基于操纵过程推演的船舶可变速自动避碰决策方法

A Decision-support System for Automated Collision Avoidance of Ships with Variable Speed Based on Simulation of Maneuvering Process

为了解决船舶部分场景中仅靠变向避让效果差的问题,研究了多物标环境下符合避碰规则的船舶可变速自动避碰决策方法。基于船舶会遇四阶段理论和船舶领域模型量化船舶碰撞危险度,通过可变速MMG模型和模糊自适应PID航向控制方法推演船舶定、变速改向操纵过程。在此基础上,改进了基于操纵过程推演和速度障碍理论的动态可行操纵区间求解算法。以实船为仿真目标,进行了不同操纵方案下的对比实验和多物标场景下的仿真实验。将程序运行步长设置为1 s,结果表明:(1)预设他船位置(4 n mile,4 n mile),航向270,航速12 kn,本船位置(0 n mile,0 n mile),航向000,航速12 kn的交叉相遇态势下,变向变速避让和仅变向避让采取操纵行动的最晚时间点分别为711 s和643 s;(2)在物标较远的多物标环境下,本船O保向保速至663 s,与目标船T_(A),T_(C),T_(D)构成碰撞危险,采取目标航向、转速区间为[48~°,61~°]、[75 r/min,85 r/min]中任意组合可让清所有物标。

A decision-making method for variable speed automatic collision avoidance of ships in a multi-objective environment meeting the International Regulations for Preventing Collisions at Sea is studied to solve the problem of the poor effect of collision avoidance only by altering the direction in some scenes of ships.The risk of ship collision is quantified based on the four-stage theory of ship encounters and the ship domain model.The variable-speed MMG model and fuzzy adaptive PID heading control method are used to derive the ships’steering process at fixed and variable speeds.On this basis,an algorithm is improved for solving the dynamic feasible maneuvering interval based on the deduction of the maneuvering process and the speed obstacle theory.Combined with the actual scenarios,comparative experiments under different maneuvering schemes,simulations,and multi-objective scenarios are carried out.The results show that:(1)The program running step length is set to 1 s.Under the pre-set position of other ship(4 n mile,4 n mile),heading 270,speed of 12 kn,ship position(0 n mile,0 n mile),heading 000,speed of 12kn,the latest time point for maneuvering action to alter directions and speeds for yielding is 711 s.The latest time point for manipulative actions to be taken only by altering directions for yielding is 643 s,and that to be taken is delayed by 68 s.(2)In a multi-object environment with distant objects,ship O driving to 663 s and keeping the speed and direction,which poses a collision risk with target ship T_(A),T_(C) and T_(D).At this time,any combination of target course interval[48°,61°]and rotation rate interval[75 r/min,85 r/min]can clear all targets.