碩士 / 國立中山大學 / 海下科技研究所 / 106 / Under the support of the National Energy Program (NEP), the Institute of Undersea Technology at National Sun Yat-sen University developed deep-towed vehicles, which have been employed to conduct seafloor surveys off southwestern Taiwan for gas hydrate investigation since 2012. From the survey results, it was found that most of the seafloor off southwestern Taiwan were barren with little or no biodiversity, whereas relatively little seafloor is geologically and biodiversily rich. We also found that some of those geologically and biodiversily rich areas were highly related to the existence of gas hydrate that was worth investigating. Compared to the deep-towed vehicle, it is much easier for a mobile underwater vehicle to implement station-keeping maneuvers for detailed observation and sample collection. At present, the research vessels in Taiwan, however, are not dynamic positioning (DP) rated, and the lift capacity of their A-frames or cranes is not enough to operate a mobile vehicle in combination with a tether management system (TMS). For a mobile vehicle with a single-cable system, the umbilical coming off the vessel’s winch is directly connected to the vehicle, which renders the vehicle sensitivity to the vessel’s motions. Therefore, we developed a mobile vehicle in combination with a depressor that is connected to the ship via an umbilical, thereby decoupling the vehicle from surface motion. The objective of this study is to design the communication and navigation systems of the mobile underwater vehicle, which transmits sensor data and control commands between the surface vessel and the underwater vehicle through the Ethernet LAN (Local Area Network). Considering that the network-induced delay affects the vehicle dynamic stability, time delay of the communication and navigation systems in the loop LAN was measured. Furthermore, motion simulations of the mobile underwater vehicle based on the time-delay measurement were performed for evaluating the control stability and performance.
| Identifer | oai:union.ndltd.org:TW/106NSYS5281008 |
| Date | January 2018 |
| Creators | Hou Tien-En, 侯天恩 |
| Contributors | 王兆璋,陳信宏, Chau-Chang Wang, 陳信宏, 王兆璋 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 105 |
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