Design Of Wireless Fire Warning System Based On Composite Sensor

Fire accident is a serious threat to the safety of human life,and it has caused a lot of economic losses.With the development of economy and society,people’s lives and property safety are paid more and more attention.The national society puts forward higher requirements for fire monitoring and early warning.The traditional fire early warning method has the problems of single detection means,high false alarm rate,poor early warning effect and low intelligent degree,which need to be improved.In this paper,a wireless fire early warning system based on composite sensor is designed,which can accurately detect the temperature,CO and smoke in the monitoring site,and comprehensively process the sensor data to realize the fire early warning.The data of each sensor node is collected to the terminal host computer for real-time monitoring and storage.At the same time,this paper explores the ZigBee address allocation and routing algorithm,and proposes an optimization algorithm for the shortcomings of routing algorithm.The main work of this paper is as followsFirst of all,the paper analyzes several stages and characteristics of the fire,and defines the information to be monitored in fire early warning.The temperature detection module based on DS18B20,CO detection module based on MQ-7 and smoke detection module based on ADPD188 BI are designed.The smoke detection module is based on Lorenz-Mie scattering theory,use two-color light to detect smoke particles,and takes the power transmission ratio PTR as the output,which is compared with the preset threshold.The ratio of PTR corresponding to two-color light reflects the information of smoke particle size,which is used to distinguish different kinds of smoke.This paper analyzes the address allocation algorithm and routing algorithm of ZigBee,and optimizes the algorithm for the defects such as not optimal forwarding path,too many forwarding times and network storm caused by RREQ flooding.By using the neighbor table to find the best node,limiting the radius of RREQ broadcast,and introducing the path scoring mechanism in route selection,the network is optimized.The simulation using NS2.35 shows that the optimized algorithm reduces the energy consumption of the network,and reduces the data transmission delay and packet loss rate.Based on CC2530 chip,ZigBee mode is used to realize wireless sensor network ad hoc network.ZigBee core board,power supply,USB serial port conversion and other peripheral circuits are designed,and SMA antenna is used for RF transceiver.Using Z-Stack protocol stack,the mechanism of osal operating system is studied,and the software is written to realize the ZigBee wireless network ad hoc network.The terminal node collects data,forwards it through the routing node,summarizes it to the coordinator,and transmits it to PC through USB.Based on Lab VIEW,the upper computer program is compiled to display and save the data curve in real time.