Assessment of UWB RTLS for Proximity Hazards Management in Construction Sites

According to statistics, the construction market is one of the most dangerous economic sector all around the world. Construction workers are continuously exposed to moving materials and machinery, often in constrained spaces, rising the risk of collision accidents. In this paper an Ultra-Wide Band (UWB) Real Time Location System (RTLS) designed in a previous work for proximity hazards management in construction sites is described in detail. An extensive measurement campaign have been carried out outdoor, using a square grid (15 m x 15 m) and 1 m step, for a total of 225 positions. For each position, 1000 location measures have been collected and the bidimensional localization resolution has been estimated. Results show that location resolution remains similar across the considered area and that it could be manually verified by construction workers. In optimal conditions, the resolution ranges are within 0.01 m and 0.05 m . The results highlight a major error contribution due to radio-frequency reflection interference, which makes impossible to measure positions under some conditions.