Particle Filter Localization Algorithm Based on LOS Possibility for Smart Vehicle Digital Key.

The new generation of digital key technology for smart vehicles imposes increasingly stringent demands on localization accuracy and security. The conventional trilateration method based on least squares is adversely affected by Non-Line-Of-Sight (NLOS), resulting in inadequate accuracy to meet the requirements. This paper presents a study on a UWB-based digital key localization algorithm for smart vehicles. We propose a localization method based on particle filtering called LOSP-PF, which leverages Line-Of-Sight (LOS) probability to enhance localization accuracy. LOSP-PF utilizes trilateration least squares error to characterize and assign LOS likelihood to Ultra-Wideband (UWB) anchors, incorporating this weighting into the particle weight assignment during posterior derivation in particle filtering. LOSP-PF eliminates the need for pre-calibration and does not rely on additional sensors. It solely relies on UWB ranging measurements for localization. Comparative analysis with the traditional PF localization algorithm demonstrates that LOSP-PF achieves accuracy improvements of 26.269%, 8.095%, and 7.928% for short, middle, and long distances, respectively.