A high-stability closed-loop measurement system based on piezoelectric translation stage

Abstract

The invention discloses a high-stability closed-loop measurement system based on a piezoelectric displacement table, comprising a piezoelectric displacement table and a sensor bracket; the piezoelectric displacement table is provided with a sample table; two mutually perpendicular reflection surfaces are provided on the sample table; a sensor chuck and a probe bracket are connected to the sensor bracket; the sensor chuck is provided with a clamping hole and three strip-shaped notches, and the three strip-shaped notches are arranged in a Y shape and intersect at the position of the clamping hole; a through hole is provided on the side of the sensor chuck, which is arranged perpendicularly to the clamping hole, and the clamping hole is divided into two front and rear sections with a total of six contact surfaces, so that the laser interferometer is clamped at six points to ensure the stability of the clamping. The invention realizes flexible clamping by providing a clamping hole and three Y-shaped strip-shaped notches on the sensor chuck, so that the sensor chuck can adapt to the stress and strain caused by the temperature of the laser interferometer probe, so that the overall measurement stability and accuracy of the measurement system are effectively improved.

Description

Technical Field

[0001] The invention relates to the field of precision measurement technology, and in particular to a high-stability closed-loop measurement system based on a piezoelectric displacement stage. Background Art

[0002] Piezoelectric nano-scanning stages are mainly used to achieve nano-level or sub-nanometer-level positioning, and are widely used in precision measurement, semiconductor equipment processing, and atomic force microscopy. Scanning diamond nitrogen-vacancy color center microscopes (NV color center scanners) have made great progress in recent years. It is a scanning system based on NV color center weak magnetic detection and laser read-in and read-out. It has ultra-high spatial resolution and ultra-high magnetic field resolution sensitivity, and is used in cell in situ imaging, superconducting magnetic imaging, and solid-state magnetic imaging.

[0003] However, due to the influence of temperature drift, various components of the existing piezoelectric nano-scanning stage may deform, which affects the overall stability and accuracy of the scanning measurement system. Summary of the invention

[0004] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0005] The present invention is a high-stability closed-loop measurement system based on a piezoelectric displacement stage, comprising a piezoelectric displacement stage and a sensor bracket respectively fixed on a base; the piezoelectric displacement stage is provided with a sample stage; the sample stage is provided with two mutually perpendicular reflection surfaces;

[0006] The sensor bracket is connected to two sensor clamps and a probe bracket; the two sensor clamps correspond to the positions of the two reflective surfaces one by one;

[0007] The sensor clamp is provided with a clamping hole and three strip-shaped notches, and the three strip-shaped notches are arranged in a Y shape and intersect at the clamping hole, so as to separate the inner wall of the clamping hole into three arc-shaped surfaces;

[0008] A through hole is provided on the side of the sensor clamp, and the through hole and the clamping hole are arranged perpendicular to each other, dividing the clamping hole into two sections, which is used to clamp and fix the laser interferometer probe through interference fit between the clamping hole and the laser interferometer probe.

[0009] Furthermore, a T-shaped slot is provided on one side of the probe bracket, and is connected to a connecting plate that cooperates with the T-shaped slot, and a screw is fixedly connected to one side of the connecting plate; the bracket is connected to a connecting block, the screw movably passes through the connecting block, and is sleeved with a compression spring, and is matched with a nut, which is used to squeeze the side of the connecting block through the compression spring, so that the probe bracket is close to the side of the connecting block.

[0010] Furthermore, the sensor clamp, probe bracket, connecting block and bracket plate are an integrated structure and are made of microcrystalline glass.

[0011] Furthermore, the probe bracket and the connecting block are in contact and fit via a motion coupling structure.

[0012] Furthermore, the bracket includes a bracket plate and a bracket seat; the bracket seat is provided with a threaded hole and threadedly matched with a knurled bolt; the knurled bolt passes through the bracket plate and is used to press down and fix the bracket plate through the knurled bolt.

[0013] Furthermore, the knurled bolt is inserted with a pressure plate and sleeved with a spring for pressing the pressure plate down through the spring; three positioning rods are fixedly connected to the lower surface of the pressure plate, and the three positioning rods are distributed in a triangle; the upper surface of the bracket plate is provided with positioning holes that cooperate with the positioning rods, which are used to press the bracket plate down through the positioning rods.

[0014] Furthermore, the lower surface of the bracket plate and the upper surface of the bracket seat are in contact and fit via a motion coupling structure.

