Research On Technique Of Routing And Node Localization For Wireless Sensor Networks

Wireless sensors network, which has a great future, is a new generation of sensor networks. Wireless sensor network has a broad spectrum of applications in many areas. It will bring on significant changes in our life. In this paper, we provide some new idea and new method about wireless sensor networks based on the study of authors, the main content of this dissertation is as follows:1. Network architecture of WSN which serves mobile robots has been studied. Hiberarchy is accepted to achieve information access between mobile robots and WSN. Based on the information access, robots implement their tasks such as navigation.2. Research has been done on Clustering routing protocol. Firstly, a routing protocol based on QoS was suggestted, in which the dual cluster-head model was adopted to improve the reliability and the steadiness of wireless sensor networks. The dual cluster-head model helps the routing protocol to balance energy consumption in all nodes and to avoid congestion at cluster-heads by distributing evenly nodes in all clusters:Secondly we developed a two-phase cluster formation algorithm, which was energy-aware. A local-centralized mechanism was suggested to elect cluster-heads. This mechanism made the election of cluster-head more flexible and reasonable. This algorithm also achieved load balance by distributing evenly the nodes in clusters; Thirdly, the Dynamic Schedule Clustering Algorithm (DSCA) was proposed for clustering nodes in wireless sensor networks based on K-means. In the algorithm, the concept of synchronous failure of sensor nodes was present. Balanced clustering is achieved by using the K-means method, which forms the basis of balancing energy consumption. A new method was developed in DSCA to get the centroid of a cluster by Received Signal Strength Indicator information. DSCA suggestted a mechanism of dynamic multi-clusterhead election and a mechanism of dynamic Time Division Multiple Access communication load schedule that are both local-centralized. These mechanisms ensure highly balanced energy consumption and synchronous failure of nodes.3. Weighted Centroid Localization Algorithm Based on RSSI for Wireless Sensor Networks Localization of nodes is supported. By analyzing the model of radio wave propagation loss, this paper suggests a weighted coefficients, which are decided by the influence of beacons to unknown nodes, to prompt localization accuracy. A criterion which is used to select beacon nodes for computing the position of nodes is also suggested in order to improve localization accuracy more. The algorithm was simple and with low computational complexity and good localization accuracy.4. A hybrid localization algorithm (HLA) was proposed based on mobile beacons. The hybrid algorithm combined weighted least squares estimation with Extended Kalman Filter (EKF). Firstly, the algorithm got an inaccurate position coordinate of node by using weighted least squares estimation. Then the algorithm achieved an accurate localization of node by using Extended Kalman Filter. An approach was proposed to determine the weight exponent. And an optimal sorting solution of beacon position was proposed for EKF iteration.