【作者】 陈卓；

【导师】 茅云生； 宋利飞；

【作者基本信息】 武汉理工大学 ， 船舶与海洋工程， 2019， 硕士

【摘要】 无人艇是一种具有自主航行能力的智能化水上平台,具有体积小、速度快、运动灵活、自动化程度高等特点,因而被越来越多地应用于民用领域和军事领域。随着各国对海洋资源勘探和海洋权益的日益重视,无人艇将承担越来越重要的角色。自主避碰系统作为无人艇实现自主导航和安全航行的关键技术之一,决定了无人艇智能化水平的高低。本文在考虑实际航行环境和无人艇运动特性的条件下,按照先全局后局部的顺序,围绕无人艇的路径规划和避碰技术展开研究。针对无人艇全局范围内的最优路径规划问题展开了研究。以FMM生成的势场作为路径规划的基本模型,在此基础上,考虑到海洋环境的复杂性和无人艇自身运动能力的局限性,对静态障碍物安全距离和无人艇航向约束进行了分析,并将其引入到势场模型中。提出了一种考虑约束的无人艇最优路径规划算法,利用仿真试验验证了算法的有效性。针对无人艇在局部范围内的动态障碍规避问题展开了研究。首先根据无人艇局部障碍的分布情况和海上避碰规则的要求,对无人艇的碰撞危险和会遇类型进行判断和分析;提出了一种基于无人艇速度窗口的局部避碰策略,通过对无人艇的有限速度空间进行离散采样来生成相应的预测轨迹,引入目标方程来对轨迹的碰撞危险度、规则一致性等进行评价,从而获得满足COLREGs规则的最优避碰速度。通过仿真试验分别对单障碍和多障碍情况下的避碰效果进行了有效验证。基于通用的无人艇平台框架,搭建了一种低成本的小型无人艇避碰系统平台;通过对全局路径规划算法与自主避碰算法的协调处理和功能整合,利用MATLAB/C++混合编程语言编写了无人艇路径规划与自主避碰综合仿真软件;基于设计的软件系统,选取典型的海事地图环境进行了无人艇自主避碰综合仿真试验,验证了本文避碰算法的可行性和优越性。更多还原

【Abstract】 Unmanned Surface Vehicle(USV)is a kind of intelligent water platform with autonomous navigation capability.It has the characteristics of small size,high speed,and high degree of flexibility and automation,which is increasingly used in civil and military fields.With the increasing attention of countries to marine resource exploration and maritime rights,USV will assume a more and more important role in the future.Autonomous collision avoidance system is one of the key technologies for smart and safe navigation,which directly determines the level of intelligence of USV.Taking into account the practical navigation environment and the motion characteristics of USV,this paper studies the path planning and collision avoidance technology of the vehicle according to the order of global first and then local.The problem of optimal path planning for USV in the global scope is studied.The potential field generated by FMM is used as the basic model of path planning.On this basis,considering the complexity of the marine environment and the limitations of the vehicle’s own kinematics ability,the obstacle safety distance and heading constraints of USV are analyzed and introduced into the potential field model.Then an optimal path planning algorithm for USV is proposed and it’s effectiveness is verified by simulation tests.The problem of dynamic obstacle avoidance for USV in the local area is studied.Firstly,according to the distribution of local obstacles and the requirements of the rules for collision avoidance at sea,the collision risk and the type of encounters between USV and obstacles are calculated and analyzed.Then a local collision avoidance strategy based on the velocity window of USV is proposed.The reachable velocity space of USV is discretely sampled to generate a set of predicted trajectories,and an objective function is introduced to evaluate the collision risk and rule consistency of each trajectory,so as to obtain the optimal velocity command for collision avoidance.The effectiveness of the method under single and multiple obstacles situations is validated by simulation tests.Based on the universal USV platform framework,a low-cost small USV collision avoidance system platform is designed.Through the coordinated processing and functional integration of the global path planning algorithm and the local collision avoidance method,an USV autonomous collision avoidance system simulation software is designed with MATLAB/C++ mixed programming language.Based on the designed software,a typical maritime map is selected to carry out the integrated simulation test on USV’s collision avoidance,the feasibility and superiority of the collision avoidance algorithms are verified.更多还原