High-precision horizontal adjusting table and control method

Abstract

The invention provides a high-precision horizontal adjusting table and a control method, and the high-precision horizontal adjusting table comprises a planar guide rail (200) which comprises a base (210) and an annular guide rail (220) fixed on the base (210); the piezoelectric driving mechanism (100) comprises a flexible plate (101); the first piezoelectric ceramic driver (107a), the second piezoelectric ceramic driver (107b), the third piezoelectric ceramic driver (103a) and the fourth piezoelectric ceramic driver (103b) are located on the first side, the second side, the third side and the fourth side respectively, and the first piezoelectric ceramic driver (107a) and the second piezoelectric ceramic driver (107b) are used for outputting displacement in the first direction. The third piezoelectric ceramic driver (103a) and the fourth piezoelectric ceramic driver (103b) are used for outputting displacement in the second direction; and the upper flat plate (300) is fixedly connected with at least partial area of the piezoelectric driving mechanism (100), and the upper flat plate (300) is used for bearing a target object and transmitting the motion to the target object.

Description

Technical Field

[0001] The present disclosure relates to the field of precision positioning technology, and particularly to a high-precision horizontal adjustment stage and a control method thereof. Background Art

[0002] With the rapid development of integrated circuit manufacturing technology, the characteristic line width dimension thereof is continuously reduced, which makes the accuracy requirement of the lithography process higher and higher. As the integrated circuit technology develops towards smaller line width dimensions, the positioning accuracy of the workpiece stage is required to reach below several nanometers. How to improve the positioning accuracy of the workpiece stage to meet the requirements of high-precision lithography is an issue that researchers have been continuously concerned about.

[0003] The above information disclosed in this section is only used for understanding the background of the inventive concept of the present disclosure. Therefore, the above information may include information that does not constitute the prior art. Summary of the Invention

[0004] In view of this, a first aspect of the present disclosure provides a high-precision horizontal adjustment stage, which is characterized in that, from bottom to top, it includes: a planar guide rail, including a base and an annular guide rail fixed on the base; a piezoelectric drive mechanism, including a flexible plate, the flexible plate including a first side and a second side oppositely arranged in a first direction, and a third side and a fourth side oppositely arranged in a second direction; a first piezoelectric ceramic driver, a second piezoelectric ceramic driver, a third piezoelectric ceramic driver, and a fourth piezoelectric ceramic driver are respectively located on the first side, the second side, the third side, and the fourth side, the first piezoelectric ceramic driver and the second piezoelectric ceramic driver are used to output displacements in the first direction, and the third piezoelectric ceramic driver and the fourth piezoelectric ceramic driver are used to output displacements in the second direction; an upper flat plate, fixedly connected to at least a part of the piezoelectric drive mechanism, the upper flat plate is used to carry a target object and transfer the movement of the piezoelectric drive mechanism to the target object.

[0005] According to an embodiment of the present disclosure, the flexible plate is divided into a first area, a second area, and a third area that are adjacent to each other in sequence, the first area surrounds the second area, and the second area surrounds the third area; four first guide pieces are respectively arranged at four corners of the second area close to the first area for providing torsional displacement; four second guide pieces are respectively arranged at four corners of the third area close to the second area for providing torsional displacement.

[0006] According to an embodiment of the present disclosure, the first guiding piece includes a first main body portion and two first branch portions oppositely arranged on the first main body portion in the second direction. The length of the first main body portion in the second direction is greater than its width in the first direction, and the width of the first main body portion in the first direction is greater than the width of the first branch portion in the first direction. The second guiding piece includes a second main body portion and two second branch portions oppositely arranged on the second main body portion in the first direction. The length of the second main body portion in the first direction is greater than its width in the second direction, and the width of the second main body portion in the second direction is greater than the width of the second branch portion in the second direction.

[0007] According to an embodiment of the present disclosure, the piezoelectric driving mechanism further includes: a first capacitance sensor and a second capacitance sensor are located on the fourth side and respectively in the opposite directions of the first piezoelectric ceramic driver and the second piezoelectric ceramic driver, for measuring the displacement of the flexible plate in the first direction; a third capacitance sensor and a fourth capacitance sensor are located on the first side and respectively in the opposite directions of the third piezoelectric ceramic driver and the fourth piezoelectric ceramic driver, for measuring the displacement of the flexible plate in the second direction; two first reinforcing plates are respectively located on the first side and the second side, for connecting the first region and the second region; two second reinforcing plates are respectively located on the third side and the fourth side, for connecting the second region and the third region.

[0008] According to an embodiment of the present disclosure, the first reinforcing plate includes a first supporting portion, two first connecting portions oppositely arranged on the first supporting portion in the second direction, and a first fixing portion oppositely arranged on the two first connecting portions in the second direction. The length of the first supporting portion in the second direction is greater than its width in the first direction, and the width of the first supporting portion in the first direction is greater than the width of the first connecting portion in the first direction. The two first fixing portions are respectively fixed to the first region and the second region. The second reinforcing plate includes a second supporting portion, two second connecting portions oppositely arranged on the second supporting portion in the first direction, and a second fixing portion oppositely arranged on the two second connecting portions in the first direction. The length of the second supporting portion in the first direction is greater than its width in the second direction, and the width of the second supporting portion in the second direction is greater than the width of the second connecting portion in the second direction. The two second fixing portions are respectively fixed to the second region and the third region.

