Multi-rate Control And Path Planning Algorithm Design For Quadrotor UAV

With the advent of information age,high-tech battlefield is rising.With the advantages of small size,flexible mobility,strong concealment,the quadrotor UAV is rapidly applied in all walks of life.In the complex environment,the control algorithm and path planning algorithm of the quadrotor UAV are particularly important.So the main work of this thesis is divided into the following two parts:Firstly,in view of the nonlinear dynamic model of the quadrotor UAV flight process,combined with the advantages of the Backstepping control method,considering the discrete-time system model,this thesis designs a backstepping controller based on multi-rate sampling.The stability of the closed-loop system can be guaranteed by Lyapunov method.The advantage of this controller is very obvious: compared with the conventional discrete sampling controller,the Backstepping controller based on multi-rate sampling designed in this thesis changes many times in each sampling interval.The information received by the computer is closer to the real-time information of the controlled system,which makes the control precision higher.Without changing the performance of the controller,the multi-rate sampling Backstepping controller allows for a larger sampling period than conventional discrete sampling.This means that under the same control accuracy requirements,the cost of the computer control system is reduced.Secondly,in view of the two defects in the traditional artificial potential field method in the path planning design of quadrotor UAV: target unreachable and trapped in local minimum,this thesis designs a new path planning algorithm by introducing adjustment factors into the repulsion function.It ensures that when the UAV is close to the target point,the gravitational force is reduced and the repulsive force is also reduced.So that the UAV can reach the target point smoothly.When the UAV enters the local minimum point in the map,by creating a virtual target point in the map,we create a new gravitational force at that point,breaking the original ”stress balance” state,and then making the UAV ”escape” from the local minimum point.