A two-dimensional micro-displacement scanning device based on flexible amplification and constraint mechanism

Abstract

The present invention discloses a two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism, which adopts a parallel and non-completely symmetrical structural form, including a motion platform, a piezoelectric actuating mechanism, a rhombus-shaped flexible constraint mechanism, a corrugated flexible beam and a flexible hinge; the motion platform is arranged in the middle position of the two-dimensional micro-displacement scanning device; the piezoelectric actuating mechanism is composed of a composite flexible amplifying mechanism including two amplification forms of rhombus and lever, a stacked piezoelectric ceramic and a wedge block assembly, and is arranged in the X and Y directions of the motion platform through a corrugated flexible beam, so that the motion platform can achieve two degrees of freedom in the XY plane; the rhombus-shaped flexible constraint mechanism is connected to the motion platform through a flexible hinge, so as to limit the coupling error and parasitic rotation generated by the motion platform during the working process. The present invention has the advantages of simple and compact structure, large working stroke, high motion accuracy, high bandwidth, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of photoelectric imaging, adopts a parallel and non-completely symmetrical structural form and a piezoelectric driven actuation mode, and specifically relates to a two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism. Background Art

[0002] In the military, aerospace and other fields, image information is an important technical means to obtain intelligence, and image quality has become an important factor related to the development of key technologies. The imaging process is usually affected by the external environment, such as vibration environment and posture changes, which will affect the clarity of the image. Therefore, it is necessary to introduce image stabilization technology in the imaging process to improve the image quality.

[0003] Optical image stabilization systems have the advantages of small size, easy implementation, and low cost, and have been widely used in high-precision small devices. The image stabilization element in the optical system is adjusted by micro-displacement using a micro-displacement scanning device to compensate for the optical axis deviation between the imaging device and the target object, thereby achieving stable image output.

[0004] In the imaging process, in addition to using image stabilization technology, micro-scanning technology can also be used to obtain higher-resolution images. Micro-scanning technology reconstructs multiple low-resolution images with slight displacements from each other by sampling the same scene multiple times, and finally obtains a high-resolution image. Micro-scanning technology based on mechanical translation is achieved by using a micro-displacement scanning device to controllably translate lenses or other optical elements.

[0005] Since the micro-displacement scanning device can be used for both optical image stabilization and micro-scanning imaging, it has been widely used in fields that require improved imaging resolution, such as military equipment, satellite remote sensing, digital aerial cameras, and mobile phones. Among them, the two-dimensional micro-displacement scanning device has the widest application occasions.

[0006] In terms of the actuation mode, the two-dimensional micro-displacement scanning device usually adopts stacked piezoelectric ceramics for actuation because it has the advantages of high precision and high bandwidth; in terms of the transmission mode, a flexible mechanism is usually used for transmission because compared with traditional transmission modes such as mechanical transmission, the flexible mechanism that uses the elastic deformation of the material to transmit motion and force has the advantages of no mechanical friction, no gap, high motion sensitivity, etc., which is very suitable for use in two-dimensional micro-displacement scanning devices with high motion accuracy requirements. However, the stacked piezoelectric ceramics also have the inherent characteristic of small output displacement. In order to make the two-dimensional micro-displacement scanning device obtain a large input displacement, it is necessary to use an amplification mechanism to amplify its small output displacement. However, a single form of amplification mechanism is widely used at present, such as a two-dimensional micro-displacement scanning device that only adopts a lever amplification mechanism. It can obtain a larger displacement magnification factor by adopting a secondary lever amplification mechanism, but the size of this type of device is usually large and has the disadvantage of not being compact enough; for example, a two-dimensional micro-displacement scanning device that only adopts a rhombus amplification mechanism, although its structure is relatively compact, the displacement magnification factor is not ideal compared with the device that adopts a lever amplification mechanism. In addition, the two-dimensional micro-displacement scanning device usually adopts a completely symmetrical structure to limit the coupling error and parasitic rotation generated during the operation, so that the entire device has higher motion accuracy. However, there is also the problem of large size, which is subject to certain limitations in practical applications.

[0007] In addition, the relevant technologies of two-dimensional micro-displacement scanning devices are currently mainly in the hands of French and German companies.

[0008] Therefore, a two-dimensional micro-displacement scanning device with a simple and compact design structure, a large working stroke, high motion accuracy and a high bandwidth has great engineering practical significance. Summary of the invention

[0009] In order to solve some problems existing in the prior art, the present invention provides a two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism, which is used to realize two-degree-of-freedom translation in the XY plane. It has the characteristics of simple and compact structure, large working stroke, no need for lubrication, high motion accuracy, fast response speed, etc. It can be used in various occasions and provides a new idea for the development of two-dimensional micro-displacement scanning devices.

