小波包分析法在提高冲击试验波形测量准确度中的应用

将小波包分析法(WPT)引入冲击试验测量波形的消噪处理.分别用傅里叶变换法、曲线拟合法、小波分析法和WPT对同一种含噪声波形进行消噪,计算了消噪后的波形参数.分析表明,噪声频率对消噪效果没有影响,曲线拟合法消噪的波形参数误差最大,WPT消噪的误差最小,而且对波前时间的影响不大,幅值基本与标准波形相同.通过对实际测量波形的消噪效果分析,验证了WPT的高效性和实用性.

Application of WPT Method for Improving the Measurement Precision of Impulse Current Waveform

The wavelet packet transform (WPT) method was proposed to de noise for the measured wave in the impulse current test. The four de noising methods, including the WPT method, the Fourier transform, the curve fitting and the wavelet transform method, were used to de noise for the same waveform with noise. Also, the de noised waveform parameters were calculated. The research indicates that the noise frequency has no impact on the de noising results. The error of waveform parameters de noised with WPT is the least. The influence on the wave front is little and the magnitude of de noised wave is almost the same with the standard wave. On the contrary, the error of de noised wave with curve fitting is the maximal. The investigation on the measured wave verifies that WPT is the most precise and practical method.