High Accuracy Visual Servoing For Aerial Manipulation Using A 7 Degrees Of Freedom Industrial Manipulator

This paper is devoted to the performance optimization of an aerial manipulation system composed of a Flettner-helicopter and 7 DoF manipulator. With experiments we demonstrate that the time delays in signal propagation between perception and actuation modules play an important role for the overall performance of an aerial manipulator system using visual servoing. We present an approach for estimation of the perception-action time delay and its active compensation based on the predicted motion of the manipulator end-effector.Experiments show that compensating these delays improve the manipulation performance even more than elaborated methods for cooperative arm-helicopter control. The proposed approach should not be considered as a replacement of arm-helicopter coordinated control but as an extension.Additionally the reliability of the visual servoing is improved by implementing a multi object localization that is robust to occlusions of the target object.The accuracy and robustness of the proposed visual servoing and active compensation algorithms are demonstrated in in-and outdoor experiments With the proposed algorithm the aerial manipulator is able to repeatedly grasp an object with an accuracy better than 2cm.