King's College London

The three-fingered robot hand can imitate the posture of the thumb, index finger, and middle finger of a human hand, thereby realizing the motion of a human hand. The introduction of metamorphic palms further enhances the manipulator's workspace and grasping adaptability. Focusing on the bionic design of the palm, based on the reconfigurable Hooke joint(rT), a novel metamorphic hand was designed to imitate the motion of real hands, so that the grasping ability of the hand could be enhanced. Because of the reconfigurable characteristic of the rT joint, the palm of the manipulator shows different motion modes in different configurations of the rT joint. The inclination angle between the palm operation plane of the metamorphic hand and the Oxy plane and the size of the palm workspace also exhibit different changes. To obtain the maximum operating workspace when the finger length is fixed, the radius of the palm and the object radius are approximately in direct proportion. Thus, the large change in the radius of the manipulator's palm significantly improves the gripping adaptability. Moreover, the characteristics of the single-degree-of-freedom of the palm in different configurations are conducive to the control of the manipulator and improve its working stability. The mobility of the palm in the two singular positions and its regular positions in the workspace was analyzed, the workspace and the position of the palm working plane of the metamorphic hand in different working modes were calculated, and the change of the inclination angles of the finger operation plane and the radius of the palm was determined. The excellent performance of the novel metamorphic hand was confirmed.