Three-degree-of-freedom micro piezoelectric actuator based on annular oscillator and excitation method

Abstract

The invention discloses a three-degree-of-freedom micro piezoelectric actuator based on an annular vibrator and an excitation method. The piezoelectric actuator comprises a lower supporting seat, an upper supporting seat, the annular vibrator and a spherical rotor, the upper supporting seat is fixedly arranged at the top of the lower supporting seat, the annular vibrator is arranged above the upper supporting seat, the spherical rotor is arranged above the annular vibrator, and the identification block is arranged on the spherical rotor. According to the three-degree-of-freedom micro piezoelectric actuator based on the annular vibrator and the excitation method, the piezoelectric actuator adopts the design of the annular vibrator with a rounded square structure, so that the structural size of the piezoelectric actuator is remarkably reduced, the system complexity is greatly simplified, the convenience of processing and manufacturing is promoted, and the piezoelectric actuator is suitable for large-scale popularization and application. The three-degree-of-freedom driving capability of the single annular vibrator can be endowed through a simple excitation method, the spherical rotor can be driven to achieve three-degree-of-freedom rotating motion only through the single annular vibrator, the driving precision and efficiency of the spherical rotor are effectively improved, and the three-degree-of-freedom spherical rotor has wider application potential in the aspect of microcosmic control.

Description

Technical Field

[0001] The invention belongs to the technical field of piezoelectric drive, and in particular relates to a three-degree-of-freedom micro piezoelectric driver based on a ring oscillator and an excitation method. Background Art

[0002] At present, with the increasingly demanding industrial needs, traditional drives such as electromagnetic motor drives, hydraulic drives, and pneumatic drives have become increasingly difficult to meet the requirements due to problems such as large equipment size, low precision, and complex maintenance. For this reason, the development of drives based on smart materials has become a research hotspot, and smart materials cover a variety of types such as dielectric elastomers, shape memory alloys, and magnetostrictive materials.

[0003] However, despite the remarkable progress made in the miniaturization of actuators, smart materials still have some problems that limit their application scope. Specifically, dielectric elastomers require high-power loading devices and have large mechanical losses; shape memory alloys have slow response speeds and are difficult to precisely control; and magnetostrictive materials have complex manufacturing processes.

[0004] Compared with the above-mentioned drivers, piezoelectric drivers have the advantages of simple structure, easy miniaturization, fast response speed, high operating efficiency and precision, and have been widely used in medical, robotics, aerospace and other fields.

[0005] However, although existing piezoelectric actuators can ensure a smaller actuator structure size, their functions are often limited to single-degree-of-freedom or even single-direction motion output. In order to expand the motion output capability of piezoelectric actuators, a common practice is to achieve this by combining multiple actuators. However, this approach not only increases the manufacturing and assembly complexity of piezoelectric actuators, but also brings additional challenges, such as the need to design more complex excitation schemes to coordinate the work of each actuator. Therefore, although piezoelectric actuators excel in miniaturization and performance, they still face certain technical barriers when achieving multi-degree-of-freedom motion.

[0006] The Chinese patent application with application number 202410158317.1 discloses a multi-degree-of-freedom piezoelectric driver and driving method based on a prismatic vibrator. The driver consists of a disc base, three prismatic vibrators on the base, and six piezoelectric ceramic sheets. By applying an alternating voltage to the piezoelectric ceramics on the inner and outer sides of the unilateral prismatic vibrator, the spherical mover rotates under the action of the static friction of a single prismatic vibrator. Although the structural design of the piezoelectric driver shows the characteristics of miniaturization, the processing of the entire special-shaped vibrator is relatively complicated. Under the excitation of the sawtooth signal, the prismatic vibrator uses structural deformation rather than resonant displacement to drive the rotation of the spherical mover, which makes the driver's working efficiency relatively low, limiting its application potential in certain high-performance demand scenarios.

