A study on MEMS vector hydrophone and its orientation algorithm

Sensor Review ◽  
2020 ◽  
Vol 40 (2) ◽  
pp. 191-201
Author(s):  
Zhenzhen Shang ◽  
Wendong Zhang ◽  
Guojun Zhang ◽  
Xiaoyong Zhang ◽  
Lansheng Zhang ◽  
...  
Keyword(s):  
Standing Wave ◽  
Phase Error ◽  
Market Potential ◽  
Vibration Velocity ◽  
Wave Tube ◽  
Detection Mechanism ◽  
Content Type ◽  
Detection Systems ◽  
Vector Hydrophone ◽  
Standing Wave Tube

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.

A New Method to Measure the Absorption Coefficient of the Automotive Driving Room Based on the Sound Pressure Delaying

2011 ◽  
Vol 415-417 ◽  
pp. 1350-1354
Author(s):  
Cong Yun Zhu ◽  
Jian Ru Shi ◽  
Shu Feng Yang
Keyword(s):  
Absorption Coefficient ◽  
Standing Wave ◽  
Sound Pressure ◽  
Measurement Methods ◽  
The Other ◽  
New Method ◽  
Wave Tube ◽  
Absorption Function ◽  
Equal Distance ◽  
Standing Wave Tube

Absorption coefficient is an important parameter of the absorption function of the absorption material. Traditional measurement methods of absorption coefficient are standing wave tube and reverberation which have some shortcomings. In this paper, phase of the sound pressure measured by two equal distance microphones placed in the front of the absorption material is delayed in order to attain the absorption coefficient. At the last, an experiment for one absorption material is carried out, the experiment results compare with the results of the other methods above mentioned that denotes that the theory is correct and practicable.

Research on double T-shape MEMS bionic vector hydrophone and its application in obstacle avoidance sonar

Sensor Review ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Liu Linxian ◽  
Zhang Wendong ◽  
Zhang Guojun ◽  
Guan Linggang ◽  
Xue Chenyang ◽  
...  
Keyword(s):  
Obstacle Avoidance ◽  
Traffic Safety ◽  
Market Potential ◽  
Detection Sensitivity ◽  
Calibration Data ◽  
Underwater Acoustic ◽  
Content Type ◽  
Sonar System ◽  
Vector Hydrophone ◽  
Highly Effective

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.

Compressible flow of liquid in a standing wave tube

2005 ◽  
Vol 536 ◽  
pp. 321-345 ◽  
Author(s):  
YOUNGSHIK SHIN ◽  
JAEWON CHUNG ◽  
NICK KLADIAS ◽  
ELIAS PANIDES ◽  
GERALD A. DOMOTO ◽  
...  
Keyword(s):  
Compressible Flow ◽  
Standing Wave ◽  
Wave Tube ◽  
Standing Wave Tube

Sound Absorption Properties of Polyester Fibers Needle-Punched Nonwoven Fabrics

2011 ◽  
Vol 332-334 ◽  
pp. 1300-1303
Author(s):  
Ke Tian Guan ◽  
Xu Pin Zhuang ◽  
Xiao Ning Jiao ◽  
Men Qin Li ◽  
Hong Jun Li ◽  
...  
Keyword(s):  
Surface Structure ◽  
Standing Wave ◽  
Sound Absorption ◽  
Fiber Diameter ◽  
Absorption Property ◽  
Wave Tube ◽  
Absorption Properties ◽  
Nonwoven Fabrics ◽  
Polyester Fibers ◽  
Standing Wave Tube

Polyester fiber needle-punched nonwovens with different structures were manufactured and their sound absorption properties were examined using the standing wave tube method. The results show that the sound absorption property of the nonwovens depends on their thickness, needling intensity, fiber diameter and surface structure.

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