Nonlinear adaptive control for an unmanned aerial payload transportation system: theory and experimental validation

In this paper, the position control and swing motion control problem are investigated for an aerial payload transportation system which consists of a quadrotor unmanned aerial vehicle (UAV) and a suspended payload. Under the constraints of underactuated properties and unknown system parameters, a nonlinear adaptive control strategy is designed based on the energy methodology, which achieves accurate position control of the UAV as well as the payload's fast swing suppression during the flight. The stability of the closed-loop system, asymptotic convergence of the UAV's position error and payload swing suppression are proved via Lyapunov-based stability analysis. Real-time experimental results validate the effectiveness of the developed technique.