[0007] The Chinese patent application with application number 201921167136.6 discloses a spherical rotor multi-degree-of-freedom piezoelectric driver, which consists of a base, a spherical rotor, a support frame, a pre-pressure adjustment mechanism, a stator bracket, and three stators with the same structure. Although the structural design of the piezoelectric driver can realize the multi-degree-of-freedom movement of the spherical rotor, three stators are required to be used in conjunction, which inevitably leads to an increase in the overall space occupancy of the driver, thereby posing a challenge to its miniaturization. In addition, the configuration of multiple stators also puts forward more stringent requirements on the processing accuracy and assembly process of the driver, which not only increases the manufacturing cost, but may also affect the stability and reliability of the final product. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a three-degree-of-freedom micro piezoelectric driver and an excitation method based on a ring oscillator. The ring oscillator design with a rounded square structure not only significantly reduces the structural size of the piezoelectric driver, but also greatly simplifies the system complexity, promotes the convenience of processing and manufacturing, and gives a single ring oscillator the three-degree-of-freedom driving capability. The spherical rotor can be driven to achieve three-degree-of-freedom rotational motion only by a single ring oscillator, which effectively improves the driving accuracy and efficiency of the spherical rotor, and has more extensive application potential in micro-manipulation.

[0009] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a three-degree-of-freedom micro piezoelectric driver based on a ring oscillator, comprising a lower support seat, an upper support seat, a ring oscillator and a spherical rotor; the upper support seat is fixedly installed on the top of the lower support seat, the ring oscillator is arranged above the upper support seat, the spherical rotor is arranged above the ring oscillator, and an identification block is arranged on the spherical rotor.

[0010] The annular oscillator includes an annular base, a first X-direction piezoelectric ceramic sheet, a second X-direction piezoelectric ceramic sheet, a first Z-direction piezoelectric ceramic sheet, a second Z-direction piezoelectric ceramic sheet, a first Y-direction piezoelectric ceramic sheet, a second Y-direction piezoelectric ceramic sheet, a third Y-direction piezoelectric ceramic sheet and a fourth Y-direction piezoelectric ceramic sheet; the annular base adopts a rounded square structure; the first X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet and the second Z-direction piezoelectric ceramic sheet are sequentially and evenly distributed on the four straight line segment side elevations of the annular base; the first Y-direction piezoelectric ceramic sheet, the second Y-direction piezoelectric ceramic sheet, the third Y-direction piezoelectric ceramic sheet and the fourth Y-direction piezoelectric ceramic sheet are sequentially and evenly distributed on the four straight line segment lower surfaces of the annular base.

[0011] Positioning holes are provided on the lower surfaces of the four rounded corner sections of the annular base; four positioning pins are evenly distributed on the upper surface of the upper support seat, and the four positioning pins correspond to the positions of the four positioning holes one by one and are plug-fitted.

[0012] The polarization direction of the first X-direction piezoelectric ceramic sheet is the positive direction of the X-axis; the polarization direction of the second X-direction piezoelectric ceramic sheet is the negative direction of the X-axis; the polarization direction of the first Z-direction piezoelectric ceramic sheet is the negative direction of the Z-axis; the polarization direction of the second Z-direction piezoelectric ceramic sheet is the positive direction of the Z-axis; the polarization direction of the first Y-direction piezoelectric ceramic sheet and the fourth Y-direction piezoelectric ceramic sheet is the negative direction of the Y-axis; the polarization direction of the second Y-direction piezoelectric ceramic sheet and the third Y-direction piezoelectric ceramic sheet is the positive direction of the Y-axis.

[0013] A first driving finger, a second driving finger, a third driving finger and a fourth driving finger are sequentially and successively fixed on the upper surface of the four straight line segments of the annular base; the first driving finger is located directly above the first Y-direction piezoelectric ceramic sheet, and the first Y-direction piezoelectric ceramic sheet and the first Z-direction piezoelectric ceramic sheet are distributed in the same direction; the second driving finger is located directly above the second Y-direction piezoelectric ceramic sheet, and the second Y-direction piezoelectric ceramic sheet and the first X-direction piezoelectric ceramic sheet are distributed in the same direction; the third driving finger is located directly above the third Y-direction piezoelectric ceramic sheet, and the third Y-direction piezoelectric ceramic sheet and the second Z-direction piezoelectric ceramic sheet are distributed in the same direction; the fourth driving finger is located directly above the fourth Y-direction piezoelectric ceramic sheet, and the fourth Y-direction piezoelectric ceramic sheet and the second X-direction piezoelectric ceramic sheet are distributed in the same direction.

