CN103252761A - Long-stroke two-dimensional nano worktable system with angle compensation function - Google Patents

Abstract

The invention discloses a large-stroke two-dimensional nanometer workbench system with angle compensation function, which uses a six-degree-of-freedom micro-motion workbench based on piezoelectric ceramic actuators and flexible hinges to perform linear positioning on the large-stroke two-dimensional workbench And the comprehensive compensation of angle error. In the present invention, the large-stroke two-dimensional workbench adopts the driving method of stepping motor combined with ball screw, which has large pitch angle, yaw angle, and roll angle error, and the positioning accuracy is at the micron level; the six-degree-of-freedom micro-motion workbench It has nanometer-level linear positioning accuracy and millisecond-level angular positioning accuracy. The combination of the two forms a large-stroke two-dimensional nano-table system. Under the control of the closed-loop control system, the system comprehensively compensates the linear positioning error and angular error of the large-stroke two-dimensional nano-table through a six-degree-of-freedom micro-motion table, and realizes two-dimensional large-stroke nanopositioning.

Description

Large-travel two-dimensional nano-table system with angle compensation function

technical field

    The invention relates to the field of large-scale and high-precision positioning workbench systems, in particular to a large-stroke two-dimensional nanometer workbench system with an angle compensation function.

Background technique

In the measurement system, the table not only needs to have extremely high linear positioning accuracy, but also needs to reduce its movement angle error as much as possible. The angular error of the worktable has a magnifying effect on its positioning error, especially in the measurement system that violates Abbe's principle, the Abbe error caused by the angular error of the worktable and the Abbe arm cannot be ignored. The traditional x-y two-dimensional worktable is mostly composed of two single-axis movable worktables. The imperfection of the guide rail causes the motion table to produce pitch, yaw, and roll motions. If the two worktables are in space at this time If there is a height difference, the positioning error of the guide rail will be amplified and reflected on the measurement plane where the stage is located. For example, the stacked two-dimensional measurement platform, the moving surfaces of the two guide rails do not overlap, there is a height difference of S = 5cm, and the inclination angle of the lower workbench is , the motion positioning error caused by the upper workbench = 250nm, this error The magnitude is not negligible for nanoscale measurements. In the ordinary precision measurement system, this error can be compensated to a certain extent through software compensation, but in the nanoscale measurement system, due to the deformation of the worktable and the change of the measurement environment, and even the difference in the position of the workpiece will cause the worktable When the stroke of the measuring machine is large, it is difficult to reach the nanometer level by compensation alone. In order to solve this problem, some studies have proposed a coplanar guide rail design. This coplanar design of the guide and measurement surfaces eliminates the amplification effect of the angular motion error of the guide rail and the height difference of the guide rail on the platform positioning error. However, when measuring, for a test piece with a certain height, the angle error of the worktable will still introduce a non-negligible measurement error, and this error varies with the shape and placement of the workpiece, making it difficult to compensate. By improving the machining accuracy and assembly accuracy of the guide rail of the worktable, there is a certain effect on reducing the positioning error and angular deviation of the worktable, but under the requirements of large stroke and high precision, the cost is extremely high and it is difficult to achieve.

Contents of the invention

The purpose of the present invention is to provide a large stroke two-dimensional nano-table system with angle compensation function to solve the problems existing in the prior art.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The large-stroke two-dimensional nano-table system with angle compensation function is characterized in that it includes a base, a large-stroke two-dimensional workbench arranged on the base, and a six-degree-of-freedom micro-motion workbench supported by the large-stroke two-dimensional workbench , Two optical length measuring and angle measuring systems distributed on two adjacent sides of the six-degree-of-freedom micro-motion table and forming an angle of 90 degrees to each other, wherein:

The two-dimensional large-stroke workbench is composed of two groups of single-axis workbenches arranged along the X and Y directions, which are superimposed up and down. The ball screw is used as the driving method, and the upper single-axis worktable is fixed on the guide rail slider of the lower single-axis worktable;

