The Research Of Wireless Sensor Networks Coverage In Rectangular Cross Section Mine Roadway

Wireless Sensor Network(WSN) has been widely applied in safety production and inspection of mine because of its low cost, its spontaneous organizational network, its multi-jump route, and its low power consumption. Mine environment were particular, it caused wireless signal reflections and refractions very easily and signal attenuation were inevitable, and further affected the communication quality between wireless sensor nodes. With the mine laneway extending, in order to ensure the coverage quality, synchronization extending the sensor nodes deployment was necessary. This required overall deployment, which adopted safe and efficient deployment and strategies.Nowadays, most research of WSN coverage were based on two-dimensional which were not suit for the 3D mine environment. Therefore, we should design a reasonable 3D coverage model. The section of mine laneway usually divided into archway, circular, and rectangle. Most of the wireless sensor node on the inner wall used linear deployment and alternate deployment. In view of the problem of how wireless sensor nodes in 3D space achieve single seamless coverage at the mine roadway of rectangular. By analyzing the geometric size of mine roadway, deduced the minimum node sensing radius in the above mentioned two kinds of deployment, help choose a reasonable type of nodes deployment. The major work and innovations in paper are as follows:(1) In the case of that the distance of adjacent nodes is known, analyzed two classic kinds of deployment ways. Firstly, by analyzing the geometric size of mine roadway, seek the preferred locations which were satisfied with overall coverage. Secondly, function relationship between the minimum node sensing radius and the geometric size of mine roadway was deduced which was satisfied with overall coverage. Finally, above function relationship was also deduced which achieved single seamless coverage in 3D nodes deployment. The inferences show that in linear deployment as the distance of adjacent nodes got bigger, the minimum node sensing radius was grew, however, in alternate deployment the minimum node sensing radius was related to the distance of adjacent nodes and the width of mine roadway. Simulation results demonstrate the validity of the derived results.(2) In the case of that the radius of sensor node is known, analyzed two deployment ways of dynamic variable position. Firstly, 3D coverage model combined with space geometry theory, deduced the distance of adjacent nodes and coverage density which were satisfied with overall coverage in the two deployment ways. Secondly, in various width of mine roadway comparing the node coverage density of two deployment types. Finally, considering nodes could not install in the ideal position in some specific regions, the offset from the ideal position was deduced. The inferences show that alternate deployment was much suitable for the mine roadway coverage when the height was bigger than the width of mine roadway. Instead, if the height was smaller than the width of mine roadway, it divided into three situations. First, alternate deployment was much suitable for the mine roadway coverage when the ratio’s square of height and width was between 2/3 and 1. Second, linear deployment was much suitable for the mine roadway coverage when the ratio’s square was between 0 and 1/3. Third, when the ratio’s square was between 1/3 and 2/3, there was a critical value of node sensing radius, choose alternate deployment when the critical value was bigger than the ratio’s square, instead, linear deployment is better. Simulation results also demonstrate the validity of the derived results.The derived results in this paper can be applied directly to calculate the minimum node sensing radius, choose the deployment way, calculate deployment location, and coverage density. Thereby these inferences improved the accuracy and instability of sensor nodes coverage. They were of great significance to reduce the engineering cost. At the same time, just do some adjustments to all of those strategies which will suitable for archway, circular, and rectangle section of mine roadway.