Three DOF wrist joint - control of joint stiffness and angle-

A mechanism of three DOF joint similar to human wrist joint is introduced in this paper. It fundamentally mimics the human muscro-skeletal system to control not only its joint angle but also its joint stiffness. The key mechanism is the originally developed ANLES (Actuator with Non-Linear Elasticity System) that can be used as a voluntary muscle. The proposed mechanism is controlled by four ANLESes and one more actuator. This paper first presents the mechanism of ANLES and the wrist joint. Next it shows the second machine that succeeded dramatically downsizing of its volume and weight compared to the first machine. It follows the experimental results of controlling the joint angle and stiffness.