The Key Technology Research Of Energy Effective Tracking System Based On Wireness Sensor Networks

Wireless sensor networks are self-organizing network which can finish certain task by mutual collaboration between large numbers of micro-sensor nodes. As an emerging technology, wireless sensor networks have comprehensive application prospects, and location and tracking is one of important applications to wireless sensor networks.In the tracking application of wireless sensor networks, energy effectiveness and accuracy of location and tracking are main factors to measure system. When the monitoring region has no tracking target, as a result of the wireless sensor network nodes are usually energy constrained, we hope to ensure the coverage to monitoring region, through the closure of the nodes radio to save energy, to improve the life of the entire network.For this reason, this paper studies two key problems in the energy-constrained location and tracking system: the node scheduling problem research to tracking application and the indoor real-time location tracking problem research to indoor environment; finally, based on the above theory, we developed a miner location tracking system to underground mine based on wireless sensor networks. Constructing a connected covering node subset is one of key technologies for enlarging lifetime and sleeping scheduling in wireless sensor networks, which is a significantly important research area. The previous researches focus on the k covering node subset construction problem. Because k covering subset is k-connected under certain conditions, people study the k-connected subset construction problem less. However, constructing k covering node subset as k-connected subset will use too many nodes, the cost is great. Therefore, this paper proposes a k-connected and 1-covered node subset construction algorithm--CPC, which can construct a node subset that is covering and k-connected with few nodes. This paper also proves the algorithm's correctness, and compares the performance with related algorithm by simulation. Experimental results show that compared with previous k covering algorithms, CPC algorithm can save about 55% of nodes.In the indoor environment, because of the complexity of building structure, and the RF propagation characteristic is influenced by multi-path interference and other factors, the outdoor location system can not simply be transplanted to the indoor environment, we need to re-design the indoor location tracking system according to the characteristics of the indoor environment. In this paper, the authors proposed RSSI-based indoor location method AIT. The method first determines which region the mobile node in by region location algorithm BCA, and then precise point location in the region which the mobile node in by point location algorithm SGL, to determine the specific location of the mobile node in the region. Once the mobile node's region is determined, the point location will only use the anchor information in the region to locate, this can improve the accuracy of point location. At the same time, AIT method can be used for regions of different sizes, so the application is broader. The evaluation results show that the BCA algorithm can improve the precision of area decision of MERIT from 71% to 86%, and the SGL algorithm decreases 32% location error compared with Ecolocation algorithm.Based on the above theory research, we developed a miner location tracking prototype system to underground mine based on wireless sensor networks.This paper focuses on the design of the functional modules which in the system server. At present, the system is in the acceptance phase.The contributions and novelties of this dissertation are as follow in:1. This paper proposes Coverage-Preserving k-Connected Subset construction algorithm—CPC for the first time, which can construct a node subset that is covering and k-connected with few nodes. So that other nodes in the network can enter sleep mode to save energy consumption of the entire network and extend the network lifetime.2. The indoor location is divided into two processes region location and point location. The region algorithm BCA proposes the concept based on region incidence graph, designs a precise mechanism to determine the region; the point location algorithm SGL proposes the probability location algorithm based on the mesh, effectively improve the location accuracy. The experiment results show that the method compared with the previous system, the location accuracy has been enhanced.3. Based on the above theory research, we developed a miner location tracking prototype system to underground mine based on wireless sensor networks. At present, the system is in the acceptance phase.