Development of new generation spherical ultrasonic motor

Abstract

We have successfully developed a new kind of spherical motor with two degree of freedom by ultrasonic vibration: it has o45 rotor; the maximum speed is 30 rpm, the maximum output torque reaches 0.7 kgf cm, the maximum positioning error is less than 0.3 mm. In order to control this new motor, we have developed a new dynamic model by the friction drive model. We demonstrated that the traction drive model explains the characteristics of the motor and this motor has good controllability of velocity and position. We can expect to apply this motor to robotics manipulator's joint and machine vision systems due to the small and simple mechanism of the motor.