Development of a multi-fingered robot hand with fingertip tactile sensors

The authors are developing a multifingered robot hand which is modeled on a human hand. The aim is to identify the technologies necessary for this type of robot hand. The hand consists of 4 fingers, each with 4 joints actuated by DC motors via wires. The hand is attached to the tip of a 6-degree-of-freedom arm. The fingers and the arm are controlled by 6 32-bit microprocessor boards. Each finger has a tactile sensor on the fingertip. This consisting of a silicone rubber cap with a cavity filled with an incompressible fluid. Using these sensors and potentiometers mounted at one side of each joint, contact forces and positions of the fingertips are controlled. Three or four fingers grasp an object cooperatively when each finger is force-controlled using the tactile sensors independently. Evaluation tests of the position and the force control were executed, and experiments requiring the robot hand to pick up a pen and write characters were conducted.