A multi-hole coding mark and measurement method for laser alignment monitoring

Abstract

The present invention relates to the field of laser alignment measurement and monitoring technology, and in particular to a multi-hole coding mark and measurement method for laser alignment monitoring, wherein the coding mark includes a mark body, a laser alignment hole is provided on the mark body, and no less than two coding holes are provided around the laser alignment hole. The laser alignment hole and the coding hole have a certain geometric position relationship, and the coding holes include a first type of coding hole and multiple second type of coding holes. Compared with traditional laser alignment marks, when using this multi-hole coding mark for position measurement, this multi-hole coding mark does not need to be tilted after adjustment and fixation, eliminating the repeatability error caused by the traditional tilted wave zone plate, and multiple marks do not affect each other when used at the same time, and can realize one-time monitoring and measurement of all monitoring points, and obtain the two-dimensional coordinate values of the monitoring points at the same time, which greatly improves efficiency and is suitable for the field of high-precision laser online alignment measurement.

Description

Technical Field

[0001] The patent of this invention relates to the field of laser alignment measurement and monitoring technology, and in particular to a porous coding mark and measurement method for laser alignment monitoring. Background Art

[0002] Laser measurement utilizes the excellent directionality, monochromaticity, and long coherence distance of laser light. Using a collimated parallel laser beam as the measurement baseline, it enables automated displacement observation over long working distances and with high measurement accuracy. In recent years, laser alignment monitoring systems have been increasingly used in engineering safety monitoring. The system uses a laser to emit a beam that passes through a zone plate (Fresnel lens) bonded to the dam's measured section, forming a diffraction spot on an imaging screen at the receiving end. This spot is captured by a high-precision area array charge-coupled device (CCD). The captured spot image is then processed to determine the coordinates of the alignment system. The displacement of the spot on the imaging screen is used to determine the displacement of the dam's measured section relative to the laser axis. The accuracy of laser alignment measurement is influenced by many factors, including the acquisition and recognition of a high-precision marker center image and the design and implementation of high-precision monitoring markers. High-precision laser alignment markers are a key technology influencing this accuracy.

[0003] At present, the laser alignment marks used at home and abroad are mainly flip-over or flip-over zone plates (Fresnel lenses). When monitoring over long distances, it is necessary to arrange several zone plate monitoring points on the laser optical path. In order to prevent the various monitoring points from affecting each other, the zone plate needs to have a flip-over mechanism to achieve the lifting and flipping of the zone plate. This will inevitably bring about certain repeatability errors, thereby affecting the final accuracy. At the same time, the zone plates cannot be used at the same time, and it is impossible to achieve one-time measurement of all monitoring points, which is inefficient. Summary of the Invention

[0004] In order to solve the technical problems of repeatability error and low efficiency when using existing laser alignment marks for alignment measurement, the present application provides a porous coding mark and a measurement method for laser alignment monitoring.

[0005] A multi-hole coding mark for laser alignment monitoring, comprising a mark body, a laser alignment hole being provided on the mark body, and at least two coding holes being provided around the laser alignment hole, wherein the laser alignment hole and the coding hole have a definite geometric position relationship;

[0006] The coding holes include a first type of coding hole and a plurality of second type of coding holes, and the aperture of the first type of coding hole is smaller than the aperture of the second type of coding hole.

[0007] In one embodiment, the distance between the center of each coding hole and the center of the laser alignment hole is the same.

[0008] In one embodiment, the angles formed by the centers of any two adjacent coding holes and the line connecting the laser collimation holes are the same.

[0009] In one embodiment, four coding holes are provided around the laser collimation hole, and the angle formed by the line connecting the centers of any two adjacent coding holes and the center of the laser collimation hole is 90°.

[0010] In one embodiment, six coding holes are provided around the laser collimation hole, and the angle between the center of any two adjacent coding holes and the center of the laser collimation hole is 60°.

[0011] In one embodiment, a sign base is further included, the sign body is vertically mounted on the sign base, and the laser alignment hole and the coding hole are both horizontal holes;

[0012] The marker base is also provided with a fixing hole for fixing the marker base on the object to be measured.