The driving element of the six-degree-of-freedom micro-motion workbench is piezoelectric ceramics, and the eight piezoelectric ceramics used are clamped and pre-tightened by piezoelectric ceramic stress-free clamping and pre-tightening mechanisms, and the guiding mechanism is a flexible hinge elastic guide rail , the six-degree-of-freedom micro-motion workbench includes a connecting plate, which is installed on the guide rail slider of the upper single-axis workbench in the large-travel two-dimensional workbench and rigidly connected, and four groups are arranged on the connecting plate along the Z direction. Piezoelectric ceramic drive unit, four groups of piezoelectric ceramic drive units are centrally symmetrical on the connecting plate and form a rectangle, and the sides of the rectangle are parallel to the X and Y directions respectively, and the connecting plate also supports a multi-degree-of-freedom plate, The multi-degree-of-freedom board is composed of an outer frame, a middle frame arranged in the outer frame, and an inner substrate arranged in the middle frame. The multi-degree-of-freedom board is fixed on a rectangular shape composed of four sets of piezoelectric ceramic drive units through its inner substrate. The top, and the side of the multi-degree-of-freedom board is parallel to the rectangular edge composed of four sets of piezoelectric ceramic drive units. Two optical length and angle measurement systems are distributed outside the two adjacent sides of the multi-degree-of-freedom board. The frame is located on the same side of one of the optical length measuring and angle measuring systems, and the top of the frame is equipped with an X-axis mirror adjustment bracket, and the outer frame of the multi-degree-of-freedom board is located on the same side of the other optical length and angle measuring system. The top of the frame is equipped with a Y-axis The mirror adjustment bracket, the X-axis mirror adjustment bracket and the Y-axis mirror adjustment bracket are distributed on the top of the multi-degree-of-freedom board frame at 90 degrees to each other, and the top of the X-axis mirror adjustment bracket is provided with an X-axis optical length measurement angle The X-axis reflector and Y-axis reflector of the system target mirror are adjusted on the top of the bracket. There is a Y-axis reflector as the target mirror of the Y-direction optical length measurement and angle measurement system. Mirror adjustment brackets are respectively installed on the top of the outer frame of the degree plate, and counterweights for balancing the weight of the opposite side mirrors are respectively fixed on the mirror adjustment brackets. The X, Y axis mirror adjustment brackets and the X, Y axis mirrors The mirror adjustment bracket used for the counterweight on the opposite side of the adjustment bracket is framed on the top of the multi-degree-of-freedom plate outer frame to form a frame shape, and the top of the multi-degree-of-freedom plate outer frame in the middle of the frame shape is also equipped with a loading platform.

The large-stroke two-dimensional nano-table system with angle compensation function is characterized in that: the optical length measurement and angle measurement system is composed of a photoelectric autocollimator and a Michelson laser interferometer.

The large-stroke two-dimensional nano-table system with angle compensation function is characterized in that: the piezoelectric ceramic stress-free clamping and pre-tightening mechanism includes rectangular piezoelectric ceramics, which are respectively stress-free clamped on the top of the piezoelectric ceramics and The gasket on the bottom insulating ceramic sheet, the steel ball with a diameter of 3mm embedded between the tapered hole of one gasket and the tapered hole of the fixed substrate, the tapered hole embedded in the other gasket and the head of the pre-tightening screw Steel balls with a diameter of 3 mm, pre-tightening screws and pre-tightening nuts between the tapered holes. The front of the gasket is processed with a chute, and the back of the gasket is processed with a tapered hole. The fronts of the two gaskets face each other and the direction of the chute It is stuck on the insulating ceramic sheet at both ends of the piezoelectric ceramic at an angle of 90 degrees, so that the position of the piezoelectric ceramic is limited, and the existence of the slide groove makes the difference between the pre-tightening screw and the tapered hole of the fixed substrate due to low processing and assembly accuracy. When the axis is used, the two gaskets can slide slightly along the direction of the chute during assembly to compensate for the additional stress that may be introduced when the pre-tightening screw and the tapered hole of the fixed base plate are not aligned due to low machining and assembly accuracy. The two gaskets Tapered holes are processed on the back of the back, the fixed base plate and the front end of the pre-tightening screw, and steel balls with a diameter of 3mm are respectively stuck in them, which play the role of positioning and transmitting force between the corresponding two tapered holes. The pre-tightening of piezoelectric ceramics Realized by pre-tightening nuts and pre-tightening screws embedded in the mobile base plate, the pitch used is 0.35mm. the

