壓電感測器應用於仿生型水下載具之狀態估測

Abstract

水下的震動源多數可近似為偶極震盪源，而魚類利用側線感測系統可偵測震盪源並進行追蹤，進而達到獵食或躲避等效果。本研究利用現有之壓電材料(PVDF)所研製成的感測器進行水中壓力訊號的擷取，藉以獲得由仿生型水下載具之仿生尾鰭所打出的訊號並利用卡曼濾波器估算其運動狀態。本文首先建立督普勒頻差的量測描述式，並以模擬之訊號進行速度與位置的估測，並驗證其可行性。接著透過多極展開描述合理簡化後的流場，利用督普勒頻差定位所獲得的位置訊息進行仿生尾鰭的拍打模式估測。最後以仿生型水下載具作為訊號源進行實驗，並加以分析各參數對於估測之影響。未來可應用此震盪源估測輔助仿生型水下載具之追蹤與躲避。

Fishes use the lateral line system to identify a vibration source such as tail flapping, to avoid predators and for tracking other fish. In this study, a pressure sensor made of piezoelectric material was used to obtain the pressure signal that produced by tail beating. Then, the motion state of a biomimetic autonomous underwater vehicle (BAUV) could be estimated by the Kalman filter. First of all, this article constructs a description of the Doppler-shift frequency, and the use of a simulated signal to estimate the location and velocity of the BAUV to prove its feasibility. Second, multipole expansion was employed to describe the fluid dynamics after a reasonable simplification, and the location information from the Doppler localization was used to estimate the tail beating direction. At last, a BAUV was used to be the vibration source in the experiment. The result would be discussing the effects of different parameters of the Doppler localization and the vibrating pattern detection. In the future, these methods could be used to help tracking and avoid collision between BAUVs.