Directional enhancements for emergency navigation

We present a novel direction based shortest path search algorithm to guide evacuees during an emergency. It uses opportunistic communications (oppcomms) with low-cost wearable mobile nodes that can exchange packets at close range of a few to some tens of meters without help of an infrastructure. The algorithm seeks the shortest path to exits which are safest with regard to a hazard, and is integrated into an autonomous Emergency Support System (ESS) to guide evacuees in a built environment. The ESS that we propose, that includes the directional algorithm and the Oppcomms, are evaluated using simulation experiments with the DBES (Distributed Building Evacuation Simulator) tool by simulating a shopping centre where fire is spreading. The results show that the directional path finding algorithm can offer significant improvements for the evacuees. In particular, we see that the improved and more reliable communications offered by Oppcomms, especially when the number of evacuees is larger, can help to compensate for the effects of congestion and improve the overall success of the evacuation scheme. Throughout the simulations we observe improvements of a few percent, which can translate into a valuable number of more people that are safely evacuated when human lives and safety are at risk.