Gas Monitoring System Based On Wireless Sensor Networks

In recent years, coal mine accidents have happened frequently in our country. These bring high casualties and huge economic losses, and ring the alarm bell for our coal industry. With the rough development of coal industry and the low network level in information technology, the underground situation can't be transferred to the monitor center on the earth in time, and this is the main reason for coal mine accident. So we need to build a high-efficient monitoring system as soon as possible.The traditional coal mine gas monitoring system uses the method of wire network, however, because of the restriction of time and space flexibility in the wire network, in the condition of the time limit and rugged surroundings, it is impossible to build a wire system in short time. In order to solve this problem, this paper designs the coal mine gas monitoring system by using wireless network, and this system can transfer the underground information to the monitor center on the earth via the wireless channel.Wireless sensor network is composed of mass mobile micro-sensor nodes connected to the network. It can be used to test, sense, collect and process information of monitored objects and transfer the processed information to the monitor center. It integrates the technique of sensor, remote measurement, remote control, embedded computing, distributed information processing, wireless communication, and makes full use of self-organized and multi-hop character of Ad Hoc network. Because of the mobility of node, no need of wire, simple manipulating, easy maintaining and low cost, it is a feasible method to realize the gas monitoring with whole orientation and real time.This paper mainly aims at the situation in which the coal mine gas accidents have happened frequently, and uses the architecture of wireless sensor network to design the intelligent alarm system which can monitor the gas concentration with whole orientation, real time and unmanned. According to the investigation and research in field, this system can be used in gas monitoring, and it has the characters of small volume, low cost, high intelligence, easy manipulating and so on. This paper introduces several aspects as follows: firstly, it introduces the architecture of wireless sensor network; secondly, it designs the architecture of this system; thirdly, it introduces the design proposal of node; fourthly, itanalyses the routing protocols in the wireless sensor network, and designs two routing-protocol proposals; lastly, it simulates the two proposals on the NS2 platform, and compares and analyses the results.Because of the restriction of condition and ability, this paper only carries out the principle design, the system simulation and the design of node hardware. The practical design hasn't been completed, and there is a lot of work to do before it can be sold in the market.