木材无损检测技术中的应力波传播时延估计算法  

Stress wave propagation time estimation algorithm for nondestructive testing of wood

作　　者：张高品 李光辉[1] 李剑[1] 冯海林[1] 

机构地区：[1]浙江农林大学信息工程学院,浙江临安311300

出　　处：《浙江农林大学学报》2014年第3期394-398,共5页Journal of Zhejiang A&F University

基　　金：国家自然科学基金资助项目(61272313;61302185);浙江省科学技术公益性项目(2012C21015;2013C31018);浙江省国际合作项目(2013C24026)

摘　　要：为了准确测量应力波在木材内部的传播时间,提高木材内部缺陷识别的精度,提出了一种基于小波变换和高阶统计量的广义相关时延估计算法。该方法利用滤波算法,将采集到的应力波信号进行滤波去噪,然后输入到广义互相关时延模型,求出传播时延估计值。仿真和实际的木材检测实验结果表明:提出的算法比传统的定时器计时法时延估计精度提高81.5%,并具有较强的抗干扰能力。The purpose of this study is to measure the stress wave propagation time and improve the accuracy of identifying the internal decay of wood.An algorithm of stress wave propagation time estimation combining high order cumulants with wavelet transformation was presented.The proposed algorithm removed the noise of stress wave signal with filtering algorithm,then input the filtered signal to the generalized cross-correlation time delay model,and calculated the estimation of the stress wave propagation time.The results of simulation and experiments showed that the accuracy of the measured stress wave propagation time was improved by 81.5 per cent.Further more,under low,medium and high signal to noise ratios （SNR）,the experimental results demonstrated the anti-interference ability of the new algorithm.

关 键 词：木材学 应力波 木材无损检测 小波变换 高阶统计量 时延估计 

分 类 号：S781.5[农业科学—木材科学与技术]