Title :
Estimating Time-of-Flight of Multi-superimposed Ultrasonic Echo Signal through Envelope
Author_Institution :
Coll. of Inf. Sci. & Eng., Guangxi Univ. for Nat., Nanning, China
Abstract :
The accurate estimation of ultrasonic Time-Of-Flight (TOF) is essential in ultrasonic non-destructive testing (NDT). In this paper, a new method for TOF estimation through envelope is proposed. Firstly, the Hilbert transform (HT) is used in ultrasonic signal processing in order to extract the envelope of the echo and to reduce the computational burden. Then, the wavelet denoising technique is applied to the extracted noisy envelope to improve the estimation accuracy. Finally, the Space Alternating Generalized Expectation-Maximization (SAGE) algorithm is adopted to estimate the parameters of M-superimposed echoes. Numerical simulation and experimental results have been carried out to show the performances of the proposed method in estimating TOF of ultrasonic signal.
Keywords :
Hilbert transforms; acoustic signal processing; echo suppression; expectation-maximisation algorithm; nondestructive testing; signal denoising; wavelet transforms; HT; Hilbert transform; SAGE algorithm; computational burden reduction; echo envelope extraction; multisuperimposed ultrasonic echo signal TOF estimation; noisy envelope extraction; numerical simulation; space alternating generalized expectation-maximization algorithm; time-of-flight estimation; ultrasonic NDT; ultrasonic nondestructive testing; ultrasonic signal processing; wavelet denoising technique; Accuracy; Acoustics; Bandwidth; Estimation; Materials; Noise; Parameter estimation;
Conference_Titel :
Computational Intelligence and Communication Networks (CICN), 2014 International Conference on
Print_ISBN :
978-1-4799-6928-9
DOI :
10.1109/CICN.2014.74
