Research And Application Of Localization Technology Based On ZigBee Technology

Wireless sensor network technology can bring convenience to people's production and life, so it has been rapidly developed. ZigBee technology has been widely used in wireless sensor networks because it has a standardized protocol. ZigBee technology can be used to build low-cost wireless sensor networks. Location information of the nodes in the network plays an important role in wireless sensor network technology, so how to conveniently get the exact location has become a hot topic in present study. There have been some solutions for positioning problems, such as RSSI-based localization, TOA-based localization, TDOA-based localization, etc. But there are some flaws in these localization technologies, so further studies are still required to better solving the positioning problems in wireless sensor networks.Localization technologies in wireless sensor networks were studied in this paper. First, ZigBee technology and already existing position solutions in wireless sensor networks were introduced, and range-based localization algorithms were focused. Second, a kind of TDOA algorithm which is suitable for wireless sensor networks was proposed. For the localization algorithm, the stability of the clock frequency offset between different chips was used and the TDOA algorithm was combined. In this localization algorithm, the clock frequency offset of crystal oscillator in different chips was taken into account, and the location was calculated after converting time difference of arrived signal to the distance difference. By using the localization algorithm, the positioning problems in the more remote location could be effectively solved, and the time synchronization problem in wireless sensor networks could be avoided.At last, the programs of the ZigBee nodes were modified; the positioning experiments were designed. It was confirmed that the distance difference between the nodes became stable as the sample number increased and the satisfied location results could be achieved. That shows the algorithm is stable and feasible. The algorithm will lay the foundation for better solving the positioning problems in wireless sensor networks in the future.