CN118842350A - Two-degree-of-freedom piezoelectric oscillating mirror based on single bending piezoelectric driver actuation and deflection method - Google Patents

Abstract

A two-degree-of-freedom piezoelectric swing mirror and deflection method based on a single bending piezoelectric driver actuation belongs to the field of high-resolution fast-response swing mirror devices, and solves the problem that the number of piezoelectric drivers used in traditional piezoelectric swing mirrors is large and the size is large. The swing mirror of the present invention includes a ceramic fixing bolt, a base, a bending piezoelectric driver, a mirror frame, and a mirror frame fixing bolt. The bending piezoelectric driver is evenly divided into four quarter-cylindrical ceramics along the radial direction. The polarization directions of the cylindrical ceramics distributed oppositely are opposite. The voltage applied to the two cylindrical ceramics distributed oppositely can produce bending motion, so the bending deformation of two degrees of freedom can be achieved by two-channel signal control. The bending deformation of the bending piezoelectric driver is converted into the swing angle of the mirror frame via a flexible hinge. The swing mirror of the present invention can achieve two-degree-of-freedom deflection with only one bending piezoelectric driver. Using fewer piezoelectric drivers can save more space occupation, and is suitable for aerospace applications with strict space requirements.

Description

A two-degree-of-freedom piezoelectric oscillating mirror and deflection method based on a single bending piezoelectric actuator

Technical Field

The present application relates to the technical field of high-resolution fast-response swing mirror device design, and in particular to a piezoelectric driven two-degree-of-freedom piezoelectric swing mirror and a deflection method.

Background Art

Airborne, shipborne and satellite-borne optical tracking and aiming systems have extremely stringent requirements on space and weight. As one of the core components in the optical tracking and aiming system, the piezoelectric swing mirror can quickly and accurately track and compensate for the displacement of the tracking target. However, the existing piezoelectric swing mirror generally uses the working principle of differential push-pull deflection achieved by the deformation of multiple piezoelectric stacks. The swing mirror actuated by a piezoelectric stack uses three to four piezoelectric stacks to achieve two-degree-of-freedom deflection. The use of multiple piezoelectric stacks will increase the size and weight of the swing mirror, which affects the development of miniaturization and lightweight of the system terminal.

Summary of the invention

The purpose of the present invention is to solve the problem that the number of piezoelectric stacks used in the conventional piezoelectric oscillating mirror is large, which increases the size and weight of the oscillating mirror structure, thereby limiting the miniaturization and lightweight of the oscillating mirror. To solve the above technical problems, the present invention is implemented by the following technical solutions:

The present invention provides a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric driver, wherein the two-degree-of-freedom piezoelectric oscillating mirror comprises a ceramic fixing bolt, a base, a bending piezoelectric driver, a mirror frame, and a mirror frame fixing bolt;

The base has a through hole at its center, which is used for positioning and overlapping with the nut of the ceramic fixing bolt;

The bending piezoelectric actuator is a cylindrical structure with a through hole, the lower surface of which is used to coincide with the bottom of the base, and the upper surface of which is used to coincide with the lower surface of the mirror frame;

The mirror frame has a threaded hole at the bottom for threaded engagement with a ceramic fixing bolt. The mirror frame includes an outer ring, a support component for fixing a central reflector, and a flexible hinge connecting the two.

The upper and lower parts of the mirror frame are connected via a flexible hinge, and the outer ring on the upper part of the mirror frame is fixedly connected to the base.

Furthermore, a preferred embodiment is provided, wherein the frame and the base are connected by any one of threaded connection, adhesive connection or welding via frame fixing bolts.

Furthermore, a preferred embodiment is provided, wherein the structure of the bending piezoelectric actuator is any one of a four-partition piezoelectric ceramic sheet stacking structure, a piezoelectric ceramic sheet structure with four sides of a rectangular beam pasted thereon, or a bending piezoelectric tube.

Furthermore, a preferred embodiment is provided in which the flexible hinge between the upper and lower parts of the frame is any one of a straight circle, an ellipse or a rectangle.

