Research On Localization And Target Tracking In Wireless Sensor Networks

Wireless Sensor Network (WSN), which integrates the sensor, micro-electro-mechanism system (MEMS), wireless communication and distributed information processing, becomes a hot research topics at the current Information Technology field. The WSN has many advantages such as self-organization, high accuracy measurements, and high fault-toleration, widely coverage et al. Characteristics of low cost, low power, flexible deployment make it more widely applied ranging from the military areas to the abundant civil areas.The dissertation deeply studied the localization and target tracking problems in wireless sensor network, including node self-localization, plume source localization and the target tracking problems. General localization and target tracking oriented platform is developed, which serves for further studying and practical applications. Due to the problems listed above, many new localization and tracking algorithms are proposed according to the practical applications in WSN, these algorithms have a certain values on theories and practical applications. Extensive simulations have been conducted to validate and evaluate the performance of the proposed algorithms.The concrete contents of this dissertation are given as below:(1) Research on node localization in wireless sensor networkNode localization in wireless sensor networks is treated as a functional dual of target tracking from a novel perspective in the dissertation. A node localization scheme is proposed based on the virtual beacons, which is different from the current fixed beacons node localization algorithm. A VB-ERL localization algorithm is proposed based on the hyper-sphere intersection mechanism. The nodes estimate their locations by solving the least cost function generated by many pairs of received virtual beacons-energy ratios. In order to eliminate the drawbacks of the VB-ERL algorithm, a localization algorithm named VB-IPF which based on the improved particle filter under Bayesian Frame is also proposed. It estimates the node location on line.(2) Research on plume source localization in wireless sensor networkA wireless sensor networks is proposed to estimate the plume source location. Such WSN can be of tremendous help to emergency personnel trying to protect people from terrorist attacks or responding to an accident. First, a robust centralized localization algorithm named maximum likelihood estimation (MLE) algorithm is proposed. It's performance is evaluated compared with the direct Trilateration (DT) algorithm and the nonlinear least square (NLS) algorithm. In order to save the energy and eliminate the various problems associated with the centralization algorithms, a hierarchical wireless sensor network is proposed to estimate the plume source location. The performed distributed algorithm is based on the improved particle filter. The source location is obtained by the manager nodes'estimation state transmission in each sub-region in turn.(3) Research on target tracking in wireless sensor networkTarget tracking applications in wireless sensor network have a great value ranging from the military to the abundant civil areas.A bearings-only tracking for maneuvering target was firstly studied in wireless sensor network. A centralized fusion scheme in WSN was proposed to estimate the target based on the SRCDKF-PF algorithm and its improved methods. It improves the target estimation accuracy from the aspect of the filters improvements.Second, a new adaptive, distributed lightweight target tracking algorithm is proposed considering the energy saving requirement in WSN. In the algorithm, an adaptive mechanism based on the node density is proposed to obtain optimal active region size. A backoff timer mechanism is proposed to elect the leader node and obtain the transmission order of the localization nodes'measurements. A localization mechanism based on the improved particle filter improves the tracking performance. A step by step recovery mechanism is proposed to relocate the missing target.(4)Research on target tracking oriented platform of WSNA target tracking oriented platform of WSN is designed and developed, including gateway and sensor node. The gateway implements the reliable link between WSN and the other networks such as Internet by TCP/IP protocol through the GPRS communication system. The sensor node based on CC1010 chip implements the communication among nodes in WSN. It offers a general target tracking oriented platform for studying of the future related problems in WSN.