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A SYSTEM THAT HAS MORE DEGREES OF FREEDOM NECESSARY TO PERCEIVE A GIVEN MOVEMENT IS KNOWN AS REDUNDANT. THERE ARE SEVERAL REDUNDANT SYSTEMS IN BIOLOGY, SUCH AS, IN THE FEET, THE HANDS, AND THE SPINE. HOWEVER, IN ROBOTICS, THESE SYSTEMS HAVE BEEN AVOIDED DUE TO DIFFICULTIES IN SIMULATION, THE IMPLEMENTATION OF ACTUATORS, AND HIGH COSTS. THIS WORK SHOWS REDUNDANCY IN A MECHANICAL HAND WITH FIVE FINGERS, EACH WITH FOUR JOINTS AT SIMPLE ROTATION. ALTHOUGH, REDUNDANCY OF SYSTEMS HAVE THE MENTIONED DIFFICULTIES, THERE ARE POSITIVE FACTORS, SUCH AS THE INCREASE OF FLEXIBILITY IN THE MANIPULATION OF DIFFERENT FORMS OF OBJECTS. IN ORDER TO CHOOSE THE BEST SOLUTION (NOT THE ONLY), RESTRICTIONS OF MOVEMENT ARE APPLIED. THE RESTRICTIONS ARE BASED ON THE POSSIBLE MOVEMENTS OF THE HUMAN HAND. IN ADDITION, THE VERSATILITY, STABILITY AND SECURITY AT GRASP MUST BE CONSIDERED. MATHEMATICAL EQUATIONS ARE PRESENTED IN THIS WORK FOR THE CRITICAL SITUATIONS, IN WHICH ONLY TWO FINGERS ARE USED AND THE OBJECT TO BE GRASPED IS A SPHERE. THE SPHERE IS AN OBJECT AT COMPLEX STABILITY, SO THE GRASP IS EFFECTUATED IN CONTACT POINTS. THE RESTRICTIONS ENCOUNTERED IN THE HUMAN HAND FOR THESE EQUATION ARE ALSO CONSIDERED.
KEYWORDS: MECHANICAL HAND, KINEMATICAL REDUNDANCY, MANIPULATION, KINEMATICS |