[0010] The technical solution adopted by the present invention to solve the above technical problems is:

[0011] A two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism adopts an integral parallel and non-completely symmetrical structure, including a motion platform, two piezoelectric actuation mechanisms, a diamond-shaped flexible constraint mechanism, first, second, and third corrugated flexible beams and first and second flexible hinges, wherein:

[0012] The motion platform is an octagonal frame structure, which is arranged in the middle of the two-dimensional micro-displacement scanning device. There is a larger through hole in the center of the motion platform to create better optical path conditions. In the thickness direction of the motion platform, reinforcing ribs are arranged along the four sides to increase the rigidity and reduce the deformation of the motion platform during operation. At the same time, it can also increase the natural frequency of the entire two-dimensional micro-displacement scanning device, thereby obtaining a higher working bandwidth. Four bosses are also evenly arranged on the inner side of the motion platform, and a threaded hole is provided in the center of each boss. Different types of external loads can be connected by screws. It has the advantages of easy disassembly and installation and a wide range of applications.

[0013] Each piezoelectric actuator includes a composite flexible amplifying mechanism, a stacked piezoelectric ceramic and a wedge assembly, wherein the composite flexible amplifying mechanism is composed of a rhombus amplifying mechanism and a lever amplifying mechanism, and is used to amplify the small output displacement of the stacked piezoelectric ceramic. A piezoelectric actuator is arranged in the negative direction of the X-axis and the Y-axis of the motion platform, respectively, to enable the motion platform to achieve two degrees of freedom of translation. One end of the rhombus amplifying mechanism in the composite flexible amplifying mechanism is connected to the lever amplifying mechanism through a second corrugated flexible beam, and the other end is connected to the fixed end through a third corrugated flexible beam; the output end of the lever amplifying mechanism is connected to the motion platform through a first corrugated flexible beam. The rhombus amplifying mechanism and the lever amplifying mechanism are used to perform primary and secondary amplification on the output displacement of the stacked piezoelectric ceramic, respectively, so as to provide a larger input displacement to the motion platform. The stacked piezoelectric ceramic and the wedge assembly are installed in the rhombus amplifying mechanism, and the wedge assembly is mainly used to apply a preload to the stacked piezoelectric ceramic.

[0014] The diamond-shaped flexible constraint mechanism is arranged at a position 45° to the positive direction of the X-axis, one end of which is connected to the motion platform through a first flexible hinge, and the other end is connected to the fixed end through a second flexible hinge. During the operation of the two-dimensional micro-displacement scanning device, the diamond-shaped flexible constraint mechanism is used to limit the coupling and parasitic motion generated by the motion platform, thereby achieving higher motion accuracy.

[0015] Among them, the composite flexible amplifying mechanism uses the principle of secondary amplification to amplify the small output displacement of the stacked piezoelectric ceramics, so as to enable the motion platform to obtain a larger input displacement. Compared with the existing displacement amplifying mechanisms at home and abroad, the diamond amplifying mechanism removes the boss on the inner side that contacts the stacked piezoelectric ceramics, increases the radius of the inner rounded corner, and significantly improves the stress concentration of the diamond amplifying mechanism at this location. In addition, the inclination angles of the inner and outer sides of the flexible arm of the diamond amplifying mechanism are different, and the inclination angle of the inner side of the flexible arm is greater than the inclination angle of the outer side, that is, the flexible arm is a variable cross-section structure, and its cross-sectional height changes with the length of the flexible arm. Designing the flexible arm as a variable cross-section structure can make the stress distribution it receives during operation more uniform, thereby obtaining better mechanical properties.

[0016] One end of the stacked piezoelectric ceramic is bonded to the inner side of the diamond-shaped amplifying mechanism by epoxy resin, and the other end is bonded to a wedge in the wedge assembly by epoxy resin, and the other wedge in the wedge assembly is in direct contact with the inner side of the diamond-shaped amplifying mechanism by interference fit. The wedge assembly is used to apply a certain amount of preload force to the stacked piezoelectric ceramic, thereby preventing the stacked piezoelectric ceramic from being damaged due to tension during operation. Using the stacked piezoelectric ceramic as an actuating element can enable the two-dimensional micro-displacement scanning device to obtain advantages such as high displacement resolution and high response speed.

