Null-Space-Based Adaptive Control for Aerial Manipulators on Cooperatively Transporting Cable-Suspended Objects

Abstract

This paper proposes a system framework for aerial manipulators to cooperatively transport a cable-suspended load. If the trajectory of the payload is considered as the control object, the entire system of the aerial manipulators and the slung load is redundant. Therefore, the null-space-based (NSB) controller can be presented to ensure the position/orientation of the slung load via the control for the quadrotors and robotic arm. The load trajectory and interactive force on the aerial manipulator during transportation are investigated. Additionally, the adaptive control method is presented in the inner controller to keep the control performance under dynamic uncertainties, interactive forces, and unknown load. To demonstrate the stability and efficacy of the proposed control structure, Lyapunov stability analysis, and numerical simulations are presented.