Formation Navigation And Coordinated Control Of Multi-AUVs Based On Acoustic Communication

In the current situation of rapid development of science and technology,many countries have turned their eyes to the ocean,AUV(Autonomous Underwater Vehicle)has become a research hotspot for its small-volume,low-cost whether in military field or resource exploration field,It can perform tasks in dangerous or unknown underwater environment.However,with the increasing complexity of underwater tasks,it is difficult to meet the requirements by relying solely on a single AUV.So researchers are considering using multiple AUV to work together after deep exploration.The ability to locate is the first and most important step no matter which task is carried out.This paper will also study the related problems involved in the multi AUV cooperative positioning system.The main work of the paper is as follows:1?Taking the application of AUV as the background,this paper introduces the development of AUV and the research results of cooperative positioning methods in various countries briefly,and the problem of communication delay and data loss in cooperative positioning system is investigated.Then the features of the sensors equipped in the multi AUV cooperative positioning system are introduced,and the principle of the coordinated positioning of the water surface unmanned craft and the realization of the cooperative positioning are expounded combining with the equipped sensors.According to the AUV dead reckoning model,system model is established by a single leader and multi-leaders cases,furthermore,the EKF based cooperative navigation and positioning algorithm is given,and the simulation analysis of two cooperative positioning methods is carried out respectively.2?In view of the effect of time delay and data loss on cooperative positioning system,a cooperative navigation positioning method based on delay and data loss is studied.First,calculate the one step prediction state error under the condition of time delay,then the state compensation based DEKF algorithm is designed,the simulation proves that the method can effectively compensate the location error caused by the time delay.3?The method of Moving Horizon Estimation(MHE)is used to solve the uncertainty of measurement caused by the loss of data in the multi AUV cooperative positioning system.First,establish a mathematical model for the process of underwater acoustic communication delay and data loss,then the feasibility analysis of follower AUV to realize the optimal estimation of the system by only a limited number of underwater acoustic equivalent measurements is carried out.Based on this,the Delayed Moving Horizon Estimation(DMHE)based on DEKF is proposed,and the location error correction caused by the restriction of underwater acoustic communication is realized by this method.4?In view of the problem of maintaining aggregation and avoiding collision among AUV clusters during the process of positioning,a dynamic network topology based formation method is adopted,each AUV is regarded as the node in the network,and the formation requirement is satisfied by setting the potential field function;In addition,in view of the possible obstacles in the navigation,the artificial potential field method is used for online planning.The simulation results show that the two methods can achieve good results in the multi AUV cooperative location system,and finally keep the aggregation of AUV clusters,and achieve the avoidance of obstacles.