Development of 3-DOF active rotational ball joint

This paper develops a 3-DOF active rotational ball joint with a simple and compact mechanism, which can realize a rotation around an any- direction rotational axis with a well manipulability and can change its direction of rotational axis smoothly and arbitrarily when it is on rotating. The mechanism principle of this joint is proposed and analyzed. Then the ball joint is developed and experimental verification on the proposed mechanism is performed. The effectiveness of the mechanism principle is outlined by some experimental results.