摘要
根据声弹性理论,将应力检测转化为超声波的传播时延估计,建立基于互相关时延估计的临界折射纵波(LCR波)应力检测系统。LCR波在发射、传播及接收过程中存在各种影响因素,这些因素导致接收到的LCR波波形及信噪比发生了较大变化。通过克拉美罗下界(CRLB)理论得到这些变化是限制时延估计精度的根本因素。利用MATLAB进行仿真验证,得到了不同的影响因素对时延估计精度的影响不同。
Based on the sound elasticity principle, stress measurement is transformed to time delay estimation of ultrasonic wave propagation,and a stress measurement system based on cross-correlation time delay estimation using critically refracted Longitudinal wave（LcR wave） is proposed in this paper. There are many factors effect greatly the waveform of LCR wave and the signal-to-noise ratio（SNR） during LCR wave being excited, propagated and received. Cram6r-rao lower bound（CRLB） is applied to track these effects fundamentally limit the accuracy of time delay estimation. After numerical analysis using MATLAB, it is indicated that different factors produce different effects on the precision of time delay estimation.
出处
《压电与声光》
CSCD
北大核心
2013年第1期24-28,共5页
Piezoelectrics & Acoustooptics
