A three-dimensional precision measurement system in accordance with the Abbe principle

Abstract

The application discloses a kind of three-dimensional precision measurement systems in accordance with Abbe principle, including three-dimensional macro stage, six degrees of freedom micro stage, laser length measurement angle measurement system, three-dimensional mirror group, low expansion measurement frame, two-dimensional fine adjustment mechanism, trigger probe or cutting tool and connecting mechanism;Laser length measurement angle measurement system realizes six degrees of freedom measurement of object table, three-axis laser interferometer is as x direction, y direction, z direction length reference, ensures that measurement beams are perpendicular to each other and intersect at measurement trigger point by two-dimensional fine adjustment mechanism, locks the relative position of three-axis length reference and trigger point, establishes three-dimensional measurement system, and working mode is object table movement, measurement system is fixed, ensure that any measured point is always located on length reference or extension line during movement process.In the application, angle meter real-time feedback object table angular motion, control micro stage to carry out angular motion error compensation, macro-micro collaborative motion realizes the measurement effect of large stroke and high resolution, and measurement is realized by triggering measured object.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional precision measurement systems, specifically to a three-dimensional precision measurement system that conforms to Abbe's principle, which can be used for the development of ultra-precision measuring instruments and the improvement of the accuracy of traditional measuring instruments or machine tools. Background Technology

[0002] With the development of modern manufacturing, the demand for high-precision machining and measurement of the three-dimensional contours of various ultra-precision machined parts, ultra-precision optical components, microelectromechanical systems (MEMS), and semiconductor devices is becoming increasingly urgent. CNC machine tools and 3D measuring instruments are key to mechanical manufacturing and metrology; their accuracy directly affects the quality and evaluation standards of the machined parts. Furthermore, most 3D measuring instruments and machine tools do not conform to Abbe's principle, severely restricting the accuracy of ultra-precision measurement and machining. Therefore, it is essential to propose a design method and device for a 3D precision measurement system that conforms to Abbe's principle, which is of great significance for the development of my country's high-end manufacturing industry.

[0003] In high-precision 3D measurement systems, geometric errors and thermal expansion errors of the motion system are the main error sources, severely limiting instrument accuracy. Geometric errors include guide rail angular motion errors, straightness errors, and positioning errors, among which the Abbe error caused by guide rail angular motion is a significant source. Current corrections for Abbe errors only target first-order Abbe errors. However, with increasingly stringent requirements for ultra-high precision measurement, simply eliminating the impact of first-order Abbe errors on the 3D measurement system is far from sufficient. Although error modeling can be used for correction, it is difficult to achieve the desired effect in micro- and nano-scale measurement and fabrication. This invention aims to eliminate the influence of Abbe errors by redesigning the measurement system layout to conform to the Abbe principle, thus eliminating first-order Abbe errors. Furthermore, by combining an angle measuring system with a micro-motion stage, second-order and higher-order Abbe errors are eliminated. Simultaneously, this metrological layout eliminates the influence of straightness errors and the thermal expansion of the motion system on the measurement, significantly improving measurement accuracy. Summary of the Invention

[0004] In order to overcome the Abbe error in traditional three-dimensional measuring instrument systems, this invention proposes a three-dimensional precision measuring system that conforms to the Abbe principle, so as to achieve high-precision three-dimensional measurement and processing.

