Design Of Intelligent Fire Fighting System Based On Wireless Networking Technology

Fire has become a frequent disaster in life,and people put forward higher demand on fire fighting system.Traditional wired transmission of the fire fighting system has problems such as complicated wiring and high installation and maintenance costs,which cannot meet the development needs of the fire fighting system.However,in large-scale applications,wireless fire fighting system using Zigbee,Wi Fi and other technologies have problems such as small coverage,poor networking capabilities,and high power consumption.The application of LoRa wireless networking technology for long-distance,low-power application scenarios in the fire fighting system has attracted more and more attention.This paper designs a intelligent fire fighting system based on LoRa wireless networking technology,realizes the software and hardware design of LoRa gateway,photoelectric smoke detector,combustible gas detector and human infrared detector,and designs LoRa wireless network protocol to enable these devices can be interconnected to monitor the coverage area in real time.And the LoRa gateway is embedded in the intelligent fire terminal to respond to the alarm in real time.The wireless transmission mode between the detector and the gateway reduces the difficulty of system installation and maintenance cost.Aiming at the low power consumption requirements of battery-powered terminal nodes in the fire fighting system,this paper designs low-power photoelectric smoke detectors and human infrared detectors from both software and hardware,and designs adaptive transmit power control algorithm based on RSSI(Received Signal Strength Indication)value correction.According to the wireless communication link state,the transmit power of two terminal nodes can be adjusted in real time to reduce the power consumption and prolong the service life of the device.Through the actual tests,the standby power consumption of the photoelectric smoke detector and the human infrared detector is 14.55 u A,the photoelectric smoke detector can be used for more than 5 years,and the human infrared detector can be used for more than 2 years.Aiming at the application requirements of the intelligent fire fighting system with large wireless network coverage,large number of nodes and high density,combined with the characteristics of actual application scenarios,this paper adpots a mesh topology structure and designs a multi-hop transmission mechanism to expand wireless network coverage and the number of nodes access.At the same time,a variety of network communication mechanisms such as a response mechanism,network detection mechanism and special data processing mechanism are designed to ensure the reliability of the system.Through the actual tests,the designed wireless network indoor horizontal communication distance is 150 meters,the vetical distance is 2 floors,and the communication delay is less than 1.2 seconds.