Research On Method Of Path Planning And Cooperative Control For Multi-UUVs Formation

Multiple unmanned underwater vehicles(multiple Autonomous underwater vehicles)refers to an independent,autonomous,recyclable and long-term underwater unmanned robot system,hereinafter referred to as the vehicle.It has been widely used in marine scientific investigation,marine search and rescue and wreck salvage.Compared with a single vehicle,the multi UUV formation system(multi vehicle formation system)improves the efficiency of the vehicle in the task and enhances the robustness of the whole system in time and space.In this paper,we will study the path planning strategy and coordinated control method of the hybrid multi vehicle formation system in the process of multi vehicle formation navigation,including formation transformation and formation keeping.The main contents of this paper are as follows:1.In this paper,two sub tasks of formation keeping and transformation in multi vehicle formation are analyzed,and the sub task flow and problem model are described respectively,and the framework of coordinated control system is selected.Secondly,the kinematic model and dynamic model of UUV with six degrees of freedom are established in fixed coordinate system and motion coordinate system,which is simplified to horizontal plane under the guarantee of main motion characteristics of UUV Based on the graph theory,the mathematical model of communication topology is established,and the general form of multi vehicle formation coordination control system is introduced.2.For the task path planning problem of formation transformation of multi-UUV formation system,firstly,the elements of path planning of multi vehicle formation system are analyzed,and the objective function is established according to the requirements of path planning;secondly,the path of optimization model is generated by dubins curve,and the multi UUV formation problem is transformed into the assignment problem in linear planning,and the optimization model is established,and the continuous Hopfield neural network is used The algorithm searches for the optimal transformation path.Finally,through the MATLAB simulation of three UUV random formation transformation to "triangle" formation,the reliability of the formation change method is verified.3.To solve the formation transformation control problem of multi-UUV formation system,a method combining the theory of backstepping and the theory of second-order consistency is proposed.Firstly,the nonholonomic constraints of the vehicle model are considered,and the error equation of multi vehicle formation system is established based on the method of path guidance point.Secondly,in the formation transformation control of multi vehicle formation system,it is divided into active mode and passive mode.In the active mode,the backstepping controller is designed by track tracking error equation to gradually stabilize the heading angle error.In the passive mode,the formation time consistency controller is designed by formation coordination error equation to gradually stabilize the velocity error Matlab simulation of formation transformation control of multi vehicle formation system verifies the correctness and effectiveness of formation transformation controller.4.Aiming at the problem of formation keeping control of multi-UUV formation system,three kinds of errors in the navigation of multi vehicle formation system are put forward and three error equations are established.Secondly,according to the error equation and the kinematic model of the vehicle,the formation keeping controller is designed based on the consistency theory of virtual navigator.Finally,the formation keeping control matla is designed through the formation keeping control of multi vehicle formation system B simulation is used to verify the correctness and effectiveness of formation keeping controller of multi vehicle formation system.