[0015] Furthermore, the sample stage is equipped with a glass slide and is connected to a spring pressing piece, which is used to press the glass slide down and fix it on the upper surface of the sample stage through the spring pressing piece.

[0016] Furthermore, the sample stage and the piezoelectric displacement stage, as well as the glass slide and the sample stage are in contact and matched via a motion coupling structure.

[0017] Furthermore, the sample stage and the glass slide are both made of microcrystalline glass.

[0018] In summary, a high-stability closed-loop measurement system based on a piezoelectric displacement table of the present invention achieves flexible clamping of the laser interferometer probe by opening a clamping hole and three Y-shaped strip notches on the sensor chuck, and by interference fit between the clamping hole and the laser interferometer probe, so that the sensor chuck can adapt to the stress and strain of the laser interferometer probe caused by temperature. The six-point contact position between the clamping hole and the laser interferometer can be adjusted by rotating the laser interferometer probe, thereby ensuring the normal operation of the laser interferometer. Low-temperature drifting microcrystalline glass material is selected for the main measurement support parts to reduce the influence of temperature on the measurement system. The Abbe principle is followed when arranging the sensors. A high-precision laser interferometer is used as the feedback sensor, thereby solving the problems of poor stability and accuracy of the existing scanning measurement system.

[0019] Specifically, the present invention has the following beneficial effects:

[0020] 1. The present invention provides a clamping hole and three Y-shaped strip notches on the sensor chuck, and an interference fit between the clamping hole and the laser interferometer probe. The middle through hole divides the contact surface into a total of six front and rear contact surfaces, thereby realizing six-point flexible clamping of the laser interferometer probe, so that the sensor chuck can adapt to the stress and strain caused by the temperature of the laser interferometer probe, thereby avoiding the drift caused by the expansion of the probe itself due to the temperature when installing the laser interferometer probe, and effectively ensuring the overall measurement stability and accuracy of the measurement system.

[0021] 2. In addition, the present invention has another advantage. Due to certain errors in processing the clamping hole, the axis of the clamping hole itself may not be completely vertical, which may cause the clamped laser interferometer to not be completely perpendicular to the target surface, failing to achieve the signal quality required by the laser interferometer, and the laser interferometer cannot work normally. However, due to its essence of six-point contact, the present invention can rotate the laser interferometer probe and continuously adjust the positions of the six contact points, so that the laser interferometer can always be perpendicular to the target surface and work normally. This is an efficient and simple adjustment method.

[0022] 3. In general, the present invention processes the sensor chuck, connecting block and bracket plate, as well as the sample stage and glass slide through microcrystalline glass material, and utilizes the low temperature drift property of microcrystalline glass material to further reduce the influence of temperature on the measurement system. The sensor arrangement complies with the Abbe principle, that is, the intersection of the measurement axes of the two laser interferometer sensors in space coincides with the vertex of the scanning probe, which further reduces the measurement error. The measurement target surface of the laser interferometer is plated on the sample stage through a silver mirror reaction, avoiding the method of bonding the reflector, making the measurement loop more stable. Since the relative position change between the reference body and the measurement object is directly measured using a high-precision and high-stability laser interferometer displacement sensor, the nonlinearity, accuracy and temperature drift of the nano scanning stage can be eliminated, and the overall measurement stability and accuracy of the measurement system are further improved through the closed loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0024] Figure 2 for Figure 1 A schematic diagram of the structure from another perspective;

[0025] Figure 3 is a schematic diagram of the structure of the sample stage;

[0026] Figure 4 It is a schematic diagram of the structure of the bracket plate and the sensor clamp;

[0027] Figure 5 This is the structural explosion diagram of the bracket;

[0028] Figure 6 for Figure 5 Schematic diagram of the structure from an upward perspective;

[0029] Figure 7 is a schematic diagram of the structure of the probe bracket;

[0030] Figure 8 is a reference diagram of the long-term stability test results of the chuck at room temperature according to an embodiment of the present invention;

[0031] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0032] 1-base, 2-piezoelectric displacement stage, 3-bracket, 31-sensor chuck, 32-probe bracket, 33-bracket plate, 34-bracket seat, 35-knurled bolt, 201-sample stage, 202-reflection surface, 203-glass slide, 204-spring pressure piece, 301-clamping hole, 302-strip notch, 303-through hole, 320-T-slot, 321-connecting plate, 322-screw, 323-connecting block, 324-compression spring, 325-nut, 350-pressure plate, 351-spring, 352-positioning rod. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0034] See also Figure 1 and 2 As shown, a high-stability closed-loop measurement system based on a piezoelectric displacement stage according to an embodiment of the present invention comprises a base 1, a piezoelectric displacement stage 2 and a sensor bracket 3 connected to the upper surface of the base 1. The piezoelectric displacement stage 2 is an XY plane scanning stage that can move in the X and Y directions, and its driving element is a piezoelectric stack, which amplifies the output displacement of the piezoelectric stack through a hinge mechanism, thereby realizing the output of the displacement.

