Maximum non-Gaussianity parameters estimation of ultrasonic echoes and its application in ultrasonic non-destructive evaluation

摘要

The accurate estimation of the ultrasonic echo pattern is essential in ultrasonic non-destructive evaluation. In this paper, a generalized parametric ultrasonic echo mode was presented. It is influenced by a set of parameters: bandwidth, arrival time, center frequency, amplitude and phase. The maximum non-Gaussianity and amplitude (MNA) principle is used to estimate these parameters. Analytically, the MNA algorithm can estimate the echo parameters accurately. Furthermore, an optimal parameter matched filter is designed with the estimated parameters to eliminate the initial phase of the ultrasonic echo. As a result, only the correlated portion remained; then, the time of arrival (TOA) and/or time of flight (TOF) of each echo can be estimated directly from the radio frequency representation of the processed ultrasonic signals. Numerical simulation and experimental results show that the optimal parameter matched filter is effective in noise suppression with improved detection signals and greater position estimation accuracy.