Research On Cooperative Control Method Of Quadrotor UAV Formation Under Multiple Constraint

With the development of science and technology,the application of UAV is no longer the topic of the minority.Due to the advantages of low cost,easy operation and simple construction,Quadrotor UAVs are widely used in both civil and military fields.However,with the expansion of UAV application scenarios and the continuous improvement of task complexity,the low working efficiency of a single UAV is no longer competent for some difficult tasks.The cooperative formation of multiple UAVs has a wide detection range and high working efficiency,it is more suitable for unpredictable environment,which has higher research value and practical significance.The top priority is how to make multiple UAVs form formation safely,carry out task allocation reasonably and complete collaborative planning is the top priority.In this thesis,the multi-UAV system is treated as the research object,referring to the problems of follower’s failure,resource loss of inter-aircraft communication and external disturbance during flight,the formation flight control algorithm is designed to ensure the overall effect of multi-UAV cooperative flight.The contents of this thesis mainly include:(1)The five-aircraft formation model is established based on the leader-follower method.The expected path and attitude tracking effect is achieved by the non-singular fast terminal sliding mode control in the single aircraft.The deviation fault and failure fault of followers in formation flight are considered.First,an extended high-gain observer is designed to observe follower’s deviation fault in formation model.Second,an adaptive sliding mode fault-tolerant control scheme is designed in the formation controller to ensure flight stability.Finally,the effectiveness of the method is verified by simulation experiments.(2)Considering the problem of resource consumption caused by inter-aircraft communication during formation flight and the practical significance of constructing timevarying formation,a time-varying formation control method of multi-UAV based on eventtriggering mechanism is proposed.First,a distributed control protocol is designed for each UAV,and triggering conditions of control input are set to avoid excessive update of controller.Second,the stability of the system is verified by the theory of the generated edge laplacian matrix.Finally,the effectiveness of the method is verified by simulation experiments.(3)Based on the research of work(2),the problem of time-varying formation control for multiple UAVs based on event-triggering mechanism in an external disturbance environment is further considered.First,auxiliary variables are defined to simplify the second-order system model of UAV.Second,a finite-time disturbance observer is designed to observe the external disturbance.Third,the triggering state of UAV is quantified uniformly and applied to a consistent distributed controller.Next,aiming at the difference of tracking errors between aircrafts,an event-triggering function is designed,which makes multiple UAVs communicate only at the trigger time.Finally,the effectiveness of the method is verified by simulation experiments.