Doppler frequency estimation using maximum likelihood function for low ultrasonic velocity profile

Thong-un, Natee; Wongsaroj, Wongsakorn; Treenuson, Weerachon; Chanwutitum, Jirasak; Kikura, Hiroshige

doi:10.1250/ast.38.268

Cited by 5 publications

(6 citation statements)

References 5 publications

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“…Firstly, evaluation of the performance of FFTbased frequency estimator in single-phase liquid flow. The accuracy of the technique was compared with other techniques such as Autocorrelation [9] and Maximum Likelihood Estimation [10]. The experiment was conducted with single-phase liquid (water) at flow rate 3 L/min and 6 L/min.…”

Section: Methodsmentioning

confidence: 99%

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Ultrasonic Measurement of Velocity Profile on Bubbly Flow Using Fast Fourier Transform (FFT) Technique

Wongsaroj

Hamdani

Thong-un

et al. 2017

IOP Conf. Ser.: Mater. Sci. Eng.

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Abstract. In two-phase bubbly flow, measurement of liquid and bubble velocity is a necessity to understand fluid characteristic. The conventional ultrasonic velocity profiler (UVP), which has been known as a nonintrusive measurement technique, can measure velocity profile of liquid and bubble simultaneously by applying a separation technique for both phases (liquid and bubble) and transparent test section is unnecessary. The aim of this study was to develop a new technique for separating liquid and bubble velocity data in UVP method to measure liquid and bubble velocity profiles separately. The technique employs only single resonant frequency transducer and a simple UVP system. An extra equipment is not required. Fast Fourier Transform (FFT) based frequency estimator paralleled with other signal processing techniques, which is called as proposed technique, was proposed to measure liquid and bubble velocity separately. The experimental facility of two-phase bubbly flow in the vertical pipe was constructed. Firstly, the Doppler frequency estimation by using the FFT technique was evaluated in single-phase liquid flow. Results showed that FFT technique showed a good agreement with autocorrelation and maximum likelihood estimator. Then, separation of liquid and bubble velocity was demonstrated experimentally in the two-phase bubbly flow. The proposed technique confirmed that liquid and bubble velocity could be measured efficiently.

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Section: Methodsmentioning

confidence: 99%

“…The maximum of signal amplitudes in each window are arranged in array form (ai) as equation (8) and (9) (10)  …”

Section: Separation Of Particle and Bubble Velocitymentioning

confidence: 99%

Ultrasonic Measurement of Velocity Profile on Bubbly Flow Using Fast Fourier Transform (FFT) Technique

Wongsaroj

Hamdani

Thong-un

et al. 2017

IOP Conf. Ser.: Mater. Sci. Eng.

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“…The objective was to estimate from a set of unknown parameter upon which the received signals depend. The MLE algorithm was first introduced to measure a flow rate of blood velocity [13] and then applied to the fluid engineering field [14]. The unknown frequency of MLE is interpreted as an estimator embodied in the observed data and the underlying PDF (assumed as noise).…”

Section: Introductionmentioning

confidence: 99%

“…Thus, the frequency estimator is referred to as the uniformly minimum variance unbiased estimator. The paper referred in [14] compared accuracy in FFT, AC, and MLE within only a profile of a low flow. Experimental results confirmed that MLE comparatively provides probability of flowrate measurement for a fully developed flow in a straight pipe with the UVP.…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study of Different Signal Processing Methods on Ultrasonic Velocity Profiles in a Single Phase Flow

Thong-un¹,

Wongsaroj²,

Treenuson³

et al. 2018

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Ultrasonic velocity profile (UVP) measurement methods have been continuously developed in the field of engineering. A UVP can visualize a fluid flow along a benchmark line. This provides a significant advantage over other conventional methods such as differential pressure, turbine, and vortex. This paper presents an experimental study of using different signal processing methods including autocorrelation (AC), fast Fourier transform (FFT), maximum likelihood estimation (MLE), multiple signal classification (MUSIC), and Estimation of signal parameter via rotational invariance technique (ESPRIT) under diverse situations as the number of pulse repetitions (Nprf), frequency of repetitions (fprf), velocity profiles, computation-time requirements and flowrates. Experimental results express that there is an optimal number and frequency of pulse repetitions for each signal processing method that depended on fprf, Nprf, and flowrate. Moreover, computation-time and statistical tests were verified from experimental results. From the comparisons, MLE was experimentally the best algorithm even though the trade-off of moderate computation-time requirements was realized. However, considering the optimization of both accuracy and computation-time consumption, MLE was determined as the preferred signal processing method based on UVP for estimating flowrate in a single phase flow.

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“…The conventional algorithms such as auto-correlation algorithm [1], cross-correlation algorithm [2] and maximum likelihood algorithm [3] are based on an idealized signal model. In this model, the residual clutter is not fully considered.…”

Section: Introductionmentioning

confidence: 99%

Online Algorithm for Velocity Estimation in Ultrasonic Doppler Measurement

Shang¹,

Hu²,

Du³

2018

Proceedings of the 2018 International Conference on Computer Science, Electronics and Communication Engineering (CSECE 2018)

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Ultrasonic Doppler technique is widely used for velocity estimation in medical electronic systems. This technique is signal-processing intensive with an increasing requirement on accuracy, real time and stability. The clutter caused by human tissues contains little information about blood flow velocity. Since conventional algorithms are based on an idealized signal model where the residual clutter is not fully considered, highperformance filters are required for clutter rejection in ultrasonic Doppler measurement. This paper focuses on how to extract the velocity information from ultrasonic echo signals without extra filters. We presented an online algorithm that identified the clutter as unknown parameters instead of filtering. The algorithm does not rely on the performance of extra clutter filters. Simulation results show that this algorithm is simpler and more stable than conventional correlation algorithms.

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Doppler frequency estimation using maximum likelihood function for low ultrasonic velocity profile

Cited by 5 publications

References 5 publications

Ultrasonic Measurement of Velocity Profile on Bubbly Flow Using Fast Fourier Transform (FFT) Technique

Ultrasonic Measurement of Velocity Profile on Bubbly Flow Using Fast Fourier Transform (FFT) Technique

An Experimental Study of Different Signal Processing Methods on Ultrasonic Velocity Profiles in a Single Phase Flow

Online Algorithm for Velocity Estimation in Ultrasonic Doppler Measurement

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