[0035] Meanwhile, the material of the piezoelectric displacement stage 2 is titanium alloy, the grade of which is TC4. Titanium alloy is a non-magnetic metal material, which enables it to be used in a strong magnetic field environment.

[0036] like Figure 3As shown, the piezoelectric displacement stage 2 is connected to a sample stage 201; the sample stage 201 is provided with two reflective surfaces 202, and the two reflective surfaces 202 are arranged perpendicular to each other. Specifically, two rectangular blocks are arranged on the piezoelectric displacement stage 2, and the reflective surfaces 202 are formed by silver-plating the sides of the two rectangular blocks using a silver mirror reaction, thereby avoiding the use of a bonding reflective mirror, thereby ensuring the stability of the measuring ring.

[0037] Meanwhile, the sample stage 201 is provided with a glass slide 203 and a spring pressing piece 204 connected by bolts, which is used to press the glass slide 203 down and fix it on the upper surface of the sample stage 201 through the spring pressing piece 204. In addition, the sample stage 201 and the glass slide 203 are both made of microcrystalline glass and have high stability.

[0038] like Figures 4 to 6 As shown, the sensor bracket 3 is connected to two sensor chucks 31 and a probe sensor bracket 32, and the sensor chucks 31 correspond to the reflective surface 202. Specifically, the sensor bracket 3 includes a bracket plate 33 and a bracket seat 34. The bracket seat 34 is provided with a threaded hole, and a knurled bolt 35 is threadedly matched. The knurled bolt 35 passes through the bracket plate 33, and is used to press the bracket plate 33 downward and fix it by the knurled bolt 35.

[0039] Among them, the knurled bolt 35 is inserted with a pressing plate 350, and a spring 351 is sleeved thereon, which is used to press the pressing plate 350 downward through the spring 351. Three positioning rods 352 are fixedly connected to the lower surface of the pressing plate 350, and the three positioning rods 352 are distributed in a triangle. The upper surface of the bracket plate 33 is provided with a positioning hole 330 that cooperates with the positioning rod 352. The lower end of the positioning rod 352 can be a conical or spherical structure, and the positioning hole 330 can be a conical hole structure that cooperates therewith, thereby facilitating the improvement of the matching accuracy and stability between the positioning rod 352 and the positioning hole 330.

[0040] During installation, the knurled bolt 35 is screwed to press down the spring 351, and the spring 351 further presses down the pressure plate 350, thereby pressing down the bracket plate 33 through the three positioning rods 352 of the pressure plate 350, so that the bracket plate 33 is fixed on the upper surface of the bracket seat 34.

[0041] The sensor clamp 31 is connected to the bracket plate 33 and is made of microcrystalline glass. The sensor clamp 31 is provided with a clamping hole 301 and three strip-shaped notches 302, one of which is vertically provided to divide the lower end of the sensor clamp 31 into two halves, and the three strip-shaped notches 302 are arranged in a Y shape and intersect at the position of the clamping hole 301, so as to divide the inner wall of the clamping hole 301 into three arc-shaped surfaces.

[0042] A through hole 303 is provided on the side of the sensor clamp 31. The through hole 303 can be a waist-shaped hole or a rectangular hole structure. The through hole 303 and the clamping hole 301 are arranged perpendicular to each other, and are used to divide the clamping hole 301 into two sections, so that the inner wall of the clamping hole 301 is divided into six arc-shaped surfaces, three in the front and three in the back, so that the sensor clamp 31 as a whole forms a flexible hinge structure, which is used to clamp and fix the laser interferometer probe through the six arc-shaped surfaces through the interference fit between the clamping hole 301 and the laser interferometer probe.

