Development of UB Hand 3: Early Results

Grasping force control of a tendon-driven prosthetic finger based on force estimation using motor current signals

“…The structure of the tendon-driven prosthetic hand is simple and compact with small size and light weight, making it easily in line with the shape, size and weight of human hands. Because this driving pattern is similar to the tendon-driven mechanism in an organism, it has been widely used in the field of bionic robots and artificial limbs [5,6].…”

A Mechatronic Perspective on Robotic Arms and End-Effectors

“…The continuum compliance of the fingers in this case is achieved using helical springs mounted inside the shell of each finger. These springs enable the phalanx of the fingers to bend in a continuous fashion, while concurrently restoring the shape of the fingers to the original non-flexed configuration when the tension in the tendons is eliminated (Lotti et al, 2005). The wrist joints of the UB hand are not integrated within the structure of the hand; rather, the wrist motion is achieved independently by the manipulator arm carrying the hand on the end-link.…”

Spherical trigonometry constrained kinematics for a dexterous robotic hand with an articulated palm

“…1 Since then, a number of multifingered robotic hands have been designed and developed all over the world. They include, to name but a few, the prosthetic hand-based Belgrade/University of Southern California (USC) hand 2 which incorporated a thumb and two more coupled pairs of fingers that adapted to the shape of the grasped object and so the whole hand needed only four motors while it had five digits; the highly integrated Deutsches Zentrum für Luft-und Raumfahrt (DLR)-Hand 3 incorporating purpose built linear actuators, position sensors both for the motors and joints, tactile sensors on each finger link, stereo camera on the palm and two axis torque sensors at the finger tips; the Robonaut hand 4,5 designed to be similar in size and capability to an astronaut's hand in a suit as well as withstand the environment of space; the tendon-driven Shadow Robot Hand 6 with a one-Degrees Of Freedom (DOF) articulated palm and a structure closely resembling the human hand with the option to either use electric motors or pneumatic artificial muscles; the self-contained three-fingered Barrett hand 7 with one finger fixed on the palm and two fingers able to rotate around the palm; the low-cost easy-to-use Laboratory of Robotics and Mechatronics in Cassino (LARM) hand 8,9 with three one-DOF fingers having each finger's joints coupled by four-bar linkages designed to mimic a human performing a cylindrical grasp; the UB hand 10,11 which has explored many novel control and actuation concepts including a twisted string actuator where by twisting two strings a rotary motion is converted to a linear one; the DLR/Harbin Institute of Technology (HIT) II hand 12 which consists of a palm module and finger modules with actuators and control system integrated in each module, and the Sungkyunkwan University (SKKU) hand 13 which also uses identical finger modules each with its own integrated control system an motors as well as six-DOF force-torque sensors at the fingertips. All these hands, anthropomorphic or non-anthropomorphic, are capable of performing certain degree of dexterous motions.…”