[0005] This invention proposes a design method for a three-dimensional measurement system that conforms to Abbe's principle. It begins with the definition of Abbe's principle, noting that its classical definition is only applicable to one-dimensional displacement and length measurements, such as... Figure 4As shown, in one-dimensional measurement, the Abbe arm H is a constant, and the Abbe error is calculated based on the magnitude of the angular motion error α. However, in three-dimensional measurement space, the distance H between the measurement point and the reference point is usually a variable, and thus the Abbe arm r projected onto the length reference of each axis is also a variable, making it difficult to separate the Abbe error of the three-dimensional measurement system. Therefore, ensuring that the Abbe arm of each axis of the three-dimensional motion system remains constant during the motion process will help separate and correct Abbe errors. Furthermore, if the Abbe arm of each axis is always 0 during the motion process, it will directly eliminate the first Abbe error caused by angular motion error, greatly improving the instrument accuracy. Based on the above assumptions, a three-dimensional precision measurement system conforming to the Abbe principle is proposed. The three-axis length references of the three-dimensional measurement system intersect at the measurement trigger point to obtain the angular relationship of the three-axis length references. The length references and the measurement trigger point are locked in place to establish a three-dimensional metrology system. The working mode is that the stage moves while the metrology system is fixed, ensuring that any measured point is always located on the length reference or its extension line during the motion process, thus eliminating the Abbe arm of each axis and eliminating the first Abbe error. For the second Abbe error, a goniometer and a micro-motion stage are used to eliminate it. The goniometer system is designed to monitor the angular motion error of the stage in real time and feed it back to the host computer, controlling the micro-motion stage to compensate for the angular motion error, thereby eliminating the second and higher-order Abbe errors. Theoretically, while the micro-stage compensates for angular motion error and eliminates angular motion error α, it also eliminates the primary Abbe error ΔH = Htanα. Therefore, it's unnecessary to further eliminate the Abbe arm H through metrological layout to eliminate the primary Abbe error. However, in reality, due to the accuracy of the x-axis and y-axis goniometers and the micro-stage, the angular motion error α cannot be completely compensated, leaving a residual angular motion error Δα. If the Abbe arm H is too large, the resulting primary residual Abbe error ΔH = HtanΔα will still be too large. Furthermore, due to assembly and adjustment issues, there are assembly and adjustment errors when aligning the three-axis length references at the measurement trigger point, resulting in a residual Abbe arm H1. Combined with the angular motion error α, this produces a primary residual Abbe error ΔH = H1tanΔα, all of which affect the accuracy of 3D measurement. Therefore, when designing a 3D ultra-precision measurement system that conforms to the Abbe principle, both angular motion error and Abbe arm elimination should be addressed simultaneously to more comprehensively eliminate primary and secondary Abbe errors. Simultaneously, during the design of the 3D measurement system, it is crucial to ensure the independence of the measurement system from the motion system as much as possible, thereby minimizing the impact of thermal expansion and geometric errors of the motion system on the measurement system. Based on the above 3D measurement system design method, a 3D precision measurement system conforming to Abbe's principle is designed as follows:

[0006] This invention achieves six-degree-of-freedom measurement of a stage using a laser interferometer length measurement system and an angle measurement system. The length measurement system's layout ensures the measurement trigger point is always located on the three-axis length reference, eliminating primary Abbe error. The angle measurement system monitors the stage's angular motion and provides feedback adjustment with the six-degree-of-freedom micro-motion stage, compensating in real-time for stage tilt caused by guide rail angular motion and eliminating the effects of secondary Abbe error. Macro-micro coordinated motion achieves large-stroke and high-resolution measurement results. Furthermore, placing the three-dimensional measurement system on a low-expansion metrology frame, independent of the motion system, greatly eliminates the effects of thermal expansion and geometric errors in the motion system.

[0007] The technical solution adopted in this invention is:

[0008] A three-dimensional precision measurement system conforming to Abbe's principle is characterized by comprising a three-dimensional macro stage, a six-degree-of-freedom micro stage, a stage, a marble base, a three-dimensional mirror assembly, a low-expansion metrology frame, a laser length and angle measurement system, a trigger-type probe or cutting tool, and a two-dimensional adjustment mechanism. The laser length and angle measurement system includes a length measurement system composed of x-axis, y-axis, and z-axis laser interferometers, and an angle measurement system composed of x-axis and y-axis goniometers. The laser length and angle measurement system uses the three-dimensional mirror assembly to feed back measurement signals, enabling six-degree-of-freedom measurement of the stage. The measurement information is fed back to the macro-micro coordinated motion system in real time, controlling the macro stage to perform large-range movements and controlling the micro stage to adjust its attitude, eliminating angular motion errors and achieving high-resolution triggering.

