基于小波分解的水中电爆炸冲击波波形重建方法研究

Reconstruction method of shock wave shape of underwater electric explosion based on wavelet decomposition

水中金属丝电爆炸产生的冲击波,上升时间仅有数十纳秒,脉冲宽度仅为十几微秒,远小于化学炸药产生的冲击波,采用现有传感器对其进行精确测量非常困难。分析了冲击波波形形成过程,基于帕塞瓦尔时频域能量守恒定律,采用多尺度小波分解的方法,给出了一种冲击波波形重建方法。采用该方法对PCB138传感器实测的压力信号进行了重建,并与Müller-plate针式压力传感器得到的波形进行了比对。结果表明:重建后的信号更加接近真实波形,基于多尺度小波分解的波形重建算法,较基于傅立叶变换的重建算法,稳定性更好,准确度更高。

The rise time and pulse width of shock wave generated by electric explosion of metal wire in water are only several tens of nanoseconds and more than ten microseconds, they are far less than those of shock wave generated by chemical explosives. It is very difficult to accurately measure shock wave with existing sensors. Here, the process of shock wave shape formation was analyzed. Based on Parseval energy conservation law in time and frequency domains, a method of shock wave shape reconstruction was proposed by using the multi-scale wavelet decomposition method. This method was used to reconstruct the pressure signal measured with PCB138 sensor, and its waveform was compared with that obtained with Müller-plate needle type pressure sensor. The results showed that the reconstructed signal is closer to the actual waveform;the waveform reconstruction algorithm based on multi-scale wavelet decomposition has better stability and higher accuracy than the reconstruction algorithm based on Fourier transformation does.