Dijkstra Algorithm Based Building Evacuation Recognition Computing and IoT System Design and Implementation

Large and complex buildings built in China in recent years, such as Olympic venues, airports, and large hospitals, have brought new fire evacuation problems. Many designs are using Internet of Things (IoT) technology to enhance buildings' perception of flames and smoke. In this paper, in addition to using IoT to improve the fire-awareness of buildings, a set of algorithms based on the Dijkstra's shortest path method is designed to operate on the local FPGA computing terminal to determine the current optimal evacuation path. An IoT system with an evacuation lighting system provides an optimal route indication for people in the building. Flame image recognition, smoke alarms and shortest path calculations are analyzed by the FPGA processor and all evacuation paths are updated every 10 seconds. The indicator system is implemented in the emergency lights, using LoRa low-power wireless communication, can update all emergency lights within 5 seconds, giving a new emergency route. The system was tested in the office building of Beijing University of Technology, which can effectively indicate the path under different fire conditions.