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Article
Publication date: 19 January 2015

Liu Linxian, Zhang Wendong, Zhang Guojun, Guan Linggang, Xue Chenyang, Zhang Hui and Xue Nan

The purpose of this paper is to develop a novel MEMS vector hydrophone with the key features of smaller size, better consistency, higher sensitivity and directional…

Abstract

Purpose

The purpose of this paper is to develop a novel MEMS vector hydrophone with the key features of smaller size, better consistency, higher sensitivity and directional reception, and to develop a highly effective and economical obstacle avoidance sonar system. Currently, the typical vector hydrophones are resonant vector hydrophones based on the accelerometer, which greatly increases the volume and constrains the detection sensitivity. Also, because the system is composed of a number of devices, its size is difficult to be reduced.

Design/methodology/approach

A novel double T-shape MEMS vector hydrophone is proposed with a fish’s lateral line organs as prototypes. The structure size and layout location of the piezoresistors were determined by simulation analysis, and the double T-shape microstructure was fabricated integrally by MEMS manufacturing technology, after which, the acoustic package of the microstructure was completed and the prototype was produced. Finally, the packaged hydrophone was calibrated in a standing wave field in the first-class national-defense underwater acoustic calibration station of China. Also, the design and test of an obstacle avoidance sonar system based on the vector hydrophone were completed.

Findings

The calibration data show that the double T-shape vector hydrophone has a flat frequency response curve, exhibits a sensitivity of −180 dB (1 kHz, 0 dB reference 1 V/uPa) and shows a good directivity pattern in the form of an “8” shape. The test results of the obstacle avoidance sonar system further verify the feasibility of detecting underwater acoustic signals.

Research limitations/implications

The next work is to increase the sensitivity by optimizing the microstructure and to realize orientation by organizing array.

Practical implications

The hydrophone has the advantages of smaller size, lower cost and directional reception. It can be used to develop highly effective and economical obstacle avoidance sonar system, thus solving the problems of water transport efficiency and traffic safety. The hydrophone has broad application prospects and a huge market potential in the civilian fields.

Originality/value

The MEMS technology and innovative bionic microstructure enable the miniaturization and low cost of the hydrophone. The hydrophone is easy to form array and can narrow the array aperture greatly. So, the hydrophone can be widely used in civil sonar systems.

Details

Sensor Review, vol. 35 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 15 June 2015

Mengran Liu, Ze ming Jian, Guojun Zhang, Nan Guo and Wendong Zhang

The purpose of this paper is to present a novel nitrile butadiene rubber (NBR) packaging structure, which can solve the problems of the low sensitivity, narrow frequency…

Abstract

Purpose

The purpose of this paper is to present a novel nitrile butadiene rubber (NBR) packaging structure, which can solve the problems of the low sensitivity, narrow frequency band and fluctuating frequency response curve of the MEMS bionic vector hydrophone.

Design/methodology/approach

A 0.05-mm-thick NBR sound-transparent cap was designed by theoretical analysis and simulation to reduce the signal attenuation caused by the packaging structure, and the frequency band of the hydrophone has been extended to 4 kHz. In this work, the vector hydrophone was fabricated by the MEMS technology and packaged with the NBR sound-transparent cap. The performance indicators were calibrated in the National Defence Underwater Acoustics Calibration Laboratory of China.

Findings

The results show that the sensitivity of NBR-packaged hydrophone reaches −170 dB (±2 dB), and the difference is less than 1 dB compared to bare chip. And the frequency band is 50 Hz-4 kHz. The hydrophone also has good directional pattern in the form of an 8-shape, and the pressure-resisting ability is more than 2 MPa.

Originality/value

The packaging structure significantly increases the sensitivity of the hydrophone and broadens the frequency band, providing a new method in the packaging design for MEMS hydrophone.

Details

Sensor Review, vol. 35 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 31 March 2020

Zhenzhen Shang, Wendong Zhang, Guojun Zhang, Xiaoyong Zhang, Lansheng Zhang and Renxin Wang

The problem of port and starboard ambiguity will exist when only utilize the vector or scalar parameters. Meanwhile, the amplitude-phase error between the vector and…

Abstract

Purpose

The problem of port and starboard ambiguity will exist when only utilize the vector or scalar parameters. Meanwhile, the amplitude-phase error between the vector and scalar can also cause this problem. In this paper, a compound MEMS vector hydrophone which contains cilia vector microstructure and piezoelectric ceramic tube has been presented to solve the problem. Compared with traditional MEMS vector hydrophone, the compound MEMS vector hydrophone can realize the measurement of sound pressure and vibration velocity simultaneously.

Design/methodology/approach

A compound MEMS vector hydrophone has been presented. The unipolar directivity of the combined signal which combine the acoustic pressure and vibration velocity is used to achieve the direction of arrival (DOA). This paper introduced the working principle and the target detection mechanism of the compound vector hydrophone. The amplitude and phase error are analyzed and corrected in the standing wave tube. After that, the authors use beam-forming algorithm to estimate the DOA.