[0017] Wherein, the wedge block assembly is composed of two identical wedge blocks with an inclination angle of 5°. By fine-tuning the contact area between the two wedge block inclined surfaces, different sizes of preload can be provided to the stacked piezoelectric ceramics. The larger the contact area between the two wedge blocks, the smaller the thickness of the entire wedge block assembly, that is, the smaller the preload provided to the stacked piezoelectric ceramics. Conversely, the smaller the contact area between the two wedge blocks, the larger the thickness of the entire wedge block assembly, and the greater the preload applied to the stacked piezoelectric ceramics. In addition, since the stacked piezoelectric ceramics and the rhombus amplifying mechanism adopt an interference fit, the use of the wedge block assembly not only facilitates the application of different sizes of preload to the stacked piezoelectric ceramics, but also facilitates the assembly between the stacked piezoelectric ceramics and the rhombus amplifying mechanism.

[0018] Among them, the first, second and third corrugated flexible beams are all composed of variable thickness units constructed by elliptical curve segments connected end to end, and four variable thickness units form a corrugated flexible beam, which is used for the flexible connection between the piezoelectric actuator, the motion platform and the fixed end, and for transmitting the displacement generated by the stacked piezoelectric ceramics, wherein the lever amplification mechanism in the piezoelectric actuator is connected to the motion platform through the first corrugated flexible beam, the diamond amplification mechanism is connected to the lever amplification mechanism through the second corrugated flexible beam, and the diamond amplification mechanism is connected to the fixed end through the third corrugated flexible beam. Compared with flexible beams of other shapes, the corrugated flexible beam composed of elliptical curve segments has the characteristics of large motion range and low stress, which can make the two-dimensional micro-displacement scanning device have better performance during the motion process.

[0019] The diamond-shaped flexible constraint mechanism is a hollow thin-walled structure. During the operation of the two-dimensional micro-displacement scanning device, it uses elastic deformation to limit the coupling error and parasitic rotation generated by the motion platform, thereby achieving higher motion accuracy. Compared with the commonly used rectangular flexible constraint mechanism, the diamond-shaped flexible constraint mechanism with uniform transition shape can improve the stress concentration on the flexible constraint mechanism of the two-dimensional micro-displacement scanning device.

[0020] The flexible hinge adopts a double-cut structure, which has the advantages of simple structure and easy processing, and is used to connect the diamond-shaped flexible constraint mechanism with the motion platform and the fixed end. Compared with the rigid connection method using screws, the flexible connection using a flexible hinge can avoid assembly errors between the motion platform and the flexible mechanism arranged separately, and no gap is generated, which can improve the overall motion accuracy and response speed of the two-dimensional micro-displacement scanning device.

[0021] The working process of the present invention is:

[0022] By applying a driving voltage to the stacked piezoelectric ceramics in the diamond-shaped amplifying mechanism arranged in the X-axis direction, the stacked piezoelectric ceramics can be extended along the Y-axis direction, and the diamond-shaped amplifying mechanism can be contracted along the X-axis direction. After the diamond-shaped amplifying mechanism performs a primary amplification on the output displacement of the stacked piezoelectric ceramics, the output displacement is transmitted to the lever amplifying mechanism through two second corrugated flexible beams. The displacement is transmitted to the motion platform through two first corrugated flexible beams as the input displacement of the lever amplifying mechanism after secondary amplification, thereby driving the motion platform to move along the X-axis direction. Similarly, when a driving voltage is applied to the stacked piezoelectric ceramics in the diamond-shaped amplifying mechanism arranged in the Y-axis direction, the motion platform can be caused to move along the Y-axis direction, thereby realizing the translation of the motion platform in two degrees of freedom in the X-axis and Y-axis directions. By changing the amplitude of the driving voltage applied to the stacked piezoelectric ceramics, the motion range of the motion platform can be changed.

[0023] The advantages of the present invention are:

[0024] (1) The present invention adopts an integral parallel structure, which has the advantages of high motion accuracy, fast response speed, and low inertia. Compared with the series structure, the parallel structure has independent and non-interfering movements along the X-axis and Y-axis directions, and can independently control each working axis. The control strategy is relatively simple, and the parallel structure is also convenient for integrating the measurement sensor with the mechanical structure for parallel measurement, thereby making the entire system more compact;

[0025] (2) The present invention adopts a non-completely symmetrical structure, with only one piezoelectric actuator arranged in the X and Y directions of the motion platform. Compared with a completely symmetrical structure, it simplifies the structure of the two-dimensional micro-displacement scanning device, reduces the overall size of the device, and has a simpler and more compact structure;

