現在陸上定位GPS技術已發展得相當成熟，可以為地球表面絕大部分地區快速地提供準確的定位，GPS應用範圍廣泛，從日常生活中到軍事用途上都可以看到GPS應用的蹤跡。但還是有其限制，GPS訊號僅能穿越海水淺層。水下的定位通常是使用應答器，將應答器佈放於海底或載台上，船上收發器發送詢答訊號，應答器接收到詢答訊號後回傳訊號給收發器。藉由水層聲速與量測收發器發出訊號到接收到應答器回訊的時間差，即可計算出位置。然而海水不是一個均質的流場，且聲速在不同密度下會並不會相同，使得計算出來位置並不是很精確。有鑑於此，本論文旨在利用電腦模擬技術預估水下載台的位置。

水下拖曳載台與船之間聯接著電纜或纜繩。載台本身並不具備動力，船藉由移動拖拉著纜繩，牽引著載台使之移動。所以要了解水下載台的移動位置，首先必須先掌握纜繩的運動。經由纜繩的力學與運動分析，在了解水下纜繩的組態與運動後，這些資訊可以用來預測未來纜繩的運動以及載台未來的位置與運動軌跡。最後分別對於真實數據中三種路徑，直線、L型、U型，進行模擬與預測，模擬結果並與真實數據中對應的真實位置進行比較。在水下纜繩於數百至近千公尺長度下，模擬速度能在12秒處理完約200筆纜繩組態，預測位置與真實位置的平均距離差達50公尺左右。所提出之模擬技術成功地展現出在快速計算效率下提供了可接受的預測成效。

GPS technology has been developed quite mature and can quickly provide accurate positioning of most Earth surface. GPS has wide range of applications, from daily life to military purposes. But it still has limitations. Because GPS signals can only pass through shallow waters, underwater positioning is usually achieved by using the transponders. The transponders, which are laid on the seabed or underwater vehicle, receive the signals transmitted by the transceiver and responses back to transceiver. Knowing the time difference between the transceiver transmitting signals and receiving signals, the position can be calculated with speed of sound in water. Nevertheless, the sea is not a homogeneous flow field and the speed of sound at different water densities varies. As a result, the calculated position is not accurate enough. Therefore, this paper aims at location prediction for the underwater towed vehicle using computer simulation technique.

The underwater towed vehicle links a surface ship with cable or rope. The towed vehicle itself does not have propulsive power. The boat by moving drags the rope and changes the underwater towed vehicle’s position by pulling. In order to estimate the position and motion of the underwater vehicle, it is required to fully understand the motion of the cable. Based on the mechanics and motion analysis of the cable, the configuration and motion of the cable can be obtained. This information will be applied to predict future movement of the cable and the underwater towed vehicle. In this thesis, three types of actual data paths, including straight lie, L-type, and U-type are investigated. Simulation results are compared with real data. The simulation speed can be completed in 12 seconds for about 200 cable configurations. Length of the underwater cable is from several hundreds to nearly a thousand meter, and average distance error between the predicted position and the corresponding actual position is about 50 meters. The presented simulation technique successfully demonstrates acceptable prediction performance with fast computational efficiency.

目錄
論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
圖目錄 viii
表目錄 x
第一章 緒論 1
1.1 研究動機與目的 1
1.2 文獻回顧 3
1.3 論文架構 5
第二章 纜繩的動態系統分析 6
2.1 纜繩系統簡介 6
2.2 纜繩組態 7
2.3 2D纜繩之力學分析與動態方程式 14
2.4 3D纜繩之力學分析與動態方程式 22
第三章 模擬模型建構與資料介紹 26
3.1模擬模型流程簡介 26
3.2 纜繩組態模擬 27
3.3 2D模擬模型流程圖 30
3.4 2D模擬 32
3.5 3D模擬模型流程圖 36
第四章 模擬與預測 38
4.1 USBL資料介紹與處理 38
4.2 洋流的設定與選用 41
4.3 直線路徑真實資料模擬 44
4.4 L型路徑真實資料模擬 49
4.5 U型路徑真實資料模擬 54
4.6 模擬總結 59
第五章 論文貢獻與未來展望 61
參考文獻 62






























