Research On Formation Control Of Unmanned Surface Vehicles Under Communication Limitation

Unmanned surface vehicle as a kind of intelligent platform on the water,has an immeasurable role both in civil and military aspects.At present,a single unmanned surface vehicle can no longer meet the task requirements in complex scenes.Formation control of unmanned surface vehicles has gradually come into people’s view and become a prerequisite for formation coordination.In this paper,the control problem of unmanned craft formation is studied under the background of limited communication.Firstly,a formation control scheme based on relative position information is proposed to solve the problem that unmanned surface vehicles cannot obtain the position and attitude information of adjacent vehicles under the communication limitation.The relative position between unmanned surface vehicles can be obtained by measuring the distance information and bearing information by the onboard sensor.Based on the design idea of backstepping control and combined with dynamic surface control,the problem of "differential explosion" generated in the calculation process is solved.At the same time,adaptive control is introduced to improve the robustness of the unmanned surface vehicle formation.In addition,radial basis function neural network combined with minimum learning parameter is used to approximate the unknown model of unmanned surface vehicle dynamically.At the same time,the computational complexity is reduced.Secondly,aiming at the high cost of distance information measurement,a formation control scheme based on bearing information is proposed.This scheme abandons the measurement and utilization of distance information and relies only on bearing information to realize formation control of unmanned surface vehicles.In order to facilitate the design of formation controller,the mathematical model of unmanned surface vehicle is converted into position subsystem and attitude subsystem.At the same time,the projection idea is introduced into the design process of virtual control law.In addition,the minimum parameter learning method is introduced to reduce the amount of computation in the uncertainty approximation process of unmanned surface vehicles.Finally,considering the convergence time of unmanned surface vehicle formation under communication constraints,a formation control scheme with finite time based on bearing information is proposed.In this scheme,the idea of finite-time filter dynamic surface is introduced.The designed virtual control law is filtered through the first-order Levant differentiator,and error compensation parameters are designed to offset the errors generated in the filtering process.At the same time,all state variables and errors of the closed loop formation system can converge in a finite time.In addition,on the basis of formation maintenance control in the first two chapters,formation scaling control is considered,so that the unmanned surface vehicles can complete the tasks such as driving in the narrow channel and avoiding obstacles at sea,so as to meet the needs of practical engineering.