A Nonlinear Trajectory Tracking Approach of Double-Pendulum Aerial Transportation Systems: Transient Performance Improvement and Saturated Inputs

This paper considers aerial cargo transportation tasks in the presence of double-pendulum swing effects. Due to the higher degree of freedom and the more intricate dynamic coupling of the system, an effective nonlinear trajectory tracking control method is proposed to effectively track a given trajectory and simultaneously suppress the swing motion during tracking. The controller is designed to achieve improved transient tracking performance and generate amplitude-saturated inputs. Specifically, a tracking performance improvement term is elaborately designed through a dynamic generator, achieving more accurate trajectory tracking with bounded overshoots. Also, saturated functions are induced to provide bounded inputs, being able to deal with input saturation problems. Using the Lyapunov stability analysis and LaSalle’s invariance theorem, the stability of the system is rigorously proven. The author’s search of relevant literature shows that the proposed method is the first method of a nonlinear anti-swing trajectory tracking controller for double-pendulum aerial transportation systems in three-dimensional space. The tracking performance, swing suppression, and robustness against external disturbances are verified through comparative simulation.