圖目錄
圖2-1 纜繩的自由體圖.......................................................................................7
圖2-2 纜繩組態圖(μ=1) ..................................................................................9
圖2-3 纜繩組態圖(μ=1)分區圖.....................................................................10
圖2-4 區域I組態..............................................................................................10
圖2-5 區域II組態..............................................................................................11
圖2-6 區域III組態............................................................................................11
圖2-7 區域IV組態............................................................................................12
圖2-8 區域V組態.............................................................................................12
圖2-9 纜繩分段意示圖.....................................................................................14
圖2-10 單段纜繩自由體圖.................................................................................14
圖2-11 最末端纜繩自由體圖.............................................................................15
圖2-12 纜繩重量分配.........................................................................................16
圖2-13 纜繩單位法線向量.................................................................................17
圖2-14 N-1、N-2、N-3自由體圖..........................................................................18
圖2-15 纜繩位置關係圖.....................................................................................20
圖2-16 纜繩3D座標系.......................................................................................22
圖3-1 纜繩組態模擬流程圖.............................................................................27
圖3-2 纜繩組態圖(μ=0.6814) .......................................................................28
圖3-3 纜繩組態.................................................................................................29
圖3-4 2D模擬流程圖........................................................................................31
圖3-5 60秒的2D模擬.......................................................................................32
圖3-6 300秒的2D模擬.....................................................................................33
圖3-7 600秒的2D模擬.....................................................................................33
圖3-8 900秒的2D模擬.....................................................................................34
圖3-9 1800秒的2D模擬...................................................................................34
圖3-10 纜繩組態圖(μ=3.08) ...........................................................................35
圖3-11 3D模擬流程圖........................................................................................37
圖4-1 超短基線水下定位系統.........................................................................38
圖4-2 USBL資料格式.......................................................................................39
圖4-3 地球半徑與所在緯度之半徑.................................................................40
圖4-4 20130906_2202真實數據標示...............................................................41
圖4-5 洋流與船之空間關係圖.........................................................................42
圖4-6 20130906_2202真實數據標示...............................................................44
圖4-7 除去誤傳點後的直線路徑.....................................................................45
圖4-8 直線路徑模擬結果(XY方向視圖) ........................................................46
圖4-9 直線路徑模擬結果(XZ方向視圖) ........................................................46
圖4-10 直線路徑X軸方向距離差.....................................................................47
圖4-11 直線路徑Y軸方向距離差.....................................................................47
圖4-12 直線路徑Z軸方向距離差......................................................................48
圖4-13 直線路徑與真實應答器距離差.............................................................48
圖4-14 20130906_0908真實數據標示...............................................................49
圖4-15 除去誤傳點後的L型路徑......................................................................50
圖4-16 L型路徑模擬結果(XY方向視圖) .........................................................51
圖4-17 L型路徑模擬結果(XZ方向視圖) .........................................................51
圖4-18 L型路徑X軸方向距離差......................................................................52
圖4-19 L型路徑Y軸方向距離差......................................................................52
圖4-20 L型路徑Z軸方向距離差......................................................................53
圖4-21 L型路徑與真實應答器距離差..............................................................53
圖4-22 20130908_1225真實數據標示...............................................................54
圖4-23 除去誤傳點後的U型路徑.....................................................................55
圖4-24 U型路徑模擬結果(XY方向視圖) ........................................................56
圖4-25 U型路徑模擬結果(XZ方向視圖) ........................................................56
圖4-26 U型路徑X軸方向距離差......................................................................57
圖4-27 U型路徑Y軸方向距離差......................................................................57
圖4-28 U型路徑Z軸方向距離差......................................................................58
圖4-29 U型路徑與真實應答器距離差..............................................................58


表目錄
表4-1 模擬結果比較表.....................................................................................59

[1] C.C. Cheng, ”Steady State of a Towing Cable,” Laboratory Report, Man-Machine Systems Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, 1989.

[2] M.A. Grosenbaugh, ”Transient Behavior of Towed Cable Systems During Ship Turning Maneuvers,” Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, 2007.

[3] J.I. Gobat, M.A. Grosenbaugh, “Time-Domain Numerical Simulation of Ocean Cable Structures,” ELSEVIER Ocean Engineering 33, 2006, pp.1373-1400.

[4] V.K. Srivastava, YVSS Sanyasiraju, M. Tamsir, ”Dynamic Behavior of Underwater Towed-cable in Linear Profile,” International Journal of Scientific & Engineering Research Volume 2, Issue 7, 2011.

[5] F.J. Sun, Z.H. Zhu, M. LaRosa, “Dynamic Modeling of Cable Towed Body Using Nodal Position Finite Element Method,” ELSEVIER Ocean Engineering 38, 2011, pp.529-540.

[6] J. Wu, A.T. Chwang, “A Hydrodynamic Model of a Two-Part Underwater Towed System,” ELSEVIER Ocean Engineering 27, 2000, pp.455-472.

[7] B. Paul, A.I. Solar, ”Cable Dynamics and Optimum Towing Strategies for Submersibles,” Towne School of Civil and Mechanical Engineering, University of Pennsylvania, Philadelphia, MTS Journal v6, 1972, pp.34-42.

[8] B. Paul, A.I. Solar, ”Analysis of Cable Dynamics and Optimum Towing Strategies for Tethered Submersibles,” Towne School of The University of Pennsylvania under a grant of the Pennsylvania Science and Engineering Foundation, 1970.

[9] W.D. Ivers, J.D. Mudie, “Towing a Long Cable at Slow Speeds: A Three-Dimensional Dynamic Model,” Marine Technology Society Journal, v7, n3, 1973.

[10] B.R. Munson, D.F. Young, T.H. Okiishi, W.W. Huebsch, “Fundamentals of Fluid Mechanics,” Sixth Edition International Student Version, 2010, pp.510, Fig 9.28.