[0026] (3) The present invention uses a composite flexible amplifying mechanism based on two amplification forms, namely, diamond amplification and lever amplification, to perform secondary amplification on the small output displacement of the stacked piezoelectric ceramics. Compared with a two-dimensional micro-displacement scanning device that only uses a diamond amplification mechanism, it can obtain a relatively compact structure while also having a larger displacement amplification factor; compared with a two-dimensional micro-displacement scanning device that only uses a lever amplification mechanism for secondary amplification, it can obtain a larger displacement amplification factor while also having a more compact structure. The composite flexible amplifying mechanism in the present invention combines the advantages of the diamond amplifying mechanism and the lever amplifying mechanism, so that it can obtain a larger displacement amplification factor in a compact structure, thereby enabling the motion platform to obtain a larger working space;

[0027] (4) The present invention uses a corrugated flexible beam composed of elliptical curve segments to connect the piezoelectric actuator, the motion platform and the fixed end. Compared with flexible beams of other shapes, it has the advantages of a large ratio of axial stiffness to lateral stiffness, a large range of motion, and can improve stress concentration, thus enriching the structural form of the flexible beam;

[0028] (5) The present invention arranges two corrugated flexible beams between the lever amplification mechanism and the motion platform, between the diamond amplification mechanism and the lever amplification mechanism, and between the diamond amplification mechanism and the fixed end. The parallelogram guide mechanism composed of two corrugated flexible beams can firstly be used to limit the parasitic rotation generated by the motion platform during operation to obtain high motion accuracy; secondly, the two groups of corrugated flexible beams arranged on both sides of the diamond amplification mechanism can also be used to improve the torsional stiffness of the amplification mechanism to avoid damage to the stacked piezoelectric ceramics due to bending moment; finally, the overall stiffness of the two-dimensional micro-displacement scanning device can be improved to obtain a high natural frequency, thereby achieving a high working bandwidth;

[0029] (6) In order to avoid large coupling errors and parasitic rotations of the motion platform during operation, a diamond-shaped flexible constraint mechanism is arranged at a position 45° to the positive direction of the X-axis, and its elastic deformation is used to limit coupling and parasitic motion, so that the two-dimensional micro-displacement scanning device has a compact structure and high motion accuracy. In addition, the shape of the diamond-shaped flexible constraint mechanism changes evenly. Compared with the commonly used rectangular flexible constraint mechanism, the diamond-shaped flexible constraint mechanism can improve the stress concentration phenomenon on the flexible constraint mechanism in the two-dimensional micro-displacement scanning device;

[0030] (7) The structure of the present invention is simple and compact, and is easy to process and assemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is an isometric view of the present invention;

[0032] Figure 2a A top view of the present invention;

[0033] Figure 2b for Figure 2a The AA cross-sectional view is a cross-sectional view of the piezoelectric actuator of the present invention;

[0034] Figure 3 It is a schematic diagram of the structure of the corrugated flexible beam in the present invention.

[0035] Figures 1 to 3 The meanings of the accompanying symbols are:

[0036] DETAILED DESCRIPTION

[0037] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0038] The two-dimensional micro-displacement scanning device based on the flexible amplification and constraint mechanism of the present invention adopts a parallel and non-completely symmetrical structural form, including a motion platform, a piezoelectric actuating mechanism, a rhombus-shaped flexible constraint mechanism, a corrugated flexible beam and a flexible hinge. The motion platform is arranged in the middle position of the two-dimensional micro-displacement scanning device. The piezoelectric actuating mechanism is composed of a composite flexible amplifying mechanism, a stacked piezoelectric ceramic and a wedge block assembly, wherein the composite flexible amplifying mechanism further includes a rhombus-shaped amplifying mechanism and a lever amplifying mechanism; the stacked piezoelectric ceramic and the wedge block assembly are installed in the rhombus-shaped amplifying mechanism through interference fit, the wedge block assembly is used to apply a preload force to the stacked piezoelectric ceramic, and the rhombus-shaped amplifying mechanism is used to perform a primary amplification on the output displacement of the stacked piezoelectric ceramic; the lever amplifying mechanism connected to the rhombus-shaped amplifying mechanism is used to perform a secondary amplification on the output displacement of the stacked piezoelectric ceramic; the piezoelectric actuating mechanism is arranged in the X and Y directions of the motion platform through a corrugated flexible beam, and the elongation and shortening of the stacked piezoelectric ceramic are used to provide actuating force to the motion platform, thereby causing the motion platform to generate micro-displacements along the two degrees of freedom of the X-axis and the Y-axis. The diamond-shaped flexible constraint mechanism is connected to the motion platform through a flexible hinge, which is arranged in a direction 45° to the positive direction of the X-axis to limit the coupling error and parasitic rotation generated by the motion platform during operation. The invention has the advantages of simple and compact structure, large working stroke, high motion accuracy, and high bandwidth.