The large-stroke two-dimensional nano-table system with angle compensation function is characterized in that: the multi-degree-of-freedom plate is made of 7075 aluminum alloy through wire cutting, and is composed of an inner base plate, a middle frame and an outer frame, and the inner base plate and the middle Two piezoelectric ceramics are installed between the frames. The clamping and preloading methods of the two piezoelectric ceramics are consistent with the structure of the stress-free clamping and preloading mechanism of the piezoelectric ceramics. The two ceramics between the inner substrate and the middle frame When elongated at the same time, the middle frame rotates relative to the inner substrate, and X-direction piezoelectric ceramics and Y-direction piezoelectric ceramics are respectively installed between the middle frame and the outer frame along the X direction and along the Y direction. The clamping and pre-tightening methods are consistent with the structure of the piezoelectric ceramic stress-free clamping and pre-tightening mechanism. When the piezoelectric ceramics are stretched in the X direction, the outer frame moves in the X direction relative to the middle frame, and when the piezoelectric ceramics are stretched in the Y direction, The outer frame moves in the Y direction relative to the middle frame. When the piezoelectric ceramics in the X direction and the piezoelectric ceramics in the Y direction are extended at the same time, the outer frame moves in the XY direction relative to the middle frame. Four groups of Z direction The piezoelectric ceramic drive unit fixing hole and four Z-direction piezoelectric ceramic drive unit pre-tightening screw holes. The four outer corners of the inner base plate are respectively processed with parallel plate flexible hinges. The inner base plate and the middle frame are connected by four sets of parallel plate flexible hinges. The outer four corners of the frame are respectively processed with two-way parallel plate flexible hinges. The middle frame and the outer frame are connected by two-way parallel plate flexible hinges. The X-direction driving ceramics and the Y-direction driving ceramics are respectively evenly distributed with three mirror adjustment bracket fixing holes, and the positions of the X-direction driving ceramics and the Y-direction driving ceramics are respectively evenly distributed with two mirror adjustment bracket fixing holes. the

The large-stroke two-dimensional nano-table system with angle compensation function is characterized in that: the flexible hinges are all parallel plate flexible hinges.

The described large-stroke two-dimensional nano-table system with angle compensation function is characterized in that: the Z-direction piezoelectric ceramic driving unit is composed of a base body and piezoelectric ceramics arranged in the base body, and the clamping and preloading of the piezoelectric ceramics The method is consistent with the structure of the piezoelectric ceramic stress-free clamping and pre-tightening mechanism, wherein the top of the substrate is provided with an upper connection hole, the center of the top of the substrate is provided with a through hole, the bottom of the substrate is provided with a lower connection hole, and the bottom of the substrate passes through The bolts installed in the lower connection hole are fixed on the connection plate, the upper connection hole on the top of the base body and the Z-direction piezoelectric ceramic drive unit fixing hole of the inner substrate of the multi-degree-of-freedom plate are fixed together by bolts, and the pre-tightening nut is embedded in the multi-degree-of-freedom plate. The Z-direction piezoelectric ceramic drive unit pre-tightening screw hole on the base plate in the multi-degree-of-freedom board, the pre-tightening screw is screwed in from the upper side of the multi-degree-of-freedom board, and passes through the through hole at the top center of the substrate to clamp and pre-tighten the piezoelectric ceramics. tight.

The present invention proposes a design scheme of a large-stroke two-dimensional nano-table based on the macro-micro combination drive method, and uses a six-degree-of-freedom micro-motion table based on piezoelectric ceramic actuators and flexible hinges to position and control the macro-motion table. The comprehensive compensation of angle error maximizes the accuracy of the entire workbench system.

