Efficient Hybrid Localization Research In Three-dimensional For Wireless Sensor Networks

Wireless Sensor Network(WSN) is a self-organized multi-hop network which is composed of a large number of wireless sensor nodes in the monitoring area. In recent years, with the development of technology, The application of wireless sensor network extends to the wider three-dimensional space, such as smart dust, marine environmental monitoring, which makes WSN has a broad application prospects. Location information is the premise for most applications so location technique is one of research hot spots. In recent years, Range-based algorithm works well in large scale application of WSN. With the improvement of energy requirements, Range-free algorithm has also been paid more and more attention.In the dissertation, an improved three-dimensional DV-Hop in the light of the characteristics of large-scale wireless sensor network in three-dimensional space is proposed. The algorithm limits hop count between nodes and introduces a weighting parameter to compute the one-hop distance. Finally, combined with Outside Coordinate System, positioning accuracy and coverage are improved significantly. After that, the dissertation summarizes advantages and disadvantages of both range-base and range-free algorithm and put forward a hybrid location algorithm and is improved to reduce its energy consumption. The main research contents are as follows:1. It studies the characteristics and structure of the network, key technologies and their applications, research status of WSN. It focus on both range-based and range-free typical localization techniques and their improvement techniques in three-dimensional space.2. It puts forward an actual WSN distribution model according to the characteristics of large-scale deployment in three-dimensional space. Based on this, it proposes the Gaussian distribution localization model in WSN。According to this model, a localization algorithm which is called DV-Hop-Cube, is proposed by correcting the method to calculate one hop distance and introducing the Outside Coordinate System. Results show that, compared to the classic three dimensional DV-hop algorithm, the proposed algorithm effectively improves the localization accuracy and coverage rate.3. It analyzes the advantages and disadvantages of two typical localization methods in three dimensional space. It improves the DV-Hop algorithm and RSSI algorithm by introducing coplanarity and error correct model. The improved DV-Hop algorithm and RSSI algorithm is called IDV-Hop and IRSSI respectively. After that, it proposes a hybrid localization algorithm called IHDR by Combining the IDV-Hop with IRSSI in both distance measurement and computation. Experimental results show that the algorithm combines the advantages of both and performances better in localization accuracy and coverage rate are improved.4. For the energy consumption and cost problems in large-scale WSN, it introduces the centralized method to improve the IDV-Hop’s routing mechanism and localization process. Analysis indicates that the improved hybrid localization algorithm can effectively reduce the energy consumption of communication and beacon node number and can effectively realize three-dimensional localization.