[0013] In one embodiment, the surface of the sign body is coated with a black anti-reflection film; or the sign body is a black sign body obtained by blackening treatment or anodizing treatment;

[0014] The roundness requirement of the coding hole is 0.003 microns

[0015] A measurement method based on the porous coded mark as described above comprises:

[0016] Calibrate the porous coding mark to obtain a calibration value;

[0017] Fixing the porous coding mark on the object to be monitored;

[0018] Adjusting the center of the laser alignment hole of the porous coding mark to be concentric with the center of the laser beam according to the calibration value;

[0019] Acquire a circular light spot formed after the laser beam passes through the coding holes on the porous coding mark, and obtain the coordinates of the center point of the circular light spot through image recognition and extraction;

[0020] The change in the position of the object to be measured is obtained by monitoring the change in the coordinates of the center point of the circular light spot.

[0021] A measurement method based on the porous coded mark as described above comprises:

[0022] Calibrate multiple porous coding marks and obtain their calibration values respectively;

[0023] Fixing a plurality of porous coding markers on a plurality of objects to be monitored respectively;

[0024] Adjusting the centers of the laser alignment holes of the plurality of multi-hole coding marks to one optical path according to the calibration value, so that the coding holes on all the coding marks in the same clock direction are on the same optical path, and each optical path passes through only one coding hole of the first type;

[0025] Acquire a circular light spot formed after the laser beam passes through the first type of coding holes on each porous coding mark, and obtain the coordinates of the center point of the circular light spot through image recognition and extraction;

[0026] By monitoring the changes in the coordinates of the center points of each circular light spot, the changes in the position of the corresponding object to be measured can be obtained.

[0027] In one embodiment, before obtaining the circular light spot formed after the laser beam passes through the first type of coding holes on each porous coding mark, the method further includes:

[0028] Expanding the laser beam incident on the porous coding mark to obtain a beam of parallel light, and injecting the parallel light into the porous coding mark from one end;

[0029] The step of acquiring a circular light spot formed after the laser beam passes through the first type of coding hole on each porous coding mark includes: using a CCD or CMOS to acquire the parallel light received at the other end of the multiple porous coding marks to form multiple circular light spots.

[0030] The laser-aligned multi-hole coding mark according to the above embodiment includes a mark body, a laser alignment hole, and at least two coding holes around the laser alignment hole, with the center of each coding hole being the same distance from the center of the laser alignment hole. The coding holes include a first-type coding hole and multiple second-type coding holes, with the aperture of the first-type coding hole being smaller than the aperture of the second-type coding holes. During measurement, the mark is fixed to the object to be measured. The expanded laser passes through the multiple coding holes and forms an image on a CCD or CMOS. After passing through the first-type coding hole, a small circle is formed. The position of the small circle's center is obtained through image processing, and the position change of the object to be measured can be obtained by monitoring the position change of the small circle's center.

[0031] The beneficial effects of the patent of the present invention are: compared with the traditional wave zone plate, the porous coding mark of this embodiment does not need to be turned over or flipped after adjustment and fixation, thereby avoiding the repetitive errors caused by the turning-over mechanism or the flipping mechanism, thereby greatly improving the accuracy, and the marks do not affect each other, and can realize one-time monitoring and measurement of all monitoring points, and obtain the two-dimensional coordinate values of the monitoring points at the same time, greatly improving work efficiency, and is particularly suitable for the field of high-precision laser online alignment measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the overall structure of a four-hole coding mark according to an embodiment of the present application;

[0033] Figure 2 This is a front view of a four-hole coding mark structure according to an embodiment of the present application;

[0034] Figure 3 This is a front view of four four-hole coding mark structures according to an embodiment of the present application;

[0035] Figure 4 This is a schematic diagram of the overall structure of a six-hole coding mark according to another embodiment of the present application;

[0036] Figure 5 This is a front view of a six-hole coding mark structure according to another embodiment of the present application;

[0037] Figure 6 This is a front view of six six-hole coding mark structures according to another embodiment of the present application;

[0038] Figure 7 This is an example diagram of laser alignment monitoring using a six-hole coding mark in this application;

[0039] Figure 8 This is a schematic diagram of the imaging on the CCD (CMOS) after the laser passes through six six-hole coding marks in this application;