[0039] like Figure 1 , Figure 2a , Figure 2b , Figure 3As shown, a two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism of the present invention comprises a motion platform 1, two piezoelectric actuating mechanisms, a rhombus-shaped flexible constraint mechanism 11, a first corrugated flexible beam 2, a second corrugated flexible beam 3, a third corrugated flexible beam 4, a first flexible hinge 10, and a second flexible hinge 12. The piezoelectric actuating mechanism is composed of a composite flexible amplification mechanism, a stacked piezoelectric ceramic 9, and a wedge assembly 8, wherein the composite flexible amplification mechanism is composed of a rhombus-shaped amplification mechanism 6 and a lever amplification mechanism 7.

[0040] The motion platform 1 is arranged in the middle of the two-dimensional micro-displacement scanning device. The motion platform 1 is connected to the output end of the lever amplification mechanism 7 in the composite flexible amplification mechanism through the first corrugated flexible beam 2, the input end of the lever amplification mechanism 7 is connected to one side of the output end of the rhombus amplification mechanism 6 through the second corrugated flexible beam 3, and the other side of the output end of the rhombus amplification mechanism 6 is connected to the fixed end 5 through the third corrugated flexible beam 4. One end of a rhombus flexible constraint mechanism 11 arranged at 45° to the positive direction of the X-axis is connected to the motion platform 1 through the first flexible hinge 10, and the other end is connected to the fixed end 5 through the second flexible hinge 12. In addition, the X-axis and Y-axis of the motion platform are perpendicular to each other, and the XY plane formed by these two axes is parallel to the horizontal plane. In the XY plane, the X-axis is arranged vertically, and its positive direction points downward; the Y-axis is arranged horizontally, and its positive direction points to the right. The Z-axis is perpendicular to the XY plane, and its positive direction is determined by the right-hand rule according to the positive directions of the X-axis and the Y-axis.

[0041] The motion platform 1 is an octagonal frame structure with a larger through hole in the center to create better optical path conditions. The present invention designs reinforcing ribs in the middle of the octagonal frame structure along the Z direction, that is, along the thickness direction of the motion platform 1, to reduce the deformation of the motion platform 1 during operation. At the same time, due to the increased rigidity, the natural frequency of the two-dimensional micro-displacement scanning device is also improved, so that the device as a whole can have a higher working bandwidth. In addition, four bosses are evenly arranged on the inner side of the motion platform 1, and an M3 threaded hole is provided in the center of each boss to connect an external load.

[0042] Two piezoelectric actuators consisting of a composite flexible amplifying mechanism, a stacked piezoelectric ceramic 9 and a wedge assembly 8 are arranged in the X and Y directions of the motion platform 1, respectively, to provide the motion platform 1 with two degrees of freedom of translational displacement. The diamond amplifying mechanism 6 in the composite flexible amplifying mechanism is fitted with the stacked piezoelectric ceramic 9 and the wedge assembly 8 by interference. Figure 2bAs shown, the right end face of the stacked piezoelectric ceramic 9 is bonded to the inner side of the diamond-shaped amplifying mechanism 6 by epoxy resin, and the wedge block assembly 8 is composed of two identical wedge blocks with an inclination angle of 5°, wherein the right wedge block uses epoxy resin to bond the vertical surface to the left end face of the stacked piezoelectric ceramic 9, and the inclined surface contacts the inclined surface of the left wedge block, and the vertical surface of the left wedge block directly contacts the inner side of the diamond-shaped amplifying mechanism 6 by interference fit. Since the stacked piezoelectric ceramic 9 cannot be subjected to tension, a certain amount of preload force is provided to the stacked piezoelectric ceramic 9 through the wedge block assembly 8, so that the stacked piezoelectric ceramic 9 is always subjected to pressure during operation, avoiding tension due to the influence of inertial force, thereby causing damage. At the same time, by fine-tuning the contact area of ​​the inclined surfaces of the two wedge blocks in the wedge block assembly 8, different amounts of preload force can be provided to the stacked piezoelectric ceramic 9 to meet the requirements for preload force in different occasions.

