Research On Path Planning And Path Tracking Method For Underwater Vehicle

The ocean is rich in marine living resources,mineral resources and energy.It is an important asset for the sustainable development of mankind.The study and rational use of the ocean is of great significance to the economic and social development of mankind.The emergence of underwater vehicles,especially unmanned underwater vehicles,provides a powerful tool for humans to explore the ocean.With the development of underwater vehicles in the direction of autonomy,intelligence and remoteness,people's demand for intelligent control and autonomous navigation technology is increasing.Path planning and path tracking related technology is an important part of the underwater vehicle navigation control system,and it is the key link for the robot to complete the underwater operation task accurately,safely and completely.Firstly,this paper elaborates the research background and research significance of underwater vehicles,and analyzes the research status,application research and technology development trend of underwater vehicles at home and abroad.For the two problems of path planning and path tracking,the theoretical and practical methods are summarized respectively,and the characteristics of various theoretical methods are analyzed.Secondly,an improved ant colony algorithm for global path planning is proposed for the problem of obstacle avoidance optimal path in autonomous underwater vehicle submarine terrain.The algorithm overcomes the shortcomings of the traditional algorithm,such as slow convergence speed and easy to fall into local optimum,and the design of the heuristic function is closer to reality.The problem of obstacle avoidance planning in large-scale three-dimensional seabed environment is studied.Different from the conventional single-objective programming problem,in order to obtain the shortest path and reduce the consumption of the path,the length of the path and the smoothness of the path are used together as the evaluation function.Simulations in a variety of seabed terrains show that the algorithm effectively reduces the length of the path while the path is smoother.Finally,based on the working points generated by the path planning problem,the path tracking problem is studied.Taking the motion model of under-actuated AUV as an example,the two-dimensional line and point tracking controller are designed by using the horizontal tracking error method and LOS method.The problem of linear track tracking control in three-dimensional environment is studied.According to the cascade method,a three-dimensional linear tracking control algorithm for under-actuated autonomous underwater vehicle is proposed.The three-dimensional linear tracking error model is decomposed into a cascade structure in which the horizontal motion is disturbed by the vertical plane motion,and the pitch angle,heading angle command,and pitching moment and yaw moment control rate are designed respectively.The simulation proves that the tracking effect is good under the condition of large posture deviation and speed deviation.