Furthermore, a preferred embodiment is provided, wherein the number of the bending piezoelectric actuator is one.

Furthermore, a preferred embodiment is provided, in which the deformation actuation method of the bending piezoelectric driver is as follows: the cylindrical structure of the bending piezoelectric driver is evenly divided into four quarter-cylindrical ceramics along the radial direction, the polarization directions of the oppositely distributed cylindrical ceramics are opposite, and the voltage is applied in a manner of independently applying voltage to two cylindrical ceramics in orthogonal directions. There are two voltage signal channels, and when a positive voltage is applied to one of the channels, the bending piezoelectric driver generates a downward bending movement, and when a negative voltage is applied, the bending piezoelectric driver generates an upward bending movement, and when a positive voltage is applied in an orthogonal direction, the bending piezoelectric driver generates a left bending movement, and when a negative voltage is applied in the orthogonal direction, the bending piezoelectric driver generates a right bending movement.

Furthermore, a preferred embodiment is provided, wherein the bending deformation of the bending piezoelectric actuator is converted into a swing angle of the mirror frame via a flexible hinge.

Furthermore, a preferred embodiment is provided, in which the swing angle is obtained by the following method: after the bending deformation degree of the bending piezoelectric actuator is amplified, a lateral displacement is generated at the straight circular flexible hinge between the upper and lower parts of the frame, and the distance between the rotation center of the frame and the straight circular flexible hinge between the upper and lower parts of the frame is the rotation radius, that is, the swing angle is the ratio of the lateral displacement to the rotation radius.

Beneficial effects of the present invention:

The present invention provides a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric driver. Two-channel driving signals can realize two-way control signals to realize two-degree-of-freedom deflection movement. Each channel signal controls one direction of movement of the bending piezoelectric driver respectively. The bending deformation of the bending piezoelectric driver realizes the rotation of the mirror frame table through a force arm. The use of a single bending piezoelectric drive reduces the space occupied by multiple piezoelectric drivers, and is more suitable for the aerospace field with small space and light weight.

The present invention can realize high-precision and fast-response angle adjustment of the reflector in a space-limited environment by using the piezoelectric swing mirror.

The present invention processes the piezoelectric ceramics through independent polarization of each partition, so that the telescopic deformation of four positions can be realized on a single ceramic. The base, the piezoelectric ceramic group after the partition polarization and the amplitude rod are combined and connected by bolts to form a sandwich bending piezoelectric driver with two-degree-of-freedom bending motion. The piezoelectric driver is used as the driving element of the two-degree-of-freedom piezoelectric oscillating mirror. The number of driving elements is only one, which is conducive to the small-size structural design of the oscillating mirror and can further reduce the weight of the oscillating mirror.

The present invention is suitable for beam control applications utilizing laser communications and image stabilization in the aerospace field.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

FIG1 is a schematic cross-sectional view of a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric actuator according to the first embodiment.

FIG. 2 is an exploded schematic diagram of a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric actuator according to the first embodiment.

FIG. 3 is an isometric schematic diagram of a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric actuator according to the first embodiment.

FIG. 4 is a schematic diagram showing the principle of deformation motion of a bending piezoelectric actuator of a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric actuator according to the first embodiment.

FIG. 5 is a schematic diagram showing the principle of the yaw motion of a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric actuator according to the first embodiment.

In the figure, ceramic fixing bolt 1; base 2; bending piezoelectric actuator 3; mirror frame 4; mirror frame fixing bolt 5.

DETAILED DESCRIPTION

In order to make the purpose, technical solutions and advantages of the implementation methods of the present application clearer, the technical solutions in the implementation methods of the present application will be clearly and completely described in combination with the drawings in the implementation methods of the present application. Obviously, the described implementation methods are only part of the implementation methods of the present application, not all of the implementation methods.

