Design And Implementation Of Upper Computer Software For Wireless Sensor Networks Localization System

Wireless sensor network(WSN) is one of the emerging hot spots at home and abroad currently. It can monitor and gather information of varieties of objects in real rime in the area of network distribution, which has a broad application prospect. Node localization technology is one of the most important support technology in the field of WSN, it is the basic guarantee for the widely using of wireless sensors. Node location information is not only a prerequisite event monitoring, but also a self-configuring and improve routing efficiency foundation in network topology. WSN deployment is random, due to layout environment and their own factors, how to maximize the localization accuracy and report to the observers with more accurate location information of the node is one of the most difficulties problem in the field of WSN locating research. Therefore, it is necessary to explore the low-cost positioning method based on WSN and the software implementation.Based on the analysis of development status of current position technology, this paper analyzed and compared the existing typical positioning algorithm and positioning systems, and studied on RSSI-based(Reveived Signal Strength Indicator) distance positioning technology of WSN, which has achieved the upper computer software based on the this technology. The main research work and results focus on the following aspects:(1) Since the existing signal propagation loss model are based on the theoretical research, and most of them does not give the corresponding environment measurement of variable parameters of the model. This paper studied on the WSN signal propagation, obtained the relation of RSSI value with the traveled distance through actual environment test, and fitted for the signal propagation loss propagation models with different antenna heights and transmits power under different conditions and signal loss parameter values of the model. And by the model we can calculate the distance between the unknown node and beacon node.(2) In order to reduce the ranging trilateral positioning accuracy error of the traditional RSSI-based location algorithms, this paper proposes a new trilateral positioning and centroid location algorithm, and this algorithm introduced the thought of centroid localization to trilateral positioning algorithm, through calculating the public areas of the center acquired by trilateral multiple node localization algorithm to improve the location estimation accuracy of the unknown node. Experimental results show that this algorithm can get smaller positioning error, compared with the traditional triangular positioning and centroid location algorithm and maximum likelihood estimation method. And in the positioning experimental results, the minimum error is only 0.14 m.(3) The upper computer software system use CC2530 nodes as hardware platform, it was designed and developed based on trilateral-centroid localization algorithm based on RSSI, and implemented the trajectory of the mobile node interface display and other functions. Finally, function testing was conducted on the upper computer software system. The experimental results showed that the positioning strategy has low hardware requirements and high practical value, which can meet the demand of the system better.