[0014] The invention discloses an excitation method for a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator. When a spherical rotor needs to rotate clockwise around a Z axis, a first excitation signal is synchronously applied to a first X-direction piezoelectric ceramic sheet, a second X-direction piezoelectric ceramic sheet, a first Z-direction piezoelectric ceramic sheet, and a second Z-direction piezoelectric ceramic sheet, and a second excitation signal is synchronously applied to a second Y-direction piezoelectric ceramic sheet and a fourth Y-direction piezoelectric ceramic sheet. Conversely, when the spherical rotor needs to rotate counterclockwise around the Z axis, a second excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, and a second Z-direction piezoelectric ceramic sheet, and a first excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic sheet and the fourth Y-direction piezoelectric ceramic sheet. The applied first excitation signal is a sinusoidal AC voltage signal with the same frequency and amplitude, and the applied second excitation signal is a cosine AC voltage signal with the same frequency and amplitude.

[0015] A method for exciting a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator. When a spherical rotor needs to rotate clockwise around an X-axis, a first excitation signal is synchronously applied to a first X-direction piezoelectric ceramic sheet, a second X-direction piezoelectric ceramic sheet, a first Z-direction piezoelectric ceramic sheet, and a second Z-direction piezoelectric ceramic sheet, and a second excitation signal is synchronously applied to a first Y-direction piezoelectric ceramic sheet and a third Y-direction piezoelectric ceramic sheet; conversely, when the spherical rotor needs to rotate counterclockwise around the X-axis, a second excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, and the second Z-direction piezoelectric ceramic sheet, and a first excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic sheet and the third Y-direction piezoelectric ceramic sheet; wherein the applied first excitation signal is a sinusoidal AC voltage signal with the same frequency and amplitude, and the applied second excitation signal is a cosine AC voltage signal with the same frequency and amplitude.

[0016] A method for exciting a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator. When a spherical rotor needs to rotate clockwise around a Y-axis, a first excitation signal is synchronously applied to a second Y-direction piezoelectric ceramic piece and a fourth Y-direction piezoelectric ceramic piece, and a second excitation signal is synchronously applied to a first Y-direction piezoelectric ceramic piece and a third Y-direction piezoelectric ceramic piece; conversely, when the spherical rotor needs to rotate counterclockwise around the Y-axis, a second excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic piece and a fourth Y-direction piezoelectric ceramic piece, and a first excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic piece and a third Y-direction piezoelectric ceramic piece; wherein the applied first excitation signal is a sinusoidal AC voltage signal with the same frequency and amplitude, and the applied second excitation signal is a cosine AC voltage signal with the same frequency and amplitude.

[0017] Beneficial effects of the present invention:

[0018] The three-degree-of-freedom micro piezoelectric driver and excitation method based on a ring oscillator of the present invention adopts a ring oscillator design with a rounded square structure, which not only significantly reduces the structural size of the piezoelectric driver, but also greatly simplifies the system complexity, promotes the convenience of processing and manufacturing, and gives a single ring oscillator a three-degree-of-freedom driving capability. The spherical rotor can be driven to achieve three-degree-of-freedom rotational motion only by a single ring oscillator, effectively improving the driving accuracy and efficiency of the spherical rotor, and has a wider application potential in micro-manipulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator according to the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of the assembly of the lower support seat and the upper support seat of the present invention;

[0021] Figure 3Schematic diagram of the structure of the ring oscillator of the present invention (viewing angle 1);

