Research On Node Positioning Algorithms Based On Wireless Sensor Network

Wireless sensor network(WSN) is composed of a large number of sensor nodes with calculation, data processing and wireless communication functions, it is a distributed and self-organizing network, and sensor nodes accomplish the monitoring task in network coverage area by a collaborative way. As one of the key technologies of wireless sensor network, positioning technology is a necessary theoretical basis in a number of related research direction, location information of the monitored object is particularly important in the data monitor, data control and wireless communications in wireless sensor network, if the location information of nodes is uncertain, the work of researchers would be meaningless. So,how to be able to get accurate location information of the monitored object has become one of the hot issues of wireless sensor network.DV-Hop algorithm is a typical rang-free positioning algorithm of wireless sensor network, the algorithm is simple and easy to implement, and it does not require additional hardware devices. This article analyzes the factors of influencing the DV-Hop algorithm performance and does theoretical analysis and researches for the existing algorithm, and then it makes improvement for the deficiencies of the existing algorithms and tries to apply the improved algorithm to the three-dimensional space. This paper is now to be summarized as follows:This paper summarizes the research background, significance and status of wireless sensor network positioning technology, and then introduces the basic theory of positioning technologies, including the basic principles of positioning algorithm, classification and performance evaluation index, and later analyses the internal and external factors affecting the accuracy of positioning, it proposes beacon node selection algorithm to improve the DV-Hop algorithm after analyzing and researching a large amount of existing algorithms. This new algorithm uses the algorithm based on jump distance correction to improve the problem of large error of average hop-distance of beacon node in traditional DV-Hop algorithm, and then the calculated distance through using the average hop-distance will be closer to real distance.The three points non-collinear is the guarantee of positioning accuracy, so this article proposes beacon node selection algorithm on considering the influence of the distribution of beacon nodes to the positioning accuracy, and it makes the path between unknown node and involved positing beacon nodes more close to the straight line, so the measurement of distance will be more accurate. MATLAB simulation results show that the improved algorithm can be good to reduce positioning errors and improve positioning accuracy.In order to solve the problem of wireless sensor networks positioning in three-dimensional space, this article combines the improved particle swarm optimization with improved DV-Hop algorithm based on beacon node selection, and applies the new algorithm to the three-dimensional space. Since the network size in three dimensions will increase and nodes distribution is more complex, locations nodes need three-dimensional coordinateinformation, so we have high demand for the location algorithm. So this paper introduces improved particle swarm optimization of adaptive inertia weight at the end of the algorithm positioning stage, it makes the algorithm also has high global search ability and high positioning accuracy. The simulation results show that the improved algorithm can effectively locate in the three-dimensional space, and has higher positioning accuracy.