[0040] Figure 9 A measurement method diagram provided in an embodiment of the present application;

[0041] Figure 10 A roadmap of another measurement method provided in an embodiment of the present application;

[0042] Figure 11 This is a schematic diagram of the arrangement of multiple coding marks during measurement in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0044] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0045] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0046] In an embodiment of the present invention, a laser alignment hole is provided on the sign body, and a plurality of coding holes are provided around the laser alignment hole based on the laser alignment hole. The coding holes include a first type of coding hole and a plurality of second type of coding holes. The aperture of the first type of coding hole is smaller than the aperture of the second type of coding hole. For a more convenient and clear description, in the following embodiments, the first type of coding hole is set as a small coding hole, and the second type of coding hole is set as a large coding hole. The size does not have a limiting meaning, but is relative to each other.

[0047] Example 1:

[0048] like Figure 1 and Figure 2As shown, this embodiment provides a laser alignment multi-hole coding mark, which includes a mark body 1 and a mark base 2. The mark body 1 has four coding holes, including a laser alignment hole 10, a first coding hole 11, a second coding hole 12, a third coding hole 13, and a fourth coding hole 14. The first coding hole 11, the second coding hole 12, the third coding hole 13, and the fourth coding hole 14 are all circular holes. The radius of the second coding hole 12, the third coding hole 13, and the fourth coding hole 14 are the same, and the radius of the first coding hole 11 is smaller than the radius of the second coding hole 12, the third coding hole 13, and the fourth coding hole 14. At the same time, the distance from the hole center (i.e., the center) of the first coding hole 11, the second coding hole 12, the third coding hole 13, and the fourth coding hole 14 to the laser alignment hole 10 is the same.

[0049] For the convenience of measurement, in this embodiment, the angle formed by the line connecting the centers of any two adjacent coding holes and the center of the laser collimation hole is 90°.

[0050] The marker base 2 of this embodiment is provided with a first marker base fixing hole 21 and a second marker base fixing hole 22 , which facilitates fixing the marker on the object to be measured by bolts or screws.

[0051] The logo body 1 of this embodiment is shaped like a table tennis racket, with the laser alignment holes 10 and the coding holes both disposed on the racket face. The handle of the racket is vertically disposed on the logo base 2, thereby enhancing the overall appearance. In other embodiments, the logo body 1 may be configured in other shapes and is not limited to the racket shape provided in this embodiment.

[0052] Furthermore, the sign body 1 of this embodiment is made of 2Cr13 stainless steel with a thickness of 2mm. The sign body 1 has five apertures, including a laser alignment aperture 10 at the center with a diameter of 2mm. Four coding apertures are evenly distributed around the laser alignment aperture 10: a first coding aperture 11, a second coding aperture 12, a third coding aperture 13, and a fourth coding aperture 14. The diameter of the first coding aperture 11 is 10mm, while the diameters of the other three coding apertures are the same, all 16mm. The roundness requirement for each of these four coding apertures is 0.003 microns, and the first, second, third, and fourth coding apertures 11, 12, 13, and 14 are all equidistant from the laser alignment aperture 10, each at a distance of 20mm.

[0053] like Figure 3 As shown, by swapping the positions of the first coding hole 11 and the other three coding holes, a total of four different forms of four-hole coding marks can be obtained. The four-hole coding marks can be used individually or in combination. When multiple different four-hole coding marks are used simultaneously, the marks do not affect each other.

[0054] In addition, in order to reduce laser reflection, the surface of the sign body of this embodiment is coated with a black anti-reflection film, or the sign body is a black sign body obtained by blackening treatment or anodizing treatment.

[0055] The expanded laser beam passes through the four-hole coded mark and forms an image on the CCD or CMOS. After passing through the small coded hole 11, a small circle is formed. The position of the small circle's center is obtained through image processing. By monitoring the change in the small circle's center position, the position change of the object under test can be obtained. When multiple marks are used simultaneously, the small coded holes on each mark can be imaged on the CCD or CMOS. By monitoring the change in the center position of each small coded hole, the position change of each object under test can be obtained.

