Parameter Adaptive Control for a Quadrotor With a Suspended Unknown Payload Under External Disturbance

Abstract

This paper focuses on the disturbance attenuation control of the quadrotor suspended payload system with unknown payload mass. Since the quadrotor transportation system is an eight-degreeof-freedom system with only four actuated degrees, it is difficult to achieve rapid stabilization of the quadrotor under varying payload and external disturbances. In this paper, a nonlinear controller based on rotation matrix is designed to rapid stabilization of attitude. By analyzing the effect of load mass on the trajectory tracking control, a parameter adaptive controller is proposed for position control. A mass estimation algorithm is established to estimate the payload mass in the air, which improves the robustness of the system. This approach can maximize load-bearing capacity within the thrust range of the quadrotor. The Lyapunov-based analysis proves the exponential convergence of the attitude error and the stability of the whole system. The contrast simulations demonstrate that the controller is superior to the sliding-mode controller incorporating input shaping on mass estimation, trajectory tracking, and disturbance resistance.

On the Effect of Flexibility on the Dynamics of a Suspended Payload Carried by a Quadrotor

“…The observer law can also be written with Equation (28), by using the relationship z(t) = ŵ(t) − Ly(t), as addressed in [53]. The RDO equation is, thus, defined as:…”

“…. z(t) = (A 22 − LA 12 )z(t) + (A 22 − LA 12 )Ly(t) + (A 21 − LA 11 )y(t) + (B 2 − LB 1 )u(t) (28) The linear quadratic regulator (LQR) technique is chosen to calculate the RDO gain vector (L).…”

“…External disturbances can also negatively affect a UAV and its payload performance by increasing the undesired vibration. A disturbance attenuation control was proposed in [28] to enhance the quadrotor stabilization under external disturbances. This approach introduced an adaptive parameter for the position control to estimate the payload mass and improve the robustness of the system.…”