Design And Implementation Of Triple Band Infrared Flame Detection System

With rapid development of fire-protection industry and the improvement of fire-protection awareness in special field, modern infrared flame detection technology has obtained rapid development. The triple band infrared flame detection system studied in this thesis is a part of intelligent fire detection equipment. It uses advanced MIR technology and three different wavelength infrared sensors with narrow-band. One sensor works in the central wavelength which shows the fire information, the other two monitor the rest of infrared radiation in the environment. According to the characteristics of flame fluctuation, only the flame with characteristics of the radiation spectrum will be recognized as a actual fire, and the other false alarm signals caused by interference factor will be excluded by the high performance microprocessor and advanced mathematical algorithm model operation analysis. This detector has good inhibition by sunlight, lightning, welding, artificial light source, environment (human activities, etc.), thermal radiation, electromagnetic interference, and mechanical vibration interference, so that the flame signals can be responded fast and identified accurately.The process of flame signal and anti-interference analysis is achieved in this thesis. Based on Multisim circuit simulation software, the front amplifer circuit of pyroelectric sensor is designed. With FFT and the special time-domain algorithm, flame signal judgment and interference signal cancellation is realized in software design. The hardware circuit uses four-layer circuit boards, to achieving the strength of signal isolation and reducing the system’s interference.RS-485interface and GPRS were included to achieving the function of remote monitoring and controlling for terminal detector.Finally, flame detection system algorithm, system displays, data storage and event recording functions were tested in laboratory and on-site. The results can meet the technical requirements. System is of features of high accuracy, strong anti-interference ability, and reliable.