Accession Number : ADA316960

Title :   A New Technique for Compensating Joint Limits in a Robot Manipulator.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Litt, Jonathan ; Hickman, Andre ; Guo, Ten-Huei

PDF Url : ADA316960

Report Date : OCT 1996

Pagination or Media Count : 26

Abstract : A new robust, optimal, adaptive technique for compensating rate and position limits in the joints of a six degree-of-freedom elbow manipulator is presented. In this new algorithm, the unmet demand as a result of actuator saturation is redistributed among the remaining unsaturated joints. The scheme is used to compensate for inadequate path planning, problems such as joint limiting, joint freezing, or even obstacle avoidance, where a desired position and orientation are not attainable due to an unrealizable joint command. Once a joint encounters a limit, supplemental commands are sent to other joints to best track, according to a selected criterion, the desired trajectory.

Descriptors :   *ALGORITHMS, *CONTROL SYSTEMS, *ROBOTS, *MANIPULATORS, *JOINTS, PATHS, ORIENTATION(DIRECTION), RATES, SATURATION, DEGREES OF FREEDOM, FREEZING, LIMITATIONS, PLANNING, BARRIERS, ADAPTIVE SYSTEMS, ACTUATORS, COMPENSATION, AVOIDANCE, TRAJECTORIES.

Subject Categories : Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE