Dynamic Reference Anchor Selection for Enhanced TDoA-Based UWB Localization in Complex Scenarios

Previous studies on time difference of arrival (TDoA)-based ultra-wideband (UWB) localization typically employed an arbitrary and fixed reference anchor during the localization process. However, this scheme fails to maintain stable and high-quality performance in complex scenarios, since the localization of mobile targets suffers from multipath interference and the change in sensor-target geometry, while the reference anchor amplifies this effect. To address this issue, we present a dynamic reference anchor selection algorithm, which determines the reference anchor by evaluating the factor that fuses geographical factor and link quality. In addition, we integrate dynamic reference anchor selection into an optimized UWB localization approach to achieve high accuracy. The position is calculated by a constrained Taylor algorithm after UWB calibration and finally fine-tuned by a Kalman filter. The proposed approach was validated using data collected in both laboratory and office scenarios. The experimental results show that the 3D dynamic localization error of the proposed approach reaches 4.9 cm on average. The dynamic reference anchor selection algorithm we proposed improves the overall localization accuracy by 18.4 %, with a dominance of 87.8 % and 100 % in the laboratory and office scenario, respectively. Furthermore, the localization stability and reliability are also validated with a reduction in maximum localization error and avoidance of extreme outliers.