[0009] A 3D macro stage is placed on a marble base, and a 6DOF micro stage is placed on the macro stage. The stage and the 3D mirror assembly are mounted on the 6DOF micro stage via a hollow support frame. The 3D mirror assembly is rigidly connected to the stage and is formed by splicing three high-precision planar mirrors, which are orthogonal to each other. The mirror assembly is mounted on the support frame through mounting holes on the z-axis mirror, and the stage is mounted above the z-axis mirror through the mounting holes. The size of the mirrors is determined by the measurement range.

[0010] The laser length and angle measurement system and the measurement trigger point (center point of the probe or cutting tool) are placed on a low-expansion metrology frame, independent of the motion system. A two-dimensional adjustment mechanism is installed below the laser interferometer and goniometer on the interferometer support plate. The trigger-type probe or cutting tool is mounted directly above the stage via an upper cantilever, and the measurement trigger point is finely adjusted through the connection mechanism with the upper cantilever.

[0011] The low-expansion measurement frame consists of an x-axis side plate, a y-axis side plate, an interferometer and goniometer support frame, a transition plate, and a cantilever, all made of a low-expansion alloy. The x-axis laser interferometer and goniometer are mounted on the x-axis side plate support frame, while the y-axis laser interferometer and goniometer are mounted on the y-axis side plate support frame, both at the same height. Their beam directions are adjusted via their respective two-dimensional fine-tuning mechanisms, and the beams are perpendicularly incident on the x and y-axis mirrors of the mirror assembly through holes in the side plates. The z-axis laser interferometer support frame is mounted directly below the x-axis support frame via the transition plate. The z-axis laser interferometer and its two-dimensional fine-tuning mechanism are mounted on the z-axis laser interferometer support frame. The z-axis beam passes through holes in the transition plate and slots on the lower cantilever, incident on a pentagonal prism supported at the end of the lower cantilever, and reflects the z-axis length-measuring beam to the z-axis mirror of the three-dimensional mirror assembly.

[0012] When setting up a three-dimensional measurement system, the length references of the x, y, and z axes are orthogonal to each other and intersect at the measurement trigger point. By locking the relative position of the length references and the trigger point, it is ensured that the trigger point is always located on the length references during the measurement process, thus eliminating the Abbe arm and structurally eliminating the impact of the first Abbe error on the measurement accuracy.

[0013] Compared with existing three-dimensional measurement systems, the advantages of this invention are as follows:

[0014] This invention designs the structural layout of the three-dimensional measurement system to ensure that the measured point is always located on the length reference of each axis during the motion process, eliminates the Abbe arms of each axis of the three-dimensional measurement system, and structurally avoids the primary Abbe error caused by the angular motion error of the three-axis guide rail.

[0015] This invention proposes a measurement system in which the motion system and the measurement system are independent of each other, which greatly avoids the influence of thermal expansion error of the motion system and guide rail straightness error on the measurement system. The displacement deviation of the measured point or machining point caused by the straightness error of each axis guide rail is fed back to the length reference value of the other two axes in real time, thereby improving the accuracy of the three-dimensional measurement system itself.

[0016] This invention monitors the angular motion error of the stage in real time through an angle measurement system and provides real-time feedback to the micro-motion stage, controlling the micro-motion stage to perform angle compensation and eliminate secondary and higher-order Abbe errors. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the three-dimensional measurement system of the present invention;

[0018] Figure 2(a) is a front view of the metering frame of the present invention;

[0019] Figure 2(b) is a reverse structural diagram of the metering frame of the present invention;

[0020] Figure 2(c) is a partial structural diagram of the metrology framework of the present invention;

[0021] Figure 3 This is a diagram of the metering layout structure of the present invention;

[0022] Figure 4 This is a schematic diagram of the Abbe error principle.

[0023] Figure 5 This is a schematic diagram of the second Abbe error principle;

[0024] Figure 6 Schematic diagram of the straightness error of the y-axis guide rail;

[0025] Figure 7 This is a schematic diagram of the thermal expansion error in the z-direction of the motion system.

[0026] The following are labeled in the figure: 1. Three-dimensional macro stage; 2. Six-degree-of-freedom micro stage; 3. Hollow support frame; 4. Pentagonal prism; 5. Stage; 6. Marble base; 7. Three-dimensional mirror group; 8. Low-expansion measurement frame; 9. Laser length and angle measurement system; 10. Trigger-type probe or cutting tool; 11. Upper cantilever connection mechanism; 12. Two-dimensional adjustment mechanism.