[0022] Figure 4 Schematic diagram of the structure of the ring oscillator of the present invention (viewing angle 2);

[0023] In the figure, 1—lower support seat, 2—upper support seat, 3—annular oscillator, 4—spherical rotor, 5—identification block, 6—annular base, 7—first X-direction piezoelectric ceramic sheet, 8—second X-direction piezoelectric ceramic sheet, 9—first Z-direction piezoelectric ceramic sheet, 10—second Z-direction piezoelectric ceramic sheet, 11—first Y-direction piezoelectric ceramic sheet, 12—second Y-direction piezoelectric ceramic sheet, 13—third Y-direction piezoelectric ceramic sheet, 14—fourth Y-direction piezoelectric ceramic sheet, 15—positioning hole, 16—positioning pin, 17—first driving finger, 18—second driving finger, 19—third driving finger, 20—fourth driving finger. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figures 1 to 4 As shown, a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator includes a lower support seat 1, an upper support seat 2, a ring oscillator 3 and a spherical rotor 4; the upper support seat 2 is fixedly installed on the top of the lower support seat 1, the ring oscillator 3 is arranged above the upper support seat 2, the spherical rotor 4 is arranged above the ring oscillator 3, and an identification block 5 is arranged on the spherical rotor 4.

[0026] In this embodiment, flange structures are provided at both upper and lower ends of the lower support seat 1, and four circumferentially evenly distributed locking bolts are arranged on the lower flange structure of the lower support seat 1. The upper flange structure of the lower support seat 1 is fixedly connected to the upper support seat 2 by four circumferentially evenly distributed fastening bolts; the spherical rotor 4 is a lightweight hollow stainless steel ball; the identification block 5 is fixed to the surface of the spherical rotor 4 by bonding, and the rotation angle of the spherical rotor 4 is calibrated by the identification block 5.

[0027] The annular oscillator 3 includes an annular base 6, a first X-direction piezoelectric ceramic sheet 7, a second X-direction piezoelectric ceramic sheet 8, a first Z-direction piezoelectric ceramic sheet 9, a second Z-direction piezoelectric ceramic sheet 10, a first Y-direction piezoelectric ceramic sheet 11, a second Y-direction piezoelectric ceramic sheet 12, a third Y-direction piezoelectric ceramic sheet 13 and a fourth Y-direction piezoelectric ceramic sheet 14; the annular base 6 adopts a rounded square structure; the first X-direction piezoelectric ceramic sheet 7, the first Z-direction piezoelectric ceramic sheet 9, the second X-direction piezoelectric ceramic sheet 8, and the second Z-direction piezoelectric ceramic sheet 10 are sequentially and evenly distributed on the four straight line segment side elevations of the annular base 6; the first Y-direction piezoelectric ceramic sheet 11, the second Y-direction piezoelectric ceramic sheet 12, the third Y-direction piezoelectric ceramic sheet 13 and the fourth Y-direction piezoelectric ceramic sheet 14 are sequentially and evenly distributed on the four straight line segment lower surfaces of the annular base 6.

[0028] In this embodiment, the first X-direction piezoelectric ceramic sheet 7, the second X-direction piezoelectric ceramic sheet 8, the first Z-direction piezoelectric ceramic sheet 9, the second Z-direction piezoelectric ceramic sheet 10, the first Y-direction piezoelectric ceramic sheet 11, the second Y-direction piezoelectric ceramic sheet 12, the third Y-direction piezoelectric ceramic sheet 13 and the fourth Y-direction piezoelectric ceramic sheet 14 have the same structural dimensions, all adopt a rectangular structure and are fixed to the surface of the annular base 6 by bonding.

[0029] Positioning holes 15 are provided on the lower surfaces of the four rounded corners of the annular base 6 ; four positioning pins 16 are evenly distributed on the upper surface of the upper support seat 2 , and the four positioning pins 16 correspond to the four positioning holes 15 in one-to-one position and are plug-fitted.

