VIRTUAL SAFETY BOUNDARY FOR UWB SAFETY APPLICATIONS IN CONSTRUCTION SITE

摘要

The high rate of recorded injuries and fatalities in construction makes it one of the most hazardous industries in Canada. According to the Workers' Compensation Board of Canada, in the last ten years 11% of the lost-time injuries and 22% of the workplace fatalities were recorded on construction sites, rendering construction the industry with most fatalities in Canada. In recent years, researchers have investigated the potentials of automated real-time location estimation in identifying and preventing accidents on construction sites. Among various technologies, Ultrawide Band (UWB) is receiving special attention as it offers a high rate of accuracy. A number of conceptual safety models have been developed, where a Virtual Safety Boundary (VSB) is defined around moving resources, and potential accidents are detected when the VSBs between two resources overlap. As a result, the size selected for the VSB is an essential parameter to the functionality of such models. There is a trade-off between the size of the VSB and the reliability of accident detection; if the VSB is too small, accidents will be detected when objects are too close to each other, leaving little time for reaction from the involved parties. If the boundaries are too large, it could lead to continuous false alarms. The objective of this study is to evaluate how the accuracy of the UWB location estimation affects the size of the VSB, accounting for the moving speed of resources. The results of this study can be used for UWB-based safety models that are proposed for construction sites.