Nonlinear Control for Aerial Transportation Systems With Double-Pendulum Swing Effects

When transporting cargoes or goods by aerial vehicles, the hook's rotation around the suspension point, together with the payload's rotation around the hook, causes the double-pendulum swing effects. However, this phenomenon is always neglected to simplify the control problem. With a more accurate description of the aerial transportation system driven by quadrotors, the analysis and careful consideration of the double-pendulum swing characteristic will improve the control effect. Nevertheless, the control design is difficult due to the increased system degrees of freedom and the more complicated dynamic coupling. To deal with these practical issues, a novel regulation oriented nonlinear antiswing controller is designed for aerial transportation systems with consideration of double-pendulum swing effects. By fabricating a new energy function, the nonlinear controller is proposed with the coupling terms incorporated to enhance the transient performance. Subsequently, in this article, we provide rigorous stability analysis based on Lyapunov theory. Experimental results are presented to demonstrate that the proposed control scheme exhibits better control performance in terms of increased transient response. The proposed method not only gives the analysis for aerial transportation systems with double-pendulum swing effects, but also solves the control problem with such behavior in the three-dimensional space, thus bringing inspiration to the effective control of other similar suspension systems.