| Author: | Wong, Chun-kong |
| Title: | Intelligent outboard engine contol |
| Degree: | M.Sc. |
| Year: | 2000 |
| Subject: | Inboard-outboard engines -- Control Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Mechanical Engineering |
| Pages: | vii, 32, [38] leaves : ill. ; 31 cm |
| Language: | English |
| Abstract: | In outboard industry, efforts have been paid on engine horsepower, efficiency and fuel economy. However, in run-time, overall engine performance is affected by mounting height and trim angle of the outboard engine, and propeller properties. The above parameters are determined during trial runs, in which a 'normal' load of the boat is assumed. When the speed and/or the load of the boat as well as the environment vary, the predetermined parameters can no longer give optimal performance. At present, there is no run-time automatic adjustment. Unless a controllable pitch propeller is used (which is not feasible for outboard due to its high complexity and hence high cost and low robustness), it is not practical to change the propeller properties in run-time. However, it is possible to change mounting height and trim angle of the outboard engine. In outboard market, there are outboard engines that have power tilt and trim feature, that is, their trim angle can be adjusted. On the other hand, power jack is available such that the outboard engine can be moved up and down. Although power actuators are available it is difficult to adjust these parameters without quantitative inputs and an effective control system. In this project, the boat status (trim angle) is used for adjusting the outboard engine trim angle. The data will be processed by a fuzzy logic controller which controls the power actuators to position the outboard engine. A computer simulation has been performed. The boat is put in a slightly wavy water. The simulated speed is around 2.5 to 4.5 m/s. It is simulated for 100s. The model used is based on mathematical model in marine vehicles mechanics. The fuzzy controller read the boat trim angle and outboard trim angle from assumed trim sensor, then process the input with fuzzy rules as stated in the fuzzy associate memory. The output signal is defuzzified using centre of gravity method. This signal is used to trigger an assumed electro-mechanical actuator to adjust the trim angle of the outboard engine. It is found that the boat with fuzzy control has a higher speed over the testing period |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b15321885.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.04 MB | Adobe PDF | View/Open |
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