[0027] Measurement trigger point 13, lower cantilever 14, adapter plate 15, z-axis support plate 16, z-axis laser interferometer 17, lower adapter plate 18, y-axis side plate 19, y-axis support plate 20, y-axis angle measuring instrument 21, y-axis laser interferometer 22, x-axis through hole 23, upper cantilever 24, upper adapter plate 25, x-axis angle measuring instrument 26, x-axis laser interferometer 27, x-axis support plate 28, x-axis side plate 29, z-axis length measuring beam 30, x-axis reflector 31, z-axis reflecting surface 32, y-axis reflector 33, x-axis angle measuring beam 34, x-axis length measuring beam 35, y-axis length measuring beam 36, y-axis angle measuring beam 37, z-axis vertical plate 38, z-axis through hole 39, y-axis through hole 40;

[0028] First measurement trigger point 41, first measured part 42, first guide rail 43, first reading point 44, first length reference 45, second measurement trigger point 46, second measured part 47, second guide rail 48, second reading point 49, second length reference 50, measured workpiece 51. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] Example 1.

[0031] like Figure 1 , 2(a)As shown in Figures 2(b), 2(c), and 3, a three-dimensional precision measurement system conforming to Abbe's principle includes a three-dimensional macro stage 1, a six-degree-of-freedom micro stage 2, a stage 5, a marble base 6, a three-dimensional mirror assembly 7, a low-expansion measurement frame 8, a laser length and angle measurement system 9, a trigger-type probe or cutting tool 10, and a two-dimensional adjustment mechanism 12. The three-dimensional macro stage 1 and the six-degree-of-freedom micro stage 2 move in tandem to achieve a wide-range, high-resolution motion effect. The low-expansion measurement frame 8 is fixed on the marble base 9, and the laser length and angle measurement system 9 and the trigger-type probe or cutting tool 10 are fixed on the low-expansion measurement frame 8. The low-expansion measurement frame 8 is constructed with an expansion coefficient of less than 1.5 × 10⁻⁶. -6 Made of Invar alloy at / ℃, thus reducing the impact of thermal error on the laser length and angle measurement system 9 and the trigger probe or cutting tool 10. The hollow support frame 3 is installed above the six-degree-of-freedom micro-motion stage 2. The pentagonal prism 4 supported by the lower cantilever 14 of the low-expansion measurement frame 8 is placed inside the hollow support frame 3, ensuring that the lower cantilever 14 and the hollow support frame 3 do not interfere during the movement. This ensures that the z-axis length measurement beam 30 of the z-axis laser interferometer 17 is reflected by the pentagonal prism 4 supported at the end of the lower cantilever 14 onto the z-axis reflecting surface 32 of the mirror group 7. The function of the pentagonal prism 4 is to bend the z-axis length measurement beam 30 by 90°. The three-dimensional mirror group 7 is installed on the hollow support frame 3, and the stage 5 is fixed above the z-axis reflecting mirror 32 of the three-dimensional mirror group 7 through the mounting holes.

[0032] The three-dimensional reflector group 7 includes an x-axis reflector 31, a y-axis reflector 33, and a z-axis reflector 32, which are orthogonally spliced ​​in pairs; the laser length and angle measurement system 9 includes a z-axis laser interferometer 17, an x-axis goniometer 26, an x-axis laser interferometer 27, a y-axis goniometer 21, and a y-axis laser interferometer 22.

