Research Of Underground Heterogeneous Wireless Sensor Network Localization Algorithm

With the development of economy, safety production has become the most attention to the current problem of coal mining enterprises, and the most important link in production safety is underground environment monitoring and personnel or positioning. In mine accident occurs due to cannot be effectively for the accident location and personnel for accurate positioning, and delay emergency assistance is often happened. More and more enterprise applications of wireless sensor network (WSN) for mine environment monitoring and positioning. Because of underground roadway environment is complex, some wireless sensor network localization algorithm on the ground cannot be directly applied to it. It is necessary to study space structure and the adaptation of topology in the underground roadway in detail,and analyze the characteristics and shortcomings of traditional localization algorithm, to design wireless sensor network node localization algorithm could meet the needs of the mine environment of underground.In order to realize the mine sensor node localization, it is necessary to study the topology relations of underground and set up positioning model. This paper gives a method to describe the network structure of underground roadway, and focuses on the roadway to bend, twist and linearization method. Because of the loss of electromagnetic wave in the borehole environment condition are different from free space, through the analysis of several common wireless signal transmission loss model,due to shielding model considering the influence of the actual channel wireless electromagnetic wave transmission that could meet the need of underground complex environment.Based on heterogeneity in the underground wireless sensor network, analyzes the existing advantages and limitations of typical localization algorithm. In view of the mine roadway environment and special characteristics of heterogeneous wireless sensor network and puts forward an improved DV-HOP fixed node localization algorithm and a mobile node localization algorithm based on monte carlo algorithm (MCL).DV-HOP improved fixed node localization algorithm based the influence of borehole distribution and average jump away from the deviation degree on positioning accuracy, divide the communication area of the node, and introduce a filter factor in the process of selecting jump hop count and average distance, To get a more accurate average hop and jump distance, purpose to improve the positioning accuracy. The simulation results show that this scheme can effectively improve the DV-HOP algorithm localization accuracy, better suited to bend downhole complex scenes.And the improved MCL is based on underground mobile node movement to establish proper mobile model, combining with the characteristics of underground roadway, will be introduced to the region this thought MCL algorithm, using the relationship between node communication radius to improve the filtering precision of the algorithm, so as to achieve the goal of improving positioning accuracy. The simulation results show that, in the node movement speed is constant, improve the positioning accuracy of monte carlo algorithm accuracy is higher than the traditional algorithm, the positioning of the mobile node is suitable for downhole.