[0056] Example 2

[0057] like Figure 4 and Figure 5 As shown, this embodiment provides a laser alignment six-hole coded sign, comprising a sign body 1 and a sign base 2. The sign body 1 has seven light holes, including a laser alignment hole 10, a first coded hole 11, a second coded hole 12, a third coded hole 13, a fourth coded hole 14, a fifth coded hole 15, and a sixth coded hole 16. The distances from the centers of the six coded holes to the center of the laser alignment hole 10 are all the same. The radius of the first coded hole 11 is smaller than that of the remaining five coded holes, and the radii of the remaining five coded holes are all the same.

[0058] For the convenience of measurement, the angle between the center of any two adjacent coding holes and the center of the laser collimation hole 10 is 60°.

[0059] The marker base 2 of this embodiment is provided with a first marker base fixing hole 21 and a second marker base fixing hole 22 , which facilitates fixing the marker on the object to be measured by bolts or screws.

[0060] Furthermore, the sign body 1 of this embodiment is made of 2Cr13 stainless steel with a thickness of 2mm. The sign body 1 has seven apertures, including a laser alignment aperture 10 at the center with a diameter of 2mm. Six coded apertures are evenly distributed around the laser alignment aperture 10: a first coded aperture 11, a second coded aperture 12, a third coded aperture 13, a fourth coded aperture 14, a fifth coded aperture 15, and a sixth coded aperture 16. The diameter of the first coded aperture 11 is 8mm, while the diameters of the remaining five coded apertures are the same, all 12mm. The roundness requirement for all six coded apertures is 0.003 microns, and the distances from the laser alignment aperture 10 are all equal, at 20mm.

[0061] like Figure 6As shown, by exchanging the positions of the first coding hole 11 and the remaining five coding holes, a total of 6 six-hole coding marks can be obtained. The six-hole coding marks can be used alone or in combination. When multiple six-hole coding marks are used simultaneously, the marks do not affect each other.

[0062] The expanded laser beam passes through the six-hole coded mark of this embodiment and is imaged on a CCD or CMOS. After passing through the first coded hole 11, a small circle is formed. The position of the small circle's center is determined through image processing, and the position change of the object under test can be determined by monitoring the change in the center position of the small circle. When multiple marks are used simultaneously, the small coded holes on each mark can be imaged on the CCD or CMOS, and the position change of each object under test can be determined by monitoring the change in the center position of each small coded hole.

[0063] In addition, the number of coding holes in this embodiment is not limited to the four-hole and six-hole forms provided in Example 1 and Example 2. In other embodiments, other numbers of coding holes can be set as needed, and the coding holes do not necessarily need to be evenly distributed along the circumference, that is, the angles formed by the centers of any two adjacent coding holes and the line connecting the laser collimation holes do not need to be the same.

[0064] Compared with traditional laser alignment marks (such as wave plate (Fresnel lens)), the porous coding mark of this embodiment does not need to be turned over after adjustment and fixation, eliminating the repeatability error caused by the traditional turned-over wave plate, and multiple marks do not affect each other when used at the same time, and can realize one-time monitoring and measurement of all monitoring points, and obtain the two-dimensional coordinate values of the monitoring points at the same time, which greatly improves efficiency and is particularly suitable for high-precision laser measurement and monitoring fields.

[0065] Example 3

[0066] The porous coding mark provided in the above embodiment can be used alone or in combination with multiple coding marks of different forms. When multiple coding marks of different forms are used simultaneously, the individual marks do not affect each other. Generally, the number of porous coding marks required for laser monitoring is equal to the number of objects to be monitored, and the number of coding holes on the porous coding mark is equal to the number of objects to be monitored. Each mark has one and only one coding mark of the first type (i.e., small coding hole), and the rest are coding marks of the second type (i.e., large coding hole). In addition, coding marks of the same type cannot be used, that is, coding marks with small coding holes in the same clock direction cannot be used.

[0067] This embodiment provides a method for measuring a porous coding mark, which uses a single porous coding mark to measure the object to be measured. Figure 9 , the method specifically includes:

[0068] Step 301: calibrate the porous coding mark to obtain the calibration value.

[0069] Step 302: Fix the porous coding mark on the object to be monitored.