[0033] The low-expansion metering frame 8 includes an x-axis side plate 29, a y-axis side plate 19, a z-axis vertical plate 38, an upper transition plate 25, a lower transition plate 18, an upper cantilever 24, and a lower cantilever 14. The x-axis side plate 29 and the y-axis side plate 19 are orthogonally spliced ​​to form the frame body. The upper part of the frame body is connected to the upper cantilever 24 via the upper transition plate 25, and the lower part of the frame body is connected to the z-axis vertical plate 38 via the lower transition plate 18. One side of the z-axis vertical plate 38 is connected to the lower cantilever 14 via the transition plate 15; the other side of the z-axis vertical plate 38 is supported and installed by a z-axis support plate 16. An x-axis goniometer 26 and an x-axis laser interferometer 27 are mounted on the outer wall of the x-axis side plate 29 via an x-axis support plate 28. A y-axis goniometer 21 and a y-axis laser interferometer 22 are mounted on the outer wall of the y-axis side plate 19 via a y-axis support plate 20. The x-axis side plate 29, y-axis side plate 19, and z-axis vertical plate 38 are respectively provided with x-axis through holes 23, y-axis through holes 40, and z-axis through holes 39. An upper cantilever 24 supports the trigger probe or cutting tool 10, and a lower cantilever 14 supports a pentagonal prism 4 and holds the pentagonal prism... 4 is placed inside the hollow support frame 3; the x-axis angle measuring beam 34, x-axis length measuring beam 35, y-axis length measuring beam 36, and y-axis angle measuring beam 37 generated by the x-axis goniometer 26, x-axis laser interferometer 27, y-axis goniometer 21, and y-axis laser interferometer 22, respectively, are incident on the x-axis reflector 31 and y-axis reflector 33 of the three-dimensional reflector group 7 through the x-axis through-hole 23 and y-axis through-hole 40 on the low-expansion metrology frame 8; the z-axis length measuring beam 30 generated by the z-axis laser interferometer 17 is incident on the end support of the lower cantilever 14 through the z-axis through-hole 39. On the pentagonal prism 4, the z-direction length measuring beam 30 is deflected by 90° and reflected onto the z-direction mirror 32 of the three-dimensional mirror assembly 7. The x-direction goniometer 26, y-direction goniometer 21, z-direction laser interferometer 17, x-direction laser interferometer 27, and y-direction laser interferometer 22 provide real-time feedback to the three-dimensional macro stage 1 and the six-degree-of-freedom micro stage 2 through the angle and length measuring signals fed back by the three-dimensional mirror assembly 7. This controls the three-dimensional macro stage 1 to perform a wide range of movements and controls the six-degree-of-freedom micro stage 2 to compensate for the tilt of the stage 5 caused by the guide rail angular motion error. This structural layout achieves independence between the measurement system and the motion system. The six degrees of freedom of the stage 5 are monitored only through the three-dimensional mirror assembly 7, minimizing the influence of the motion system on the measurement system and improving measurement or processing accuracy.

[0034] As shown in Figures 2(a), 2(b), and 2(c), specifically, the upper adapter plate 25 is used to connect the upper cantilever 24 to the x-direction side plate 30 and the y-direction side plate 20; the lower adapter plate 18 is used to connect the adapter plate 15 to the z-direction support plate 16 and fix the low-expansion measurement frame 8 to the marble base 6; the lower cantilever 14 is fixed to the adapter plate 15; the x-direction support plate 28 is fixed to the x-direction side plate 29 and is used to support the x-direction laser interferometer 27 and the x-direction goniometer 26; the y-direction support plate 20 is fixed to the y-direction side plate 19 and is used to support the y-direction laser interferometer 22 and the y-direction goniometer 26. Angle measuring instrument 21; the x-axis support plate 28 and the y-axis support plate 20 are fixed at the same height. The z-axis laser interferometer 17 is installed on the z-axis support plate 16 directly below the y-axis laser interferometer 22, so that the length measuring beams can be adjusted to intersect at a point. The z-axis vertical plate 38 is fixed below the lower adapter plate 18 and is used to connect the z-axis support plate 16 and the adapter plate 15. The five measuring beams of the laser length and angle measuring system 9 are incident on the axial reflecting surfaces of the three-dimensional reflecting mirror group 7 fixed on the motion system through the x-axis through hole 23, the z-axis through hole 39 and the y-axis through hole 40 on the low expansion metrology frame 8.

