Distributed Cooperative Control Of Multiple Underwater Vehicles

There are abundant natural resources stored in the ocean,such as oil,natu-ral gas,marine biological resources,and mineral resources.For this reason,the exploration and development of the world's marine resources has received great attention from all countries and has become one of the hot topics in the scien-tific research field.In recent years,autonomous underwater vehicles(AUV),as the most important means of exploring the ocean,have also attracted people's attention.They have been widely used in ocean observation,maritime rescue,minefield search,submarine pipeline maintenance,and enemy reconnaissanceHowever,with the deepening of ocean exploration and development activities and the increasing complexity and diversification of requirements,the optimiza-tion of certain indicators of a single AUV is far from being able to meet the needs of complex tasks.In order to solve this problem,on the one hand,it is necessary to develop underwater robots with stronger functions and higher intelligence.On the other hand,on the basis of the existing AUV with simple functions,the tasks that a single AUV cannot complete or are difficult to complete can be completed through the mutual cooperation between multiple AUVs.The core idea of multi-AUVs system collaboration is to make multiple AUVs with simple functions form a group,assign corresponding tasks to each AUV in the group,and then make each AUV in the team cooperate with each other through a certain control strategy.Compared with a single AUV,the multi-AUV collaborative operation system has the advantages of time and space distribution,perception distribution,function distribution,etc.In this paper,through theoretical analysis and numerical simulation,a certain research on multi-AUV collaborative operation is carried out,the main research is as follows:1.The modeling of underwater robot system.First,two coordinate systems-fixed coordinate system and carrier coordinate system are defined,and then the Euler angle representation method is used to represent the attitude of the AUV.Then according to Newton's second law and the law of rotation,the dynamic equations and kinematics equations of the system can be obtained.Finally,the approximate linearization method is used to obtain the linear system model of the AUV.2.Consistency control method based on virtual leader.In the leader-follow consistency control algorithm,the leader can control the movement trend of the entire system,and each follower reaches a consistent state under the control of the controller.However,in the"Leader-Follower" control method,since the move-ment of all followers depends on the leader,once the leader fails,the formation will lose control.Although the design of a candidate leader can cope with the failure of the leader to a certain extent,there is also a probability that the candi-date leader will fail before the leader,and thus cannot play a role as a substitute,so the problem cannot be fundamentally solved.This paper uses a virtual leader control method to design the controller,and finally uses the Lyapunov equation to analyze the consistency error.3.Consensus error analysis for multiple AUVs under non-ideal channels.The paper mainly studies the consistency of multi-AUV systems under the fading channel of additive observation noise and communication noise.The paper uses the Kalman filter algorithm to deal with the noise,and then propose a consistency protocol based on the relative estimated state to control the consistency.Finally,the Lyapunov equation is used to accurately describe the consistency error.