Nonlinear Control Method Design of A Quadrotor Unmanned Aerial Vehicle With A Suspended Load Using An Elastic Rope

The system of quadrotor unmanned aerial vehicle (UAV) with suspended load has great research significance. Aiming at the instability of load swing, a new nonlinear control method is proposed in this paper. The load is suspended using an elastic rope suspended at the center of gravity of the quadrotor. The dynamics modeling of the mechanical system is built. Based on the energy analysis method, the nonlinear controller of the system is designed. By taking advantage of the Lyapunov stability theory and LaSalle's invariance principle the stability of the closed-loop system is proved. Finally, the numerical simulation verifies that the control method can not only suppress the swing of the payload, but also accurately control the UAV to the target position.