Findings

The experimental results in the standing wave tube and the external field verified the vector hydrophone's directional accuracy up to 1 and 5 degrees, respectively.

Practical implications

The research of compound vector hydrophone plays an important role in marine acoustic exploration and engineering applications.

Originality/value

This research provides a basis for MEMS hydrophone directivity theory. The compound vector hydrophone has been applied in the underwater location, with a huge market potential in underwater detection systems.

Article
Publication date: 5 December 2017

Yang Zi Kang, Chi Feng, Liang Zhi Liu, Shan Gao and Yan Cang

Hydroelectric power is widely used because it is environmental friendly, renewable and green. The cavitation is an inevitable phenomenon during the operation of hydro…

Abstract

Purpose

Hydroelectric power is widely used because it is environmental friendly, renewable and green. The cavitation is an inevitable phenomenon during the operation of hydro turbine, which is related to the efficiency and service life of the unit. This paper aims to discriminate the phenomenon of the incipient cavitation, prevent the early destruction and avoid the irreversible damage to hydro turbine.

Design/methodology/approach

The paper tries to find out the characteristics of cavitation entirely through a variety of features. The method comprises collection of the signals using a hydrophone, acceleration sensor and acoustic emission sensor; analyzing cavitation signal by using the way of wavelet time-frequency, peak factor and power spectral density; and comparing the different wavelet basis for analyzing signals and find the most suitable one.

Findings

The analyzed results show that the wavelet basis of morlet is more suitable for the cavitation signals. The hydrophone can distinguish the different operating conditions and discriminate the difference between the phenomenon of incipient cavitation and the other state of cavitation. The results show that when the hydrophone and acceleration sensors are used, the accuracy rate goes up to 75 per cent, which meets the requirements for the detection for incipient cavitation.

Originality/value

This paper focuses on finding the best sensor to discriminate the operating state of incipient cavitation to prevent early destruction.

Article
Publication date: 6 September 2019

Andreas Diermeier, Dirk Sindersberger, Peter Angele, Richard Kujat and Gareth John Monkman

Ultrasound is a well-established technology in medical science, though many of the conventional measurement systems (hydrophones and radiation force balances [RFBs]) often…

Abstract

Purpose

Ultrasound is a well-established technology in medical science, though many of the conventional measurement systems (hydrophones and radiation force balances [RFBs]) often lack accuracy and tend to be expensive. This is a significant problem where sensors must be considered to be “disposable” because they inevitably come into contact with biological fluids and expense increases dramatically in cases where a large number of sensors in array form are required. This is inevitably the case where ultrasound is to be used for the in vitro growth stimulation of a large plurality of biological samples in tissue engineering. Traditionally only a single excitation frequency is used (typically 1.5 MHz), but future research demands a larger choice of wavelengths for which a single broadband measurement transducer is desirable. Furthermore, because of implementation conditions there can also be large discrepancies between measurements. The purpose of this paper deals with a very cost-effective alternative to expensive RFBs and hydrophones.

Design/methodology/approach

Utilization of cost-effective piezoelectric elements as broadband sensors.

Findings

Very effective results with equivalent (if not better) accuracy than expensive alternatives.

Originality/value

This paper concentrates on how very cost-effective piezoelectric ultrasound transducers can be implemented as sensors for ultrasound power measurements with accuracy as good, if not better than those achievable using radiation force balances or hydrophones.

Article
Publication date: 1 March 1987

V.J. Hughes, J.G. Boulton, J.M. Coles, T.R. Empson and N.J. Kerry

A new type of hydrophone using optical technologies has distinct advantages over traditional types.

Abstract

A new type of hydrophone using optical technologies has distinct advantages over traditional types.

Details

Sensor Review, vol. 7 no. 3
Type: Research Article
ISSN: 0260-2288

Article
Publication date: 1 July 2006

Osama Hunaidi and Alex Wang

To introduce a new, low‐cost and easy‐to‐use leak detection system to help water utilities improve their effectiveness in locating leaks. The paper also presents an…

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Abstract

Purpose

To introduce a new, low‐cost and easy‐to‐use leak detection system to help water utilities improve their effectiveness in locating leaks. The paper also presents an overview of leakage management strategies including acoustic and other leak detection techniques.

Design/methodology/approach

The design approach was based on the use personal computers as a platform and enhanced signal processing algorithms. This eliminated the need for a major component of the usual hardware of leak pinpointing correlators which reduced the system's cost; made it easy to use, and improved the effectiveness of locating leaks in all types of pipes.

Findings

Effectiveness of the new leak detection system for pinpointing leaks was demonstrated using real world examples. The system has promising potential for all water utilities, including small and medium‐sized ones and utilities in developing countries.

Practical implications

The leak detection system presented in the paper will help all water utilities, including small and medium‐sized ones and utilities in developing countries, to save water by dramatically improving their effectiveness in locating leaks in all types of pipes.