[0070] Step 303: Adjust the center of the laser alignment hole of the porous coding mark to be concentric with the center of the laser beam according to the calibration value.

[0071] Step 304: Obtain a circular light spot formed after the laser beam passes through the coding holes on the porous coding mark, and obtain the coordinates of the center point of the circular light spot through image recognition and extraction.

[0072] The laser emitted by the laser obtains a beam of parallel light with low emittance after passing through the beam expander. After passing through the porous coding mark, a circular light spot will eventually be formed on the CCD or CMOS. In order to make the coding hole able to be fully imaged on the CCD or CMOS, the diameter of the laser beam obtained after laser beam expansion must be larger than the outer contour diameter of the large coding hole of the porous mark.

[0073] Step 305: The position change of the object to be measured is determined by monitoring the change in the coordinates of the center point of the circular light spot. Specifically, the two-dimensional coordinates of the center point of the circular light spot are obtained through image recognition and extraction technology. The position change of the object to be measured can be determined by monitoring the change in the two-dimensional coordinates of the circular light spot.

[0074] When measuring the position of the object to be measured by this method, there is no need to tilt or flip the wave plate, thereby avoiding the repeatability error caused by the tilting mechanism or the flipping mechanism. Therefore, the accuracy can be greatly improved, and the various marks do not affect each other. One-time monitoring and measurement of all monitoring points can be achieved, and the two-dimensional coordinate values of the monitoring points can be obtained at the same time, which greatly improves work efficiency. It is particularly suitable for the field of high-precision laser online alignment measurement.

[0075] Example 4

[0076] When multiple coding marks are used simultaneously, the expanded laser beam can form small circular light spots on the CCD or CMOS at one time when passing through the small coding holes on each mark. The two-dimensional plane coordinates of the centers of these small circular light spots are obtained through image recognition and extraction, thereby obtaining the two-dimensional coordinate values of each monitoring point. By monitoring the changes in the two-dimensional coordinate values of the centers of each small coding hole, the position changes of each object to be measured can be obtained.

[0077] This embodiment provides a method for measuring a porous coding mark, which uses multiple porous coding marks of different forms to measure the object to be measured. Specifically, this embodiment uses the following method: Figure 3 The six-hole coding marks shown in the figure do not affect each other when used together. Figure 7This is an example diagram of laser alignment monitoring using six-hole coding marks. The first object to be monitored 31, the second object to be monitored 32, the third object to be monitored 33, the fourth object to be monitored 34, the fifth object to be monitored 35, and the sixth object to be monitored 36 are placed in a vacuum box 54. Each object to be monitored has a fixed six-hole coding mark, namely six-hole coding mark 41, six-hole coding mark 42, six-hole coding mark 43, six-hole coding mark 44, six-hole coding mark 45, and six-hole coding mark 46. These six six-hole coding marks correspond to Figure 3 This embodiment provides a measurement method based on the six coding marks. Figure 10 , the method specifically includes:

[0078] 401: Calibrate the six multi-hole coding marks and obtain their calibration values respectively; adjust the centers of the laser alignment holes of the six multi-hole coding marks to a single optical path according to the calibration values. Specifically, before using the six-hole coding marks for laser monitoring, it is first necessary to calibrate the six six-hole coding marks, then use a laser tracker and the calibration values to align the center holes of the marks to be concentric with the center of the laser beam, and finally fix the marks to the object to be tested through the fixing holes of the mark base. A set of electric adjustment mechanisms are provided at the locations where the six-hole marks are placed on the six objects to be tested, which can adjust the height and horizontal direction of the marks.

[0079] 402: Fix six porous coding markers on multiple objects to be monitored respectively;

[0080] 403: Adjust the centers of the laser alignment holes of the six multi-hole coding marks to one optical path according to the calibration value, so that the coding holes on all coding marks in the same clock direction are on the same optical path, and each optical path only passes through one first type of code. Figure 11 In this embodiment, six-hole coding marks 41, 42, 43, 44, 45, and 46 are respectively fixed to the first object to be monitored 31, the second object to be monitored 32, the third object to be monitored 33, the fourth object to be monitored 34, the fifth object to be monitored 35, and the sixth object to be monitored 36. On the same optical path, light beam 57 passes through only the small coding holes on one six-hole coding mark, while the remaining light beams pass through the large coding holes on the other five six-hole coding marks. Ultimately, only the small coding holes and the laser collimation hole are imaged on the CCD (CMOS), forming six circular light spots of equal size. Changes in the center position of the light spots reflect changes in the position of the object to be monitored where the corresponding coding mark is located.

