振动声窄带信号采集与分析

水下航行体的振动、声信号采集处理是分析水下航行体振动噪声情况的重要过程,很多情况下采集分析的振动噪声信号为高频窄带信号。实航时采集记录设备采用同步实时有限数据采集记录速率的采集记录仪,利用Nyquist 定理的常规信号采集方法要求高频数据抽样将导致大量的数据存储和处理,增加了采集分析软硬件的成本。根据振动声高频窄带信号的特征,本文介绍了振动噪声高频窄带信号采集方法,信号复原及处理过程。通过对振动噪声实测数据进行处理分析,结果表明,当高频窄带信号采集前的带通滤波器的滤波效果不低于50 dB时,利用本文所介绍的振动噪声高频窄带信号采集方法可完全恢复振动噪声高频信号的信息,且数据采样频率可至少降低4倍。

Acquisition and Analysis of Vibration and Noise Narrow-Band Signal in Undersea Vehicle

Acquisition and process of the vibration and noise signal in undersea vehicle are important to analyze the vibration and noise. In many cases, the collected signals are of high-frequency and narrow-band. During sea trials, the data acquisition and recording equipment is a synchronous real-time recorder with limited data acquisition and recording rate. If signal data are acquired by using conventional signal acquisition method based on Nyquist theorem, the amount of the data is large and the processing cost is high. Therefore, this paper presents a vibration and noise narrow-band signal acquisition method, and the procedure for restoring and processing signal according to the characteristic of the narrow-band signal. The tested data processing results show that the proposed narrow-band signal acquisition method can wholly restore the high-frequency signal information with the sampling frequency four-time less than that of the conventional method when the filtering result of the band-pass filter is at least 50 dB.