[0043] Since the outer shell of the laser interferometer probe is metal, its thermal expansion coefficient is greater than the thermal expansion coefficient of the microcrystalline glass material of the sensor clamp 31. The sensor clamp 31 that forms a flexible hinge structure as a whole can absorb the stress and strain caused by the inconsistency between its own thermal expansion coefficient and the microcrystalline glass, reduce the deformation of the laser interferometer probe itself, and avoid the laser interferometer probe being affected by temperature, which causes its own deformation to affect the measurement, thereby effectively ensuring the overall measurement stability and accuracy of the measurement system.

[0044] In addition, the arrangement of the two laser interferometer probes satisfies the Abbe principle. The intersection of the measuring axes of the two laser interferometer probes in space coincides with the vertex of the scanning probe connected to the probe sensor bracket 32. The laser interferometer is used to provide feedback on the position of the sample stage 201, so that the overall measurement system can achieve closed-loop feedback control, thereby maintaining high stability of the measurement system.

[0045] At the same time, the laser interferometer probe and the reflective surface 202 are arranged relatively close to each other, so that the measurement chain distance is relatively short, which is beneficial to improving the overall measurement accuracy.

[0046] like Figure 7 As shown, a T-shaped slot 320 is formed on one side of the probe sensor bracket 32 ​​, and a connecting plate 321 matching the T-shaped slot 320 is connected thereto, and a screw rod 322 is welded on one side of the connecting plate 321 .

[0047] The sensor bracket 3 is connected to a connecting block 323 , and the sensor clamp 31 , the connecting block 323 and the bracket plate 33 are an integrated structure and are made of microcrystalline glass. Similarly, the probe sensor bracket 32 ​​may also be made of microcrystalline glass.

[0048] The screw rod 322 movably passes through the connecting block 323 and is sleeved with a compression spring 324 and a nut 325. The compression spring 324 is squeezed by screwing the nut 325. The compression spring 324 is used to squeeze the side of the connecting block 323 through the compression spring 324, so that the nut 325 pulls the probe sensor bracket 32 ​​toward the connecting block 323, thereby making the probe sensor bracket 32 ​​close to the side of the connecting block 323, thereby realizing the installation and fixation of the probe sensor bracket 32.

[0049] By making the sensor chuck 31, the probe sensor bracket 32, the connecting block 323 and the bracket plate 33, as well as the sample stage 301, the glass slide 203, and the base 1 all of them be made of microcrystalline glass material, and utilizing the low temperature drift property of the microcrystalline glass material, the influence of temperature on the measurement system is further reduced, thereby further improving the overall measurement stability and accuracy of the measurement system.

[0050] The probe sensor bracket 32 ​​and the connecting block 323 are in contact with each other through a kinematic coupling structure. At the same time, the lower surface of the bracket plate 33 and the upper surface of the bracket seat 34 are in contact with each other through a kinematic coupling structure, and the sample stage 201 and the piezoelectric displacement stage 2, as well as the slide glass 203 and the sample stage 201 are in contact with each other through a kinematic coupling structure, which has a very high repeatability positioning accuracy.

[0051] Specifically, Figure 5 and 6 As shown, taking the bracket plate 33 and the bracket seat 34 as an example, three V-shaped grooves are opened on the upper surface of the bracket seat 34, and the three V-shaped grooves intersect at a threaded hole connected to the knurled bolt 35.

[0052] The lower surface of the bracket plate 33 is provided with three spherical protrusions corresponding to the V-shaped grooves one by one. The spherical surface of the spherical protrusion cooperates with the inner surface of the V-shaped groove to realize the relative positioning of the bracket plate 33 and the bracket seat 34, making the overall installation more convenient and having the advantage of high positioning repeatability, which is beneficial to improving the overall installation accuracy and stability of the measurement system.

[0053] Specifically, in order to achieve ultra-high stability of the scanning system in the specific implementation, the measures taken by the embodiment of the present invention include selecting microcrystalline glass materials with extremely small temperature drift coefficients as the materials of the main parts in the feedback measurement chain, using feedback control and reducing the control links of feedback control, using high-precision, high-stability displacement stages, and using high-stability sensors. Because it is in a strong magnetic field environment, metal components are likely to have large noise under a strong magnetic field. The material of the nano scanning stage is titanium alloy, which is TC4, a non-magnetic metal material. Microcrystalline glass materials can also be used in a strong magnetic field environment.

