High-precision size measuring device

Abstract

The invention relates to a high-precision size measuring device, and the device comprises an adjustable light source module which is adjustable in output light color; the jig module is located on one side of the adjustable light source module, and the jig module is used for fixing an object to be detected; the imaging module is located on one side of the jig module; and the calculation module is used for calculating the size of the to-be-measured area of the to-be-measured object based on the image acquired by the imaging module. The color of the output light can be regulated and controlled through the adjustable light source module, the output light of different colors is correspondingly set for different colored rod-shaped to-be-measured objects, the contrast ratio and the measurement precision are improved, and then the size of the to-be-measured area of the to-be-measured object is calculated based on the high-precision image obtained by the imaging module; one measuring device can be applied to measuring requirements of multicolor products; meanwhile, the inner diameter and the outer diameter of the hollow rod can be measured, and the device is applicable to objects to be measured regardless of the length.

Description

Technical Field

[0001] The present application relates to the field of optical detection technology, and in particular to a high-precision dimension measuring device. Background Art

[0002] At present, many rods and slits such as optical fiber cores, grating slits, wire copper cores and machine tool lead screws are important components of precision instruments and measurement systems. The processing and detection accuracy of their geometric cross-sections and slit diameters directly affects the performance and accuracy of the instruments and systems. Therefore, high-precision and rapid detection of slits or rods is particularly important.

[0003] In the related art, in measuring the cross-sectional diameter of rod-shaped test objects, current measuring equipment has obvious differences in image contrast for rod-shaped test objects of different colors due to the different transmittances of different colors to light. This leads to deviations in the measurement accuracy of rod-shaped test objects of different colors, and cannot be well applied to the measurement needs of multi-color products.

[0004] Therefore, it is necessary to design a new high-precision dimension measuring device to overcome the above problems. Summary of the invention

[0005] The present application provides a high-precision dimension measuring device, which can solve the technical problem in the related art that the image contrast of rod-shaped objects to be measured with different colors is obviously different, resulting in deviation in the measurement accuracy of rod-shaped objects to be measured with different colors.

[0006] In a first aspect, an embodiment of the present application provides a high-precision dimension measurement device, which includes: an adjustable light source module, the output light color of which is adjustable; a fixture module, the fixture module is located on one side of the adjustable light source module, and the fixture module is used to fix the object to be measured; an imaging module, the imaging module is located on one side of the fixture module; and a calculation module, which is used to calculate the size of the area to be measured of the object to be measured based on the image acquired by the imaging module.

[0007] In combination with the first aspect, in one implementation, the adjustable light source module includes a light source and a rotating color wheel, and the light source and the fixture module are located on opposite sides of the rotating color wheel.

[0008] In combination with the first aspect, in one implementation, the adjustable light source module further includes a collimator and an aperture, the collimator and the aperture are located between the rotating color wheel and the fixture module, and the aperture is located between the collimator and the fixture module.

[0009] In combination with the first aspect, in one implementation, the minimum clear diameter of the aperture is greater than 0.5 mm.

[0010] In combination with the first aspect, in one implementation, the fixture module includes a fixed rail, on which two clamping members are slidably mounted, and the two clamping members are used to fix the object to be tested.

[0011] In combination with the first aspect, in one embodiment, the high-precision dimension measuring device further includes a precision controllable slide rail; the fixture module further includes a fixed plate, the fixed plate is mounted on the precision controllable slide rail, and the fixed rail is fixed to the fixed plate.

[0012] In combination with the first aspect, in one implementation, each of the clamping members is provided with a mounting hole, and the mounting hole penetrates the clamping member along an extension direction of the fixing rail.

[0013] In combination with the first aspect, in one embodiment, a flexible anti-injury layer is provided on the sides of the two clamping members that are close to each other.

[0014] In combination with the first aspect, in one embodiment, the imaging module and the adjustable light source module are located on the same side of the fixture module, and the axis of the imaging module and the axis of the adjustable light source module are arranged symmetrically about a symmetry plane passing through the center of the mounting hole; or, the imaging module and the adjustable light source module are located on opposite sides of the fixture module.

[0015] In combination with the first aspect, in one embodiment, the range of the angle α between the axis of the imaging module and the symmetry plane is: α<=arctan(V / 2H); wherein V is the inner diameter of the mounting hole; and H is the distance between the outer side surfaces of the two clamping members along the axial direction of the mounting hole when the object to be measured is mounted on the two clamping members.

[0016] In combination with the first aspect, in one embodiment, the imaging module includes an imaging lens and a camera spaced apart from the imaging lens, the imaging lens is located between the fixture module and the camera, and the focal plane of the imaging lens coincides with an imaging plane of the camera.

[0017] In combination with the first aspect, in one implementation, the imaging module and the adjustable light source module are located on opposite sides of the fixture module.