The beneficial effects of the present invention are: a large motion range of 200mm×200mm, low cost, and simple control; the control method is simple, no complicated algorithm is required, and the parasitic motion between each degree of freedom is small; the motion range is large, the positioning accuracy is high, and the motion angle The advantages of small error and low cost.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

Fig. 2 is a structural diagram of a large-travel two-dimensional workbench of the present invention.

Fig. 3 is a structural diagram of a six-degree-of-freedom micro-motion workbench of the present invention.

Fig. 4 is a stress-free clamping and pre-tightening mechanism for piezoelectric ceramics of the present invention.

Fig. 5 is a structure diagram of the multi-degree-of-freedom plate of the present invention.

Fig. 6 is a structural diagram of a Z-direction piezoelectric ceramic driving unit of the present invention.

Detailed ways

Referring to Fig. 1, Fig. 2 and Fig. 3, the present invention includes a base 1, a two-dimensional workbench 5 with a large stroke, a micro-motion workbench 3 with six degrees of freedom, and two sets of optical length and angle measuring devices arranged at an angle of 90 degrees. Systems 2 and 4; in order to make the linear positioning accuracy of the X and Y axes of the table positioning system reach the nanometer level, the linear motion of the six-degree-of-freedom micro-motion table 3 is used to compensate the linear positioning error of the large-stroke two-dimensional table 5, In order to make the workbench positioning system obtain a very small angle error, the angular error compensation of the large-stroke two-dimensional workbench 5 is performed through the angular movement of the six-degree-of-freedom micro-motion table 3;

The large-stroke two-dimensional workbench 5 is composed of two sets of single-axis workbenches arranged along the X direction and the Y direction, which are superimposed up and down. Each single-axis workbench uses a recirculating ball guide rail pair The ball screw 8 is used as the driving method, wherein the upper single-axis worktable is fixed on the guide rail slider 10 of the lower single-axis worktable, and the stroke of the superimposed large-stroke two-dimensional worktable 5 is 200mm×200mm.

The six-degree-of-freedom micro-motion workbench 3 is rigidly connected to the guide rail slider 9 of the single-axis workbench located on the upper part of the large-travel two-dimensional workbench 5 through the adapter plate 11, and the four sets of Z-direction pressure plates fixed on the adapter plate 11 The electroceramic driving unit 12 provides the lift of the worktable along the Z direction and the rotation around the X axis and the Y axis. The four groups of Z direction piezoelectric ceramic driving units 12 are centrally symmetrical on the connecting plate 11 and surround a rectangle, and the sides of the rectangle The sides are respectively parallel to the X direction and the Y direction, and the multi-degree-of-freedom board 13 is fixed on the top of the rectangle composed of four groups of piezoelectric ceramic drive units 12 through its inner substrate 39, and the sides of the multi-degree-of-freedom board 13 are connected to the four groups of piezoelectric ceramic drive units. The edges of the rectangle formed by the unit 12 are parallel, and the two optical length measuring and angle measuring systems 2 and 4 are distributed outside the two adjacent sides of the multi-degree-of-freedom plate 13. The translation of the worktable along the X direction and the Y direction and the movement around the Z axis The rotation is realized by the multi-degree-of-freedom board 13, and the inner substrate 39 of the multi-degree-of-freedom board 13 is connected with four groups of Z-direction piezoelectric ceramic drive units 12 through the Z-direction piezoelectric ceramic drive unit fixing holes 38 around the inner substrate 39, so that the four The pitch motion generated by the combined motion of the Z-direction piezoelectric ceramic drive unit 12 can be transmitted to the multi-degree-of-freedom board 13, and the outer frame 41 of the multi-degree-of-freedom board 13 is located on the same side of one of the optical length and angle measurement systems. The top of the frame is provided with an X-axis Mirror adjustment bracket 17, the outer frame of the multi-degree-of-freedom board is located at the top of the frame on the same side as another optical length measurement and angle measurement system. A Y-axis mirror adjustment bracket 14 is arranged on the top. The brackets 14 are distributed on the top of the outer frame 41 of the multi-degree-of-freedom board 13 at 90 degrees to each other, and are connected to the outer frame 41 of the multi-degree-of-freedom board 13 by three screws. The top of the mirror adjustment bracket 17 is provided with the X-axis reflector 16 as the target mirror of the X-direction optical length measurement and angle measurement system. Mirror 15, X-axis reflector 16, Y-axis reflector 15 are equipped with reflector adjustment brackets 21 and 20 respectively on the multi-degree-of-freedom plate outer frame edge tops on opposite sides respectively, and reflector adjustment brackets 21 and 20 are respectively fixed with balance pairs. The counterweights 22 and 19 of the side mirror weight, the mirror adjustment brackets 21 and 20 of the counterweights on the opposite side of the X and Y axis mirror adjustment brackets 17 and 14 and the X and Y axis mirror adjustment brackets are free The top of the outer frame of the degree plate is framed to form a frame shape, and the top of the outer frame of the multi-degree-of-freedom plate in the middle of the frame shape is also equipped with a stage 18, and the stage 18 is connected to the outer frame 41 of the multi-degree-of-freedom plate 13 by screws.

