2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Farnaz Sadeghpour, University of Calgary
Dr. George Jergeas , University of Calgary
Safety issues are an inherent concern in construction sites and assuring a safer working environment is a never-ending endeavor in construction projects. Increasingly, the applications of Real Time Location estimation Systems (RTLS) in safety management in construction sites are studied. Ultra-Wide Band (UWB), as one of the RTLS systems, has demonstrated great suitability for construction site conditions due to its higher static and dynamic accuracies lower dependency on the Line-Of-Site, and less signal attenuation and multipath effect in comparison to other systems. Nonetheless, the difficulty of relocating and reconfiguration of the readers from one location to another, requirements for time cables between readers for the location estimation algorithms, as well as the large cost of the system, greatly decrease the practicality of its use on construction sites. Under this circumstance, a new-generation UWB RTLS has emerged that seems to overcome the shortcoming of previous systems. The system consists of devices that are much smaller in scale. The infrastructure is much simpler, with devices that can be used interchangeably as a reader or a tag. In addition, unlike older systems, the specific location estimation algorithm utilized in this system does not require time cables for time synchronization of anchors and tags. This is very desirable for construction sites as it greatly decreases interference with the movements on sites and increase the speed of relocating readers as the construction progresses. The system is also significantly less expensive compared to the older systems. Typically with RTLS, such conveniences come at the cost of lower accuracy or strength of signal. The objective of this study is to investigate the feasibility of using the new generation of UWB RTLS on construction sites and measure its accuracy compared with the older generations. The specific subobjectives of this study are to (1) measure the location estimation accuracy of the new generation UWB RTLS in both static and dynamic modes; (2) investigate the sensitivity of configuration variables such as the setup angle and distance between the readers; (3) investigate the impact of Line-Of-Site and signal blockage on its accuracies. An interpolation algorithm was developed for error distribution in static tests. For the dynamic accuracy, a robotic Total Station was synchronized and integrated with the system. The results of these experiments will be discussed in detail and compared with those from the older systems to draw conclusions on the applicability of the new generation UWB RTLS in construction sites.