[0043] The first corrugated flexible beam 2, the second corrugated flexible beam 3, and the third corrugated flexible beam 4 have a periodic corrugated structure, and are formed by continuously connecting four variable thickness units constructed by elliptical curve segments, including the first corrugated flexible beam 2 for connecting the lever amplification mechanism 7 and the motion platform 1, the second corrugated flexible beam 3 connecting the rhombus amplification mechanism 6 and the lever amplification mechanism 7, and the third corrugated flexible beam 4 connecting the rhombus amplification mechanism 6 and the fixed end 5. The two parallelogram guide mechanisms formed by the first corrugated flexible beams 2 have good motion performance and guiding accuracy, and can be used to limit the parasitic rotation generated by the motion platform during operation; the two groups of corrugated flexible beams arranged on both sides of the rhombus amplification mechanism 6 are respectively composed of two second corrugated flexible beams 3 and two third corrugated flexible beams 4, and the parallelogram guide mechanisms formed can improve the torsional stiffness of the rhombus amplification mechanism 6, thereby preventing the stacked piezoelectric ceramics 9 from being damaged due to bending moment.

[0044] The diamond-shaped flexible constraint mechanism 11 adopts a hollow thin-wall structure, and uses its elastic deformation to limit the coupling error and parasitic rotation generated by the motion platform 1 during operation, so that the two-dimensional micro-displacement scanning device can obtain higher motion accuracy. The overall shape of the diamond-shaped flexible constraint mechanism 11 changes evenly, and there is no place where the shape changes sharply, such as sharp corners. Therefore, the use of the diamond-shaped flexible constraint mechanism 11 can reduce the concentrated stress on the flexible constraint mechanism of the two-dimensional micro-displacement scanning device and improve the mechanical properties.

[0045] The first flexible hinge 10 and the second flexible hinge 12 both adopt a double-cut structure, which has the advantages of simple structure and easy processing. They are used for flexibly connecting the diamond-shaped flexible constraint mechanism 11 with the motion platform 1 and the fixed end 5. Compared with the method of rigid connection using screws, the present invention simplifies the structure and avoids assembly errors with other flexible mechanisms by adopting an integral structure. At the same time, no gap is generated, thereby improving the motion accuracy and response speed of the two-dimensional micro-displacement scanning device.

[0046] The assembly process of the present invention is:

[0047] First, the stacked piezoelectric ceramic 9 and the wedge block are bonded, that is, the vertical surface of a wedge in the wedge block assembly 8 is bonded to one end of the stacked piezoelectric ceramic 9 by using epoxy resin; secondly, the other end of the stacked piezoelectric ceramic 9 to which one wedge has been bonded is bonded to the inner side of the diamond-shaped amplifying mechanism 6 by using epoxy resin; finally, the other wedge in the wedge block assembly 8 is installed by interference fit, and the contact area of ​​the two wedge block inclined surfaces is adjusted according to the requirements of the preload force of the stacked piezoelectric ceramic 9 in the application scenario to complete the assembly of the two-dimensional micro-displacement scanning device.

[0048] The working process of the present invention is:

[0049] By applying a driving voltage to the stacked piezoelectric ceramic 9 in the diamond-shaped amplification mechanism 6 arranged in the X-axis direction, the stacked piezoelectric ceramic 9 is extended, and the diamond-shaped amplification mechanism 6 performs a primary amplification on the output displacement of the stacked piezoelectric ceramic 9, and uses the output displacement of the diamond-shaped amplification mechanism 6 as the input displacement of the lever amplification mechanism 7, and completes the displacement transmission through the second corrugated flexible beam 3, and then after the displacement is secondary amplified by the lever amplification mechanism 7, the output displacement of the lever amplification mechanism 7 is transmitted to the motion platform 1 by the first corrugated flexible beam 2, and the motion platform 1 moves along the X-axis direction. When the motion platform moves along the X-axis direction, the first corrugated flexible beam 2, the second corrugated flexible beam 3, and the third corrugated flexible beam 4 located in the Y-axis direction undergo elastic deformation, all of which play a guiding role. At the same time, the diamond-shaped flexible constraint mechanism 11 undergoes elastic deformation, which plays a role in limiting the motion platform 1 from generating coupling errors along the Y direction and parasitic rotation around the Z axis. Similarly, when a driving voltage is applied to the stacked piezoelectric ceramic 9 arranged in the diamond-shaped amplification mechanism 6 in the Y-axis direction, the motion platform 1 can be moved along the Y-axis direction, and the first corrugated flexible beam 2, the second corrugated flexible beam 3, and the third corrugated flexible beam 4 in the X-axis direction are elastically deformed, playing a guiding role. At this time, the diamond-shaped flexible constraint mechanism 11 is elastically deformed, which plays a role in limiting the coupling error of the motion platform 1 along the X-axis and the parasitic rotation around the Z-axis. In summary, by applying a driving voltage to the stacked piezoelectric ceramic 9, the motion platform 1 can achieve two degrees of freedom in the XY plane. In addition, by changing the amplitude of the driving voltage applied to the stacked piezoelectric ceramic 9, the motion range of the motion platform 1 can be changed. The larger the amplitude of the driving voltage, the larger the motion range of the motion platform 1, and vice versa.

