Providing Proximity Safety Alerts to Workers on Construction Sites Using Bluetooth Low Energy RTLS

Struck-by equipment is one of the main reasons of accidents on construction sites. In order to improve construction safety, previous research proposed using Real-Time Location Systems (RTLS) to track the location of workers and equipment on construction sites. However, using ultra-wideband RTLS on large sites is difficult because it needs many timing cables to synchronize the data of the sensors surrounding the site. Furthermore, providing safety alerts to workers within dangerous proximity to equipment has not been addressed in previous research. Instead, the alerts were sent only to the safety manager. This paper aims to develop a method for providing proximity safety alerts to workers on construction sites using Bluetooth Low Energy (BLE) RTLS. BLE RTLS can provide acceptable accuracy coupled with large coverage and without the need of timing cables. In addition, with the support of two-way communications between the tags and sensors, it is possible to provide vibro-tactile alerts to the workers using wristbands. A prototype system is developed to filter the location data and remove outliers using averaging over time and averaging over tags of the objects. A case study is applied on a construction site to demonstrate the feasibility and performance of the proposed method.