Path-following control for aerial manipulators robots with priority on energy saving

Abstract

Nowadays, performing active tasks with aerial robots has become a great challenge to execute them autonomously or semi-autonomously. In this context, there is great importance to emphasize the control and energy consumption that is produced at the time of performing these tasks with an aerial mobile manipulator robot. In this context, this paper presents a new control scheme for the task of path-following through the end-effector of an aerial mobile manipulator robot prioritizing energy consumption. The proposed controller is designed according to the kinematics of the system considering the high redundancy of the aerial mobile manipulator robot composed of an aerial platform and an anthropomorphic robotic arm. Therefore, the proposed controller allows two control objectives. The main objective is the path-following by the end-effector of the aerial mobile manipulator robot, considering a variable path-following speed according to the references of the desired task; and the secondary objective is the energy saving by modifying the internal structure of the robot according to the parameters of the desired path to follow. Three configurations are proposed to modify the internal structure of the robot: (i) configuration for paths with curvature variations on the Z-axis of the fixed reference system; (ii) configuration with curvature variations of the desired path in the XY plane and; and (iii) configuration for curvature variations of the desired path in the XYZ space. In order to validate the proposed controller different experimental tests are performed in an unstructured environment, the proposed controller is compared with a path following controller based on inverse kinematics that allows to complete the desired task at constant speed and constant internal configuration of the robot. Through the experimental results an approximate 10% energy saving is achieved with the proposed controller during path-following.