Research On Node Location Of Wireless Sensor Networks And Information Management In Workshop

The research in this thesis stems from the needs of parts' management in the railway vehicle maintenance process in a railway vehicle maintenance workshop. The Wireless Sensor Networks have characteristics of low power consumption, low communication rate and can construct the network by themselves, and also it can wirelessly locate the nodes in the network. Based on the Wireless Sensor Network, this thesis integrates the wireless location technology and the information management technology into the wireless location management technique. Thus, the needs of location management by the maintenance workshop can be satisfied. The main contents of this paper are as follows:(1)Two positioning devices are designed and developed respectively through full-function nodes and tabbed nodes which are based on CC2430. The devices can be used to construct the positioning system, track and locate objects which are being monitored. Then the CC2430's power consumption modes are analyzed, and the battery life is gained by designing the operation mode of power-saving for location tags.(2) RSSI's ranging model parameters and effective measurement range of the positioning system are determined by experiments. In order to reduce the errors of location algorithms, a location algorithm by PSO which is based on distance weighted is designed, then this algorithm in the simulation environment of MATLAB is analyzed and compared with other algorithms. The results show that compared with the least squares by multilateral distance and the Min-Max algorithm, the PSO location algorithm based on distance weighted has less error. And the error of the location algorithm generally is decreased by 1.6%-12.8% compared to the normal PSO location algorithm.(3)Equipment firmware of the locating system is designed. This firmware can normalize the data format of serial communication ports, set the reference node coordinates and work-sleep time ratio, locate network nodes, automatically acquire the RSSI and the reference node coordinates, and realize information exchange between locating system and the top system management computer.(4)The software, the functions of which are positioning and monitoring, is designed and developed. It can be regarded as a wireless location system combines locating with visualization and information management. The results of this thesis show that the wireless locating management system based on RSSI has the advantages of simple locating theory, convenient region expansion and low power consumption, and is suitable for the management of parts information and location of their regions. The research expands the support field of information management technology, enriches the application forms of RSSI in manufacture, thus increases the productivity and efficiency of management information.