An Online Trajectory Planning Approach for a Quadrotor UAV With a Slung Payload

In this article, a novel online antiswing trajectory planning approach is proposed for a quadrotor slung-load system, which is an underacuated, strong coupling, and nonlinear system so that it is difficult to achieve the quadrotor's precise positioning and the payload's swing suppression simultaneously. The proposed trajectory planning approach is efficient and convenient without iterative optimizations. Specially, the proposed trajectory planning strategy is composed of two parts: a target positioning part and an antiswing part. The convergence of the quadrotor's positioning and payload's swing suppression is proved by Lyapunov-based analysis. Experimental results show that the proposed trajectory has achieved satisfied control performance.