Research On Multi-vehicle Fixed-time Cooperative Formation Control Algorithm

With the rapid development of driverless technology and people’s growing need for a better life,smart drones will play an important role in intelligent transportation in the future.As a part of the intelligent transportation field,vehicle formation control has been paid more and more attention by experts and scholars.At the same time,fixed-time collaborative control has the advantages of predicting the convergence time range of the system in advance,faster convergence speed,and stronger robustness,and the system convergence time does not depend on the initial state,making fixed-time collaborative control applied in various practical projects.Therefore,this dissertation discusses the problem of vehicle formation collaborative control based on fixed-time.The main research content can be summarized as follows:(1)A fixed-time controlled vehicle formation control strategy is proposed to address the issue of traditional multi vehicle collaborative formation control systems being unable to predict system convergence time.At first,the problem of vehicle formation is transformed into the control problem of the specific error system between the following vehicle and the leader vehicle by using the leader following mode,and the mathematical model is established by using the distance error function.Based on the established error model,a linear and angular velocity controller for the following vehicle is designed using fixed-time theory and Lyapunov function.Then,the error model was divided into two systems,and the stability of the system was proved and the upper bound of the convergence time of the position error system was derived.Firstly,the effectiveness of the proposed fixed-time formation controller is verified through software simulation.The simulation results show that the proposed method can ensure that the vehicle formation error system quickly converges within a fixed-time,forming the expected formation formation,and the system convergence time is independent of the initial state of the system.(2)Considering the influence of external natural environment and internal model parameter uncertainty on the actual operation of intelligent unmanned vehicles,which weakens the control effect on the vehicle,a formation control algorithm with disturbance observer is proposed.At first,the formation error model is replaced with the general dynamic and kinematics model,and the disturbance observer is introduced to enable the system to accurately identify the composite disturbance.Using the idea of fixed-time theory to design a controller for the following vehicle,the Lyapunov stability theory was used to prove that both controllers can converge within a fixed-time range,and then it was proved that the entire vehicle formation control system can converge within a fixed-time range.Firstly,the effectiveness of the proposed disturbance observer based fixed-time vehicle formation controller is verified through simulation.The simulation results show that the proposed controller can quickly converge the vehicle formation within a fixed-time,and the system convergence time is independent of the initial state of the system.