Originality/value

The paper presents information about a new effective system for locating leaks in water distribution pipes. Effective leak detection tools are needed by water utilities worldwide.

Details

Management of Environmental Quality: An International Journal, vol. 17 no. 4
Type: Research Article
ISSN: 1477-7835

Keywords

Article
Publication date: 22 March 2013

Yanqiang Feng, Haijiang Zhu and Ping Yang

This paper aims to characterize the acoustic field radiated by the piston transducer and measure a few parameters through the data visualization method.

Abstract

Purpose

This paper aims to characterize the acoustic field radiated by the piston transducer and measure a few parameters through the data visualization method.

Design/methodology/approach

Using the theoretical model of the ultrasonic transducer, the acoustic field data were acquired by scanning the ultrasound field of the piston transducer. And the visualized graphs of the ultrasonic data were displayed through 3D graphs including slice, iso‐surface and volume rendering, respectively. Furthermore, a few parameters of the transducer including beam width and spread angle were measured using the visualized data.

Findings

The visualized graphs of the acoustic field radiated by the piston transducer show that the data visualization method can expose obviously the space distribution of the ultrasound field and describe directly the cylindrical shape. And this method provides the basis of reliable measurement and assess for the ultrasonic transducer.

Research limitations/implications

This paper presents a kind of measured method of the acoustic parameters using the visualized data. The measurement range has limitation.

Practical implications

This method is possible used in Medical ultrasonic.

Originality/value

This paper presents the visualized description of the acoustic field of the piston transducer and a measurement of two acoustic parameters using the visualized data.

Article
Publication date: 12 March 2018

Sepideh Yazdekhasti, Kalyan Ram Piratla, John C. Matthews, Abdul Khan and Sez Atamturktur

There has been a sustained interest over the past couple of decades in developing sophisticated leak detection techniques (LDTs) that are economical and reliable. Majority…

Abstract

Purpose

There has been a sustained interest over the past couple of decades in developing sophisticated leak detection techniques (LDTs) that are economical and reliable. Majority of current commercial LDTs are acoustics based and they are not equally suitable to all pipe materials and sizes. There is also limited knowledge on the comparative merits of such acoustics-based leak detection techniques (ALDTs). The purpose of this paper is to review six commercial ALDTs based on four decisive criteria and subsequently develop guidance for the optimal selection of an ALDT.

Design/methodology/approach

Numerous publications and field demonstration reports are reviewed for evaluating the performance of various ALDTs in this study to inform their optimal selection using an integrated multi-criteria decision analysis (MCDA) framework. The findings are validated using interviews of water utility experts.

Findings

The study approach and the findings will have a broad impact on the water utility industry by identifying a suite of suitable ALDTs for a range of typical application scenarios. The evaluated ALDTs include listening devices, noise loggers, leak-noise correlators, free-swimming acoustic, tethered acoustic, and acoustic emissions. The evaluation criteria include cost, reliability, access requirements, and the ability to quantify leakage severity. The guidance presented in this paper will support efficient decision making in water utility management to minimize pipeline leakage.

Originality/value

This study attempts to address the problem of severe dearth of performance data for pipeline inspection techniques. Performance data reported in the published literature on various ALDTs are appropriately aggregated and compared using a MCDA, while the uncertainty in performance data is addressed using the Monte Carlo simulation approach.

Details

Management of Environmental Quality: An International Journal, vol. 29 no. 2
Type: Research Article
ISSN: 1477-7835

Keywords

Article
Publication date: 30 March 2012

Fang Ji, Xiongliang Yao, Aman Zhang and Xi Ye

Laying the acoustic decoupling material on the surface of underwater structures is an effective noise reduction technology. The underwater sound radiation experiment of…

Abstract

Purpose

Laying the acoustic decoupling material on the surface of underwater structures is an effective noise reduction technology. The underwater sound radiation experiment of finite stiffened double cylindrical shell with separate‐sound and decoupled tile is carried out with the aim of finding out the most effective laying condition.

Design/methodology/approach

The segmentation power function interpolation method and vertex extreme value envelope continuation method are introduced into basic theory of empirical mode decomposition (EMD). The original measured sound pressure signals are decomposed to intrinsic mode function (IMF) group through EMD, and the high‐frequency components are filtered out. Because the mechanical noise of submarine is mainly at low frequency, the IMFs in low frequency are researched through power spectrum analysis. The noise reduction effects of different separate‐sound and decoupled tile laying conditions are compared.

Findings

The sound pressure signal components' amplitudes, periods and phases are obtained through EMD. The test data show that the double cylindrical shell entirely covered with separate‐sound and decoupled tile is the most effective laying condition in noise reduction.

Originality/value

With reference to the case study, this is believed to be the first application of the EMD in sound radiation time‐frequency characteristics of double cylindrical shell. The evaluation of separate‐sound and decoupled tile laying conditions is of great importance in engineering applications.

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