[0009] According to an embodiment of the present disclosure, the piezoelectric driving mechanism further includes: two first pre-tightening springs are respectively located on the first side and the second side, for connecting the first region and the second region; the two first pre-tightening springs respectively provide pre-tightening forces for the first piezoelectric ceramic driver and the second piezoelectric ceramic driver; two second pre-tightening springs are respectively located on the third side and the fourth side, for connecting the second region and the third region; the two second pre-tightening springs respectively provide pre-tightening forces for the third piezoelectric ceramic driver and the fourth piezoelectric ceramic driver.

[0010] According to an embodiment of the present disclosure, the annular guide rail includes a bottom support plate, a cover plate, and a set of steel balls located between the bottom support plate and the cover plate. The cover plate is fixedly connected to the third region. Each set of steel balls includes a cage and steel balls, and the cage is used to limit the steel balls. The annular guide rail is used to provide high-rigidity support in the direction perpendicular to the upper surface of the base and guiding function in the direction parallel to the upper surface of the base. The materials of the bottom support plate and the cover plate include silicon carbide. The material of the cage includes nylon and copper. The materials of the steel balls include bearing steel and ceramics.

[0011] According to an embodiment of the present disclosure, the annular guide rail includes at least three sets of steel balls, and the sets of steel balls are evenly distributed in the annular guide rail. The steel balls are distributed along the radial direction of the annular guide rail.

[0012] According to an embodiment of the present disclosure, the upper flat plate is fixedly connected to the third region; and / or the material of the flexible plate includes titanium alloy and manganese alloy. The material of the upper flat plate includes aerospace aluminum alloy and ceramics.

[0013] The second aspect of the present disclosure provides a control method for the high-precision horizontal adjustment table according to the above, which is characterized by including:

[0014] S1. Use the first piezoelectric ceramic actuator and the second piezoelectric ceramic actuator to output the target displacement, and drive the upper flat plate to move along the first direction through the C region of the flexible plate;

[0015] S2. Use the first capacitance sensor and the second capacitance sensor to measure the displacement X and rotation angle θ of the upper flat plate along the first direction z ;

[0016] S3. Calculate the displacement output amounts of the first piezoelectric ceramic actuator and the second piezoelectric ceramic actuator through a control algorithm, and then complete a motion closed-loop;

[0017] Repeat S1-S3 to achieve displacement control in the first direction;

[0018] S4. Use the third piezoelectric ceramic actuator and the fourth piezoelectric ceramic actuator to output the target displacement, and drive the upper flat plate to move along the second direction through the C region of the flexible plate;

[0019] S5. Use the third capacitance sensor and the fourth capacitance sensor to measure the displacement Y of the upper flat plate along the second direction;

[0020] S6. Calculate the displacement output amounts of the third piezoelectric ceramic actuator and the fourth piezoelectric ceramic actuator through a control algorithm, and then complete a motion closed-loop;

[0021] Repeat S4-S6 to achieve displacement control in the second direction. Description of the Drawings

[0022] Through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, the above and other objects, features, and advantages of the present disclosure will become clearer. In the drawings:

[0023] Figure 1 Schematically shows the overall structure diagram of a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0024] Figure 2 Schematically shows the three-dimensional assembly diagram of a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0025] Figure 3 Schematically shows the plan view of the piezoelectric drive mechanism in a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0026] Figure 4A Schematically shows the plan view of the first guide piece in a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0027] Figure 4B Schematically shows the plan view of the second guide piece in a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0028] Figure 5A Schematically shows the plan view of the first reinforcing plate in a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0029] Figure 5B Schematically shows the plan view of the second reinforcing plate in a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0030] Figure 6 Schematically shows the cross-sectional view of a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0031] Figure 7 Schematically shows the cross-sectional view of a partial plane guide rail in a high-precision horizontal adjustment table according to an embodiment of the present disclosure;

[0032] Figure 8 Schematically shows the flowchart of the control method of the high-precision horizontal adjustment table described above.

[0033] Description of reference numerals:

[0034] 100, piezoelectric drive mechanism; 101, flexible plate; 102, 102a, 102b, second reinforcing plate; 1021, second support portion; 1022, second connecting portion; 1023, second fixing portion; 103a, third piezoelectric ceramic actuator; 103b, fourth piezoelectric ceramic actuator; 104, 104a, 104b, second pre-tightening spring; 105, 105a, 105b, 105c, 105d, second guide piece; 1051, second main body portion; 1052, second branch portion; 106a, third capacitance sensor; 106b, fourth capacitance sensor; 107a, first piezoelectric ceramic actuator; 107b, second piezoelectric ceramic actuator; 108, 108a, 108b, first reinforcing plate; 1081, first support portion; 1082, first connecting portion; 1083, first fixing portion; 109, 109a, 109b, first pre-tightening spring; 110a, first capacitance sensor; 110b, second capacitance sensor; 111, 111a, 111b, 111c, 111d, first guide piece; 1111, first main body portion; 1112, first branch portion; 200, planar guide rail; 210, base; 220, annular guide rail; 201, bottom support plate; 202, steel ball; 203, cage; 204, cover plate; 300, upper flat plate. Detailed implementation manners

