A two-degree-of-freedom spherical ultrasonic motor and its control method

Abstract

The invention discloses a two-freedom spherical ultrasonic motor and a control method therefor. The ultrasonic motor comprises an upper oscillator, a lower oscillator and a spherical rotor, wherein the upper oscillator and the lower oscillator are the same in structure; each of the upper oscillator and the lower oscillator comprises a circular ring structure, two beams and four piezoelectric films; one end of each of two beams is fixedly connected with the outer side wall of the corresponding circular ring structure; the axes of two beams point to the circle center of the corresponding circular ring structure and are located on a straight line; four piezoelectric films are symmetrically arranged on the upper surfaces and the lower surfaces of two corresponding beams respectively and are polarized along the thickness direction; the piezoelectric films arranged on the upper surfaces and the lower surfaces of two beams are opposite in polarization direction; the spherical rotor is arranged on an inner circular ring of the circular ring structure of the lower oscillator; the inner circular ring of the circular ring structure of the upper oscillator is arranged on the spherical rotor; and the upper oscillator and the lower oscillator are orthogonally distributed in parallel. The modes of the upper oscillator and the lower oscillator are adjusted, so that spherical rotor is controlled to achieve two-freedom motion. The two-freedom spherical ultrasonic motor is low in cost, simple in structure, high in mechanical integration level and easy to miniaturize.

Description

technical field [0001] The invention relates to the field of multi-degree-of-freedom ultrasonic motors, in particular to a two-degree-of-freedom spherical ultrasonic motor and a control method thereof. Background technique [0002] With the development of science and technology, precision positioning devices have higher and higher requirements for motion, and single-degree-of-freedom drives can no longer meet the requirements. If the movement of each degree of freedom is completed by a single-degree-of-freedom motor, the whole mechanism will inevitably become complicated, the control difficulty will increase, and the production cost will increase. Compared with single-degree-of-freedom ultrasonic motors, multi-degree-of-freedom ultrasonic motors have higher mechanical integration and more compact mechanisms. They have broad application prospects in devices that require multi-degree-of-freedom movements, and can be used for micro-robot joints and eyeballs. Drives, as well as...

AI Technical Summary

Problems solved by technology

[0003] However, the stator structure of the traditional multi-degree-of-freedom ultrasonic motor is relatively complex, difficult to manufacture and redundant in the control system, and it is difficult to miniaturize the entire structure.

Images