[0030] The polarization direction of the first X-direction piezoelectric ceramic sheet 7 is the positive direction of the X-axis; the polarization direction of the second X-direction piezoelectric ceramic sheet 8 is the negative direction of the X-axis; the polarization direction of the first Z-direction piezoelectric ceramic sheet 9 is the negative direction of the Z-axis; the polarization direction of the second Z-direction piezoelectric ceramic sheet 10 is the positive direction of the Z-axis; the polarization direction of the first Y-direction piezoelectric ceramic sheet 11 and the fourth Y-direction piezoelectric ceramic sheet 14 is the negative direction of the Y-axis; the polarization direction of the second Y-direction piezoelectric ceramic sheet 12 and the third Y-direction piezoelectric ceramic sheet 13 is the positive direction of the Y-axis.

[0031] A first driving finger 17, a second driving finger 18, a third driving finger 19 and a fourth driving finger 20 are sequentially and successively fixed on the upper surface of the four straight line segments of the annular base 6; the first driving finger 17 is located directly above the first Y-direction piezoelectric ceramic sheet 11, and the first Y-direction piezoelectric ceramic sheet 11 and the first Z-direction piezoelectric ceramic sheet 9 are distributed in the same orientation; the second driving finger 18 is located directly above the second Y-direction piezoelectric ceramic sheet 12, and the second Y-direction piezoelectric ceramic sheet 12 and the first X-direction piezoelectric ceramic sheet 7 are distributed in the same orientation; the third driving finger 19 is located directly above the third Y-direction piezoelectric ceramic sheet 13, and the third Y-direction piezoelectric ceramic sheet 13 and the second Z-direction piezoelectric ceramic sheet 10 are distributed in the same orientation; the fourth driving finger 20 is located directly above the fourth Y-direction piezoelectric ceramic sheet 14, and the fourth Y-direction piezoelectric ceramic sheet 14 and the second X-direction piezoelectric ceramic sheet 8 are distributed in the same orientation.

[0032] In this embodiment, the first driving finger 17, the second driving finger 18, the third driving finger 19 and the fourth driving finger 20 have the same structural dimensions, and the tops of the four driving fingers are all ball head structures and are fixed to the surface of the annular base 6 by bonding.

[0033] A method for exciting a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator. When a spherical rotor 4 needs to rotate clockwise around a Z axis, a first excitation signal is synchronously applied to a first X-direction piezoelectric ceramic sheet 7, a second X-direction piezoelectric ceramic sheet 8, a first Z-direction piezoelectric ceramic sheet 9, and a second Z-direction piezoelectric ceramic sheet 10, and a second excitation signal is synchronously applied to a second Y-direction piezoelectric ceramic sheet 12 and a fourth Y-direction piezoelectric ceramic sheet 14. Conversely, when the spherical rotor 4 needs to rotate counterclockwise around the Z axis, a second excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet 7, the second X-direction piezoelectric ceramic sheet 8, the first Z-direction piezoelectric ceramic sheet 9, and the second Z-direction piezoelectric ceramic sheet 10, and a first excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic sheet 12 and the fourth Y-direction piezoelectric ceramic sheet 14. The first excitation signal applied is a sinusoidal AC voltage signal with the same frequency and amplitude, and the second excitation signal applied is a cosine AC voltage signal with the same frequency and amplitude.

