Development of a server-independent algorithm for safe evacuation systems utilizing exit signs

A smart exit-sign system is an exit-sign system that can proactively orient the direction of an exit sign toward the shortest safe path in fire situations. In a previous study, an automated direction setting algorithm for a smart exit sign was proposed that assumed the exit signs were controlled by the main central server. This study proposes a new direction setting algorithm for a server-independent smart exit-sign system. The server-independent direction setting algorithm (SIDSA) can be divided into four main steps once the smart exit-sign system is installed and initialized: (1) update of the fire-status information detected by a sensor; (2) sharing of the fire-status information with neighboring exit-sign modules; (3) update of the shortest-path (distance) information according to the fire situation; (4) update of the direction on the display board. SIDSA has been validated through multiple simulations.