自主式水下載具利用單向聲音傳遞時間之導引演算法研究

Guidance Algorithm for an Autonomous Underwater Vehicle Using One-Way-Travel-Time

任健柏(CHIEN-PO JEN)

指導教授 ： 郭振華

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201610152

摘要

水聲海洋層析法是海洋學用以分析一海域內流速及溫度分布的方法，係在一區域內散布水聲儀器節點，每個節點輪流發送聲波至其他的節點，並利用同步時鐘計算傳遞及接收的時間差，進而獲取海洋的聲速資訊。本研究藉由水聲海洋層析法的架構設計一水下無人載具作為移動式節點，接收固定節點間的信號，除了可以有效增加節點間的聲音連線之外，並由載具與固定節點間聲學傳播時間差得到的距離量測值，使得水下無人載具能有更好的定位準確度，使得載具可以控制在設定的路徑移動。由於節點間為輪流發送訊號，載具在同一時間只收到一個節點的聲音，並據之推算與該節點間距離，因此本文首先探討接收單一節點單向聲音所推算距離下之載具的定位方法。本文使用線性化載具運動模式下之狀態觀測性，求得載具在單一距離觀測條件下之可觀測路徑之限制條件。接著設計一個可以調控載具追蹤動態誤差之控制器，考慮螺槳之推進能力下將載具控制在設定路徑上。本文最後以海域試驗證明路徑追隨控制器之可行性。
關鍵字：自主式水下載具、水下定位、路徑導引系統、水聲層析

關鍵字

自主式水下載具 ； 水下定位 ； 路徑導引系統 ； 水聲層析

並列摘要

Tomography is a method of oceanography to analyze the current velocity and temperature by measuring the travel time of sound between fixed beacons arranged in an array. It is necessary to separate the acoustic modems over large regions and broadcast the sound periodically. In this work, we discuss the necessary technique to deploy a mobile modem by an AUV under the framework of Tomography. The AUV is a mobile modem that could not only increase the number of acoustic paths but also improve the accuracy of localization by the increased number of travel time measurements of distances between the AUV and fixed beacons. To achieve this aim, the AUV must move along trajectories on those the AUV is always observable by the localization algorithm. The beacon is broadcasting periodically, the AUV could only receive one acoustic beacon at a time. The localization technique based on a single-beacon one-way-travel-time is discussed. Simulations based on a set of sea trial data is used to analyze the constraint of observable positions of the single-beacon by using observability matrix. Trajectory tracking controller is then proposed for the AUV to track the trajectory by consideration the maximum outputs of propellers within admissible localization errors. At sea experiments results are shown to prove the feasibility of the tracking controller.
Keywords: AUV、Underwater localization、Path Guidance System、Tomography

並列關鍵字

AUV ； Underwater localization ； Path Guidance System ； Tomography

參考文獻

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