[0034] Specifically, when the first X-direction piezoelectric ceramic piece 7, the second X-direction piezoelectric ceramic piece 8, the first Z-direction piezoelectric ceramic piece 9, and the second Z-direction piezoelectric ceramic piece 10 are synchronously applied with the first excitation signal, under the action of the first excitation signal, the annular base 6 can be in a plane bending vibration mode of alternating expansion and contraction in the radial direction, and then the first driving finger 17, the second driving finger 18, the third driving finger 19, and the fourth driving finger 20 are synchronously in a plane bending vibration mode of alternating expansion and contraction in the radial direction through the annular base 6; at the same time, when the second Y-direction piezoelectric ceramic piece 12 and the fourth After the second excitation signal is synchronously applied to the Y-axis piezoelectric ceramic piece 14, under the action of the second excitation signal, the annular base 6 can be in a bending vibration mode of reciprocating oscillation along the axial direction, thereby driving the second driving finger 18 and the fourth driving finger 20 to be synchronously in a bending vibration mode of reciprocating oscillation along the axial direction, and the oscillation direction of the second driving finger 18 and the oscillation direction of the fourth driving finger 20 are always in a mutually opposite state; finally, under the superposition of the above two bending vibration modes, the second driving finger 18 and the fourth driving finger 20 can cooperate to drive the spherical rotor 4 to rotate clockwise around the Z axis. Similarly, when the application objects of the first excitation signal and the second excitation signal are interchanged, the rotation direction of the spherical rotor 4 is changed.

[0035] A method for exciting a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator. When a spherical rotor 4 needs to rotate clockwise around an X-axis, a first excitation signal is synchronously applied to a first X-direction piezoelectric ceramic sheet 7, a second X-direction piezoelectric ceramic sheet 8, a first Z-direction piezoelectric ceramic sheet 9, and a second Z-direction piezoelectric ceramic sheet 10, and a second excitation signal is synchronously applied to a first Y-direction piezoelectric ceramic sheet 11 and a third Y-direction piezoelectric ceramic sheet 13. Conversely, when the spherical rotor 4 needs to rotate counterclockwise around the X-axis, a second excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet 7, the second X-direction piezoelectric ceramic sheet 8, the first Z-direction piezoelectric ceramic sheet 9, and the second Z-direction piezoelectric ceramic sheet 10, and a first excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic sheet 11 and the third Y-direction piezoelectric ceramic sheet 13. The first excitation signal applied is a sinusoidal AC voltage signal with the same frequency and amplitude, and the second excitation signal applied is a cosine AC voltage signal with the same frequency and amplitude.

[0036] Specifically, when the first X-direction piezoelectric ceramic piece 7, the second X-direction piezoelectric ceramic piece 8, the first Z-direction piezoelectric ceramic piece 9, and the second Z-direction piezoelectric ceramic piece 10 are synchronously applied with the first excitation signal, under the action of the first excitation signal, the annular base 6 can be in a plane bending vibration mode of alternating expansion and contraction along the radial direction, and then the first driving finger 17, the second driving finger 18, the third driving finger 19, and the fourth driving finger 20 are synchronously in a plane bending vibration mode of alternating expansion and contraction along the radial direction through the annular base 6; at the same time, when the first Y-direction piezoelectric ceramic piece 11 and the third After the second excitation signal is synchronously applied to the Y-axis piezoelectric ceramic piece 13, under the action of the second excitation signal, the annular base 6 can be in a bending vibration mode of reciprocating oscillation along the axial direction, thereby driving the first driving finger 17 and the third driving finger 19 to be synchronously in a bending vibration mode of reciprocating oscillation along the axial direction, and the oscillation direction of the first driving finger 17 and the oscillation direction of the third driving finger 19 are always in a mutually reverse state; finally, under the superposition of the above two bending vibration modes, the first driving finger 17 and the third driving finger 19 can cooperate to drive the spherical rotor 4 to rotate clockwise around the X axis. Similarly, when the application objects of the first excitation signal and the second excitation signal are interchanged, the rotation direction of the spherical rotor 4 is changed.

[0037] A method for exciting a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator. When the spherical rotor 4 needs to rotate clockwise around the Y-axis, a first excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic plate 12 and the fourth Y-direction piezoelectric ceramic plate 14, and a second excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic plate 11 and the third Y-direction piezoelectric ceramic plate 13; conversely, when the spherical rotor 4 needs to rotate counterclockwise around the Y-axis, a second excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic plate 12 and the fourth Y-direction piezoelectric ceramic plate 14, and a first excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic plate 11 and the third Y-direction piezoelectric ceramic plate 13; wherein the applied first excitation signal is a sinusoidal AC voltage signal with the same frequency and amplitude, and the applied second excitation signal is a cosine AC voltage signal with the same frequency and amplitude.