The two-dimensional large-stroke workbench 5 and the six-degree-of-freedom micro-motion workbench 3 use the common position detection system 2 and 4. The position detection system 2 is composed of a photoelectric autocollimator and a Michelson laser interferometer. The position detection system 4 The structure is the same as that of the position detection system 2; the photoelectric autocollimator is used to measure the pitch angle and the yaw angle of the stage 18, and the Michelson laser interferometer is used to measure the linear positioning error of the stage 18; the position detection system 2 and 4 use two high-precision strip-shaped plane mirrors 16 and 15 arranged at an angle of 90 degrees fixed on the six-degree-of-freedom micro-motion worktable 3 as target mirrors to avoid large-stroke two-dimensional workbench 5 and six-freedom The accumulative error introduced by the inconsistency of the measurement reference when the micro-motion workbench 3 performs position measurement respectively.

Referring to Figure 4, the eight piezoelectric ceramics in the six-degree-of-freedom micro-motion workbench are clamped by a stress-free clamping and pre-tightening mechanism. The insulating ceramic sheets at both ends of the ceramic 26 are equivalent to clamping the piezoelectric ceramic 26 in a cross chute, so that the position of the piezoelectric ceramic 26 is limited, and the existence of the chute 32 makes the pre-tightening screw 31 and the fixed substrate 23 When the tapered hole is not coaxial due to low processing and assembly accuracy, the two gaskets 25 and 27 can slide slightly along the direction of the chute to compensate for the pre-tightening screw 31 and the tapered hole of the fixed base plate 23 due to processing And the additional stress that may be introduced when the assembly accuracy is low and different from the axis, the back of the gasket 25 and 27 is processed with a tapered hole 33, and the front end of the fixed base plate 23 and the pre-tightening screw 31 is also processed with a tapered hole. Steel with a diameter of 3mm The balls 24 and 28 are respectively stuck in the tapered hole between the gasket 25 and the fixed base plate 23, between the gasket 27 and the tapered hole at the front end of the pre-tightening screw 31, and position and transmit force between the corresponding two tapered holes. The role of the piezoelectric ceramic 26 is preloaded through the preloaded nut 29 and the preloaded screw 31 embedded in the moving substrate 30 to achieve.

Referring to Fig. 3, Fig. 5, and Fig. 6, the flexible hinges are all parallel plate flexible hinges, and the parallel plate flexible hinges have a simple structure, are easy to process, and have no principle error.

