Analysing Ultra-Wide Band Positioning for Geofencing in a Safety Assurance Context

Abstract

There is a desire to move towards more flexible and automated factories. To enable this, we need to assure the safety of these dynamic factories. This safety assurance must be achieved in a manner that does not unnecessarily constrain the systems and thus negate the benefits of flexibility and automation. We previously developed a modular safety assurance approach, using safety contracts, as a way to achieve this. In this case study we show how this approach can be applied to Autonomous Guided Vehicles (AGV) operating as part of a dynamic factory and why it is necessary. We empirically evaluate commercial, indoor fog/edge localisation technology to provide geofencing for hazardous areas in a laboratory. The experiments determine how factors such as AGV speeds, tag transmission timings, control software and AGV capabilities affect the ability of the AGV to stop outside the hazardous areas. We describe how this approach could be used to create a safety case for the AGV operation.

Untethered Ultra-Wideband-Based Real-Time Locating System for Road-Worker Safety

“…As a solution, different works present untethered UWB systems for their use in construction sites [ 27 , 28 ] or as a safety system with a geofencing strategy [ 29 ]. However, the removal of synchronisation cables can come at the expense of poorer accuracy [ 28 ].…”

“…However, these types of solutions may have some drawbacks because of the difficulty of deploying an RTLS [ 11 ] and the dynamic nature of construction environments [ 12 ]. Most safety systems based on RTLS [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ] need to deploy some fixed sensors with known positions around the working environment and define safe and dangerous zones. Some time has to be spent fixing sensors where needed, measuring their positions and introducing the limits of the safe and danger zones to the system.…”