[0050] The present invention adopts a parallel and non-completely symmetrical integral structure, and includes a motion platform with a large light-through hole in the center of the device, and uses stacked piezoelectric ceramics 9 for actuation and a flexible mechanism for transmission, so that the two-dimensional micro-displacement scanning device can achieve a large working stroke, high motion accuracy and high bandwidth in a compact structure while generating two degrees of freedom motion along the X-axis and the Y-axis. The technology not disclosed in detail in the present invention belongs to the common knowledge of those skilled in the art.

[0051] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any replacement or addition or reduction that can be understood by anyone familiar with the technology within the technical scope disclosed by the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism, characterized in that: An integral parallel and non-completely symmetrical structure is adopted, comprising a motion platform (1) having a central light-through hole, two piezoelectric actuating mechanisms, a rhombus-shaped flexible constraint mechanism (11), a first corrugated flexible beam (2), a second corrugated flexible beam (3), a third corrugated flexible beam (4), a first flexible hinge (10), and a second flexible hinge (12), wherein: The motion platform (1) is an octagonal frame structure, arranged in the middle of the two-dimensional micro-displacement scanning device, and has a relatively large light-through hole at the center; in the thickness direction of the motion platform (1), reinforcing ribs are arranged along the periphery of the motion platform (1); four bosses are evenly arranged on the inner side of the motion platform (1), the angle between every two adjacent bosses is 90°, and a threaded hole is provided at the center of each boss; Each piezoelectric actuating mechanism comprises a composite flexible amplifying mechanism, a stacked piezoelectric ceramic (9) and a wedge assembly (8), wherein the composite flexible amplifying mechanism is composed of a rhombus amplifying mechanism (6) and a lever amplifying mechanism (7); a piezoelectric actuating mechanism is arranged in the negative direction of the X-axis and the Y-axis of the motion platform (1); the lever amplifying mechanism (7) in the piezoelectric actuating mechanism is connected to the motion platform (1) via a first corrugated flexible beam (2), one end of the rhombus amplifying mechanism (6) is connected to the lever amplifying mechanism (7) via a second corrugated flexible beam (3), and the other end of the rhombus amplifying mechanism (6) is connected to the lever amplifying mechanism (7) via a third corrugated flexible beam. (4) connected to the fixed end (5); the X-axis and the Y-axis are perpendicular to each other, and the XY plane formed by the two axes is parallel to the horizontal plane; in the XY plane, the X-axis is arranged vertically, and its positive direction points downward; the Y-axis is arranged horizontally, and its positive direction points to the right; the Z-axis is perpendicular to the XY plane, and its positive direction is determined by the right-hand rule based on the positive directions of the X-axis and the Y-axis; the diamond-shaped flexible constraint mechanism (11) is a hollow thin-walled structure, arranged at a position 45° to the positive direction of the X-axis, one end of which is connected to the motion platform (1) through a first flexible hinge (10), and the other end of which is connected to the fixed end (5) through a second flexible hinge (12); The diamond-shaped amplifying mechanism (6) is connected to the lever amplifying mechanism (7) via two second corrugated flexible beams (3) on one side of the output end, and is connected to the fixed end (5) via two third corrugated flexible beams (4) on the other side of the output end; The lever amplification mechanism (7) is connected to the motion platform (1) at the output end via two first corrugated flexible beams (2); The first corrugated flexible beam (2), the second corrugated flexible beam (3), and the third corrugated flexible beam (4) are variable thickness units constructed using elliptical curve segments, and four identical variable thickness units are connected end to end to form a flexible beam; the diamond-shaped flexible constraint mechanism (11) is a hollow thin-walled structure, arranged at a position 45 degrees to the positive direction of the X-axis, and connected to the motion platform (1) and the fixed end (5) via a first flexible hinge (10) and a second flexible hinge (12); only one diamond-shaped flexible constraint mechanism (11) is used in the device, and is connected in parallel with the composite flexible amplification mechanisms on the two motion axes.