[0081] During measurement, after the fixture is complete, the HeNe laser 51 is turned on. The laser light emitted by the HeNe laser 51 passes through the attenuator 52, the laser beam expander 53, and the reflector 55 to produce a parallel beam 57 with low emittance. The unexpanded spot diameter of the HeNe laser 51 is 0.63 mm. To ensure that all six-hole coding holes can be fully imaged on the CCD (CMOS) 60, the laser beam 57 obtained after passing through the 80x laser beam expander 53 has a diameter of 50.4 mm, which is larger than the outer diameter of the coding holes (46 mm).

[0082] The light beam 57 passes through six porous coding marks and the reflector 56 and eventually becomes 7 circular spots on the CCD (CMOS) 60, including 6 coded hole circular spots and 1 laser collimation hole spot. The 6 coded hole circular spots have the same diameter. The 2D plane coordinates of the centers of the 6 coded hole circular spots and 1 laser collimation hole spot are obtained through image recognition and extraction technology. By monitoring the changes in the 2D plane coordinates of the 6 coded hole circular spots, the position changes of the 6 objects to be measured can be obtained.

[0083] 404: Obtain the circular spot formed after the laser beam passes through the first type of coding hole on each multi-hole coding mark, and obtain the coordinates of the center point of the circular spot through image recognition and extraction. After the laser passes through the six six-hole coding marks, only the small coding holes on the coding marks can form a circular spot on the CCD or CMOS, such as Figure 8 , where the circular light spot 61 corresponds to the small coding hole of the six-hole coding mark 41, the circular light spot 62 corresponds to the small coding hole of the six-hole coding mark 42, the circular light spot 63 corresponds to the small coding hole of the six-hole coding mark 43, the circular light spot 64 corresponds to the small coding hole of the six-hole coding mark 44, the circular light spot 65 corresponds to the small coding hole of the six-hole coding mark 45, the circular light spot 66 corresponds to the small coding hole of the six-hole coding mark 46, and the circular light spot 60 corresponds to the laser collimation holes (i.e., center holes) of the 6 six-hole coding marks.

[0084] 405: By monitoring the change in the coordinates of the center points of the six circular light spots, the change in the position of the corresponding object to be measured is obtained. That is, by monitoring the change in the two-dimensional coordinates of the center points of the circular light spots formed by the six small coded holes, the change in the position of the corresponding monitored object is obtained.

[0085] Compared with the traditional wave zone plate, the measurement method of this embodiment does not need to be tilted or flipped after the multi-hole coding mark is adjusted and fixed during measurement, thereby avoiding the repeatability error caused by the tilting mechanism or the flipping mechanism. Therefore, the accuracy can be greatly improved, and the various marks do not affect each other. One-time monitoring and measurement of all monitoring points can be achieved, and the two-dimensional coordinate values of the monitoring points can be obtained at the same time, which greatly improves work efficiency. It is particularly suitable for the field of high-precision laser online alignment measurement.

[0086] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A device for laser alignment monitoring, characterized in that: The porous coding mark comprises a mark body, a laser alignment hole is provided on the mark body, and at least two coding holes are provided around the laser alignment hole, and the laser alignment hole and the coding hole have a certain geometric position relationship; The coding holes include a first type of coding hole and a plurality of second type of coding holes, and the aperture of the first type of coding hole is smaller than the aperture of the second type of coding hole; By arranging multiple porous coding marks in sequence along the direction of the laser light path, the position of the first type of coding hole in any porous coding mark is at a different position from the position of the first type of coding hole in other porous coding marks in the same clock direction, and remains concentric with the second type of coding holes in other porous coding marks; the center of the laser beam must be adjusted to be concentric with the center of the laser collimation hole, and the diameter of the laser beam obtained after beam expansion is larger than the outer contour diameter of the second type of coding hole in the porous coding mark.

