碩士 / 國立臺灣海洋大學 / 資訊工程學系 / 99 / In this thesis, new mathematical models for simulating fish
locomotions are presented. The proposed models include a physical model for generating burst-and-coast swimming, a Bezier-curve-based method for producing the three basic types of turning, and a physical model for ascending and descending swimming. In the burst-and-swimming model, we modify the existing two-wave system and incorporate periodic square wave impulse sequences to control the frequency and magnitude of fish body undulation and oscillation. Therefore, the resulted swimming patterns are more flexible and realistic. Fish can perform three basic types of turning. Few research results have been reported on simulating the turning motions of fish. In the second model, we use cubic Bezier curves to produce the trajectories of the
turning motions at first. During the turning motions, the fish body is rotated to be aligned with the tangent vectors of the trajectories such that the fish can turn according to the predefined trajectories. We can tune the control points of Bezier curves to generate trajectories of different curvatures. Therefore, the S-, C-, and L-shape turning motions can be
accomplished. In the third mathematical model, a method for ascending and descending swimming is developed. In the model, we regard the fish as a mass-point and pitch the fish head up and down to change its swimming direction vertically. Then the fish performs steady swimming to move upward or downward. After the fish reaching the target attitude, the fish head is pitched down or up to be aligned with the horizon and the whole ascending and descending motion is completed. In order to verify our models, a simulation program has been developed and some experiments are conducted by using the simulation program. In the simulations, several synthetic fish models and an artificial aquarium are built. The physics engines of these fishes are constructed by using our mathematical models. They are programmed to swim automatically in the artificial aquarium. The motions of the fishes are rendered and displayed in real time such that users can easily comprehend the intrinsic behaviors of the fishes. Test results reveal that our models can simulate the three motions accurately. Compared with current fish motion models, ours are more flexible, easier to control, and realistic.
| Identifer | oai:union.ndltd.org:TW/099NTOU5394015 |
| Date | January 2011 |
| Creators | Hong-Kai Chen, 陳弘凱 |
| Contributors | Shyh-Kuang Ueng, 翁世光 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 41 |
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