Research Of Fire Detecting Nodes Based On Wireless Sensor Network

Wireless sensor network (WSN) consists of a large number of micro and low-cost sensor nodes in the monitoring area, which implement self-organize network automatically through wireless communication and can work in collaboration for collecting and processing and then transmitting the information of the monitoring area. In recent years, with the rapid development of embedded technology, semiconductor technology, sensor technology and wireless communication technology, wireless sensor network has been concerned widely. The research on WSN has become a worldwide focus. Wireless sensor network has a bright future in the application of environment monitoring, military sensing, health care, and commerce. As a new short-distance wireless communication protocol, Zigbee technology has the features of low complexity, low-cost and low power consumption, which make it more suitable for wireless sensor network.The development of fire detection technology is introduced and the system structure of WSN is described firstly. Then, the characteristics, some crucial technologies and domain application of WSN are summed up. The structure of protocol and characteristics of the wireless communication protocol-Zigbee are introduced in detail. The feasibility of fire detecting using wireless sensor network technology is discussed, and a design of wireless fire detecting nodes is proposed in this thesis, the solution of wireless fire detecting is provided in detail: the schematic circuit diagram of hardware is provided at first, including sensors of smoke and temperature, especially the circuit of RF interface of the CC2431 chip. Then the practical software implementation of the system is described with consideration of its low power consumption demand. The monitoring software based on LabVIEW is developed to collect fire parameters and analyze the parameters for fire alarm. At last, the fire detecting nodes are used to form a star network to detect smoke and temperature signals for fire detection testing, and then some capabilities of the system is analyzed. The experimental results show that the wireless fire detecting system can detect fire early and accurately according the complex parameter including temperature and smoke concentration.