Referring to Figure 5, the multi-degree-of-freedom board 13 is made of 7075 aluminum alloy through wire cutting, and is composed of an inner substrate 39, a middle frame 40 and an outer frame 41, and two piezoelectric ceramics 42 are installed between the inner substrate 39 and the middle frame 40 and 44, the clamping and preloading methods of the two piezoelectric ceramics 42 and 44 are consistent with the structure of the piezoelectric ceramic stress-free clamping and preloading mechanism, and the two piezoelectric ceramics 42 between the inner substrate 39 and the middle frame 40 When stretching at the same time as 44, the middle frame 40 rotates around the Z-axis relative to the inner substrate 39, and X-direction piezoelectric ceramics 37 and Y-direction piezoelectric ceramics 37 and Y direction piezoelectric ceramic 34, the clamping and pre-tightening methods of the two piezoelectric ceramics 37 and 34 are consistent with the structure of the piezoelectric ceramic stress-free clamping and pre-tightening mechanism, when the X-direction piezoelectric ceramic 37 is elongated, the outer frame 41 Relative to the middle frame 40, when the piezoelectric ceramics 34 in the Y direction move in the X direction, the outer frame 41 moves in the Y direction relative to the middle frame 40, and when the X direction piezoelectric ceramics 37 and the Y direction piezoelectric ceramics 34 elongate simultaneously, the outer frame 41 The frame 41 performs joint movement along the XY direction relative to the middle frame 40. Four sets of Z-direction piezoelectric ceramic drive unit fixing holes 38 and four Z-direction piezoelectric ceramic drive unit pre-tightening screw holes 43 are evenly distributed around the inner substrate 39. The four outer corners of the inner base plate 39 are respectively processed with parallel plate flexible hinges 36, the inner base plate 39 and the middle frame 40 are connected by four sets of parallel plate flexible hinges 36, and the outer four corners of the middle frame 40 are respectively processed with two-way parallel plate flexible hinges 35, The middle frame 40 and the outer frame 41 are connected by a two-way parallel plate flexible hinge 35. The four corners of the frame opening of the outer frame 41 are evenly distributed with a total of eight stage fixing holes 45. The outer frame 41 drives the ceramic 37 on the outside and in the X direction, and drives in the Y direction. The relative positions of the ceramics 34 are respectively evenly distributed with three mirror adjustment bracket fixing holes 46, the mirror adjustment bracket fixing holes 46 are used for fine-tuning and fixing the mirror adjustment brackets 17 and 14, the X direction drives the ceramic 37, and the Y direction drives the ceramic 34 Two mirror adjustment bracket fixing holes 47 are evenly distributed on the same side respectively, for fixing the mirror adjustment brackets 21 and 20 .

Referring to Fig. 6, the Z-direction piezoelectric ceramic driving unit 12 is composed of a base body 55 and a piezoelectric ceramic 54 disposed in the base body 55. The clamping and preloading mode of the piezoelectric ceramics 54 and the stress-free clamping and preloading of the piezoelectric ceramics The mechanism is the same, wherein the top of the base body 55 is provided with an upper connection hole 49, the top center of the base body 55 is provided with a through hole 52, the bottom of the base body 55 is provided with a lower connection hole 48, and the bottom of the base body 55 passes through the bottom of the base body 55 installed in the lower connection hole 48. Bolts are fixed on the connection plate 11, the upper connection hole 49 on the top of the base body 55 and the Z-direction piezoelectric ceramic drive unit fixing hole 38 of the inner substrate 39 of the multi-degree-of-freedom plate 13 are fixed together by bolts, and the pre-tightening nuts are embedded in multiple In the Z-direction piezoelectric ceramic drive unit pre-tightening screw hole 43 on the inner base plate 39 of the degree-of-freedom plate 13, the pre-tightening screw 51 is screwed in from the top of the multi-degree-of-freedom plate 13, and passes through the through hole 52 at the center of the top of the substrate 55. The piezoelectric ceramic 54 is clamped and preloaded.