[0035] like Figure 3 As shown, specifically, the reflective coatings of the x-axis reflector 31, y-axis reflector 33, and z-axis reflector 32 of the three-dimensional reflector group 7 are on the outside of the reflectors. The three reflectors have a reflectivity of 90% and a transmittance of 10%, facilitating the observation of the position of the transmitted light spot. A through hole is left in the center of the stage 5 to ensure the transmission of the z-axis beam. The triaxial length measuring beams are adjusted to intersect at the measurement trigger point 13. The directions of the five beams are adjusted by five two-dimensional fine-tuning mechanisms 12, so that the x-axis angle measuring beam 34 is perpendicular to the x-axis reflector 31; the y-axis angle measuring beam 37 is perpendicular to the y-axis reflector 33; the x-axis length measuring beam 35 is perpendicular to the x-axis reflector 31; the y-axis length measuring beam 36 is perpendicular to the y-axis reflector 33; and the z-axis length measuring beam 30 is perpendicular to the z-axis reflector 32. The triaxial length measuring beams intersect at the measurement trigger point 13, and the triaxial displacement l of the stage 5 is adjusted accordingly. x ,l y ,l z Measurements are performed, and the position of the measurement trigger point 13 can be adjusted via the connection mechanism 11 between the trigger probe or the cutting tool 10 and the upper cantilever. During the measurement process, the stage 5 and the three-dimensional mirror group 7 move, while the laser length and angle measurement system 9 remains fixed to the measurement trigger point 13, ensuring that the measurement trigger point 13 is always located on the length reference, eliminating the Abbe arm, and thus eliminating the first Abbe error. The x-axis goniometer 26 and the y-axis goniometer 21 measure the angular motion error ε of the stage 5 and the three-dimensional mirror group 7 around each axis through the x-axis mirror 31 and the y-axis mirror 33. x ,ε y ,ε z Measurements are taken, and the angular motion error is fed back to the micro-motion stage 2 for attitude adjustment, compensating for the angular motion error and thus eliminating the second Abbe error.

[0036] like Figure 4 The above describes the principle of first Abbe error. The first measurement trigger point 41 contacts the first measured object 42, and the first reading point 44 moves on the first length reference 45 to take a length reading. There is a height difference H between the first measured object 42 and the first length reference 45. When the first guide rail 43 produces an angular motion error of α, a first Abbe error ΔH = Htanα is generated. The three-dimensional measurement system of this invention uses a working mode where the stage 5 moves while the measurement trigger point 13 and the laser length and angle measuring system 9 are fixed. This ensures that the measured point is always located on the length measuring beam, eliminating the Abbe arm H, and thus eliminating the influence of the first Abbe error, conforming to the Abbe principle.

[0037] Although the first Abbe error is eliminated, the second Abbe error is still significant for micro- and nano-scale measurement and processing instruments. Figure 5 The diagram illustrates the principle of the second Abbe error. The second measured component 47, the second measurement trigger point 46, the second reading point 49, and the second length reference 50 are all located on a straight line, which conforms to Abbe's principle. However, when the second guide rail 48 generates an angular motion error α, a second Abbe error occurs. When the measurement length L is large, ΔL cannot be ignored. The six-degree-of-freedom micro-motion stage 2 adjusts the attitude of the stage 5 based on the angular motion error fed back by the x-axis goniometer 26 and the y-axis goniometer 21, eliminating the angular motion error α and avoiding the influence of the second Abbe error. Theoretically, while compensating for the angular motion error and eliminating the angular motion error α, the six-degree-of-freedom micro-motion stage 2 also eliminates the first Abbe error ΔH = Htanα. There is no need to eliminate the Abbe arm H through metrological layout to further eliminate the first Abbe error. However, in reality, due to the accuracy limitations of the x-axis goniometer 26, the y-axis goniometer 21, and the six-degree-of-freedom micro-motion stage 2, the angular motion error α cannot be fully compensated, resulting in residual angular motion Δα. If the Abbe arm H is too large, the resulting primary residual Abbe error ΔH = HtanΔα will still be too large. Furthermore, due to assembly and adjustment issues, there are assembly and adjustment errors when assembling the triaxial length references at the measurement trigger point 13, resulting in a residual Abbe arm H1. Combined with the angular motion error α, this produces a primary residual Abbe error ΔH = H1tanΔα, all of which affect the accuracy of three-dimensional measurement. Therefore, in designing a three-dimensional ultra-precision measurement system that conforms to the Abbe principle, both angular motion error and Abbe arm elimination should be addressed simultaneously to more comprehensively eliminate primary and secondary Abbe errors.