[0038] Specifically, when the first excitation signal is synchronously applied to the second Y-axis piezoelectric ceramic piece 12 and the fourth Y-axis piezoelectric ceramic piece 14, under the action of the first excitation signal, the annular base 6 can be in a bending vibration mode of reciprocating oscillation along the axial direction, thereby driving the second driving finger 18 and the fourth driving finger 20 to be synchronously in a bending vibration mode of reciprocating oscillation along the axial direction, and the oscillation direction of the second driving finger 18 and the oscillation direction of the fourth driving finger 20 are always in a mutually reverse state; at the same time, when the second Y-axis piezoelectric ceramic piece 11 and the third Y-axis piezoelectric ceramic piece 13 are synchronously applied with the second excitation signal After the second excitation signal is applied, the annular base 6 can be in a bending vibration mode of reciprocating oscillation along the axial direction, thereby driving the first driving finger 17 and the third driving finger 19 to be synchronously in a bending vibration mode of reciprocating oscillation along the axial direction, and the oscillation direction of the first driving finger 17 and the oscillation direction of the third driving finger 19 are always in a mutually opposite state; finally, under the superposition of the above two bending vibration modes, the first driving finger 17, the second driving finger 18, the third driving finger 19 and the fourth driving finger 20 can cooperate to drive the spherical rotor 4 to rotate clockwise around the Y axis. Similarly, when the application objects of the first excitation signal and the second excitation signal are interchanged, the rotation direction of the spherical rotor 4 is changed.

[0039] The solutions in the embodiments are not intended to limit the protection scope of the present invention. All equivalent implementations or changes that do not deviate from the present invention are included in the protection scope of the present invention.

Claims

1. A three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator, characterized in that: It includes a lower support seat, an upper support seat, an annular vibrator and a spherical rotor; the upper support seat is fixedly installed on the top of the lower support seat, the annular vibrator is arranged above the upper support seat, the spherical rotor is arranged above the annular vibrator, and an identification block is arranged on the spherical rotor.

2. The three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator according to claim 1, characterized in that: The annular oscillator includes an annular base, a first X-direction piezoelectric ceramic sheet, a second X-direction piezoelectric ceramic sheet, a first Z-direction piezoelectric ceramic sheet, a second Z-direction piezoelectric ceramic sheet, a first Y-direction piezoelectric ceramic sheet, a second Y-direction piezoelectric ceramic sheet, a third Y-direction piezoelectric ceramic sheet and a fourth Y-direction piezoelectric ceramic sheet; the annular base adopts a rounded square structure; the first X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet and the second Z-direction piezoelectric ceramic sheet are sequentially and evenly distributed on the four straight line segment side elevations of the annular base; the first Y-direction piezoelectric ceramic sheet, the second Y-direction piezoelectric ceramic sheet, the third Y-direction piezoelectric ceramic sheet and the fourth Y-direction piezoelectric ceramic sheet are sequentially and evenly distributed on the four straight line segment lower surfaces of the annular base.

3. The three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator according to claim 2, characterized in that: Positioning holes are provided on the lower surfaces of the four rounded corner sections of the annular base; four positioning pins are evenly distributed on the upper surface of the upper support seat, and the four positioning pins correspond to the positions of the four positioning holes one by one and are plug-fitted.

4. The three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator according to claim 2, characterized in that: The polarization direction of the first X-direction piezoelectric ceramic sheet is the positive direction of the X-axis; the polarization direction of the second X-direction piezoelectric ceramic sheet is the negative direction of the X-axis; the polarization direction of the first Z-direction piezoelectric ceramic sheet is the negative direction of the Z-axis; the polarization direction of the second Z-direction piezoelectric ceramic sheet is the positive direction of the Z-axis; the polarization direction of the first Y-direction piezoelectric ceramic sheet and the fourth Y-direction piezoelectric ceramic sheet is the negative direction of the Y-axis; the polarization direction of the second Y-direction piezoelectric ceramic sheet and the third Y-direction piezoelectric ceramic sheet is the positive direction of the Y-axis.