Claims (6)

1. The large-stroke two-dimensional nano-table system with angle compensation function is characterized in that it includes a base, a large-stroke two-dimensional worktable set on the base, and a six-degree-of-freedom micro-motion supported by the large-stroke two-dimensional worktable Workbench, two optical length measurement and angle measurement systems distributed on two adjacent sides of the six-degree-of-freedom micro-motion workbench and forming an angle of 90 degrees to each other, wherein: The two-dimensional large-stroke workbench is composed of two groups of single-axis workbenches arranged along the X and Y directions, which are superimposed up and down. The ball screw is used as the driving method, and the upper single-axis worktable is fixed on the guide rail slider of the lower single-axis worktable; The driving element of the six-degree-of-freedom micro-motion workbench is piezoelectric ceramics, and the eight piezoelectric ceramics used are clamped and pre-tightened by piezoelectric ceramic stress-free clamping and pre-tightening mechanisms, and the guiding mechanism is a flexible hinge elastic guide rail , the six-degree-of-freedom micro-motion workbench includes a connecting plate, which is installed on the guide rail slider of the upper single-axis workbench in the large-travel two-dimensional workbench and rigidly connected, and four groups are arranged on the connecting plate along the Z direction. Piezoelectric ceramic drive unit, four groups of piezoelectric ceramic drive units are centrally symmetrical on the connecting plate and form a rectangle, and the sides of the rectangle are parallel to the X and Y directions respectively, and the connecting plate also supports a multi-degree-of-freedom plate, The multi-degree-of-freedom board is composed of an outer frame, a middle frame arranged in the outer frame, and an inner substrate arranged in the middle frame. The multi-degree-of-freedom board is fixed on a rectangular shape composed of four sets of piezoelectric ceramic drive units through its inner substrate. The top, and the side of the multi-degree-of-freedom board is parallel to the rectangular edge composed of four sets of piezoelectric ceramic drive units. Two optical length and angle measurement systems are distributed outside the two adjacent sides of the multi-degree-of-freedom board. The frame is located on the same side of one of the optical length measuring and angle measuring systems, and the top of the frame is equipped with an X-axis mirror adjustment bracket, and the outer frame of the multi-degree-of-freedom board is located on the same side of the other optical length and angle measuring system. The top of the frame is equipped with a Y-axis The mirror adjustment bracket, the X-axis mirror adjustment bracket and the Y-axis mirror adjustment bracket are distributed on the top of the multi-degree-of-freedom board frame at 90 degrees to each other, and the top of the X-axis mirror adjustment bracket is provided with an X-axis optical length measurement angle The X-axis reflector and Y-axis reflector of the system target mirror are adjusted on the top of the bracket. There is a Y-axis reflector as the target mirror of the Y-direction optical length measurement and angle measurement system. Mirror adjustment brackets are respectively installed on the top of the outer frame of the degree plate, and counterweights for balancing the weight of the opposite side mirrors are respectively fixed on the mirror adjustment brackets. The X, Y axis mirror adjustment brackets and the X, Y axis mirrors The mirror adjustment bracket used for the counterweight on the opposite side of the adjustment bracket is framed on the top of the multi-degree-of-freedom plate outer frame to form a frame shape, and the top of the multi-degree-of-freedom plate outer frame in the middle of the frame shape is also equipped with a loading platform. 2. The large-stroke two-dimensional nano-table system with angle compensation function according to claim 1, characterized in that: the optical length measurement and angle measurement system is composed of a photoelectric autocollimator and a Michelson laser interferometer. 3. The large-stroke two-dimensional nano-table system with angle compensation function according to claim 1, characterized in that: the piezoelectric ceramic stress-free clamping and pre-tightening mechanism includes rectangular piezoelectric ceramics, respectively stress-free clamping Gaskets on the top and bottom insulating ceramic sheets of piezoelectric ceramics, a steel ball with a diameter of 3 mm embedded between the tapered hole of one of the gaskets and the tapered hole of the fixed substrate, and a tapered hole embedded in the other gasket A steel ball with a diameter of 3 mm between the tapered hole on the head of the pre-tightening screw, a pre-tightening screw and a pre-tightening nut, the front of the gasket is processed with a chute, the back of the gasket is processed with a tapered hole, and the front of the two gaskets The direction of the chute is opposite and the direction of the chute is stuck at an angle of 90 degrees