Introduction of measurement techniques in ultrasonic electronics: Basic principles and recent trends

Mizutani, Koichi; Wakatsuki, Naoto; Ebihara, Tadashi

doi:10.7567/jjap.55.07ka02

Cited by 28 publications

(25 citation statements)

References 595 publications

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“…This method is widely used to calculate the impulse response of an underwater channel. [12][13][14][15][16][17][18][19][20][21][22][23][24] One of the challenges in acoustic positioning is the occurrence of missing measurements and large errors in multipath environments. In a multipath environment, where multiple reflected waves exist in addition to the direct wave, the amplitude of a reflected wave may be larger than that of the direct wave due to interference between the reflected waves, as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Underwater acoustic positioning in multipath environment using time-of-flight signal group and database matching

Yoshihara¹,

Ebihara

Mizutani

et al. 2022

Jpn. J. Appl. Phys.

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One of the challenges in underwater acoustic positioning is the occurrence of missing measurements and large errors in multipath environments, such as shallow water and harbor areas. In this paper, we propose a new underwater positioning method for multipath environments by using direct wave arrival time groups and database matching. The proposed method accurately measures baseline length from the impulse response of the underwater channel by calculating time window groups that cover the propagation time from the sound source to each hydrophone in advance and then extracting only the impulse response around the propagation time of the direct waves when the sound source exists in a certain region of the measurement space. The performance of the proposed method was experimentally evaluated in a static environment. The results showed that the proposed method achieved an accuracy of 0.03 m and a precision of 0.02 m in a test tank.

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Section: Introductionmentioning

confidence: 99%

Underwater acoustic positioning in multipath environment using time-of-flight signal group and database matching

Yoshihara¹,

Ebihara

Mizutani

et al. 2022

Jpn. J. Appl. Phys.

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“…Ultrasonic sensors measure distance by measuring the time it takes for the sound to reach the receiver from the transmitter. [15][16][17][18][19] Various time-of-flight (ToF) measurement methods have been proposed by applying digital communication technology. [20][21][22][23][24][25][26][27] Numerical methods for moving sources have also been proposed for the design of sensors and measurement algorithms.…”

Section: Introductionmentioning

confidence: 99%

Indoor self-localization using multipath arrival time measured by a single acoustic ranging sensor

Tsuchiya

Wakatsuki

Ebihara

et al. 2022

Jpn. J. Appl. Phys.

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The objective of this study is to achieve vehicle self-localization using a single acoustic ranging sensor in a multipath environment. For this purpose, we proposed a measurement method of multiple Time-of-Flight (ToF) using an acoustic ranging sensor and a self-localization method using the ToFs. The proposed method predicts the ToFs based on the wall position and the predicted self-location and corrects the self-location by comparing it with the actual ToFs. Sound waves radiated indoors are reflected multiple times by every wall, ceiling, and floor. Therefore, the observed signal contains multiple reflected waves. Since the conventional method only considers a single reflection, self-localization becomes challenging in a multiple reflection environment. We showed that the estimation accuracy can be improved by utilizing the multiple reflections of sound waves in three-dimensional space and modeling them. The experiments confirm that the average location error of the proposed method is 0.084 m.

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“…3 × 10 2 m/s) is much slower than the speed of light (approx. 3×10 8 m/s) [21]. To exploit this difference in speed, the acoustic beacon emits encoded sound from beacons located on known locations.…”

Section: Introductionmentioning

confidence: 99%

Robust Indoor Localization in a Reverberant Environment Using Microphone Pairs and Asynchronous Acoustic Beacons

et al. 2019

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In this paper, a robust indoor localization method using microphone pairs and asynchronous acoustic beacons was proposed. The proposed method is applicable even with a two-channel microphone pair, which is the minimal configuration of a microphone array. The proposed method estimates location by using the cross-correlation functions of the measured signals as location likelihoods. Three experiments were conducted to evaluate the proposed method. Four beacons were located at the corners of a localizing area of 4 m by 4 m and emitted signals with a bandwidth of 2 kHz. The localization results were compared to the previous method with deterministic direction-of-arrival estimation. The 90th percentiles of the localization error were 0.23 m for the proposed method with two microphones, 0.19 m for the proposed method with four microphones, and 0.30 m for the previous method under conditions without significant reverberation. Under a condition with reflective walls, the 90th percentile of the localization error of the previous method increased to 0.49 m, while that of the proposed method was only increased to 0.23 m for two microphones and 0.19 m for four microphones. The proposed method contributes to a robust localization in indoor environments and relieves the constraints of receiver configuration.INDEX TERMS Acoustic beacons, cross correlation, indoor localization, microphone pairs, particle filter.

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Introduction of measurement techniques in ultrasonic electronics: Basic principles and recent trends

Cited by 28 publications

References 595 publications

Underwater acoustic positioning in multipath environment using time-of-flight signal group and database matching

Underwater acoustic positioning in multipath environment using time-of-flight signal group and database matching

Indoor self-localization using multipath arrival time measured by a single acoustic ranging sensor

Robust Indoor Localization in a Reverberant Environment Using Microphone Pairs and Asynchronous Acoustic Beacons

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