Title page for etd-0810115-163410


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URN etd-0810115-163410
Author Min Lei
Author's Email Address No Public.
Statistics This thesis had been viewed 5565 times. Download 400 times.
Department Mechanical and Electro-Mechanical Engineering
Year 2014
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Prediction of Motion Trajectory for the Underwater Towed Vehicle
Date of Defense 2015-07-28
Page Count 74
Keyword
  • motion of underwater cable
  • underwater cables
  • cable dynamics
  • trajectory prediction
  • underwater towed vehicles
  • underwater cable configuration
  • Abstract 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.
    Advisory Committee
  • Chau-Chang Wang - chair
  • Hsin-Hung Chen - co-chair
  • Chi-Cheng Cheng - advisor
  • Files
  • etd-0810115-163410.pdf
  • Indicate in-campus at 2 year and off-campus access at 2 year.
    Date of Submission 2015-09-10

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