[0035] In order to make the objectives, technical solutions and advantages of the present disclosure more clear and understandable, the present disclosure will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0036] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0037] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0038] In the case of using expressions such as "at least one of A, B, and C, etc.", generally, it should be interpreted according to the meaning that those skilled in the art usually understand this expression (for example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", generally, it should be interpreted according to the meaning that those skilled in the art usually understand this expression (for example, "a system having at least one of A, B, or C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). In addition, the X-axis, Y-axis, and Z-axis are not limited to the three axes of a rectangular coordinate system and can be interpreted in a broader sense. For example, the X-axis, Y-axis, and Z-axis can be perpendicular to each other, or can represent different directions that are not perpendicular to each other. For the purposes of this disclosure, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" can be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z such as XYZ, XY, XZ, and YZ.

[0039] It should be noted that in this article, the X direction, Y direction, and θ z Among the three degrees of freedom, the X direction represents the translational motion of an object in the X-axis direction, the Y direction represents the translational motion of the object in the Y-axis direction, and θ z represents the rotational motion of the object around the Z-axis.

[0040] Some block diagrams and / or flowcharts are shown in the accompanying drawings. It should be understood that some of the blocks or combinations thereof in the block diagrams and / or flowcharts can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when these instructions are executed by the processor, they can create a device for implementing the functions / operations illustrated in these block diagrams and / or flowcharts. The technology of this disclosure can be implemented in the form of hardware and / or software (including firmware, microcode, etc.). Additionally, the technology of this disclosure can take the form of a computer program product on a computer-readable storage medium storing instructions, which can be used by or in conjunction with an instruction execution system.

[0041] Figure 1 The overall structure diagram of a high-precision horizontal adjustment table according to an embodiment of the present disclosure is schematically shown. Figure 2 The three-dimensional assembly diagram of the high-precision horizontal adjustment table according to an embodiment of the present disclosure is schematically shown. Figure 3Schematically shown is a plan view of a piezoelectric drive mechanism in a high-precision horizontal adjustment stage according to an embodiment of the present disclosure.

[0042] Referring to Figures 1 - 3 , the high-precision horizontal adjustment stage includes, from bottom to top: a planar guide rail 200, including a base 210 and an annular guide rail 220 fixed to the base 210; a piezoelectric drive mechanism 100, including a flexible plate 101, the flexible plate 101 including a first side S1 and a second side S2 oppositely arranged in a first direction X, and a third side S3 and a fourth side S4 oppositely arranged in a second direction Y; a first piezoelectric ceramic actuator 107a, a second piezoelectric ceramic actuator 107b, a third piezoelectric ceramic actuator 103a, and a fourth piezoelectric ceramic actuator 103b are respectively located on the first side S1, the second side S2, the third side S3, and the fourth side S4, the first piezoelectric ceramic actuator 107a and the second piezoelectric ceramic actuator 107b are used to output displacements in the first direction X, and the third piezoelectric ceramic actuator 103a and the fourth piezoelectric ceramic actuator 103b are used to output displacements in the second direction Y; a first capacitance sensor 110a and a second capacitance sensor 110b are located on the fourth side and are respectively in the opposite directions of the first piezoelectric ceramic actuator 107a and the second piezoelectric ceramic actuator 107b, and are used to measure the displacement of the flexible plate 101 in the first direction X, and a third capacitance sensor 106a and a fourth capacitance sensor 106b are located on the first side and are respectively in the opposite directions of the third piezoelectric ceramic actuator 103a and the fourth piezoelectric ceramic actuator 103b, and are used to measure the displacement of the flexible plate 101 in the second direction Y; an upper flat plate 300 is fixedly connected to at least a part of the piezoelectric drive mechanism 100, and the upper flat plate 300 is used to carry a target object and transmit the movement of the piezoelectric drive mechanism 100 to the target object.

[0043] The planar guide rail 200 is located below the piezoelectric drive mechanism 100 and supports the horizontal adjustment stage in a third direction Z, ensuring high-stiffness support and guidance of the horizontal adjustment stage in the third direction Z. The piezoelectric drive mechanism 100 uses a flexible plate 101 and is respectively provided with dual piezoelectric ceramic actuators for driving in the first direction X and the second direction Y, and uses capacitance sensors to measure displacements, realizing a three-degree-of-freedom nano-level micro-displacement drive and positioning motion platform in the first direction X, the second direction Y, and the rotation angle θ z The upper flat plate 300 is a motion output member, fixed to the piezoelectric drive mechanism 100, and is driven by the piezoelectric drive mechanism 100, thereby driving the target object to move. For example, the target object is a material such as a silicon wafer. It can be understood that the displacements of the flexible plate 101 in the first direction and the second direction can also be measured by tools such as grating rulers, and the present disclosure is not limited to using capacitance sensors to measure displacements.

