蛙人呼吸特征实验研究

Experimental study of frogman breathing features

为研究蛙人的声辐射特性,对蛙人的被动探测及其警戒系统的建立提供数据与实验支撑,进行了以携带开放式呼吸器的蛙人为对象的实验研究。通过湖上实验,采集了蛙人的呼吸声信号,利用功率谱、时域波形包络、包络谱对信号的时频特征进行了分析。结果认为蛙人的功率谱在低频段起伏比较明显,高频段比较平稳;高频段时域波形包络比低频段时域波形包络呈现更加明显的周期性,周期约为3s;时域波形的包络谱在0.3~0.4Hz之间有一个明显的峰值,此特征可作为识别蛙人的重要依据之一。采用包络谱法提取信号特征时,信号的高频段是理想选择,并且信号周期在10个以上时效果较好。

In order to study the sound radiation features of frogman, as well as to provide data and experimental supports to passive detection, a frogman equipped with an open-circuit scuba was selected as a study object for lake trail. Breathing signals of the frogman were acquired during the trail, and the time and frequency domain features were analyzed by utilizing power spectrum, time domain waveform envelop, and waveform envelop spectrum. The results show that power spectrum of the breathing signal is fluctuated much heavier in low frequency band than that in high frequency band, while the periodicity of the time domain waveform envelop in high frequency band is more obvious（the duration is about 3s）. The time domain waveform envelop spectrum has a distinct peak between 0.3Hz and 0.4Hz, this feature can be used as one of the important bases to identify frogman. When use the waveform envelop spectrum method to extract the signal features, high frequency band and more than 10 signal cycles are better choices.