Coordinated Control Of Underactuated Surface Unmanned Vehicles

With the development of the marine science and technology,the unmanned surface vehicle(USV)is well known by people as a kind of important tool of oceanic works.The research of single USV is the main objective of traditional USV research,not the coordinated formation control of multiple unmanned surface vehicles(USVs).Therefore,with the development of automation technology,computer technology and communication technology,the coordinated formation problems of multiple USVs are researched by more and more researchers and scholars.The coordinated formation technology of USV cluster has a high value of application in the field of military and civilian areas.At the same time,USV is a kind of nonlinear system which has many special properties,such as essential nonlinearity,nonholonomic constraints,underactuated and so on.Therefore,it is valuable to study the coordinated formation control of multiple USVs.In this thesis,many native and foreign research results about control problem of underactuated USV are deeply analyzed.Based on the backstepping technique and Lyapunov stability theory,the problems about trajectory-tracking control and formation control of underactuated USV is researched in this thesis.The contents are as follows: First of all,the problems about formation control of multiple underactuated USVs are described.The movement state of USV is described by the earth-fixed frame and the body-fixed frame,and the coordinate transformation is described.The mathematical model of USV,that is kinematics and kinetics,is researched.And the control targets of trajectory-tracking and formation is presented.Secondly,the trajectory-tracking control of underactuated USV.The simplified three degrees of freedom horizontal model is researched,and the trajectorytracking error model is built.The time-varying state feedback and backstepping technique is used to design the trajectory-tracking controller.Lyapunov direct method is used to analyze the stability of control system.The simulation results reveal that the controller is available.Finally,the formation control of multiple underactuated USVs.The leader-follower control method is used for building formation control model.According to control targets,formation controller is designed by using backstepping technique and Lyapunov direct method in this chapter.The simulation results reveal that the controller is available.The trajectory-tracking control and formation control of USV are achieved by the designed controllers.At the same time,the work and the deficiencies of this thesis are summarized,and the further improved aspects are proposed.