Embodiment 1, as shown in FIG. 1 to FIG. 3 , the present invention proposes that the two-degree-of-freedom piezoelectric oscillating mirror includes a ceramic fixing bolt 1, a base 2, a bending piezoelectric driver 3, a mirror frame 4, and a mirror frame fixing bolt 5;

The base 2 has a through hole in the center, which is used for positioning and overlapping with the nut of the ceramic fixing bolt 1;

The bending piezoelectric driver 3 is a cylindrical structure with a through hole, the lower surface of which is used to coincide with the bottom of the base 2, and the upper surface of which is used to coincide with the lower surface of the mirror frame 4;

The mirror frame 4 has a threaded hole at the bottom thereof for threadedly engaging with the ceramic fixing bolt 1. The mirror frame 4 includes an outer ring, a support component for fixing the reflector at the center, and a flexible hinge connecting the two.

The upper and lower parts of the frame 4 are connected via a flexible hinge, and the outer ring of the upper part of the frame 4 is fixedly connected to the base 2 .

The piezoelectric oscillating mirror described in this embodiment can realize the two-degree-of-freedom deflection motion output of the mirror frame.

Embodiment 2: This embodiment further limits the two-degree-of-freedom piezoelectric oscillating mirror based on a single bending piezoelectric driver described in embodiment 1, wherein the mirror frame 4 and the base 2 are connected by threaded connection, adhesive connection or welding via the mirror frame fixing bolts 5.

Embodiment 3. This embodiment is a further limitation of the two-degree-of-freedom piezoelectric oscillating mirror based on a single bending piezoelectric driver as described in embodiment 1. The structure of the bending piezoelectric driver 3 is any one of a four-partition piezoelectric ceramic sheet stacking structure, a piezoelectric ceramic sheet structure pasted on four sides of a rectangular beam, or a bending piezoelectric tube, which is used to realize bending motion in two orthogonal directions of freedom.

Embodiment 4: This embodiment further limits the two-degree-of-freedom piezoelectric pendulum mirror actuated by a single bending piezoelectric driver described in embodiment 1, wherein the flexible hinge between the upper and lower parts of the mirror frame 4 is any one of a straight circle, an ellipse or a rectangle.

The elastic deformation of the flexible hinge is used to compensate for the displacement caused by the opposite deformation of the bending piezoelectric driver and the mirror frame.

Through the flexible hinge in this embodiment, the bending deformation of the bending piezoelectric driver 3 can be converted into the deflection of the frustum in the mirror frame 4.

Embodiment 5: This embodiment further limits the two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric driver described in Embodiment 1, and the number of the bending piezoelectric driver 3 is one.

Embodiment 6. This embodiment proposes a deflection method for a two-degree-of-freedom piezoelectric pendulum mirror based on deformation actuation of a single bending piezoelectric driver as described in any one of embodiments 1 to 5, wherein the deflection method is as follows: the cylindrical structure of the bending piezoelectric driver 3 is evenly divided into four quarter-cylindrical ceramics along the radial direction, and the polarization directions of the cylindrical ceramics distributed in opposite directions are opposite. The voltage is applied in a manner of independently applying voltage to two cylindrical ceramics in orthogonal directions to each other. There are two voltage signal channels, and when a positive voltage is applied to one of the channels, the bending piezoelectric driver generates a downward bending movement, and when a negative voltage is applied, the bending piezoelectric driver generates an upward bending movement, and when a positive voltage is applied in an orthogonal direction, the bending piezoelectric driver generates a left bending movement, and when a negative voltage is applied in an orthogonal direction, the bending piezoelectric driver generates a right bending movement.

Embodiment 7: This embodiment further limits the deflection method of a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric driver as described in embodiment 6, wherein the bending deformation of the bending piezoelectric driver 3 is converted into a swing angle of the mirror frame 4 via a flexible hinge.

Embodiment 8. This embodiment is a further limitation of the two-degree-of-freedom piezoelectric pendulum mirror based on a single bending piezoelectric driver actuation described in embodiment 7. The swing angle is obtained by the following method: the bending deformation degree of the bending piezoelectric driver 3 is amplified to produce a lateral displacement at the straight circular flexible hinge between the upper and lower parts of the mirror frame 4. The distance between the rotation center of the mirror frame 4 and the straight circular flexible hinge between the upper and lower parts of the mirror frame 4 is the rotation radius, that is, the swing angle is the ratio of the lateral displacement to the rotation radius.