[0054] The micro-displacement platform is an XY plane scanning platform that can scan in the X and Y directions. Its driving element is a piezoelectric stack. The output displacement of the piezoelectric stack is amplified by a hinge mechanism to achieve the output of displacement. Ideally, the displacement output by the piezoelectric stack is proportional to the voltage across its two ends. However, due to the hysteresis and nonlinearity of the piezoelectric ceramic itself, the displacement and voltage output by the micro-displacement platform also have certain nonlinearity and hysteresis. Therefore, it is necessary to perform feedback closed-loop control of the output displacement in order to achieve the output of the ideal displacement, so that the displacement output can be performed according to the specified control signal during scanning.

[0055] In the whole system, low temperature drifting microcrystalline glass is used as sensor bracket, sample stage, probe connector and main measurement support, so that the stability of the structural transmission chain from the sample surface to the probe can be improved to the greatest extent. In this transmission chain, microcrystalline glass with high stability is selected, and the transmission chain between the sensor clamping position and the measurement surface of the sample stage is as short as possible. At the same time, low temperature drifting microcrystalline glass is used as sensor bracket and sample stage, and laser interferometer displacement sensor is used to directly measure the relative position change between the reference body and the measurement object, which can eliminate the accuracy of the nano scanning stage and its temperature drift influence. The performance of the system is mainly determined by the high-precision laser displacement sensor in the feedback loop, and the thermal drift and linearity of the nano scanning stage itself have little effect on the system. Therefore, the stability of the laser interferometer itself determines the performance of the whole system, but the existing laser interferometer probe housing will also undergo thermal expansion, which will affect its stability. The present invention designs a microcrystalline glass six-point support chuck with extremely high stability.

[0056] Among them, the laser interferometer chuck design: considering that the shell of the laser interferometer itself is made of metal material, and the material of the sensor bracket is microcrystalline glass, the sensor bracket needs to be specially designed. The sensor chuck itself adopts an inverted Y-shaped chuck. The inner diameter size of the chuck is an interference fit with the laser interferometer probe, with an interference amount of 0.02mm. Since it is an interference assembly during assembly, the chuck design uses a flexible hinge structure to disperse the stress generated by the interference. In addition, since the shell of the laser interferometer probe is metal, its thermal expansion coefficient is greater than that of the microcrystalline glass material. The existence of the hinge can absorb the stress and strain caused by the inconsistency between the metal probe's own thermal expansion coefficient and the microcrystalline glass, and reduce the deformation of the probe itself; the chuck design has a through hole in the middle, which is cut into three parts by a flexible hinge, and there is a through hole on the side, which divides the middle through hole into front and back sides, so that there are a total of six points in contact with the chuck when installing the laser interferometer probe. This chuck design ensures the stability of the laser interferometer probe.

[0057] Measuring principle: The sensor layout complies with the Abbe principle, that is, the intersection of the measuring axes of the two laser interferometer sensors in space coincides with the vertex of the scanning probe. The reflection surfaces of the two laser interferometer probes are silver-plated on the sample stage through silver mirror reaction to form a reflection surface. The stability of the measurement ring is guaranteed by not bonding the reflection mirror. The distance between the reflection surface and the probe can be controlled by feedback to eliminate the influence of the motion accuracy and temperature drift of the scanning stage, completely ensuring the accuracy of the output displacement of the scanning stage and the stability of the entire system.

[0058] In specific applications, the installation is as follows: In this structure, a large number of Boyce motion positioning support structures (called kinematic couplings in the literature) are used, that is, three ball points and three V-grooves are used for complete positioning in six degrees of freedom. The positioning of the sensor bracket and the support seat, the sample stage and the displacement table, the sample and the sample stage, the probe bracket and the sensor bracket all adopt this structure. The connection between the support seat and the base adopts a positioning structure with three balls and three V-holes. This structure itself has high installation repeatability, high positioning accuracy, and is convenient for clamping.

[0059] Figure 8 This is a measurement result diagram of the long-term stability of the reference chuck clamping laser interferometer at room temperature of an embodiment of the present invention. It can be seen from the figure that the chuck clamping laser interferometer sensor has a certain drift, but this is at room temperature without any control over the external environment. The drift result includes the thermal drift of the laser interferometer and the drift result of the clamping mechanism itself. It can be seen that the stability of the reference probe is within the range of 3nm, indicating that the design of the chuck of the present invention is very stable.