[0044] In the high-precision horizontal adjustment stage of the present disclosure, dual piezoelectric ceramic actuators are used for piezoelectric driving in the first direction X and the second direction Y, which improves the structural stiffness in both the translation direction and the rotation direction, thereby improving the positioning accuracy. Two sets of capacitive sensors are provided in the first direction X and cooperate with the upper flat plate 300 to measure the displacement in the first direction X, so as to achieve closed-loop control in the first direction X and the rotation angle θ z direction; two sets of capacitive sensors are provided in the second direction Y and cooperate with the upper flat plate 300 to measure the displacement in the second direction Y, so as to achieve closed-loop control in the second direction Y and θ z direction; thus, three-degree-of-freedom adjustment in the first direction X, the second direction Y and the rotation angle θ z can be realized, and the positioning accuracy reaches the nanometer level.

[0045] In some embodiments of the present disclosure, the flexible plate 101 is divided into a first region A, a second region B and a third region C that are adjacent to each other in sequence. The first region A surrounds the second region B, and the second region B surrounds the third region C; four first guiding pieces 111 (including 111a, 111b, 111c, 111d) are respectively arranged at the four corners of the second region B close to the first region A to provide torsional displacement; four second guiding pieces 105 (including 105a, 105b, 105c, 105d) are respectively arranged at the four corners of the third region C close to the second region B to provide torsional displacement.

[0046] Refer to Figure 3 , the piezoelectric driving mechanism 100 makes the third region C perform translational and rotational movements relative to the second region B, the second region B perform translational and rotational movements relative to the first region A, and the A region is fixed. This kind of motion control logic of the series motion structure is simple and there is no over-constraint on the piezoelectric ceramics, and the assembly and debugging processes are simple.

[0047] Figure 4A Schematically shows a plan view of the first guiding piece in the high-precision horizontal adjustment stage according to an embodiment of the present disclosure; Figure 4B Schematically shows a plan view of the second guiding piece in the high-precision horizontal adjustment stage according to an embodiment of the present disclosure.

[0048] In some embodiments of the present disclosure, the first guiding piece 111 includes a first main body portion 1111 and two first branch portions 1112 oppositely arranged on the first main body portion 1111 in the second direction Y. The length L2 of the first main body portion 1111 in the second direction Y is greater than its width W1 in the first direction X, and the width W1 of the first main body portion 1111 in the first direction X is greater than the width W2 of the first branch portion 1112 in the first direction X; the second guiding piece 105 includes a second main body portion 1051 and two second branch portions 1052 oppositely arranged on the second main body portion 1051 in the first direction X. The length L1 of the second main body portion 1051 in the first direction X is greater than its width W3 in the second direction Y, and the width W3 of the second main body portion 1051 in the second direction Y is greater than the width W4 of the second branch portion 1052 in the second direction Y.

[0049] Referring to Figure 3 , Figures 4A - 4B , the flexible plate 101 adopts a four-guiding-piece structure in each movement direction. The structures of the first guiding piece 111 and the second guiding piece 105 are the same, but their installation orientations are different. Each guiding piece adopts a structure with a thicker middle and thinner ends, so that a certain displacement can be achieved in the movement direction, and a relatively high bi-directional tensile and compressive stiffness can be obtained in the non-movement direction, and a certain torsional displacement can be achieved, which is beneficial to improving the flexibility of the adjustment platform. Specifically, for the first guiding pieces 111 at the four corners of the second region B close to the first region A, the length direction of the first main body portion 1111 extends along the second direction Y, and two relatively thin first branch portions 1112 are provided on both sides along the second direction Y. Therefore, the first guiding piece 111 has a certain flexibility in the first direction X, so that the second region B has a small displacement ability in the first direction X and the rotation angle θ z direction, while ensuring the stiffness along the second direction Y. For the second guiding pieces 105 at the four corners of the third region C close to the second region B, the length direction of the second main body portion 1051 extends along the first direction X, and two relatively thin second branch portions 1052 are provided on both sides along the first direction X. Therefore, the second guiding piece 105 has a certain flexibility in the second direction Y, so that in addition to being able to make small displacement movements in the first direction X, the third region C can also make small displacement movements in the second direction Y and the rotation angle θ z direction through the driving of the third piezoelectric ceramic actuator 103a and / or the fourth piezoelectric ceramic actuator 103b, while ensuring the stiffness along the first direction X.

[0050] In some embodiments of the present disclosure, the piezoelectric driving mechanism 100 further includes: two first reinforcing plates 108 (including 108a, 108b), respectively located on the first side S1 and the second side S2, for connecting the first region A and the second region B; two second reinforcing plates 102 (including 102a, 102b), respectively located on the third side S3 and the fourth side S4, for connecting the second region B and the third region C.

[0051] The high-precision horizontal adjustment table of the present disclosure is provided with 2 X-direction reinforcing plates between the first region A and the second region B of the flexible plate 101, and 2 Y-direction reinforcing plates are installed between the second region B and the third region C. By making full use of the bidirectional high stiffness of the X-direction reinforcing plates and the Y-direction reinforcing plates, the stiffness of the beam structure in the second region B is enhanced, and thus the overall stiffness of the horizontal adjustment table is improved.