Embodiment 9: This embodiment proposes the following embodiments, which are used to explain the above embodiments 1 to 8. The embodiments are specifically as follows:

1 to 3 illustrate this embodiment, a two-degree-of-freedom piezoelectric oscillating mirror actuated by a single bending piezoelectric driver, which mainly includes: a ceramic fixing bolt 1, a base 2, a bending piezoelectric driver 3, a mirror frame 4, and a mirror frame fixing bolt 5.

The base 2 has a through hole at the bottom center, which is used to locate and coincide with the nut of the ceramic fixing bolt 5. The bending piezoelectric actuator 3 is a cylindrical structure with a through hole, and the upper surface is used to coincide with the bottom of the base 2 and the lower surface of the mirror frame 4.

A threaded hole is provided at the bottom of the lower part of the mirror frame 4 for threaded cooperation with the ceramic fixing bolt 1. The upper part of the mirror frame 4 is composed of an outer ring, a support structure for fixing the reflector in the center, and a flexible hinge connecting the two. The upper and lower parts of the mirror frame 4 are connected by a straight circular flexible hinge. The outer ring above the mirror frame 4 is threadedly connected to the base 2 by a mirror frame fixing bolt 5.

The cylindrical structure of the bending piezoelectric driver 3 is evenly divided into four quarter-cylindrical ceramics along the radial direction. The polarization directions of the cylindrical ceramics distributed opposite to each other are opposite, so as to realize bending deformation by push-pull method.

The bending piezoelectric actuator 3 is a four-partition piezoelectric ceramic stacked structure, which is used to achieve bending motion in two orthogonal directions of freedom.

Referring to FIG. 4 , the polarization direction of the quarter-cylindrical ceramics in the positive direction of the Y axis and the negative direction of the X axis is positive, and the polarization direction of the quarter-cylindrical ceramics in the negative direction of the Y axis and the positive direction of the X axis is negative. When a positive voltage is applied to the two quarter-cylindrical ceramics along the Y axis, the bending piezoelectric driver 3 generates a bending motion upward along the Y axis. When a negative voltage is applied, the bending piezoelectric driver 3 generates a bending motion downward along the Y axis. When a positive voltage is applied to the two quarter-cylindrical ceramics along the X axis, the bending piezoelectric driver 3 generates a bending motion upward along the X axis. When a negative voltage is applied, the bending piezoelectric driver 3 generates a bending motion downward along the X axis.

Referring to FIG5 , the present embodiment is described. The bending deformation of the bending piezoelectric actuator 3 is amplified to produce a lateral displacement at the straight circular flexible hinge between the upper and lower parts of the mirror frame 4. The distance between the rotation center of the mirror frame 4 and the straight circular flexible hinge between the upper and lower parts of the mirror frame 4 is the rotation radius. The swing angle is the ratio of the lateral displacement to the rotation radius.

1 to 5 , there are two voltage signal channels, which are used to drive the two-degree-of-freedom bending of the bending piezoelectric actuator 3 , and further drive the mirror frame 4 to generate two-degree-of-freedom deflection in orthogonal directions.

In this embodiment, the piezoelectric ceramics are polarized independently in each partition, so that four positions of telescopic deformation can be achieved on a single ceramic. The base, the piezoelectric ceramic group after partition polarization, and the amplitude rod are combined and connected by bolts to form a sandwich bending piezoelectric driver with two degrees of freedom bending motion. The piezoelectric driver is used as the driving element of the two-degree-of-freedom piezoelectric pendulum mirror, and the number of driving elements is only one, which is conducive to the small-size structural design of the pendulum mirror and can further reduce the weight of the pendulum mirror.

The piezoelectric oscillating mirror of this embodiment can realize two-degree-of-freedom deflection motion output. Only one bending piezoelectric driver is needed to realize the two-degree-of-freedom deflection of the oscillating mirror, which has the advantage of occupying a small space.

