work process of it. The ZigBee network form and design is analyzed after that. Eachnode of the signal receiving and sending function are also introduced. Software flowof the coordinator and terminal nodes are introduced and the star network structure isformed.Finally, we set up the network we have designed. And the established network istested by serial debugging tools. The main test the packet loss rate and the RSSI valueof the network. And then to test the performance of the system, different networktransmission distance was tested too. The data transmission is tested for the cases withobstructions.The results show that the network will transfer the data that it gets timely to thecoordinator. And the function of the wireless network system was realized. But thereis also some defects in the design. For example the transmission distance may belimited for the reason of Remote RF Unit. Because of the star configuration, the scopeof network coverage may not be far enough.