Modeling and UDE-Based Disturbance Rejection Control of the Quadrotor With a Cable-Suspended Payload

In this paper, the disturbance rejection control problem of the quadrotor with a cable-suspended payload is investigated. To quantitatively analyze the disturbance forces caused by the payload swing, the classic quadrotor single rigid body model is modified into a comprehensive quadrotor-payload coupling model. Based on this model, an uncertainty and disturbance estimator-based control is proposed for the quadrotor outer and inner loop. The stability of the control system is analyzed, and the disturbance rejection performance is theoretically proven to be related monotonically to a single UDE parameter T, which allows us to improve the system robustness easily by tuning T. Comparative simulation results are presented to show the performance advantage of the proposed control over classic PID controller.