Those skilled in the art will appreciate that the above are only preferred embodiments of the present invention, and the various embodiments of the present disclosure and/or the features described in the claims may be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or perform equivalent substitutions on some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (8)

1. The two-degree-of-freedom piezoelectric swing mirror based on single bending piezoelectric driver deformation actuation is characterized by comprising a ceramic fixing bolt (1), a base (2), a bending piezoelectric driver (3), a mirror bracket (4) and a mirror bracket fixing bolt (5);

the center of the base (2) is provided with a through hole, and the through hole is used for positioning and overlapping matching with a nut of the ceramic fixing bolt (1);

The bending piezoelectric driver (3) is of a cylindrical structure with a through hole, the lower surface of the bending piezoelectric driver is used for being matched with the bottom of the base (2) in a superposition manner, and the upper surface of the bending piezoelectric driver is used for being matched with the lower surface of the lens frame (4) in a superposition manner;

A threaded hole is arranged below the mirror bracket (4) and is used for being matched with the ceramic fixing bolt (1) through threads, the upper part of the mirror bracket (4) comprises an outer ring, a supporting part for fixing the reflecting mirror at the center and a flexible hinge for connecting the outer ring and the supporting part,

The upper part and the lower part of the glasses frame (4) are connected through a flexible hinge, and the outer ring above the glasses frame (4) is fixedly connected with the base (2).

2. The two-degree-of-freedom piezoelectric swing mirror based on single bending piezoelectric actuator deformation actuation according to claim 1, wherein the frame (4) and the base (2) are any one of screwed, glued or welded by a frame fixing bolt (5).

3. The two-degree-of-freedom piezoelectric swing mirror based on single bending piezoelectric actuator deformation actuation according to claim 1, wherein the structure of the bending piezoelectric actuator (3) is any one of a four-zone piezoelectric ceramic sheet stacked structure, a rectangular beam four-side-attached piezoelectric ceramic sheet structure, or a bending piezoelectric tube.

4. The two-degree-of-freedom piezoelectric swing mirror based on single bending piezoelectric actuator deformation actuation according to claim 1, wherein the flexible hinge between upper and lower in the frame (4) is any one of a right circular, elliptical or rectangular shape.

5. The two-degree-of-freedom piezoelectric swing mirror based on single bending piezoelectric actuator deformation actuation according to claim 1, wherein the number of bending piezoelectric actuators (3) is one.

6. A method of deflection of a two degree of freedom piezoelectric swing mirror based on single bending piezoelectric driver deformation actuation according to any one of claims 1 to 5, wherein the method of deflection is: the cylindrical structure of the bending piezoelectric driver (3) is equally divided into four quarter cylindrical ceramics along the radial direction, the polarization directions of the cylindrical ceramics which are distributed oppositely are opposite, the voltage application mode is that voltage is respectively and independently applied to the two cylindrical ceramics which are in the mutually orthogonal directions, the number of voltage signal channels is two, wherein the bending piezoelectric driver generates downward bending motion when one path of voltage is applied, the bending piezoelectric driver generates upward bending motion when negative voltage is applied, the bending piezoelectric driver generates leftward bending motion when positive voltage is applied in the orthogonal direction, and the bending piezoelectric driver generates rightward bending motion when negative voltage is applied in the orthogonal direction.

7. The method of deflection of a two-degree-of-freedom piezoelectric swing mirror based on single bending piezoelectric actuator deformation actuation according to claim 6, wherein the bending deformation of the bending piezoelectric actuator (3) is converted into the swing angle of the mirror frame (4) via a flexible hinge.

8. The method of deflection of a two-degree-of-freedom piezoelectric oscillating mirror based on deformation actuation of a single bending piezoelectric actuator according to claim 7, wherein the oscillation angle is obtained by: after the bending deformation degree of the bending piezoelectric driver (3) is amplified, transverse displacement is generated at the straight round flexible hinge between the upper part and the lower part of the mirror bracket (4), and the distance between the rotation center of the mirror bracket (4) and the straight round flexible hinge between the upper part and the lower part of the mirror bracket (4) is the rotation radius, namely the swing angle is the ratio of the transverse displacement to the rotation radius.