Improving dynamic proximity sensing and processing for smart work-zone safety

- We used Bluetooth Low Energy to develop a proximity sensing and alert system.
- A method was developed to address signal delay of proximity sensing and alert systems.
- Another method addressed the issue of inconsistent performance of the systems.
- We conducted a multitude of field trials to assess the performance of the BLE system.
- The methods showed improved performance with respect to delay and inconsistency.

Equipment/vehicles striking workers is one of the most frequent accidents that occur in roadway workzones. As a means of prevention, a number of active technologies have been developed to provide proximity sensing and alerts for workers and equipment operators. However, most of these systems are based on the distance/proximity level between workers and equipment and neglect the variations caused by different settings and environmental conditions, such as equipment types and approaching speeds, which can result in inconsistency and delay of the systems. As of yet, previous research has insufficiently investigated these issues. This research addresses the issues by utilizing the Bluetooth Low Energy (BLE)-based proximity sensing and alert system developed by the authors. This paper discusses the development and assessment of parameter adjustment and adaptive signal processing (ASP) methods. The research conducted field trials in various dynamic conditions and settings to assess the performance of the system. The test results showed that the parameter adjustment function reduced the inconsistency of the alert distances resulting from different types of equipment, and that the ASP method reduced the time delay resulting from high approaching speeds. The developed proximity safety alerts system provides stakeholders with better understanding of dynamic spatial relationships among equipment, operator, workers, and a surrounding work environment; thus, improving construction work zone safety.