Enhancing workers safety in worksites through augmented GNSS sensors

Human-assistive wearable technologies can monitor the position of a worker in a critical worksite and improve his safety by raising warnings when he is in a dangerous zone. In railway worksites, it is observed that GNSS localization is not applicable due to the relevant localization errors, which are only partially attributable to the specific characteristics of the worksite. Besides, alternative solutions that rely on the support of anchors have the drawback of lengthening the set-up and dismantle time of the worksite. To provide safe localization of railway trackside workers, a system that exploits augmented-GNSS wearable sensors is proposed. Each sensor includes a GPS receiver capable of sharing its coordinates with the other sensors, and is further complemented with a low-cost multi-way distance meter to measure its distance from the other sensors. The main attention is paid to the data fusion approach adopted to improve the accuracy of the position estimate by combining the relative distance measurements to the GPS coordinates.