[0060] In summary, the high-stability closed-loop measurement system based on the piezoelectric displacement stage in the embodiment of the present invention uses low-temperature drift microcrystalline glass as the sensor bracket, main support, sample carrier, and probe connector, and uses a high-precision laser interferometer displacement sensor to directly measure the relative position change between the reference body and the measurement object. The measurement link is very short, and the accuracy of the nano scanning stage and its temperature drift influence are eliminated. A high-stability closed-loop system can be obtained by using closed-loop feedback control.

[0061] At the same time, the embodiment of the present invention is also characterized by the bracket design of the interferometer sensor probe. The shell of the interferometer probe is a metal shell, and its bracket is made of low-temperature drift microcrystalline quartz glass. Considering that the combination of materials with different temperature coefficients may produce a more serious temperature drift multiplication phenomenon caused by bending deformation, a high-stability laser interferometer bracket is designed.

[0062] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-stability closed-loop measurement system based on a piezoelectric displacement stage, comprising a piezoelectric displacement stage (2) and a sensor bracket (3) respectively fixed on a base (1); the piezoelectric displacement stage (2) is provided with a sample stage (201); the sample stage (201) is provided with two mutually perpendicular reflection surfaces (202); the characteristics are: The sensor bracket (3) is connected to two sensor clamps (31) and a probe bracket (32); the two sensor clamps (31) correspond to the two reflection surfaces (202) in one-to-one position; The sensor clamp (31) is provided with a clamping hole (301) and three strip-shaped notches (302), and the three strip-shaped notches (302) are arranged in a Y shape and intersect at the clamping hole (301), so as to separate the inner wall of the clamping hole (301) into three arc-shaped surfaces; A through hole (303) is provided on the side of the sensor clamp (31), and the through hole (303) and the clamping hole (301) are arranged perpendicular to each other, dividing the clamping hole (301) into two sections, so as to achieve clamping and fixing of the laser interferometer probe through interference fit between the clamping hole (301) and the laser interferometer probe; A T-shaped slot (320) is formed on one side of the probe bracket (32), and is connected to a connecting plate (321) that matches the T-shaped slot (320), and a screw rod (322) is fixedly connected to one side of the connecting plate (321); The sensor bracket (3) is connected to a connecting block (323), the screw rod (322) movably penetrates the connecting block (323), is sleeved with a compression spring (324), and is matched with a nut (325) for squeezing the side of the connecting block (323) through the compression spring (324), so that the probe bracket (32) is closely attached to the side of the connecting block (323); The sensor clamp (31), the probe bracket (32), the connecting block (323) and the bracket plate (33) are an integrated structure and are made of microcrystalline glass; The sample stage (201) is equipped with a glass slide (203) and is connected to a spring pressing piece (204) for pressing the glass slide (203) downward and fixing it on the upper surface of the sample stage (201) via the spring pressing piece (204); The sample stage (201) and the glass slide (203) are both made of microcrystalline glass.

2. A high-stability closed-loop measurement system based on a piezoelectric displacement stage according to claim 1, characterized in that: The probe bracket (32) and the connecting block (323) are in contact and fit via a kinematic coupling structure.

3. The high-stability closed-loop measurement system based on a piezoelectric displacement stage according to claim 1, characterized in that: The sensor bracket (3) comprises a bracket plate (33) and a bracket seat (34); the bracket seat (34) is provided with a threaded hole and is threadedly fitted with a knurled bolt (35); The knurled bolt (35) passes through the bracket plate (33) and is used to press the bracket plate (33) downward and fix it via the knurled bolt (35).

4. A high-stability closed-loop measurement system based on a piezoelectric displacement stage according to claim 3, characterized in that: The knurled bolt (35) is penetrated by a pressing plate (350) and is sleeved with a spring (351) for pressing the pressing plate (350) downward via the spring (351); The lower surface of the pressing plate (350) is fixedly connected to three positioning rods (352), and the three positioning rods (352) are distributed in a triangle; the upper surface of the bracket plate (33) is provided with positioning holes (330) that cooperate with the positioning rods (352) and are used to press the bracket plate (33) downward through the positioning rods (352).

5. The high-stability closed-loop measurement system based on a piezoelectric displacement stage according to claim 3, characterized in that: The lower surface of the support plate (33) and the upper surface of the support seat (34) are in contact and fit via a kinematic coupling structure.

6. The high-stability closed-loop measurement system based on a piezoelectric displacement stage according to claim 1, characterized in that: The sample stage (201) and the piezoelectric displacement stage (2), as well as the glass slide (203) and the sample stage (201) are in contact and matched via a kinematic coupling structure.

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