on the insulating ceramic sheets at both ends of the piezoelectric ceramic, so that the position of the piezoelectric ceramic is limited, and the existence of the chute makes the pre-tightening screw and the tapered hole of the fixed substrate due to processing and When the assembly accuracy is low and the axis is different, the two gaskets can slide slightly along the direction of the chute during assembly to compensate for the possible introduction of the pre-tightening screw and the tapered hole of the fixed base plate due to the low machining and assembly accuracy. Additional stress, the back of the two gaskets, the fixed base plate and the front end of the pre-tightening screw are all processed with tapered holes, and steel balls with a diameter of 3mm are respectively stuck in them, which play the role of positioning and transmitting force between the corresponding two tapered holes. The pre-tightening of the piezoelectric ceramics is achieved through the pre-tightening nuts and pre-tightening screws embedded in the moving substrate, and the pitch used is 0.35mm. 4. The large-stroke two-dimensional nano-table system with angle compensation function according to claim 1, characterized in that: the multi-degree-of-freedom board is made of 7075 aluminum alloy through wire cutting, and consists of an inner substrate, a middle frame and an outer frame Composition, two piezoelectric ceramics are installed between the inner substrate and the middle frame, the clamping and preloading methods of the two piezoelectric ceramics are consistent with the structure of the stress-free clamping and pretensioning mechanism of the piezoelectric ceramics, the inner substrate and the middle frame When the two ceramics in between are elongated at the same time, the middle frame rotates relative to the inner substrate, and X-direction piezoelectric ceramics and Y-direction piezoelectric ceramics are respectively installed between the middle frame and the outer frame along the X direction and along the Y direction. The clamping and pre-tightening methods of the two piezoelectric ceramics are consistent with the structure of the stress-free clamping and pre-tightening mechanism of the piezoelectric ceramics. When the piezoelectric ceramics are stretched in the X direction, the outer frame moves in the X direction relative to the middle frame, and the Y direction compresses. When the electric ceramic is stretched, the outer frame moves in the Y direction relative to the middle frame. When the piezoelectric ceramics in the X direction and the Y direction piezoelectric ceramics are elongated at the same time, the outer frame moves in the XY direction relative to the middle frame. There are four sets of Z-direction piezoelectric ceramic drive unit fixing holes and four Z-direction piezoelectric ceramic drive unit pre-tightening screw holes. The four outer corners of the inner base plate are respectively processed with parallel plate flexible hinges. The inner base plate and the middle frame pass through four sets of parallel plates. The plates are connected by flexible hinges, and the outer four corners of the middle frame are respectively processed with two-way parallel plate flexible hinges, the middle frame and the outer frame are connected by two-way parallel plate flexible hinges, and the four corners of the frame opening of the outer frame are evenly distributed with a total of eight stage fixing holes , the outer frame is equipped with three mirror adjustment bracket fixing holes on the outer side of the X-direction drive ceramics and Y-direction drive ceramics, and there are two reflectors on the same side of the X-direction drive ceramics and Y-direction drive ceramics. Mirror adjustment bracket fixing hole. 5. The large-stroke two-dimensional nano-table system with angle compensation function according to claim 4, characterized in that: the flexible hinges are all parallel plate flexible hinges. 6. The large-stroke two-dimensional nano-table system with angle compensation function according to claim 1, characterized in that: the Z-direction piezoelectric ceramic driving unit is composed of a substrate and piezoelectric ceramics arranged in the substrate, and the piezoelectric ceramics The clamping and pre-tightening method is consistent with the structure of the piezoelectric ceramic stress-free clamping and pre-tightening mechanism, wherein the top of the substrate is provided with an upper connection hole, the center of the top of the substrate is provided with a through hole, and the bottom of the substrate is provided with a lower connection hole , the bottom of the base body is fixed on the connecting plate through bolts installed in the lower connecting hole, the upper connecting hole at the top of the base body and the Z-direction piezoelectric ceramic drive unit fixing hole of the multi-degree-of-freedom plate inner substrate are fixed together by bolts, The pre-tightening nut is embedded in the pre-tightening screw hole of the Z-direction piezoelectric ceramic drive unit on the base plate of the multi-degree-of-freedom board. Ceramic for clamping and preloading.

Images