[0018] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0019] 1. The color of the output light can be adjusted by the adjustable light source module, and different colors of output light are set for different colored rod-shaped objects to be tested, so as to improve the contrast and measurement accuracy, and then calculate the size of the test area of ​​the object to be tested based on the high-precision image obtained by the imaging module; and a measuring device is used to meet the measurement needs of multi-color products, which solves the technical problem in the related art that the image contrast of rod-shaped objects to be tested with different colors is obviously different, resulting in deviation in the measurement accuracy of rod-shaped objects to be tested with different colors.

[0020] 2. This high-precision dimension measuring device can measure the outer diameter of a solid rod or the inner and outer diameters of a hollow rod, and can measure both long and short rods. For measuring the inner and outer diameters of longer ports, the adjustable light source module and the imaging module can be rotated to a symmetrical position in front of the fixture module, so that there is enough free space behind the fixture module, which is suitable for measuring longer rods. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic diagram of a structure in which an imaging module and an adjustable light source module are located on different sides in a high-precision dimension measurement device provided in an embodiment of the present application;

[0023] Figure 2 A schematic diagram of the three-dimensional structure of a fixture module provided in an embodiment of the present application;

[0024] Figure 3 A schematic diagram of a structure in which an imaging module and an adjustable light source module are located on the same side in a high-precision dimension measurement device provided in an embodiment of the present application;

[0025] Figure 4 (a) is a schematic diagram of the shooting result of a thick rod-shaped object to be tested or a regular gap, (b) is a diagram of the processing result of (a) after edge recognition, (c) is a schematic diagram of the shooting result of a regular inner diameter, and (d) is a diagram of the processing result of (c) after edge recognition;

[0026] Figure 5 (a) is a schematic diagram of the shooting results of a thinner rod-shaped object to be tested or a regular gap, and (b) is a curve diagram of the relationship between the intensity distribution and the distance of (a);

[0027] Figure 6 (a) is a schematic diagram of the shooting results of a thinner regular inner diameter, and (b) is a curve diagram of the relationship between the intensity distribution and distance of (a).

[0028] In the figure:

[0029] 1. Adjustable light source module; 11. Light source; 12. Rotating color wheel; 13. Collimator; 14. Aperture;

[0030] 2. fixture module; 21. fixing rail; 22. clamping piece; 221. mounting hole; 222. outer side surface; 23. fixing plate; 24. flexible anti-injury layer;

[0031] 3. Imaging module; 31. Imaging lens; 32. Camera;

[0032] 4. Precision controllable slide rail; 5. Object to be tested. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] In the related technology, the current measurement methods for thin gaps or thin rods include contact measurement and non-contact measurement. The contact measurement methods include the probe spacing method and the caliper reading method. The contact measurement method requires close contact with the object to be measured. The metal probe will deform or scratch the object to be measured, which will affect the subsequent high-precision use requirements. The non-contact measurement methods mainly include laser diameter gauges or photoelectric diameter gauges. The instruments with high measurement accuracy are often large and complex in structure, while the measurement accuracy of small devices is insufficient. There are multiple variables in the measurement method, and it is difficult to complete high-precision testing through a simple system and measurement method. It is also impossible to take into account the measurement of multiple types of thick outer diameters, thin outer diameters, and hollow inner diameters in the same device.

[0035] In measuring the cross-sectional diameter of thick rod-shaped objects to be tested, the current measuring equipment has obvious differences in image contrast for rod-shaped objects of different colors due to different light transmittances of different colors, resulting in deviations in the measurement accuracy of thin rod-shaped objects of different colors, and cannot be well applied to the measurement needs of multi-color products. In the measurement of thin slits and thin rods of a few millimeters or even smaller, due to their small cross-sectional diameter, the direct image algorithm calculation is easily affected by diffraction and cannot accurately measure the cross-sectional diameter of thin slits and thin rods.

[0036] The embodiment of the present application provides a high-precision dimension measuring device, which can solve the technical problem in the related art that the image contrast of rod-shaped objects to be measured with different colors is obviously different, resulting in deviation in the measurement accuracy of rod-shaped objects to be measured with different colors.

[0037] See also Figure 1 As shown, a high-precision dimension measuring device provided in an embodiment of the present application may include: an adjustable light source module 1, the output light color of the adjustable light source module 1 is adjustable; a fixture module 2, the fixture module 2 is located on one side of the adjustable light source module 1, and the fixture module 2 is used to fix the object to be measured 5; an imaging module 3, the imaging module 3 is located on one side of the fixture module 2; and a calculation module, which is used to calculate the size of the area to be measured of the object to be measured 5 based on the image obtained by the imaging module 3.

