水下气动发射装置振动信号的时频分析

为研究某型水下气动发射装置的振动特性,对发射管的径向加速度信号进行了短时Fourier变换分析,结合内弹道过程发现:发射管的径向加速度振动信号主要由两个时频区组成。时频区1为发射管充压、密封片剪断和弹药刚开始运动的内弹道阶段,该部分信号主振频率在1 400 Hz附近,高频成分一直延伸至约5 000 Hz,信号持续时间约0.038 s。时频区2为弹药已出管、发射管泄压阶段,该部分信号持续时间为0.016 s,主振频率在1 100 Hz附近。对加速度信号进行小波包能量谱分析,结果表明:时频区1信号能量占发射过程总能量的79%,时频区2能量占总能量的10%。因此,时频区1振动为整个发射振动信号的主要成分。

Time frequency Analysis on the Vibration Signals of an Underwater Launch Model

The vibration characteristics of an underwater pneumatic launcher model were studied. Short-time Fourier transform method was used to analyze the radial acceleration signals of the launching tube. Combined the interior ballistic process, it was shown that the vibration signals contained two parts. Part 1 was mainly caused by the inflating of the launch tube, the cutting-off of the sealing metal film and the starting to move of the weapon. A main vibration frequency of 1 400 Hz was found with high frequency components reaching about 5 000 Hz and a duration time of about 0.038 s. Part 2 was caused mainly by the emitting of the weapon from the launch tube and the deflating process of the chamber pressure, with a main vibration frequency of 1 100 Hz and a duration time of 0.016 s. The energy spectrum of wavelet packet transform indicated that the energy percentages of part 1 and part 2 were 79% and 10% of the total, respectively. Therefore part 1 of the vibration signals has main contribution to the whole vibration of the launching process.