Fixed-Time Anti-Swing Control of Quadrotor UAV Slung-Load System With Unknown Cable Length and Load Mass
针对物流和救援中负载质量和缆绳长度未知的问题，提出一种自适应固定时间三环控制方案，实现四旋翼无人机吊挂系统的快速轨迹跟踪和负载摆动抑制。
In aerial load transportation scenarios, such as logistics and emergency rescue operations, the load mass and cable length are often unknown in advance, posing significant challenges for the control of quadrotor uncrewed aerial vehicle (UAV) slung-load systems. This article addresses trajectory tracking and anti-swing control of quadrotors under unknown load mass and cable length. First, the system’s dynamic model is established using 3-D force decomposition and the Newton–Euler method. Then, based on the system’s cascade structure, a novel adaptive fixed-time three-loop control scheme is proposed, including the quadrotor’s position and attitude controllers as well as the load’s swing angle controller. Unlike existing asymptotic convergence methods, the approach guarantees fixed-time convergence regardless of initial states, ensuring rapid trajectory tracking and effective suppression of load swing. Notably, the controller integrates adaptive parameter estimation laws that enable real-time online estimation without prior knowledge of system parameters. Moreover, adaptive compensation terms are embedded to enhance robustness against external disturbances. Theoretical analysis guarantees the fixed-time stability of the closed-loop system, while comparative simulations validate the effectiveness and advantages of the proposed method.