Toward Air Operation Aerial Manipulator Control With a Refined Anti-Disturbance Architecture

Abstract

Due to the presence of strong inner dynamic coupling and changes in center of mass (CoM) during tasks execution, the precise tracking control problem of aerial manipulator systems becomes challenging. When the mounted manipulator is performing a task, the movements of the manipulator will cause the inherent dynamic coupling force/torque disturbances. Such disturbances are quickly acted on the position loop and the orientation loop of the UAV body, to the detriment of the control accuracy. On the other hand, the fluctuation of the UAV body leads to the base floating, resulting in a significantly adverse influence on the precision of the manipulator end-effector. Since different disturbances have distinct mathematical properties, i.e., norm bounded and rate bounded, currently, there is no control framework that is able to tackle the dynamic coupling, model uncertainty and base floating simultaneously. In this paper, a refined anti-disturbance control architecture is proposed for the decentralized aerial manipulator model, where various disturbances with different mathematical properties are well explored and tackled according to their positions and effects acting on the system. The stability of the proposed control framework is ensured by using Lyapunov-like analysis. Experimental results are presented to illustrate the performance of the proposed control framework. Note to Practitioners-One of the key challenges that hinder the aerial manipulator potential applications is its stability and accuracy due to the existence of various disturbances. Most of disturbance rejection control methods in the literature for aerial manipulator always deal with the various disturbances as the lumped one. Their distinct mathematical properties and different impacts on the system are not well explored, which may result in the performance degradation and limit its practical implementation. In this article, a refine anti-disturbance architecture is proposed, which is able to handle various disturbances in a more systematical way according to their mathematical properties and effects acting on the system. Physical experiments suggest that finely tackling the different disturbances enjoys a better performance in aerial manipulator trajectory tracking control problem and thus can promote the aerial manipulator to be deployed in the tasks demanding on the accuracy. In addition, such control strategy can also be extended to other robotic systems suffering from various disturbances.