5. The three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator according to claim 4, characterized in that: A first driving finger, a second driving finger, a third driving finger and a fourth driving finger are sequentially and successively fixed on the upper surface of the four straight line segments of the annular base; the first driving finger is located directly above the first Y-direction piezoelectric ceramic sheet, and the first Y-direction piezoelectric ceramic sheet and the first Z-direction piezoelectric ceramic sheet are distributed in the same direction; the second driving finger is located directly above the second Y-direction piezoelectric ceramic sheet, and the second Y-direction piezoelectric ceramic sheet and the first X-direction piezoelectric ceramic sheet are distributed in the same direction; the third driving finger is located directly above the third Y-direction piezoelectric ceramic sheet, and the third Y-direction piezoelectric ceramic sheet and the second Z-direction piezoelectric ceramic sheet are distributed in the same direction; the fourth driving finger is located directly above the fourth Y-direction piezoelectric ceramic sheet, and the fourth Y-direction piezoelectric ceramic sheet and the second X-direction piezoelectric ceramic sheet are distributed in the same direction.

6. The excitation method of a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator as claimed in claim 5, characterized in that: When the spherical rotor needs to rotate clockwise around the Z-axis, a first excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, and the second Z-direction piezoelectric ceramic sheet, and a second excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic sheet and the fourth Y-direction piezoelectric ceramic sheet; conversely, when the spherical rotor needs to rotate counterclockwise around the Z-axis, a second excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, and the second Z-direction piezoelectric ceramic sheet, and a first excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic sheet and the fourth Y-direction piezoelectric ceramic sheet; wherein the applied first excitation signal is a sinusoidal AC voltage signal with the same frequency and amplitude, and the applied second excitation signal is a cosine AC voltage signal with the same frequency and amplitude.

7. The excitation method of a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator as claimed in claim 5, characterized in that: When the spherical rotor needs to rotate clockwise around the X-axis, a first excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, and the second Z-direction piezoelectric ceramic sheet, and a second excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic sheet and the third Y-direction piezoelectric ceramic sheet; conversely, when the spherical rotor needs to rotate counterclockwise around the X-axis, a second excitation signal is synchronously applied to the first X-direction piezoelectric ceramic sheet, the second X-direction piezoelectric ceramic sheet, the first Z-direction piezoelectric ceramic sheet, and the second Z-direction piezoelectric ceramic sheet, and a first excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic sheet and the third Y-direction piezoelectric ceramic sheet; wherein the applied first excitation signal is a sinusoidal AC voltage signal with the same frequency and amplitude, and the applied second excitation signal is a cosine AC voltage signal with the same frequency and amplitude.

8. The excitation method of a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator as claimed in claim 5, characterized in that: A method for exciting a three-degree-of-freedom micro piezoelectric actuator based on a ring oscillator. When a spherical rotor needs to rotate clockwise around a Y-axis, a first excitation signal is synchronously applied to a second Y-direction piezoelectric ceramic piece and a fourth Y-direction piezoelectric ceramic piece, and a second excitation signal is synchronously applied to a first Y-direction piezoelectric ceramic piece and a third Y-direction piezoelectric ceramic piece; conversely, when the spherical rotor needs to rotate counterclockwise around the Y-axis, a second excitation signal is synchronously applied to the second Y-direction piezoelectric ceramic piece and a fourth Y-direction piezoelectric ceramic piece, and a first excitation signal is synchronously applied to the first Y-direction piezoelectric ceramic piece and a third Y-direction piezoelectric ceramic piece; wherein the applied first excitation signal is a sinusoidal AC voltage signal with the same frequency and amplitude, and the applied second excitation signal is a cosine AC voltage signal with the same frequency and amplitude.

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