The creation of advanced dexterous mechanical manipulators and actuators is increasingly important for development of intelligent robots, which are capable of performing any human arm task. This paper deals with a spherical ultrasonic motor which is an application of an ultrasonic motor to such a dexterous actuator which has multi-degree of freedom. As a prototypal spherical ultrasonic motor, we have developed successfully two kinds of spherical motor with two-degree of freedom which has a spherical body driven by two pairs of ultrasonic actuator. The spherical ultrasonic motors show good controlability and high accurate positioning.