2. A two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism according to claim 1, characterized in that: The two-dimensional micro-displacement scanning device is a symmetrical structure, and its configuration in two movement directions is completely the same, and it is symmetrical about a direction that is 45° to the positive direction of the X-axis.

3. The two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism according to claim 1, characterized in that: The diamond-shaped amplifying mechanism (6) and the lever amplifying mechanism (7) of the composite flexible amplifying mechanism are connected in series via the second corrugated flexible beam (3).

4. The two-dimensional micro-displacement scanning device based on a flexible amplification and constraint mechanism according to claim 1, characterized in that: The inner side of the diamond-shaped amplifying mechanism (6) does not have a boss in contact with the stacked piezoelectric ceramic (9); the flexible arm of the diamond-shaped amplifying mechanism (6) adopts a variable cross-section structure, and the inner and outer sides have different inclination angles, and the inclination angle of the inner side is greater than the inclination angle of the outer side.

5. The two-dimensional micro-displacement scanning device based on a flexible amplification and restraint mechanism according to claim 1, characterized in that: One end of the stacked piezoelectric ceramic (9) is bonded to the inner side of the diamond-shaped amplifying mechanism (6) by epoxy resin, and the other end is bonded to a wedge in the wedge assembly (8) by epoxy resin.

6. The two-dimensional micro-displacement scanning device based on a flexible amplification and restraint mechanism according to claim 1, characterized in that: The wedge block assembly (8) is composed of two identical wedge blocks with an inclination angle of 5°, and is assembled together with the stacked piezoelectric ceramic (9) in the diamond-shaped amplification mechanism (6) through interference fit.

7. A scanning method of a two-dimensional micro-displacement scanning device based on a flexible amplification and restraint mechanism according to any one of claims 1 to 6, characterized in that: Two piezoelectric actuators arranged in the X and Y axis directions provide input displacement to the motion platform (1), thereby realizing translation of the motion platform (1) in two degrees of freedom in the XY plane; when a driving voltage is applied to the stacked piezoelectric ceramics (9) in the rhombus amplifying mechanism (6) arranged in the X axis direction, the stacked piezoelectric ceramics (9) are extended, and the rhombus amplifying mechanism (6) performs a first-stage amplification on the output displacement of the stacked piezoelectric ceramics (9), and uses the output displacement of the rhombus amplifying mechanism (6) as the input displacement of the lever amplifying mechanism (7), and completes the transmission of the displacement through the second corrugated flexible beam (3), and then through the lever amplifying mechanism (7) After the lever amplification mechanism (7) performs secondary amplification on the displacement, the output displacement of the lever amplification mechanism (7) is transmitted to the motion platform (1) by using the first corrugated flexible beam (2), and the motion platform (1) moves along the X-axis direction; when the motion platform moves along the X-axis direction, the first corrugated flexible beam (2), the second corrugated flexible beam (3), and the third corrugated flexible beam (4) located in the Y-axis direction undergo elastic deformation, all of which play a guiding role; at the same time, the diamond-shaped flexible constraint mechanism (11) undergoes elastic deformation, which plays a role in limiting the motion platform (1) from generating coupling errors along the Y-axis direction and parasitic rotation around the Z-axis; When a driving voltage is applied to the stacked piezoelectric ceramic (9) in the rhombus amplifying mechanism (6) arranged in the Y-axis direction, the displacement of the stacked piezoelectric ceramic (9) is transmitted to the motion platform (1) through the first corrugated flexible beam (2) and the second corrugated flexible beam (3) in the Y-axis direction, and the motion platform (1) moves along the Y-axis direction; the first corrugated flexible beam (2), the second corrugated flexible beam (3) and the third corrugated flexible beam (4) in the X-axis direction undergo elastic deformation, playing a guiding role; at the same time, the rhombus flexible constraint mechanism (11) undergoes elastic deformation, playing a role in limiting the motion platform (1) from generating coupling errors along the X-axis direction and parasitic rotation around the Z-axis; that is, by applying a driving voltage to the stacked piezoelectric ceramic (9), the motion platform (1) achieves motion with two degrees of freedom in the XY plane.

8. The scanning method of the two-dimensional micro-displacement scanning device based on the flexible amplification and restraint mechanism according to claim 7, characterized in that: By applying a driving voltage, the motion platform (1) realizes scanning motion with two degrees of freedom along the positive direction and the negative direction of the X-axis or Y-axis; by changing the amplitude of the driving voltage applied to the stacked piezoelectric ceramic (9), the motion range of the motion platform (1) is changed; the greater the amplitude of the driving voltage, the greater the motion range of the motion platform (1), and vice versa.

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