A Novel PDR Aided UWB Indoor Positioning Method

Abstract

Ultra-wide Band (UWB) plays an increasingly important role in indoor positioning due to its advantages of low emission power, high multipath resolution, and centimeter level positioning accuracy. However, the UWB system is vulnerable to Non-Line of Sight (NLOS) because of human or vehicle occlusion. In this paper, a novel Pedestrian Dead Reckoning (PDR) aided UWB indoor positioning method is proposed. Firstly, an NLOS accuracy factor model is constructed according to the distance difference between UWB and PDR. This accuracy factor judges whether UWB works normally or not. Once the accuracy factor exceeds a certain threshold, PDR positioning is adopted. Meanwhile, the direction and the position predicted by the extended extrapolation method from UWB are applied to provide the initial value for PDR processing. If the accuracy factor is within the threshold range, PDR is replaced by UWB. The experimental results show that the method proposed improves the positioning accuracy of UWB, and that the generalized extrapolation model can calculate more reliable initial values before PDR operates. The obtained results have validated that the proposed method can effectively restrain the impact of NLOS on stable and accurate positioning.