Abstract:

Diverse sources of radio signal interference and the complex topology of mul$-level indoor structures o>en impede reliable posi$on tracking. Therefore, a solu$on based on a Pedestrian Dead- Reckoning (PDR) naviga$on module u$lizing high-frequency data from IMU, as well as two complementary technologies: BLE - employing RSSI-based distance es$ma$on and UWB, which relies on ToF signal, was proposed. The con$nuous, high-frequency mo$on tracking provided by the IMU was periodically corrected using absolute, though inherently noisy, radio-based measurements. This fusion strategy allowed for the mi$ga$on of dri> accumula$on, yielding a trajectory es$mate that remains both locally smooth over short intervals and globally accurate over extended dura$ons. An EKF served as the fusion mechanism, integra$ng rela$ve mo$on es$mates from the PDR with absolute posi$onal updates to perform a series of controlled experiments under diverse condi$ons. The analysis of the collected data revealed that the standalone PDR system exhibited a substan$al dri> error on average between 10% and 15% of the total traversed distance. Sensor fusion with BLE measurements significantly reduced this error, achieving a localiza$on accuracy of RMSE = 0.98 m. Under analogous condi$ons, the UWB-based system demonstrated a decisive advantage, reaching an accuracy level of RMSE = 0.21 m, corresponding to nearly a fivefold improvement compared to BLE. The experimental results confirm that UWB, when combined with sensor fusion frameworks, provides a balance among posi$onal accuracy and robustness to environmental disturbances, making it effec$ve for precise indoor localiza$on.