Evaluating UWB Localization Performance in Multi-Level Industrial Environments

Accurate indoor localization is a key requirement for safety-critical applications in industrial environments, particularly in vertically segmented buildings where operators move across multiple floors. Ultra-wideband (UWB) technology is recognized for its high positioning accuracy; however, non-line-of-sight (NLOS) conditions induced by thick floors and staircases remain a major challenge. This study experimentally evaluates the performance of UWB-based multilateration in a two-floor industrial-like environment, focusing on the impact of anchor placement on localization accuracy and coverage. A set of controlled experiments was conducted using UWB anchors deployed across different floors and zones. Results show that using only four anchors on a single floor fails to provide reliable multi-floor localization, with positioning errors exceeding 1.7 m in second floor area. By contrast, deploying additional anchors on the upper floor significantly improves performance, reducing the mean localization error to approximately 22 cm and achieving full trajectory coverage. These findings highlight the critical role of vertical anchor distribution and provide practical guidelines for UWB deployment in complex industrial environments.