Design Of Dangerous Gas Monitoring System With Patrol And Regional Positioning Function Based On WSN

In all kinds of public places or production range, operational errors, deliberate hu-man and aging equipment may lead to leakage of explosive, poisonous and dangerou-s gas. If the leakage can’t be found in time, it will bring serious damage to public security and production safety. So effective monitoring of dangerousgas leakage is very im-portant to production security and public safety. Traditional gas monitoring system based on wire lacks the flexibility because of undue relianceon wire and cable-based communicati-ons infrastrcture, and the scalability is poor. Even the latest wireless gas monitoring system, defects such as high cost, simple node type still exist. For these reasons, this thesis designs a wireless dangerous gas monitoring system with patrol and regional posit-ioning function.This system uses ZigBee as communication technology. The hardware devices includes the coordination, routers, anchor nodes, fixed monitoring nodes and patrol handheld nodes. Fixed monitoring nodes are arranged in different positions within the monitored area.When the coordinator turn on all fixed monitoring nodes, all fixed monitoring nodes into the monitoring state after apply and save the nearest anchor node ID (used to implement the regional positioning function). Patrol handheld node as a separate mobile monitoring nodes, it detects gas leakage in the process of patrol, will generate sound and light alarm, then the alarm signal will be send to the coordinator. When the fixed monitoring node discovery dangerous gas concentrations exceeded, it will send a dangerous message while the coordinator and patrol handheld nodes,the message including the position and level of the danger. Patrol will immediately rush to the dangerous position to verify, if the risk is confirmed,the patrol can send a signal to ask for help through the HELP button on the node. The coordinator will be gathering all the information and realize the format conversion. PC is responsible for all the nodes in real-time data display and monitoring.This thesis designs and implement the gas monitoring system with patrol and regional positioning function based on wireless sensor network. First, for the main shortcomings of traditional wireless gas monitoring system, the requirement analysis was conducted in terms of flexibility and reliability requirements, at the same time, the overall architecture of the system was designed. Second, based on modular design model, This system designs the hardware equipment include TGS813gas acquisition and processing module, power management module, information display module, sound and light alarm module, JTAG module and key module.etc. According to the function of each node is different, every node hardware parts was designed through the reasonable combination module. Then design the software part of each node based on the Z-Stack Protocol. And then design a hazardous gas monitoring system based on C/S architecture. The main achievement of the work is displaying the monitoring node status and its surrounding gas leaks (leak time, grade and location of the leak), the system will promptly give tips when detects danger. Finally, the joint commissioning of the system hardware and software, is to verify its feasibility and functional integrity. The test results show that the system has completed the original design, has a certain practicality.