Research On Cooperative Formation Control Of Multi-UAV Under Leader-follower Structure

Due to the quadrotor unmanned aerial vehicle(UAV)small size,simple structure,easy to flight characteristics has received the widespread attention from all sectors of society in recent years.Especially,multi-UAV cooperation formation can complete more complicated tasks and it has a good fault tolerance and robustness.Therefore,multi-UAV cooperative control system has gradually become a research hotspot.This paper mainly establishes the mathematical model of the quadrotor UAV according to the strong coupling,nonlinearity,and underactuated of the quadrotor UAV.Under the Leader-Follower structure,in view of different communication structures,a cooperative formation controller is designed to realize the quadrotor UAV cooperative formation.The main work is as follows:Under the condition that Leader-Follower structure and communication topology are fixed,the cooperative formation control of multi-UAV is realized by hierarchical communication:the mathematical model is established based on the flight principle of the quadrotor UAV.The trajectory tracking controller is designed for the Leader UAV by integral backstepping method.Under the Leader-Follower structure,a controller is designed for each follower UAV to ensure that the multi-UAV cooperative system can achieve desired formation and track the desired reference trajectory.The proposed algorithm was verified by simulation and experimental platform composed of visual positioning system+MATLAB+ROS+Bebop2 quadrotor UAV.Under arbitrary topology,a finite time sliding mode control strategy is used to achieve the multi-UAV cooperative formation:under the Leader-Follower structure,a continuous distributed finite-time state observer is designed for each Follower quadrotor UAV to estimate the state of the virtual Leader quadrotor UAV,according to the observed state,the sliding mode control method is used to design the cooperative formation controller,and the stability of the system is proved by analyzing the yaw and position error.A cooperative system composed of five quadrotor UAVs is simulated to verify that the multi-UAV formation can converge to the desired geometric formation,while the multi-UAV formation can track the reference trajectory of the virtual leader UAV.