[0038] The motion system and the measurement system are independent of each other. The three-dimensional reflecting mirror assembly 7 is rigidly connected to the stage 5 and fixed to the three-dimensional macro stage 1 and the six-degree-of-freedom micro stage 2 through the hollow support frame 3. The straightness error of each guide rail and each axis is transmitted to the three-dimensional reflecting mirror assembly 7 and the stage 5 in real time. Figure 6Taking the movement of the y-axis guide rail as an example, when the guide rail y drives the three-dimensional reflecting mirror group 7 to move y L At that time, the straightness error δ generated by the y-guide rail x (y L ) and δ z (y L The error is transmitted in real time to the three-dimensional reflector group 7, generating the straightness error δ in the x-direction of the guide rail. x (y L The error δ in the z-direction straightness of the guide rail is generated by the real-time feedback from the x-direction reflector 31 to the x-direction laser interferometer 27. z (y L The straightness error of the other guide rails is fed back to the laser interferometer 17 in real time through the z-axis reflector 32. Similarly, the straightness error is measured in real time by the laser interferometer through the reflector group 7, thus avoiding the influence of the straightness error on the measurement results.

[0039] like Figure 7 The motion system consists of a three-dimensional macro stage 1 and a six-degree-of-freedom micro stage 2. The hollow support frame 3 drives the three-dimensional reflector group 7. The stage 5 and the workpiece 51 being measured move in three-dimensional space. Measurement or processing is completed by touching the measurement trigger point 13. Assuming that the distance from the bottom of the three-dimensional macro stage 1 to the z-direction reflecting surface of the reflector group 7 is L, when the thermal expansion of the motion system and the hollow support frame 3 in the Z direction is ΔL, the movement of the z-direction reflecting surface of the three-dimensional reflector group 7 is ΔL. This is fed back to the z-direction laser interferometer 17 in real time, eliminating the influence of the thermal expansion error in the z direction of the motion system. The same applies to the other two directions.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A three-dimensional precision measurement system conforming to Abbe's principle, characterized in that, The system includes a three-dimensional macro stage (1), a six-degree-of-freedom micro stage (2), a stage (5), a marble base (6), a three-dimensional mirror assembly (7), a low-expansion measurement frame (8), a laser length and angle measurement system (9), and a trigger probe or cutting tool (10). The six-degree-of-freedom micro stage (2) is mounted on the three-dimensional macro stage (1) and moves in coordination with it. The low-expansion measurement frame (8) is fixed on the marble base (6). The laser length and angle measurement system (9) and the trigger probe or cutting tool (10) are fixed on the low-expansion measurement frame (8). The three-dimensional mirror assembly (7) is installed above the six-degree-of-freedom micro stage (2). A hollow support frame (3) is installed between the six-degree-of-freedom micro stage (2) and the three-dimensional mirror assembly (7). The stage (5) is fixed above the z-axis mirror (32) of the three-dimensional mirror assembly (7). The low-expansion measurement frame (8) places the trigger probe or cutting tool (10) directly above the stage (5). The three-dimensional mirror group (7) includes an x-axis mirror (31), a y-axis mirror (33), and a z-axis mirror (32), which are orthogonally spliced ​​together in pairs; The laser length and angle measurement system (9) includes a z-axis laser interferometer (17), an x-axis goniometer (26), an x-axis laser interferometer (27), a y-axis goniometer (21), and a y-axis laser interferometer (22). The low-expansion measurement frame (8) includes an x-axis side plate (29), a y-axis side plate (19), a z-axis vertical plate (38), an upper adapter plate (25), a lower adapter plate (18), an upper cantilever (24), and a lower cantilever (14). The x-axis side plate (29) and the y-axis side plate (19) are orthogonally spliced ​​to form the frame body. The upper part of the frame body is connected to the upper cantilever (24) through the upper adapter plate (25), and the lower part of the frame body is connected to the z-axis vertical plate (38) through the lower adapter plate (18). One side of the z-axis vertical plate (38) is connected to the lower cantilever (14) through the adapter plate (15). The other side of the z-axis vertical plate (38) is supported and installed by a z-axis laser interferometer (17) through a z-axis support plate (16). An x-axis goniometer (26) and an x-axis laser interferometer (27) are mounted on the outer wall of the x-axis side plate (29) via an x-axis support plate (28). A y-axis goniometer (21) and a y-axis laser interferometer (22) are mounted on the outer wall of the y-axis side plate (19) via a y-axis support plate (20). An x-axis through hole (23), a y-axis through hole (40), and a z-axis through hole (39) are respectively opened on the x-axis side plate (29), the y-axis side plate (19), and the z-axis vertical plate (38). The upper cantilever (24) is used to support the trigger probe or the cutting tool (10). The lower cantilever (14) supports a pentagonal prism (4) and places the pentagonal prism (4) inside the hollow support frame (3). The x-angle measuring beam (34), x-length measuring beam (35), y-length measuring beam (36), and y-angle measuring beam (37) generated by the x-angle measuring instrument (26), x-laser interferometer (27), y-angle measuring instrument (21), and y-laser interferometer (22) respectively are incident on the x-angle mirror (31) and y-angle mirror (33) of the three-dimensional mirror group (7) through the x-angle through hole (23) and y-angle through hole (40) on the low-expansion metrology frame (8); the z-angle measuring beam (30) generated by the z-axis laser interferometer (17) is incident on the pentagonal prism (4) supported at the end of the lower cantilever (14) through the z-angle through hole (39), and the pentagonal prism (4) bends the z-angle measuring beam (30) by 90° and reflects it onto the z-angle mirror (32) of the three-dimensional mirror group (7); The x-axis goniometer (26), y-axis goniometer (21), z-axis laser interferometer (17), x-axis laser interferometer (27), and y-axis laser interferometer (22) provide real-time feedback to the three-dimensional macro stage (1) and the six-degree-of-freedom micro stage (2) through the angle and length measurement signals fed back by the three-dimensional mirror group (7). This controls the three-dimensional macro stage (1) to perform large-scale movements and controls the six-degree-of-freedom micro stage (2) to compensate for the tilt of the stage (5) caused by the guide rail angular motion error.

