| Quadrotor aircraft has excellent characteristics such as simple structure and flexible operation.It is widely used in human activities and has also become a current research hotspot.The flight control system is the core system of the quadrotor,and the attitude control is the key to the flight control system.The quadrotor aircraft system has many complex characteristics such as nonlinearity and strong coupling,and the flight environment is complex,which makes it difficult to establish an accurate model.Therefore,the quadrotor attitude control is a difficult point in the design of the flight control system.In order to overcome these difficulties,this paper applies Adaptive Dynamic Programming(ADP)algorithm to the design of the quadrotor’s attitude control system,and conducts a series of simulation experiments to verify the effectiveness of the algorithm.In view of the large amount of calculation of the ADP attitude controller,this paper combines the ADP algorithm with the event trigger mechanism,and studies its control performance through simulation experiments.The main contents of this article are as follows:(1)Design the attitude control system using traditional control algorithms.By analyzing the motion principle of the quadrotor flight simulator,the state space model is established,and the attitude control system is designed with PID algorithm,and then the simulation experiment is carried out in Simulink environment to study the step response curve of the PID attitude controller.Considering the limited energy of quadrotor aircraft,LQR algorithm is used to design the attitude controller,and the constraint on the control output is added to the performance index function.Similarly,a simulation experiment is carried out on the LQR attitude controller and the result analysis is carried out.(2)In view of the difficulty in modeling the quadrotor system and the limited energy of quadrotor aircraft,the ADP algorithm is used to design the attitude controller.This paper converts the quadrotor attitude tracking problem into an optimal adjustment problem,and then designs a performance index function including tracking error and control output,and uses ADP algorithm to solve the optimal control problem.Two algorithms are given: value iterative algorithm and policy iterative algorithm,and the neural networks are used to implement two algorithms.In the simulation,the control performance of the controllers designed by two algorithms are studied separately and compared with the PID and LQR controllers.The results show that the ADP controller can achieve good control effects.(3)In view of the large amount of calculation of the ADP attitude controller,this paper combines the event-triggered mechanism with the ADP attitude controller.Simulation experiments show that the event-triggered ADP attitude controller can effectively reduce the update frequency of controller and maintain good control performance. |
