Localization And Tracking Of Moving Targets Based On Convey Tree In Wireless Sensor Networks

Recent advances in wireless communications, electronics and Micro Electro Mechanical System (MEMS) have enabled the appearance of low-cost, low-power, multifunctional sensor nodes, which are small in size and communicate in short distances. Wireless sensor networks (WSN) can monitor, sense and collect the information which may be of interest to the users from the inaccessible environment and the monitoring objects. As an important military and civilian application, target tracking offers user the capability to locate and track moving targets and has become one of the current research focus in the wireless sensor network scenarios. The accuracy and energy constraints, however, challenge moving target tracking.Target localization is the prerequisite and basis for moving targets tracking. In this thesis, some existing popular target localization algorithms are reviewed at first. After an analysis of centroid algorithm, the improved weighted centroid localization algorithm was proposed by using the detected target signal strength at every sensor node. And the simulation results unveils that, the proposed weighted centroid localization algorithm is able to outperform the centroid localization algorithm in terms of the localization accuracy. Moreover, a vertical collaboration location algorithm was proposed. It is also validated that, as a class of simplified localization algorithm, the location algorithm based on vertical collaboration can meet the needs of the general target tracking, which only requires simple computation and is straightforward to be implemented while achieving reasonable localization accuracy.Both the significance and importance of mobile target tracking in wireless sensor networks are highlighted. After a survey of several mobile targets tracking scheme, the thesis focus on the dynamic convoy tree-based collaboration algorithm (DCTC). Basically, convoy tree is a dynamic tree structure which is made up of the nearby nodes who monitor the presence of the mobile target, and could be updated by adding or removing those nodes, which may out of their sensing coverage during the target movement. Nodes around the moving target collaborate through the convey tree structure, which can minimize the energy consumption when ensureing the efficient target tracking. In this thesis, the convoy tree scheme is simulated on the OPNET platform. Based on the analysis of energy consumption model of wireless sensor node, an improved convoy tree scheme was proposed by adjusting the sensing coverage of sensor nodes. And the simulation results unveils that, the improved DCTC algorithm can effectively reduce energy consumption under the premise of the target tracking successfully.