超声声表面波检测信号时差的倒频谱分析  

Cepstrum analysis method for surface acoustic wave signal time delay estimation

作　　者：闫晓玲[1,2] 董世运[2] 徐滨士[2] 刘彬[2] 王望龙[2] 

机构地区：[1]北京理工大学机械与车辆学院,北京100081 [2]装甲兵工程学院装备再制造技术国防科技重点实验室,北京100072

出　　处：《振动与冲击》2013年第12期159-162,共4页Journal of Vibration and Shock

基　　金：国家自然科学基金项目资助(50975287);国家973项目课题(2011CB013405)

摘　　要：采用超声表面波检测激光熔覆层残余应力时,表面波检测信号声时差的精确读取非常关键。传统的相关法无法精确地辨别表面超声波的声时差。文中提出基于复数倒频谱的表面超声波声时差辨别算法,采用该算法对计算机模拟信号和实际检测信号做了声时差分析,并与相关法的时间分析结果做了对比。计算机模拟和实验结果均表明,倒频谱分析方法是一种精度高,具有一定抗干扰能力的声时差估计算法。最后结合表面超声波检测信号的特点,从理论上分析了倒频谱分析方法优于相关法的原因。When residual stress in a laser cladding layer is measured by means of surface acoustic wave （SAW）, it is critical that the time delay of SAW signals can be read precisely. The time delay of SAW signals can＇t be estimated precisely with the traditional correlation analysis method. A time delay estimation algorithm based on complex cepstrum was proposed here, from computer simulations and test results it was shown that the new algorithm has a higher precision and a certain anti-jamming capability in comparison with the traditional correlation analysis method. According to the characteristics of SAW signals, the reason why the time delay estimation algorithm based on complex cepstrum is superior to the correlation analysis method was analyzed theoretically.

关 键 词：表面超声波 声时差 倒频谱 相关法 

分 类 号：O343[理学—固体力学] TB55[理学—力学]