Robonaut: a telepresence-based astronaut assistant

Robonaut, NASA's latest anthropomorphic robot, is designed to work in the hazards of the space environment as both an astronaut assistant and, in certain situations, an astronaut surrogate. This highly dexterous robot is now performing complex tasks under telepresence control in the Dexterous Robotics Laboratory at the Johnson Space Center that could previously only be carried out directly by humans. With 43 degrees of freedom (DOF), Robonaut is a state-of-the-art human size telemanipulator system. It has a three-DOF articulated waist and two seven-DOF arms, giving it an impressive work space for interacting with its environment. Its two five-fingered hands allow manipulation of a wide range of common tools. A pan/tilt head with multiple stereo camera systems provides data for both teleoperators and computer vision systems. Telepresence control is the main mode of operation for Robonaut. The teleoperator dons a variety of sensors to map hand, head, arm and body motions to control the robot. A distributed object-oriented network architecture links the various computers used to gather posture and joint angle data from the human operator, to control the robot, to generate video displays for the human operator and to recognize and generate human voice inputs and outputs. Distributed object-oriented software allows the same telepresence gear to be used on different robots and allows interchangable telepresence gear in the laboratory environment. New telepresence gear and new robots only need to implement a standard software interface. The Robonaut implementation is a two-tiered system using Java/Jini for distributed commands and a commercial-off-the-shelf data sharing protocol for high-speed data transmission. Experimental telepresence gear is being developed and evaluated. Force feedback devices and techniques are a focus, and their efforts on teleoperator performance of typical space operations tasks is being measured. Particularly, the augmentation of baseline Robonaut teleoperation control techniques with force feedback information is shown to significantly reduce potentially damaging contact forces and improve operator consistency.