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DOA Estimation of Ultrasonic Signal by Indirect Phase Shift Determination

Kreczmer Bogdan

Archives of Acoustics

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2024

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Vol. 49, nr 1

107--120

EN

The paper presents the concept of the method of determining the direction of ultrasonic signal arrival, i.e., the azimuth and elevation angles. This method is an extension of the previous approach which was proposed to determine only the azimuth angle. The approach is based on the indirect phase determination. This makes it possible to tolerate spacing of receivers greater than half the wavelength of the received signal. At the same time, it provides increased measurement accuracy and reduced hardware requirements. To check the robustness of the method, simulations were carried out for the geometric arrangement of the receivers of the sonar module, for which the method was then implemented. This sonar module was used in the conducted experiments. The results of these simulations and experiments are included in the paper and discussed.

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Estimation of the Azimuth Angle of the Arrival Direction for an Ultrasonic Signal by Using Indirect Determination of the Phase Shift

Kreczmer Bogdan

Archives of Acoustics

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2019

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Vol. 44, No. 3

585--601

EN

The paper presents and discusses a method of azimuth determination of ultrasonic echo arrival in air. The basis of the presented approach is the assumption that the received signal is a narrowband one. In this way, the direction of the signal arrival can be determined based on its phase shift using two receivers. When the distance between the receivers exceeds half of the wavelength of the received signal, a problem of ambiguity in determining the angle of arrival arises. To solve this, a method using multiple pairs of receivers was used. Its robustness and temperature dependence is analysed. The most import ant advantages of the presented approach are simplified computations and low hardware requirements. Experimental data made it possible to show that for strong echoes, the accuracy is higher than 0.5°. In the case of weak echos, it is reduced to about 2°. Because the method is based on phase shift measurement, the ultrasonic sonar that uses this method can be compact in size. Moreover, owing to the theoretical analysis, certain properties of the mutual location of the receivers were found and formally proved. They are crucial for determining proper receivers’ inter-distances.

3

Azimuth angle determination for the arrival direction for an ultrasonic echo signal

Kreczmer B.

Journal of Automation Mobile Robotics and Intelligent Systems

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2017

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Vol. 11, No. 2

31--41

EN

In the paper, an idea of a method of signal arrival direction estimation is presented. The influence of time error measurements on the usage of the method is described. An approach to the problem of an increase in the robustness of the method is proposed. The results of experiments are presented and discussed.

4

Connections between object classification criteria using an ultrasonic bi-sonar system

Kreczmer B.

International Journal of Applied Mathematics and Computer Science

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2016

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Vol. 26, no. 1

123--132

EN

The paper presents connections between the criteria which make three types of objects possible to be recognized, namely, edges, planes and corners. These criteria can be applied while a binaural sonar system is used. It is shown that the criteria are specific forms of a general equation. The form of the equation depends on a single coefficient. In the paper, the meaning of this coefficient is discussed. The constructions of the arrangement of objects are presented and are bound with values of the coefficient.