[0052] Figure 5A Schematically shows a plan view of the first reinforcing plate in the high-precision horizontal adjustment table according to an embodiment of the present disclosure; Figure 5B Schematically shows a plan view of the second reinforcing plate in the high-precision horizontal adjustment table according to an embodiment of the present disclosure.

[0053] In some embodiments of the present disclosure, the first reinforcing plate 108 includes a first support portion 1081, two first connection portions 1082 oppositely arranged in the second direction Y on the first support portion 1081, and a first fixing portion 1083 oppositely arranged in the second direction Y on the two first connection portions 1082. The length L3 of the first support portion 1081 in the second direction Y is greater than its width W5 in the first direction X, the width W5 of the first support portion 1081 in the first direction X is greater than the width W6 of the first connection portion 1082 in the first direction X, and the two first fixing portions 1083 are respectively fixed to the first region A and the second region B; the second reinforcing plate 102 includes a second support portion 1021, two second connection portions 1022 oppositely arranged in the first direction X on the second support portion 1021, and a second fixing portion 1023 oppositely arranged in the first direction X on the two second connection portions 1022. The length L4 of the second support portion 1021 in the first direction X is greater than its width W7 in the second direction Y, the width W8 of the second support portion 1021 in the second direction Y is greater than the width W8 of the second connection portion 1022 in the second direction Y, and the two second fixing portions 1023 are respectively fixed to the second region B and the third region C.

[0054] The first reinforcing plate 108 has the same structure as the second reinforcing plate 102, but is arranged in a different orientation. The first reinforcing plate 108 connects the first region A and the second region B of the flexible plate 101, and the second reinforcing plate 102 connects the second region B and the third region C of the flexible plate 101, improving the structural stiffness of the flexible plate 101; both the first reinforcing plate 108 and the second reinforcing plate 102 have sufficient thickness in the middle but are thinner at both ends, so they have a certain torsional displacement, ensuring that the flexible plate 101 can achieve a certain displacement in the moving direction and has a higher connection stiffness in the non-moving direction, which is beneficial to improving the flexibility of the horizontal adjustment table.

[0055] In some embodiments of the present disclosure, the piezoelectric driving mechanism 100 further includes: two first pre-tightening springs 109, respectively located on the first side S1 and the second side S2, for connecting the first region A and the second region B; the two first pre-tightening springs 109 respectively provide pre-tightening forces for the first piezoelectric ceramic driver 107a and the second piezoelectric ceramic driver 107b; two second pre-tightening springs 104, respectively located on the third side S3 and the fourth side S4, for connecting the second region B and the third region C; the two second pre-tightening springs 104 respectively provide pre-tightening forces for the third piezoelectric ceramic driver 103a and the fourth piezoelectric ceramic driver 103b.

[0056] The first piezoelectric ceramic driver 107a and the second piezoelectric ceramic driver 107b are pre-tightened by using the elastic restoring force of the first pre-tightening spring 109 in the X direction, and the third piezoelectric ceramic driver 103a and the fourth piezoelectric ceramic driver 103b are pre-tightened by using the elastic restoring force of the second pre-tightening spring 104 in the Y direction.

[0057] Figure 6 A cross-sectional view of a high-precision horizontal adjustment table according to an embodiment of the present disclosure is schematically shown; Figure 7 A cross-sectional view of a partial plane guide rail in a high-precision horizontal adjustment table according to an embodiment of the present disclosure is schematically shown.

[0058] In some embodiments of the present disclosure, the annular guide rail 220 includes a bottom support plate 201, a cover plate 204, and a set of steel balls located between the bottom support plate 201 and the cover plate 204. The cover plate 204 is fixedly connected to the third region. Each set of steel balls includes a cage 203 for limiting the steel balls 202; the annular guide rail 220 is used to provide high-stiffness support in the direction perpendicular to the upper surface of the base 210 and guiding function in the direction parallel to the upper surface of the base 210; the materials of the bottom support plate 201 and the cover plate 204 include silicon carbide; the material of the cage 203 includes materials with relatively small friction coefficients such as nylon and copper; the material of the steel balls 202 includes high-hardness materials such as bearing steel and ceramics.

[0059] The annular guide rail 220 has rolling friction, with a small friction coefficient and few non-linear factors, enabling high positioning accuracy. Through the cooperation of the bottom support plate 201, the cover plate 204, and the steel ball group, the planar motion guiding function is achieved and high stiffness support along the third direction Z is provided. At the same time, the load capacity of the horizontal adjustment table is also improved. It should be noted that the bottom support plate 201 and the cover plate 204 are made of silicon carbide material, and the steel balls 202 are made of high-hardness materials such as bearing steel and ceramics, which is beneficial to improving the contact stiffness, reducing the friction force, reducing the rail creeping phenomenon, and enhancing the guiding accuracy and motion control accuracy.

[0060] In some embodiments of the present disclosure, the annular guide rail 220 includes at least three groups of steel ball groups, which are evenly distributed in the annular guide rail 220; the steel balls 202 are distributed radially along the annular guide rail 220.

