A Novel Anthropomorphic Robot Hand and its Master Slave System

Abstract

Future humanoid robots will execute various complicated tasks based on communication with human users. These humanoid robots will be equipped with anthropomorphic robot hands much like the human hand. The robots will eventually supplant human labor in the execution of intricate and dangerous tasks in areas such as manufacturing, space exploration and the seabeds. Many multi-fingered robot hands (Salisbury & Craig, 1982) (Jacobsen et al., 1984) (Jau, 1995) (Kyriakopoulos et al., 1997) have been developed. These robot hands are driven by actuators in a location remote from the robot hand frame and are connected by tendon cables. Elasticity in the tendon cable causes inaccurate joint angle control, and the long wiring of tendon cables may obstruct the motion of the robot when the hand is attached to the tip of a robot arm. To solve these problems, robot hands in which the actuators are built into the hand (Bekey et al., 1990) (Rosheim, 1994) (Lin & Huang, 1996) (Butterfass et al., 2001) (Namiki et al., 2003) (Yamano et al., 2003) have been developed. However, these hands have the problem that their movement differs from that of the human hand because both the number of fingers and the number of joints in the fingers are insufficient. Recently, many reports (Fearing, 1990) (Howe, 1994) (Shimojo et al., 1995) (Johnston et al., 1996) (Jockusch et al., 1997) have been presented on the use of tactile sensors that attempt to realize adequate object manipulation through contact with the fingers and palm. There has been only the slight development of a hand that combines a 6-axes force sensor attached to the fingertips with a distributed tactile sensor mounted on the hand surface. To provide a standard robot hand used to study grasping and dexterous manipulation, our group has developed the Gifu Hand I (Kawasaki & Komatsu, 1998) (Kawasaki & Komatsu, 1999), the Gifu Hand II (Kawasaki et al., 1999), the Gifu Hand III (Mouri et al., 2002), and the kinetic humanoid hand (Kawasaki et al., 2004). This paper presents a novel robot hand called the KH (Kinetic Humanoid) Hand type S for sign language, which requires a high degree of fingertip velocity. In addition, we construct a PC-based master slave system to demonstrate effectiveness in grasping and manipulating objects. An experiment involving grasping and manipulating objects by the master slave control is shown. Our results show that the KH Hand type S has a higher potential than previous robot hands in rendering a picturesque hand shape and performing dexterous object manipulations like the human hand.