Travel-Time Ultrasonic Computed Tomography Applied to Quantitative 2-D Imaging of Standing Trees: A Comparative Numerical Modeling Study

Arciniegas, Andres; Brancheriau, Loïc; Gallet, Philippe; Lasaygues, Philippe

doi:10.3813/aaa.918781

Cited by 8 publications

(7 citation statements)

References 25 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Threshold level for the received signal had to be defined above the noise level [16]. The threshold level is defined to be m times the standard deviation of the noise, with m as a user-defined parameter.…”

Section: Thresholdmentioning

confidence: 99%

See 1 more Smart Citation

Accuracy on the Time-of-Flight Estimation for Ultrasonic Waves Applied to Non-Destructive Evaluation of Standing Trees: A Comparative Experimental Study

Espinosa¹,

Bacca²,

Prieto³

et al. 2018

Acta Acustica united with Acustica

View full text Add to dashboard Cite

Time-of-flight measurement is a critical step to per-2 form ultrasonic non-destructive testing of standing 3 trees, with direct influence on the precision of de-4 fect detection. Aiming to increase the accuracy on 5 the estimation, the characteristics of the ultrasonic 6 measurement chain should be adapted to the con-7 straints of wood testing in living condition. This 8 study focused on the excitation signal parameters, 9 such as shape, temporal duration, and frequency re-10 sponse, and then the selection of a suitable time-11 of-flight determination technique. A standing plane 12 tree was tested, placing ultrasonic receivers at four 13 different positions, with five different excitation sig-14 nals and three time-of-flight detection methods. The 15 proposed ultrasonic chain of measurement resulted in 16 high signal-to-noise ratios in received signals for all 17 configurations. A time-frequency analysis was used 18 to determine the power distribution in the frequency 19 domain, showing that only chirp signal could concen-20 trate the power around the resonant frequency of the 21 sensor. Threshold and Akaike information criterion 22 method performed similar for impulsive signals with 23 decreasing uncertainty as sensor position approached 24 to the radial direction. Those two methods failed to 25 accurate determine time-of-flight for Gaussian pulse 26 and chirp signals. Cross-correlation was only suitable 27 for the chirp signal, presenting the lower uncertainty 28 values among all configurations.

show abstract

Section: Thresholdmentioning

confidence: 99%

“…Considering 2D imaging, ultrasonic tomography is one of the techniques used for non-destructive control of standing trees [12,13,14,15,16,17,18]. This method consists on cross-sectional imaging from the tree trunk using either reflection or transmission wave propagation data.…”

mentioning

confidence: 99%

Accuracy on the Time-of-Flight Estimation for Ultrasonic Waves Applied to Non-Destructive Evaluation of Standing Trees: A Comparative Experimental Study

Espinosa¹,

Bacca²,

Prieto³

et al. 2018

Acta Acustica united with Acustica

View full text Add to dashboard Cite

show abstract

“…Several factors influence the quality of the acoustic and ultrasonic images [10]. The number of sensors, for example, is directly related to the spatial resolution of the image; a larger number of sensors allows a smaller defective area detection [11,12]. The excitation signal used for testing is directly related to the precision of the TOF estimation, affecting the image reconstruction method [13,14].…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic imaging of standing trees: factors influencing the decay detection

Espinosa

Prieto

Brancheriau

et al. 2019

2019 XXII Symposium on Image, Signal Processing and Artificial Vision (STSIVA)

View full text Add to dashboard Cite

Ultrasound Computed Tomography is a widely used technique for nondestructive control of materials. One application is the evaluation of the inner state of standing trees in urban areas. The quality of the tomographic image depends on several factors, such as the number of probes used and the image reconstruction algorithm. Here we are interested in evaluating the influence of using a reconstruction algorithm adapted to wood anisotropy, compared to the classic methods using an isotropic model, and the effect of numerically increasing the number of sensors and the time-of-flight measurements using an interpolation method, known as sinogram interpolation. A numerical configuration was tested, simulating the presence of an eccentric defect in a wood section. Reconstructed images were compared before and after the interpolation process, and a thresholding was applied to quantify the decay area estimation. A more detailed defect identification was obtained with the reconstruction algorithm adapted to wood anisotropy and the interpolation of the sensors.

show abstract

“…Several approaches have already been proposed to solve this problem including filtering, spectrum analysis, and a deconvolution-based method based on a characteristic transfer function of the experimental device. The main drawback of the most precise algorithms is the heavy computational cost, which makes them incompatible with automatic processing of a large number of data [5].…”

Section: Introductionmentioning

confidence: 99%

“…Even if the coded excitation methods are a way to improve the SNR at the receiver, the study of the effect of noise is not included in the parameters to be controlled here. In previous studies, we analyzed some noise effects on experimental and numerical data [5], [15], [16]. The objective of this academic study is to compare the two methods on calibrated and clean wood samples, before testing uncalibrated natural medium and wooden logs.…”

Section: Introductionmentioning

confidence: 99%

Accuracy of coded excitation methods for measuring the time of flight: Application to ultrasonic characterization of wood samples

et al. 2018

View full text Add to dashboard Cite

Ultrasound computed tomography (USCT) using the transmission mode is a way to detect and assess the extent of decay in wood structures. The resolution of the ultrasonic image is closely related to the different anatomical features of wood. The complexity of the wave propagation process generates complex signals consisting of several wave packets with different signatures. Wave paths, depth dependencies, wave velocities or attenuations are often difficult to interpret. For this kind of assessment, the focus is generally on signal pre-processing. Several approaches have been used so far including filtering, spectrum analysis and a method involving deconvolution using a characteristic transfer function of the experimental device. However, all these approaches may be too sophisticated and/or unstable. The alternative methods proposed in this work are based on coded excitation, which makes it possible to process both local and general information available such as frequency and time parameters. Coded excitation is based on the filtering of the transmitted signal using a suitable electric input signal. The aim of the present study was to compare two coded-excitation methods, a chirp- and a wavelet-coded excitation method, to determine the time of flight of the ultrasonic wave, and to investigate the feasibility, the robustness and the precision of the measurement of geometrical and acoustical properties in laboratory conditions. To obtain control experimental data, the two methods were compared with the conventional ultrasonic pulse method. Experiments were conducted on a polyurethane resin sample and two samples of different wood species using two 500 kHz-transducers. The relative errors in the measurement of thickness compared with the results of caliper measurements ranged from 0.13% minimum for the wavelet-coded excitation method to 2.3% maximum for the chirp-coded excitation method. For the relative errors in the measurement of ultrasonic wave velocity, the coded excitation methods showed differences ranging from 0.24% minimum for the wavelet-coded excitation method to 2.62% maximum for the chirp-coded excitation method. Methods based on coded excitation algorithms thus enable accurate measurements of thickness and ultrasonic wave velocity in samples of wood species.

show abstract

Travel-Time Ultrasonic Computed Tomography Applied to Quantitative 2-D Imaging of Standing Trees: A Comparative Numerical Modeling Study

Cited by 8 publications

References 25 publications

Accuracy on the Time-of-Flight Estimation for Ultrasonic Waves Applied to Non-Destructive Evaluation of Standing Trees: A Comparative Experimental Study

Accuracy on the Time-of-Flight Estimation for Ultrasonic Waves Applied to Non-Destructive Evaluation of Standing Trees: A Comparative Experimental Study

Ultrasonic imaging of standing trees: factors influencing the decay detection

Accuracy of coded excitation methods for measuring the time of flight: Application to ultrasonic characterization of wood samples

Contact Info

Product

Resources

About