[0061] The planar guide rail 200 includes multiple groups of steel ball groups, which are evenly distributed in the annular guide rail 220. Each group of steel ball groups is evenly arranged between the bottom support plate 201 and the cover plate 204. The cover plate 204 is connected to the third area C of the piezoelectric driving mechanism 100 to achieve the horizontal guiding function of the piezoelectric driving mechanism 100. The upper flat plate 300 is also connected to the third area C of the piezoelectric driving mechanism 100 and moves synchronously with the third area C to achieve the transmission of motion.

[0062] In some embodiments of the present disclosure, the material of the flexible plate 101 includes elastic materials such as titanium alloy and manganese alloy. The material of the upper flat plate 300 includes aerospace aluminum alloy, ceramics, etc.

[0063] The titanium alloy flexible plate has a small density, high strength and fatigue strength. After adopting the flexible plate structure, it can meet the functional requirements of repeated bending without damaging the structural performance.

[0064] Figure 8 A flowchart of the control method of the high-precision horizontal adjustment table according to the above is schematically shown.

[0065] Refer to Figure 8 , the control method of the high-precision horizontal adjustment table may include operations S1 to S6.

[0066] S1, using the first piezoelectric ceramic driver 107a and the second piezoelectric ceramic driver 107b to output the target displacement, driving the upper flat plate 300 to move along the first direction through the third area C area of the flexible plate 101;

[0067] S2, using the first capacitance sensor 110a and the second capacitance sensor 110b to measure the displacement X and rotation angle θ of the upper flat plate 300 along the first direction z ;

[0068] S3. Calculate the displacement output of the first piezoelectric ceramic actuator 107a and the second piezoelectric ceramic actuator 107b through a control algorithm, and then complete a motion closed-loop.

[0069] Repeat S1 - S3 to achieve displacement control in the first direction.

[0070] S4. Use the third piezoelectric ceramic actuator 103a and the fourth piezoelectric ceramic actuator 103b to output the target displacement, and drive the upper flat plate 300 to move in the second direction through the third region C region of the flexible plate 101.

[0071] S5. Measure the displacement Y of the upper flat plate 300 in the second direction by using the third capacitance sensor 106a and the fourth capacitance sensor 106b.

[0072] S6. Calculate the displacement output of the third piezoelectric ceramic actuator 103a and the fourth piezoelectric ceramic actuator 103b through a control algorithm, and then complete a motion closed-loop.

[0073] Repeat S5 - S6 to achieve displacement control in the second direction.

[0074] In operation S1, the first piezoelectric ceramic actuator 107a and the second piezoelectric ceramic actuator 107b control the output target displacement by adjusting the output voltage, and then transmit the motion to the third region C region of the flexible plate 101 through the second region B region of the flexible plate 101, realizing the movement of the third region C region in the first movement direction; the third region C region of the flexible plate 101 is fixedly connected to the upper flat plate 300, thereby realizing the movement of the upper flat plate 300 in the first direction.

[0075] In operation S2, both the first capacitance sensor 110a and the second capacitance sensor 110b are single-pole capacitors, and the measurement surface is the first side surface of the upper flat plate 300. As long as it is a metal surface, the displacement of the upper flat plate 300 can be measured; the displacement measured by the first capacitance sensor 110a is X1, and the displacement measured by the second capacitance sensor 110b is X2. Then the displacement X in the first direction = (X1 + X2) / 2; at the same time, the rotation angle θ z = (X1 - X2) / L, where L is the distance between the first capacitance sensor 110a and the second capacitance sensor 110b.

[0076] In operation S3, the displacement X and the rotation angle θ z Are fed back to the motion controller for calculation. Through the corresponding control algorithm, calculate the displacement output of the first piezoelectric ceramic actuator 107a and the second piezoelectric ceramic actuator 107b, and then complete a motion closed-loop; repeat the piezoelectric ceramic actuator displacement output - capacitance sensor measurement - motion controller calculation - piezoelectric ceramic actuator displacement output to realize the displacement control in the first direction.

[0077] In operation S4, the third piezoelectric ceramic actuator 103a and the fourth piezoelectric ceramic actuator 103b control the output target displacement by adjusting the output voltage, and then transmit the motion to the C region of the flexible plate 101 through the B region of the flexible plate 101, realizing the motion of the C region in the second direction; the C region of the flexible plate 101 is fixedly connected to the upper flat plate 300, thereby realizing the motion of the upper flat plate 300 in the second direction;

[0078] In operation S5, the third capacitance sensor 106a and the fourth capacitance sensor 106b are both single-pole capacitors, and the measurement surface is the second side surface of the upper flat plate 300. As long as it is a metal surface, the displacement of the upper flat plate 300 can be measured; the displacement measured by the third capacitance sensor 106a is Y1, and the displacement measured by the fourth capacitance sensor 106b is Y2, then the displacement Y in the second direction = (Y1 + Y2) / 2;

[0079] In operation S6, the displacement Y is fed back to the motion controller for calculation, and the displacement output amounts of the third piezoelectric ceramic actuator 103a and the fourth piezoelectric ceramic actuator 103b are calculated through corresponding control algorithms, thereby completing a motion closed loop; repeating the piezoelectric ceramic actuator output displacement - capacitance sensor measurement - motion controller calculation - piezoelectric ceramic actuator output displacement, thereby realizing the displacement control in the second direction.

