Abstract

Roll-on and roll-off (Ro-Ro) ships are economical transportation vessels that are very useful for transporting large freights, such as plant equipment and aircraft bodies. To load a large freight on a Ro-Ro ship, a tractor is generally used to pull a trailer on which the cargo is secured via a ramp from the port berth to the ship deck. In the case of a long cargo, the trajectory of the trailer is not the same as that of the tractor, which can cause a collision with the ramp or the gate or obstacles on the deck. Also, if the freight is too high, it may overturn when the trailer is tilted due to the ramp slope. This research proposes a method for calculating the best and safest trajectories for large freights to be loaded on Ro-Ro ships without the occurrence of any collisions or overturns. By reasonably assuming a low speed of the tractor, the proposed method generates all the possible tractor paths based on the Bezier curve and also calculates the trajectories of trailers when moving on inclined ramps; thus, it is the first method to calculate 3D trajectories for trailers when the tractor and trailer move on different planes. Besides, it searches for the best paths without any collisions or overturns and with the minimum shipping time possible. Since the proposed method calculates the paths by taking the ramp angle as a variable input, the trajectories can be automatically generated based on the change in the waterline of the ship according to the loading of the cargoes. Overall, the proposed method can be useful for transportation companies when planning the shipping of large freights, and it can also be beneficial for future autonomous driving systems.

中文翻译：

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根据滚装船的坡度自动生成拖挂车的路径

摘要

滚装（Ro-Ro）船是经济的运输船，对于运输大型货物（例如工厂设备和飞机机身）非常有用。为了在滚装船上装载大量货物，通常使用牵引车来拖曳拖车，通过舷梯将货物固定在拖车上，从港口泊位到船甲板。在长货物的情况下，拖车的轨迹与拖拉机的轨迹不同，这可能导致与坡道或闸门的碰撞或甲板上的障碍物。同样，如果货物太高，则由于坡道倾斜而导致拖车倾斜时，货物可能会倾覆。这项研究提出了一种用于计算在滚装船上装载的大型货物的最佳和最安全轨迹的方法，而不会发生任何碰撞或倾覆。通过合理地假设拖拉机低速行驶，提出的方法基于贝塞尔曲线生成所有可能的牵引车路径，并计算在倾斜坡道上行驶时拖车的轨迹。因此，这是在牵引车和拖车在不同平面上移动时计算拖车的3D轨迹的第一种方法。此外，它搜索最佳路径，而不会发生任何碰撞或倾覆，并尽可能缩短运输时间。由于所提出的方法通过将倾斜角作为变量输入来计算路径，因此可以根据船上水线的变化根据货物的载重自动生成轨迹。总体而言，所提出的方法对于运输大型货运的运输公司很有用，对于将来的自动驾驶系统也很有用。