Design and Analysis of an Active Reflection Controller That Can Reduce Acoustic Signal Refer to the Angle of Incidence.

Joo Young Pyun,Yeong Bae Won,Beom Hoon Park,Hak Yi,Jeong-Min Lee,Kwan Kyu Park,Young Hun Kim,Hee-Seon Seo

doi:10.3390/s21175793

Abstract

Techniques for reducing the reflection of acoustic signals have recently been actively studied. Most methods for reducing acoustic signals were studied using the normal-incidence wave reduction technique. Although the technique of canceling an object from the normal incidence wave is essential, research on reducing acoustic signals according to the angle of incidence is required for practical applications. In this study, we designed, fabricated, and experimented with an active reflection controller that can reduce acoustic signals according to the angle of incidence. The controller consists of a transmitter on one layer, a receiver sensor on two layers, and an acoustic window on three layers. To reduce the reflected signal, a combination of the time delay and phase was applied to the controller to minimize the acoustic signal by up to −23 dB at an angle of 10°. A controller array simulation was performed based on the results of a controlled experiment. In conclusion, our proposed controller can reduce acoustic signals according to the angle of incidence, which makes it suitable for many applications.

Highlights

Research has been conducted on reducing or scattering acoustic signals as a countermeasure against underwater acoustic detection systems
To design an anechoic panel made of baffle, aluminum backing, and rubber, a study was conducted to vary the tip angle at the end of the panel in a specific frequency range [6]
Our study proposes a technique for reducing the acoustic signals by referring to the angle of incidence, in which the underwater controller and sensor are packaged together

Summary

Introduction

Research has been conducted on reducing or scattering acoustic signals as a countermeasure against underwater acoustic detection systems. Anechoic coatings, and met surfaces have been developed to reduce acoustic signals [1,2,3]. The wedge shape was developed using butyl rubber, and the technique of annihilating sound waves was applied to it. Designing the wedge shape involves relatively fewer design steps compared to those in other methods; attaching it to a moving object is ineffective for reducing low-frequency signals. If the absorber is attached to a moving object, it may affect the movement of the object owing to the load of the thick sound-absorbing material [4,5]. To absorb the acoustic signal in the low-frequency region, the samples were compared to select a suitable sound-absorbing structure [7,8]

Methods

Results

Discussion

Conclusion