[0080] The present disclosure has a high-precision horizontal adjustment table with three-degree-of-freedom motion and nano-positioning accuracy, including: an upper flat plate, a piezoelectric drive mechanism, and a planar guide rail. Among them, the upper flat plate is the output port of the motion, and the upper flat plate is fixed on the piezoelectric drive mechanism, and is driven and positioned by the piezoelectric drive mechanism to realize the horizontal adjustment function; the piezoelectric drive mechanism includes a flexible plate, piezoelectric ceramic actuators, capacitance sensors, guide pieces, reinforcing plates, and pre-tightening springs in the first direction X; piezoelectric ceramic actuators, capacitance sensors, guide pieces, reinforcing plates, and pre-tightening springs in the second direction Y. Two sets of piezoelectric ceramic actuators are arranged in the first direction X and installed on the first direction X of the flexible plate, serving as the drive motors in the first direction X; the pre-tightening springs in the first direction X are used to respectively provide pre-tightening forces for the piezoelectric ceramic actuators in the first direction X; the reinforcing plate in the first direction X is used to connect the first region A and the second region B of the flexible plate to improve the stiffness of the flexible plate; two sets of capacitance sensors are arranged in the first direction X, and cooperate with the upper flat plate as the detection surface to measure the displacement in the first direction X, realizing the first direction X and the rotation angle θ zClosed-loop control in the second direction. Two sets of piezoelectric ceramic actuators are arranged in the second direction Y and installed on the flexible plate in the second direction Y as the drive motors in the second direction Y; pre-tightening springs in the second direction Y are used to provide pre-tightening forces for the piezoelectric ceramic actuators in the second direction Y respectively; the reinforcing plate in the second direction Y is used to connect the second area B and the third area C of the flexible plate to improve the stiffness of the flexible plate; two sets of capacitance sensors are arranged in the second direction Y, and cooperate with the upper flat plate as the measurement surface to measure the displacement in the second direction Y, so as to realize the closed-loop control in the Y direction and θ z Closed-loop control in the second direction. The planar guide rail includes a base, a bottom support plate, steel balls, a cage and a cover plate; the base serves as the base of the high-precision horizontal adjustment table and is responsible for supporting the horizontal adjustment table; the combination of the bottom support plate, steel balls, cage and cover plate forms a planar annular guide rail structure to realize the planar motion guiding function of the piezoelectric drive mechanism.

[0081] Those skilled in the art can understand that the features recited in the various embodiments and / or claims of the present disclosure can be combined or / and combined in various ways, even if such combinations or combinations are not explicitly recited in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features recited in the various embodiments and / or claims of the present disclosure can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present disclosure.

[0082] Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, those skilled in the art should understand that various changes in form and detail can be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above embodiments, but should be determined not only by the appended claims but also by the equivalents of the appended claims.

Claims

1. A high-precision horizontal adjustment table, characterized in that, From bottom to top, it includes: A planar guide rail (200), including a base (210) and an annular guide rail (220) fixed on the base (210); A piezoelectric driving mechanism (100), including a flexible plate (101), the flexible plate (101) including a first side and a second side oppositely arranged in a first direction, and a third side and a fourth side oppositely arranged in a second direction; a first piezoelectric ceramic driver (107a), a second piezoelectric ceramic driver (107b), a third piezoelectric ceramic driver (103a), and a fourth piezoelectric ceramic driver (103b) are respectively located on the first side, the second side, the third side, and the fourth side, the first piezoelectric ceramic driver (107a) and the second piezoelectric ceramic driver (107b) are used to output displacements in the first direction, and the third piezoelectric ceramic driver (103a) and the fourth piezoelectric ceramic driver (103b) are used to output displacements in the second direction; An upper flat plate (300), fixedly connected to at least a part of the piezoelectric driving mechanism (100), the upper flat plate (300) being used to carry a target object and transmit the movement of the piezoelectric driving mechanism (100) to the target object.

2. The high-precision horizontal adjustment table according to claim 1, wherein The flexible plate (101) is divided into a first area, a second area, and a third area adjacent to each other in sequence, the first area surrounding the second area, and the second area surrounding the third area; four first guiding pieces (111) are respectively arranged at four corners of the second area close to the first area for providing torsional displacement; four second guiding pieces (105) are respectively arranged at four corners of the third area close to the second area for providing torsional displacement.

3. The high-precision horizontal adjustment table according to claim 2, wherein The first guiding piece (111) includes a first main body part (1111) and two first branch parts (1112) oppositely arranged in the second direction on the first main body part (1111), the length of the first main body part (1111) in the second direction being greater than its width in the first direction, and the width of the first main body part (1111) in the first direction being greater than the width of the first branch part (1112) in the first direction; The second guiding piece (105) includes a second main body part (1051) and two second branch parts (1052) oppositely arranged in the first direction on the second main body part (1051), the length of the second main body part (1051) in the first direction being greater than its width in the second direction, and the width of the second main body part (1051) in the second direction being greater than the width of the second branch part (1052) in the second direction.