2. The three-dimensional precision measurement system conforming to Abbe's principle according to claim 1, characterized in that, The low-expansion metering frame (8) has an expansion coefficient of less than 1.5 × 10⁻⁶. -6 It is made of Invar alloy steel at ℃.

3. A three-dimensional precision measurement system conforming to Abbe's principle according to claim 1, characterized in that, The upper cantilever (24) consists of three cantilever arms, which are connected to the upper cantilever arm connection mechanism (11). The position of the measurement trigger point (13) can be adjusted by adjusting the trigger probe or cutting tool (10) and the upper cantilever arm connection mechanism (11).

4. A three-dimensional precision measurement system conforming to Abbe's principle according to claim 1, characterized in that, Each of the z-axis laser interferometer (17), x-axis goniometer (26), x-axis laser interferometer (27), y-axis goniometer (21), and y-axis laser interferometer (22) is equipped with a two-dimensional adjustment mechanism (12). By adjusting the two-dimensional adjustment mechanism (12), the x-axis length measuring beam (35), y-axis length measuring beam (36), and z-axis length measuring beam (30) are intersected at the measurement trigger point (13). The x-axis angle measuring beam (34), x-axis length measuring beam (35), y-axis length measuring beam (36), y-axis angle measuring beam (37), and z-axis length measuring beam (30) are perpendicularly incident on the x-axis reflector (31), y-axis reflector (33), and z-axis reflector (32) of the three-dimensional reflector group (7).

5. A three-dimensional precision measurement system conforming to Abbe's principle according to claim 1, characterized in that, The stage (5) has a through hole in the center.

6. A three-dimensional precision measurement system conforming to Abbe's principle according to claim 1, characterized in that, The reflective coatings of the x-axis reflector (31), y-axis reflector (33), and z-axis reflector (32) of the three-dimensional reflector group (7) are on the outside of the reflectors. The three reflectors have a reflectivity of 90% and a transmittance of 10%.

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