碩士 / 國立臺灣海洋大學 / 通訊與導航工程學系 / 99 / This work uses the National Taiwan Ocean University(NTOU) Shiphandling Simulator (SHS) as the testbed to examine the performance of three types of guidance schemes that guide a ship towards a prescribed straight water channel. Specifically, the first two types of guidance methods are based on image processing technique; namely, the fore-aft leading mark and the left-right leading mark guidance methods, and the third one is a GPS-based Line-of-Sight (LOS) guidance method. The Labview working environment is adopted for the design of the Fuzzy Logic Controller (FLC) and the Internal Model Controller (IMC) adopted in this study. An image processing unit placing inside of bridge of the SHS is used to acquire images of leading marks projected onto the screen. The images of the leading marks are acquired through a sequence of image processing steps: color space transformation, threshold value screening, median filtering and closing operations, then the centers of the leading marks are identified. Finally, the angle between the leading marks and the distance from the leading marks to the center of the CCD camera are fed into controllers to steer the ship towards a prescribed channel. The LOS guidance method uses precise GPS positioning information to compute a reference heading angle to steer the ship through a sequence of course-changing maneuvers. Simulations under the wind and current effects indicate that the fore-aft leading mark guidance method with FLC autopilot has better performance than with the IMC autopilot. The left-right leading mark guidance scheme is less satisfactory because of its single leading mark like performance, and the performance of the LOS guidance scheme under different disturbances depends greatly on the selection of a proper virtual waypoint makes it not reliable in practical use.
| Identifer | oai:union.ndltd.org:TW/099NTOU5300010 |
| Date | January 2011 |
| Creators | Cheng- Yu Chang, 張正鈺 |
| Contributors | Ching-Yaw Tzeng, Sin-Der Lee, 曾慶耀, 李信德 |
| 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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