仿生微型化陣列應用於波源方向判定

Abstract

近年來，生物啟發設計和仿生工程受到了許多關注，利用工程技術達到生物之功能。其廣泛的應用包括機器人，傳感器和復合材料等。本研究中，我們提出了一種微型化的聲學定向判斷系統，其靈感來自於模仿Ormia ochracea的特殊耦合結構。一般的兩個元件接收陣列由兩個接收器組成，兩個接收器至少要以半波長的距離分開，以便獲得可明顯區分的相位差或時間差，以便確定入射聲音的到達角度。兩個接收器之間的間距可以藉由質量塊，彈簧和阻尼器組成的機械耦合系統，來大幅降低已克服物理限制。由於耦合機制，兩個接收器之間的相位差可以被放大多倍，因此可以用於定位波源。根據接收器，為聲壓感測器或天線，可應用於聲源或電磁波波源方向判斷。 本研究中，我們提出了一個由純集總元件組成的電耦合電路來取代機械耦合系統以實現微型化。其系統包含兩個聲壓感測器(麥克風)、電耦合電路與其相位比較器。本論文內容包含理論分析，電路模擬驗證，與製作及無響室量測，經由最佳化相位放大與接收能量之參數，所設計之電路作用於10kHz，可針對前方180度入射角，其相位具有在-90度~90度之放大效果與接收能量。此外，本研究亦探討此耦合電路之使用頻寬與雜訊之影響。本研究成果預期將有助於發展與設計小型化聲納與雷達系統。

In recent years, bio-inspired devices and biomimetic engineering materials have attracted lots of attentions. The wide applications include multi-robots, actuators, sensors, and composite materials. In this research, we proposed a miniaturized acoustic directional finding system inspired by mimicking the fly ears of Ormia ochracea. A conventional two-element sensor array is composed of two sensors separated with a distance of at least of half wavelength for obtaining a distinguishable phase difference or time difference in order to determine the angle of arrival of incident sounds. It was demonstrated that the separating distance between the two sensors could be reduced significantly via a mechanical coupling system composed of masses, springs, and dampers. Due to the coupling mechanism, the phase difference between two sensors could be enhanced several times and can be used to locate the sound sources. The receiver can be a sound pressure sensor or an antenna, which can be applied to the direction of the sound source or the electromagnetic wave source. In this study, we proposed an electrical coupling circuit consisting of pure lumped elements to replace the mechanical coupling system to achieve miniaturization. The system consists of two microphones, an electrical coupling circuit and its phase comparator. The content of this thesis includes theoretical analysis, circuit simulation verification, fabrication and measurement in anechoic chamber. By optimizing the parameters of phase amplification and receiving energy, the designed circuit operates at 10 kHz and can be used for the 180 degree angle from incidence angle. It has a magnification effect over -90 degrees to 90 degrees with receiving energy. In addition, this study also explores the effects of the bandwidth and noise of this coupling circuit. The results of this research are expected to contribute to the development and design of miniaturized sonar and radar systems.