NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Configuration control of seven degree of freedom armsA seven-degree-of-freedom robot arm with a six-degree-of-freedom end effector is controlled by a processor employing a 6-by-7 Jacobian matrix for defining location and orientation of the end effector in terms of the rotation angles of the joints, a 1 (or more)-by-7 Jacobian matrix for defining 1 (or more) user-specified kinematic functions constraining location or movement of selected portions of the arm in terms of the joint angles, the processor combining the two Jacobian matrices to produce an augmented 7 (or more)-by-7 Jacobian matrix, the processor effecting control by computing in accordance with forward kinematics from the augmented 7-by-7 Jacobian matrix and from the seven joint angles of the arm a set of seven desired joint angles for transmittal to the joint servo loops of the arms. One of the kinematic functions constrains the orientation of the elbow plane of the arm. Another one of the kinematic functions minimizing a sum of gravitational torques on the joints. Still another one of the kinematic functions constrains the location of the arm to perform collision avoidance. Generically, one of the kinematic functions minimizes a sum of selected mechanical parameters of at least some of the joints associated with weighting coefficients which may be changed during arm movement. The mechanical parameters may be velocity errors or position errors or gravity torques associated with individual joints.
Document ID
20080004770
Acquisition Source
Headquarters
Document Type
Other - Patent
Authors
Seraji, Homayoun
Date Acquired
August 24, 2013
Publication Date
July 4, 1995
Subject Category
Cybernetics, Artificial Intelligence And Robotics
Report/Patent Number
Patent Number: US-PATENT-5,430,643
Patent Application Number: US-PATENT-APPL-SN-849629
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-PATENT-5,430,643
Patent Application
US-PATENT-APPL-SN-849629
No Preview Available