Research On Mathematical Model Of Tug Pushing Operation In Shiphandling Simulator

With the rapid development of marine transportation, tug assistance has become more and more important. The research of tug operation has attracted much attention in the field of shiphandling simulator. So it is of important practical and theoretical significance. This paper addresses the mathematical modeling of tug pushing operation for shiphandling simulator. The main contributions of this thesis are summarized as follows.Firstly, from the outline of tug and towed vessel with polygons, collision detection algorithm is used to judge whether one point of the polygon is contained within the other or not. In order to avoid misjudgment, the collision point is ascertained by two-way collision detection algorithm.Secondly, the model of fender reaction is established. The bounding box of towed vessel is assumed as fenders. The distance between contour line and towed vessel outline is used as fender thickness. After the collision detection, fender force is obtained by the shortest distance between the collision point and the outline of fenders.Thirdly, testing platform is established for tug pushing operation by use of Visual C++ 6.0. The test contains two stages. In the first stage, tug and towed vessel move independently. In the second stage, the model of pushing operation is in action when tug collides with the towed vessel. The simulation research demonstrates that the proposed pushing operation model is reasonable and effective.