Enhancing the usability of the MANUS manipulator by using visual servoing

Manus is a wheelchair mounted manipulator, meant to assist severely handicapped people in carrying out all day living tasks, such as eating, drinking, scratching etc. The manipulator has six rotational degrees of freedom for positioning and orienting the gripper, one degree of freedom for opening and closing the gripper, and one (optional) degree of freedom for lifting the entire manipulator. MANUS is designed to operate in an unstructured environment, where the user is responsible for driving the robot to the required position (telemanipulation). Compared with industrial robots, MANUS has low accuracy and low repeatability. These deficiencies have to be compensated by the end-user who guides the system to the required position, based on visual observations (dotted lines in fig.1).