基於卡爾曼濾波之加權式訊號強度主動式室內定位系統

Abstract

本論文為室內定位系統的實際實行，使用了ZIGBEE無線通訊技術為傳輸媒介，將無線訊號強度轉換成距離的方式來達成三角定位，ZIGBEE有高資料傳輸可靠度、低功耗、低成本、支援多樣性的網路架構(Star、Mesh和Cluster Tree)低功率、長距離體積小等特性，非常適合應用於室內定位的建構。室內的環境多樣化且複雜造成接收訊號強度受到多重路徑傳播效應(Multipath Propagation Effect)、遮蔽物干擾而影響接收訊號的大小使得傳統的三角定位法容易產生誤差。待定位目標離基地台愈近時因為中間的障礙物愈少所以愈不容易受干擾，我們依照此特性提出的主動式加權三角定位結合卡爾曼濾波器定位法，由待定位目標主動號傳送訊號至基地台以及對近距離的基地台的訊號強度做加權提升近距離內的定位效果，離基地較遠時則結合卡爾曼濾波器的遞迴數據法在雜訊環境中找出最佳的估測定位座標。運用此方法可以讓基地台密度減少、增加定位準確度、減少佈建成本。實作部份則使用了Jennic公司開發的ZIGBEE PRO模組作為開發平台，實驗結果可以減少約11%到20%定位誤差。

This thesis is the practical implementation of indoor positioning system, using wireless communication technology ZIGBEE transmission media, data transmission due to ZIGBEE high reliability, low power, low cost, support diversity, network infrastructure (Star, Mesh and Cluster Tree ), low-power long-distance and other characteristics, is ideally suited for the construction of indoor positioning. Due to diverse and complex indoor environment block the received signal and attenuated the received signal strength cause the traditional triangulation method is prone to error. When user closer to the base station will get more correct received signal strength since less of block between them, in accordance with this feature we developed an active weighted triangulation positioning combined with the Kalman filter, the use send signals to the base station and weighted the station's signal strength to enhance the positioning effect within a short distance, far away from the base is a combination of the Kalman filter recursive data in noise environment to find the best estimation location coordinates. The use of this method allows the base station density decreased, increasing positioning accuracy, reduce the cost of construction. This thesis uses the Jennic ZIGBEE PRO modules as a development platform, The experimental results can reduce the positioning error of about 11% to 20%.