Formation Control Of Quadrotor UAVs Based On Multiagent System Theory

Quadrotor UAV is widely used in many occasions because of its simple structure,convenient operation and low cost.Compared with single UAV,UAV formation has the advantages of wide detection range,high execution efficiency and good fault tolerance.It has broad application prospects in agriculture,military,transportation,environmental monitoring and so on.At present,the mainstream formation control methods mostly adopt centralized control,and centralized control means to uniformly send the real-time flight data of UAVs in the formation to the ground station.According to the collected information,the ground station plans the optimal flight command and sends it to the aircraft group,so as to complete the formation flight mission.Although the centralized formation flight control strategy has high control accuracy and fast response speed,it does not perform well in flexibility and reliability.This method has high requirements for the data processing capacity of the ground station,so it is not suitable for large-scale cluster applications.In order to solve the above problems,a formation control method of quadrotor UAV based on multi-agent theory is proposed and the feasibility of this method is verified by numerical simulation.The main contents of this paper are as follows:Firstly,this paper briefly introduces the structure and flight principle of four rotor aircraft.Different coordinate systems are established to describe the pose state of UAV in space.Combined with Newton-Euler formula and the transformation relationship between coordinate system,the dynamic model of quadrotor UAV is deduced,and the model is appropriately simplified to facilitate the development of control work.According to the simplified model of four rotor aircraft and its characteristics,a method based on integral backstepping and active disturbance rejection control（IBKADRC）is designed to realize the position and attitude control of quadrotor UAV.An appropriate extended state observer is built to observe the total disturbance of the attitude channel,and the observation results are offset in the control input to achieve the purpose of anti-interference.Finally,the observation effect of the extended state observer on the total disturbance is tested by numerical simulation,and the algorithm is compared with the traditional PID algorithm to prove its advantages in response speed,steady-state error and anti-interference ability.Next,taking multi-agent theory as the starting point,a formation control method based on multi-agent consistency theory is proposed.There is a set of adaptive coupling weights in the controller,which can adaptively adjust its size to meet the stability conditions of the formation system.The control effect of the controller in second-order linear multi-agent system is verified by numerical simulation.In addition,it is also used as the formation controller of quadrotor UAV cluster,which is combined with IBKADRC to realize the formation control of quadrotor UAV cluster,and its effectiveness is proved by simscape visual simulation.Aiming at the problem that formation control based on consistency theory is difficult to meet the requirements of obstacle avoidance and collision avoidance in practical work,this paper applies distributed model predictive control to multi-agent formation.Combined with the characteristics of distributed model predictive control,the requirements of collision avoidance and obstacle avoidance are taken as the nonlinear constraints of its optimal objective function.The objective function of the demand solution is constructed according to the tracking demand and formation demand.The control input of the multi-agent system is obtained by solving the optimal solution of the objective function,and the optimal control input is taken as the input of the multi-agent system to realize its formation control.In this paper,the method is also applied to four rotor formation,and its feasibility is illustrated by visual simulation.