Bionic design of universal gripper for nursing robot with hybrid joints and variable Equivalent Link Length

Currently, most rehabilitation/nursing robots attach the human body to end of robot by ‘binding’ solution, which makes operation complicated and greatly limits their applications. Therefore, it is necessary study a universal gripper that can directly grasp limbs as end-effector robot. Inspired hand, this paper proposes bionic under-actuated imitates structure hand. The concept Equivalent Link Length (ELL) proposed optimize envelope effect. And with hybrid rotational translational joints increase gripping stiffness avoid harmful component in grip force. Theoretical analyses experiments on effect, force distribution load capacity show propose cylindrical (limb-shaped) objects wide applicable size range, also has high capacity. Furthermore, characteristic almost constant transfer ratio, reduces number sensors required system. These results potential be used nursing