Design of Hover Flying Adaptive PD Controller for Four Rotor Unmanned Aerial Vehicle

Abstract

An adaptive PD controller design method based on model reference is proposed, which is used to control the suspension of the four rotorcraft with variable quality. The reference model is obtained by approximating the attitude angle of the hovercraft by the kinetic equation of the UAV, and a second order system is selected according to the reference model which is similar to the actual system and has the expected dynamic characteristics. Based on the method of Lyapunov’s stability theory, the parameters of the controller are determined by the error between the output of the controlled object and the output of the reference model. When the controlled object parameter changes, the adaptive mechanism adjusts the PD controller by parameter estimation so that the estimated value of the controlled object parameter can always track its actual value. The adaptive controller is compared with the conventional PD controller and the PD controller with speed limit compensation in the simulation experiment. The results show that the control signal of the controller is smaller than that of the conventional PD controller. It is faster and more stable than the PD controller with the speed limit compensation. It has better control effect on the hover of quadrotor drone.