4. The high-precision horizontal adjustment table according to claim 2, characterized in that, The piezoelectric driving mechanism (100) further includes: The first capacitance sensor (110a) and the second capacitance sensor (110b) are located on the fourth side and are respectively located in the opposite directions of the first piezoelectric ceramic actuator (107a) and the second piezoelectric ceramic actuator (107b), and are used to measure the displacement of the flexible plate (101) in the first direction. The third capacitance sensor (106a) and the fourth capacitance sensor (106b) are located on the first side and are respectively located in the opposite directions of the third piezoelectric ceramic actuator (103a) and the fourth piezoelectric ceramic actuator (103b), and are used to measure the displacement of the flexible plate (101) in the second direction; Two first reinforcing plates (108) are respectively located on the first side and the second side and are used to connect the first region and the second region; Two second reinforcing plates (102) are respectively located on the third side and the fourth side and are used to connect the second region and the third region.

5. The high-precision horizontal adjustment table according to claim 4, wherein The first reinforcing plate (108) includes a first support portion (1081), two first connection portions (1082) oppositely arranged in the second direction on the first support portion (1081), and a first fixing portion (1083) oppositely arranged in the second direction on the two first connection portions (1082). The length of the first support portion (1081) in the second direction is greater than its width in the first direction. The width of the first support portion (1081) in the first direction is greater than the width of the first connection portion (1082) in the first direction. The two first fixing portions (1083) are respectively fixed to the first region and the second region; The second reinforcing plate (102) includes a second support portion (1021), two second connection portions (1022) oppositely arranged in the first direction on the second support portion (1021), and a second fixing portion (1023) oppositely arranged in the first direction on the two second connection portions (1022). The length of the second support portion (1021) in the first direction is greater than its width in the second direction. The width of the second support portion (1021) in the second direction is greater than the width of the second connection portion (1022) in the second direction. The two second fixing portions (1023) are respectively fixed to the second region and the third region.

6. The high-precision horizontal adjustment table according to claim 2, characterized in that, The piezoelectric driving mechanism (100) further includes: Two first pre-tightening springs (109) are respectively located on the first side and the second side and are used to connect the first region and the second region; the two first pre-tightening springs (109) respectively provide pre-tightening forces for the first piezoelectric ceramic actuator (107a) and the second piezoelectric ceramic actuator (107b); Two second pre-tightening springs (104) are respectively located on the third side and the fourth side and are used to connect the second region and the third region; the two second pre-tightening springs (104) respectively provide pre-tightening forces for the third piezoelectric ceramic actuator (103a) and the fourth piezoelectric ceramic actuator (103b).

7. The high-precision horizontal adjustment table according to claim 2, wherein, The annular guide rail (220) includes a bottom support plate (201), a cover plate (204), and a set of steel balls located between the bottom support plate (201) and the cover plate (204). The cover plate (204) is fixedly connected to the third region. Each set of steel balls includes a cage (203) and steel balls (202), and the cage (203) is used to limit the steel balls (202). The annular guide rail (220) is used to provide high-stiffness support in the direction perpendicular to the upper surface of the base (210) and guiding function in the direction parallel to the upper surface of the base (210). The materials of the bottom support plate (201) and the cover plate (204) include silicon carbide. The material of the cage (203) includes nylon and copper. The materials of the steel balls (202) include bearing steel and ceramic.

8. The high-precision horizontal adjustment table according to claim 7, wherein, The annular guide rail (220) includes at least three sets of steel balls, and the sets of steel balls are evenly distributed in the annular guide rail (220). The steel balls (202) are distributed radially along the annular guide rail (220).

9. The high-precision horizontal adjustment table according to claim 2, wherein, The upper flat plate (300) is fixedly connected to the third region. The material of the flexible plate (101) includes titanium alloy and manganese alloy. The material of the upper flat plate (300) includes aerospace aluminum alloy and ceramic.

10. A control method for the high-precision horizontal adjustment table according to any one of claims 1 to 9, characterized in that, Including: S1. Using the first piezoelectric ceramic actuator (107a) and the second piezoelectric ceramic actuator (107b) to output the target displacement, driving the upper flat plate (300) to move along the first direction through the third region of the flexible plate (101). S2, measure the displacement X and rotation angle θ of the upper plate (300) in the first direction by using the first capacitance sensor (110a) and the second capacitance sensor (110b) z ; S3. Calculating the displacement output of the first piezoelectric ceramic actuator (107a) and the second piezoelectric ceramic actuator (107b) through the control algorithm, and then completing a motion closed-loop. Repeating S1 - S3 to achieve displacement control in the first direction. S4. Using the third piezoelectric ceramic actuator (103a) and the fourth piezoelectric ceramic actuator (103b) to output the target displacement, driving the upper flat plate (300) to move along the second direction through the third region of the flexible plate (101). S5. Measuring the displacement Y of the upper flat plate (300) along the second direction by using the third capacitance sensor (106a) and the fourth capacitance sensor (106b). S6. Calculating the displacement output of the third piezoelectric ceramic actuator (103a) and the fourth piezoelectric ceramic actuator (103b) through the control algorithm, and then completing a motion closed-loop. Repeating S4 - S6 to achieve displacement control in the second direction.

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