Flickering Signal Flame Detection Method Using a Matched Filter

Abstract

Flame combustion is a type of decomposition in which materials are combusted using oxygen in the air and a visible flame. During combustion, the respiratory process is detected as a flickering signal. Flame detectors recognize combustion by monitoring the generated infrared (IR) radiation. However, IR signals derived from artificial lighting and sunlight are also detected. Thus, a method for distinguishing nonflame-derived IR signals, such as artificial lighting, from flame-derived IR signals is required. In this study, a method for identifying a flickering signal using a matched filter that distinguishes between nonflame- and flame-derived IR signals was investigated. Matched filters selectively irradiate a frequency of the target signal by regulating the frequency of the waveform generator. When the frequencies of the inspection and flickering signal waveforms coincide, phase information may be obtained from the target waveform, and phase deviation may be minimized. Additionally, the magnitude of the detected IR signal, including the flickering signal, can be determined from the evaluation results of the waveform in the phase-locked state. Therefore, the flickering detection method using a matched waveform filter is effective for identifying IR signals and can be used as an economical fire detection method.