Research On Navigation Positioning And Path Planning Of Unmanned Ships

At present,with the development of people’s exploration of the ocean,river and lake supervision,water environmental protection monitoring,water rescue and water military activities,etc.,unmanned ships with mobility and low risk have received attention and research.Among them,the navigation and positioning technology and path planning technology of the unmanned ship,as its intelligent core technology and safety foundation,have important research value.This research is aimed at small-scale waters,and conducts research on the navigation,positioning and path planning of unmanned ships.First,establish a suitable environment model to lay the foundation for the research of unmanned ship’s navigation and positioning and path planning.In this paper,GPS electronic satellite map fusion grid method is used to model the operating environment of unmanned ships.The task area is planned on the satellite map by the host computer,and then binarized and rasterized.Finally,the task is The area is transformed into a raster map to complete the environmental modeling of this research.Then,research is conducted on the problem that the unmanned ship cannot effectively carry out navigation and positioning when the unmanned ship navigates to the harsh environment.The INS/GPS combined positioning module mounted on the unmanned ship platform is used to perform basic real-time positioning of the unmanned ship,and adopt it through the host computer.The improved integrated navigation method processes the positioning information collected by the unmanned vessel,improves the accuracy of the unmanned vessel’s navigation and positioning,and obtains more accurate positioning information for the unmanned vessel.Finally,this research focuses on the path planning of the unmanned ship from two aspects: the global path planning under static obstacles and the local path planning when the unmanned ship encounters dynamic obstacles in the process of motion.Aiming at the problems of slow convergence speed,large number of iterations,and long search time in traditional path search algorithms in the path planning of unmanned ships,an improved global/local path planning combined with A* ant colony is proposed.algorithm.The algorithm is based on the simplified A* algorithm to optimize the initial pheromone distribution of the ant colony,improve the convergence speed of the algorithm,and improve the ant colony pheromone enhancement coefficient to avoid the local optimization problem caused by the accumulation of too much pheromone in the later stage of the ant colony algorithm.The grid environment penalty coefficient is set based on the established grid environment model,which can further improve the algorithm’s convergence speed while avoiding unmanned ships from falling into local optimum in complex environments.The experimental results show that the path planned by the improved algorithm is shortened by nearly 20% compared with the path planned by the traditional path planning algorithm,and has fewer inflection points,is smoother,the convergence speed is increased by 40%,the search time is reduced by 40%,and It has better adaptability to complex environments and meets the different requirements of unmanned ships under global path planning and local path planning.For the problem of unmanned ships encountering unknown obstacles or dynamic obstacles in local path planning,this research uses the unmanned ship platform to detect the environment information around the unmanned ship through the millimeter wave radar mounted on it,and then sets the risk coefficient CRI and CRL and its corresponding threshold complete the unmanned ship’s obstacle avoidance movement for unknown obstacles,and re-plan the route to the target point and drive to the target point.This study verifies the effectiveness of the method in this paper through the MATLAB simulation platform and the unmanned ship’s physical platform.The experimental results show that in small waters,the method proposed in this paper can make the unmanned ship have better positioning accuracy and accurate and efficient planning.Create a smooth,optimal path to drive safely to the target point.