2. The device for monitoring laser alignment according to claim 1, wherein: The distance between the center of each coding hole and the center of the laser collimation hole is the same.

3. The device for laser alignment monitoring according to claim 1, wherein: The angles formed by the centers of any two adjacent coding holes and the line connecting the laser collimation holes are the same.

4. The device for monitoring laser alignment according to claim 1, wherein: Four coding holes are provided around the laser collimation hole, and the angle formed by the line connecting the centers of any two adjacent coding holes and the center of the laser collimation hole is 90°.

5. The device for monitoring laser alignment according to claim 1, wherein: Six coding holes are provided around the laser collimation hole, and the angle between the center of any two adjacent coding holes and the center of the laser collimation hole is 60°.

6. The device for monitoring laser alignment according to claim 1, wherein: It also includes a sign base, the sign body is vertically mounted on the sign base, and the laser alignment hole and the coding hole are both horizontal holes; The marker base is also provided with a fixing hole for fixing the marker base on the object to be measured.

7. The device for monitoring laser alignment according to claim 1, wherein: The surface of the sign body is coated with a black anti-reflection film; or the sign body is a black sign body obtained by blackening treatment or anodizing treatment; The roundness of the coding hole is required to be 0.003 microns.

8. A measurement method for the device for laser alignment monitoring according to any one of claims 1 to 7, characterized in that: include: Calibrate the porous coding mark to obtain a calibration value; Fixing the porous coding mark on the object to be monitored; Adjusting the center of the laser alignment hole of the porous coding mark to be concentric with the center of the laser beam according to the calibration value; Acquire a circular light spot formed after the laser beam passes through the coding holes on the porous coding mark, and obtain the coordinates of the center point of the circular light spot through image recognition and extraction; The change of the position of the object to be measured is obtained by monitoring the change of the coordinates of the center point of the circular light spot; In which, by arranging multiple porous coding marks in sequence along the direction of the laser light path, the position of the first type of coding hole in any porous coding mark is at a different position from the position of the first type of coding hole in other porous coding marks in the same clock direction, and remains concentric with the second type of coding hole in other porous coding marks; the diameter of the laser beam after expansion is larger than the outer contour diameter of the second type of coding hole in the porous coding mark.

9. A measurement method for the device for laser alignment monitoring according to any one of claims 1 to 7, characterized in that: include: Calibrate multiple porous coding marks and obtain their calibration values respectively; Fixing a plurality of porous coding markers on a plurality of objects to be monitored respectively; Adjusting the centers of the laser alignment holes of the plurality of multi-hole coding marks to one optical path according to the calibration value, so that the coding holes on all the coding marks in the same clock direction are on the same optical path, and each optical path passes through only one coding hole of the first type; Acquire a circular light spot formed after the laser beam passes through the first type of coding holes on each porous coding mark, and obtain the coordinates of the center point of the circular light spot through image recognition and extraction; By monitoring the changes in the coordinates of the center points of each circular light spot, the changes in the position of the corresponding object to be measured can be obtained; Among them, by arranging multiple porous coding marks in sequence along the direction of the laser light path, the position of the first type of coding hole in any porous coding mark is at a different position from the position of the first type of coding hole in other porous coding marks in the same clock direction, and remains concentric with the second type of coding holes in other porous coding marks; the center of the laser beam must be adjusted to be concentric with the center of the laser collimation hole, and the diameter of the laser beam after beam expansion is larger than the outer contour diameter of the second type of coding hole in the porous coding mark.

10. The measuring method of the device for monitoring laser alignment according to claim 9, characterized in that: Before acquiring the circular light spot formed after the laser beam passes through the first type of coding holes on each porous coding mark, the method further includes: Expanding the laser beam incident on the porous coding mark to obtain a beam of parallel light, and injecting the parallel light into the porous coding mark from one end; The obtaining of the circular light spots formed after the laser beam passes through the first type of coding holes on each porous coding mark includes: using CCD or CMOS to receive the parallel light at the other end of the multiple porous coding marks to form multiple circular light spots.

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