Research On Fault-tolerant Tracking Control Of Multi-quadrotor UAV Based On Observe

Due to the advantages of simple structure,convenient operation,small body and flexibility,quadrotor unmanned aerial vehicles(UAVs)are often used in many related fields.Due to the low efficiency and short endurance of a single quadrotor UAV in the process of performing tasks,a large number of experts and scholars had gradually been attracted by the cooperative control of multiple UAVs,and some results had been achieved.Affected by the external disturbance and the aging of the UAVs’ parts,quadrotor UAVs are easy to break down during cluster flight,and result in UAVs are unable to maintain their formation and complete the target mission,and even crash.It is of broad application prospect and research value to realize the fault-tolerant control of multiple quadrotor UAVs system in the cooperative tracking process in case of failure.In this thesis,the multiple quadrotor UAVs are taken as the research object,aiming at the problems of failure of followers,communication link failure and sensor failure in the multiple quadrotor UAVs system,the fault-tolerant control algorithm is designed based on observer technology and adaptive method to realize the cooperative tracking control of multiple quadrotor UAVs system.The contents of this thesis mainly include:(1)An adaptive observer-based fault-tolerant tracking control method is designed to solve the problem of bias failure of the followers in the formation system.Firstly,the adaptive observer is designed to observe the fault and state in the position subsystem,and then the observed information is used to design the state feedback controller.Secondly,the adaptive method is adopted to design the controller in the yaw angle subsystem.Finally,the effectiveness of the fault-tolerant control method is verified by simulation.(2)For the multiple quadrotor UAVs system with communication link failure,a faulttolerant tracking control method based on the leader state observer is designed.Firstly,the leader state observer is designed to estimate the state of the leader.Secondly,the state feedback controller is designed according to the observed information to ensure that the system state tracking error converges,so as to realize the accurate tracking of the leader by the follower.Finally,the effectiveness of the designed fault-tolerant control algorithm is verified by simulation.(3)For the multiple quadrotor UAVs system with disturbance and sensor failure,a faulttolerant tracking control method based on unknown input observer is designed.Firstly,the quadrotor UAV system with sensor failure is expanded,and the unknown input observer is designed for the expanded system.Secondly,the output feedback controller is designed based on the observational information to ensure that the system state tracking error converges,and the followers can accurately track the leader.Finally,the effectiveness of the fault-tolerant control algorithm is verified by simulation.