Free-Flying Robot Tested on Parabolic Flights: Kinematic Control

During servicing operations, free-flying robots equipped with robotic arms are required to operate without disturbing the nearby environment through unwanted base oscillations. We present underlying theory, kinematic control software, and experimental results of a three-dimensional free-flying robot prototype able to follow a given trajectory with its end-effector while base movements are minimized. Experiments were performed in a microgravitational environment obtained during parabolic flight tests. For the purposes of this study, only rotation of the base around its yaw axis was minimized, and a robotic arm with four degrees of freedom was used. The displacements of the robot base were monitored by an inertial platform positioned on the base. Results obtained during experiments prove the feasibility of testing such a robot during parabolic flights, show the effectiveness of the kinematic control software developed to minimize base displacements, and suggest directions for future development.