Design and control of an automated yacht berthing solution

Abstract

Automated yacht mooring is seen by many as a future possibility wherein one would enter a marina, select a berth and automatically moor one's yacht in the desired place. With this final year project, we will hopefully bring the future to the present as we will be developing, testing and implementing such a system, whereby upon selecting the desired berthing location the system will take over and moor the boat without any immediate intervention from the user. This system will be aimed at the conventional cabin cruiser, which normally ranges from 12 to 20 meters and consists of two normal shaft driven engines, supported by one at the bow of the boat. The system will not make use of any modern technologies such as the azipod propulsion systems as this project is aimed at mass production boats, these being old motor yachts or new motor yachts, which most often do not have such advanced technology onboard. A fuzzy logic control system was designed and implemented in order to automate the berthing process of modern conventional motor yachts taking into consideration the dynamics, momentum and motion of the boat and sea characteristics. The controller, which is based on fuzzy logic, has been tested and implemented both on a virtual yacht simulator (Virtual Sailor 7) as well as on an actual model boat. The simulator was fed with command controls via a separate library, which simulated key board keys being pressed, as this is how the boat is controlled in the actual game; whereas the actual model boat was fed commands to its controller via a cable from the controlling pc. In the simulator all sensory distances were calculated by image processing done on screen shots of the simulator, whereas when testing on the model boat an overhead camera was used and the processing was done on these captured images as well as through the results obtained from the sensors on the boat. The system being created is very similar to the systems used in autonomous parking vehicles with two main differences. Firstly Instead of having a servo to control the angle of the front wheels in order to turn the vehicle as is the case with autonomous vehicles, here the system makes use of the two independent engines, by altering the revs to the engines in order to turn the boat. Secondly the surface is unstable (sea), compared to the solid testing grounds used to test such autonomous parking vehicles. These two differences will pose new and greater challenges in achieving the necessary satisfactory results.