仿生型水下載具側線系統之設計與環境特徵量測

Abstract

魚類身體兩側佈有側線系統以感測流場的變化，藉此神經組織可使魚類達成避障、追餌等效果。本研究利用壓電材料(PVDF)製作出仿生型側線系統，經過防水及校正即可成功的量測水下聲壓，並運用在仿生型自主式水下載具(BAUV)的壓力量測。本文首先簡介側線系統與壓電片感測器，隨後利用振動小球模擬水中常見的偶極聲源發出聲壓，分別以水下麥克風(B&K 8104)與壓電片作量測，比較其數據並校正壓電片感測器，最後利用虛源法，以仿生型自主式水下載具結合壓電片感測陣列實際量測尾巴拍打反彈自牆壁的聲壓，並整合卡曼濾波器減少不確定性，可增加與牆壁近距離時載具前進的穩定性。未來應用側線感測器原理將可補足聲納與視覺在海底無法運作時的缺陷。

Both sides of a fish are distributed by a lateral line system which can sense the variances of the surrounding flow field. Fishes can avoid colliding with obstacles and track baits depending on this organization. In this study, a piezoelectric material PVDF sensor is used to mimic as a lateral line system, which after being calibrated can measure the underwater acoustic pressure. Then the lateral line system is used on a biomimetic autonomous underwater vehicle (BAUV) to measure the pressure. This article first brief mentions about the lateral line system and the PVDF sensor. Then it was simulated the most common acoustic source, a dipole, by a small vibrating sphere. The pressure was measured by the hydrophone (B&K 8104) and the PVDF film, then the measured data was compared and the PVDF sensors were calibrated. Finally, the image source method is employed to measure the reflected acoustic wave propagated from the oscillating tail fin by the mounted PVDF sensors. Then an extended Kalman filter was used to decrease the uncertainty in the data measurement and increase the stability of the BAUV, while the BAUV is moving forward near a wall. The principle of the lateral line systems can be applied for future applications, and it will be able to supplement the defect of sonar and vision systems in the deep sea.