被動水下聲學監測與智慧型水面無人載具整合之研究

Abstract

台灣海峽地理環境優渥，擁有世界上數一數二優良之風場，因此具備極大的潛能做離岸風電之開發。然而現階段之單樁施工，需要透過施工船進行打樁的動作，而在打樁過程中，研究顯示其施工所輻射之水下噪音會影響中華白海豚(Sousa chinensis)生態。因此，施工期間偵測是否有白海豚出沒於施工區為施工單位與環保單位關注之訊息。故本文以此為出發點，建立了一套利用水面無人載具之被動水下聲學量測系統，，透過即時水下音訊分析與即時時頻譜回傳，來得知水下之聲學環境，並且透過海豚之哨叫聲(Whistle)來判定量測區域中是否有海豚之存在，若目標訊號明確，載具將自主性移動至特定區域做進一步之量測。全系統透過C++實踐並且可應用於嵌入式系統。本文之系統可分為四大部分，分別為即時哨聲偵測、聲源方位計算、載具自主控制系統與即時監控系統。本文將詳細說明各部分並透過2018 Maritime robotX Challenge中之聲源定位任務之量測資料分析本文之聲源方位計算演算法之可行性；並於台灣基隆河大直橋下水域，驗證本文所開發之系統之可行性，並且分析本系統之誤差來源與未來可精進項目。

Due to the potential of the offshore wind energy in the Taiwan Strait, the development of the offshore wind farm is cost-effective. As the green energy concept growing, Taiwan are actively promoting the project “Thousand Wind Turbines” from 2012. Up to now, there are two mono-pile foundation wind turbines completed in 2016. The objective is to build up to 800 offshore wind turbines, and 450 onshore wind turbines before 2030. However, the expected develop area for potential offshore wind farms has overlapped with the habitat of the Sousa chinensis (also called Indo-Pacific Humpback Dolphin or Chinese White Dolphin). The impact noise from the pile driving process have shown to cause Temporary Threshold Shift (TTS) even Permanent Threshold Shift (PTS) to marine mammals at specific range from pile driving spot. Furthermore, out of the PTS and TTS range, noises from the construction are still high enough to disturb and even change the behavior of marine mammals. As a result, to know if there are dolphins in the construction area is the most important. This paper provides a process for checking if there are dolphin in the specific area and using unmanned surface vehicle to track the source and find the area they are. This process has 4 main parts, including real-time dolphin whistle detection, real-time shore side monitoring system, underwater acoustic source localization and source tracking behavior of the surface vehicle. This thesis will go into the details of those parts.