A Novel Newton-Euler Method-Based Nonlinear Anti-Swing Control for a Quadrotor UAV Carrying a Slung Load

In order to suppress the swing of slung load during the flight of the quadrotor unmanned aerial vehicle (UAV), a new double closed-loop nonlinear control method Newton-Euler is proposed based on an energy function and the LaSalle's invariance theorem. First, the forces of each part in the quadrotor-slung load system (QSLS) is analyzed separately, and the dynamics model of the QSLS is established by the Newton-Euler method. Then, an energy function is constructed based on the relative motion relationship between the UAV and the slung load, and a nonlinear position controller is designed based on the energy function to enable the UAV to suppress the swing angle of the slung load while moving to the desired position in three-dimensional space. The equilibrium point of the whole system is proved to be asymptotically stabilized by the Lyapunov technique and LaSalle's invariance theorem. Finally, some comparisons are made with a nonlinear adaptive controller and the linear quadratic regulator (LQR) to verify the effectiveness and superiority of the controller proposed in this article. It is shown that for the QSLS, the proposed controller has faster convergence speed and better transient performance during the anti-swing control.