[0038] In this embodiment, there are many ways to change the color of the output light of the adjustable light source module 1, such as self-luminescence or white light combined with a filter. The fixture module 2 is located behind the adjustable light source module 1 and is used to fix the object to be tested 5. The object to be tested 5 can be placed vertically on the fixture module 2 or horizontally on the fixture module 2. When the object to be tested 5 is measured, the object to be tested 5 is fixed to the fixture module 2, and the light emitted by the adjustable light source module 1 is irradiated to the object to be tested 5. The imaging module 3 takes a photo of the area to be tested of the object to be tested 5 to detect the size of the area to be tested. The area to be tested can be a certain area on the surface of the object to be tested 5 (such as a hole or a gap set on the object to be tested 5), or it can be the surface of the entire object to be tested 5 (such as the surface of the entire rod). The size of the area to be tested can be, for example, the diameter or cross-sectional size of the rod (the rod can be round or square or other shapes), or the inner diameter of the inner hole or the spacing of the gap. The imaging module 3 can be located behind the fixture module 2 along the axis direction of the adjustable light source module 1, or can be located at other positions, such as Figure 3 As shown, the imaging module 3 and the adjustable light source module 1 are both located in front of the fixture module 2 .

[0039] In this embodiment, the color of the output light can be adjusted by the adjustable light source module 1. Different colors of output light are set for different colored rod-shaped test objects 5. For example, the color of the output light can be adjusted to form a complementary color with the test object 5, or the output light can be adjusted to a color with a longer wavelength. For thicker test objects 5, complementary colors are selected during detection, which can improve the contrast between the background area and the test area, making the boundary segmentation closer to the true value, thereby obtaining a more accurate measurement result; for thin slits or thin rods, the output light is adjusted to a color with a longer wavelength. When the collimated detection light passes through the thin slits or thin rods, due to the wavelength The longer the length, the stronger the diffraction ability, and the more obvious the characteristic trend of the obtained detection image will be, thereby improving the detection accuracy. Therefore, the measuring device of this embodiment can improve the detection contrast and measurement accuracy by setting an adjustable light source module 1 to adjust the color of the output light, and then calculate the size of the test area of ​​the object to be tested 5 based on the high-precision image obtained by the imaging module 3; and a measuring device is used to be applicable to the measurement needs of multi-color products, which solves the technical problem in the related art that the image contrast of the rod-shaped objects to be tested 5 with different colors is obviously different, resulting in deviations in the measurement accuracy of the rod-shaped objects to be tested 5 with different colors.

[0040] The complementary colors mentioned above refer to two colors that are 180° apart on the color wheel. When these two colors are in the same interface, they will form a strong contrast effect. In this embodiment, for example, when the object to be tested 5 is a thick green rod, the color of the output light is red, which is a complementary color to the green color of the object to be tested 5.

[0041] Further, in some optional embodiments, the adjustable light source module 1 includes a light source 11 and a rotating color wheel 12, and the light source 11 and the fixture module 2 are located on opposite sides of the rotating color wheel 12. In this embodiment, the rotating color wheel 12 is located behind the light source 11, and the fixture module 2 is located behind the rotating color wheel 12. The light source 11 is preferably a white point light source 11, and the rotating color wheel 12 is preferably an adjustable single-pass rotating color wheel 12. The rotating color wheel 12 can rotate around its axis, and the rotating color wheel 12 is provided with a plurality of monochromatic (single wavelength) permeable film layers along its circumferential direction. When the rotating color wheel 12 rotates to align one of the monochromatic permeable film layers with the light source 11, the light emitted by the light source 11 passes through the monochromatic permeable film layer, and the wavelength of the output light is consistent with the wavelength of the monochromatic permeable film layer. When the object to be measured 5 is measured, the object to be measured 5 is fixed to the fixture module 2, and the light emitted by the light source 11 passes through the rotating color wheel 12 and then irradiates the object to be measured 5, and the imaging module 3 takes pictures and images the area to be measured of the object to be measured 5 to detect the size of the area to be measured. In other embodiments, the specific arrangement of the single color through the film layer is not limited to the rotating color wheel 12, and other switching mechanisms may also be used, such as stacking switching.

[0042] The rotating color wheel 12 in this embodiment can be set at a position close to the light source 11 to ensure that the irradiation range of the light source 11 is within the monochromatic area of ​​the rotating color wheel 12, and to prevent the light source 11 from irradiating two or more monochromatic areas on the rotating color wheel 12 at the same time. When irradiating multiple areas, the monochromatic modulation effect of the rotating color wheel 12 fails. At the same time, the area of ​​the monochromatic area of ​​the rotating color wheel 12 should be larger than the irradiation area of ​​the light source 11. When the area of ​​the monochromatic area on the rotating color wheel 12 is smaller, the rotating color wheel 12 needs to be closer to the light source 11 to ensure that the modulation effect of the rotating color wheel 12 on the color of the light source 11 is effective.

[0043] In this embodiment, the preferred fixed colors of the rotating color wheel 12 are transparent (can be detected by a white light source) and 660nm red (can be detected by a 660nm single-wavelength red light). Other colors can be installed with complementary colors in other areas of the color wheel according to the color of the object to be tested 5 (e.g., if the object to be tested 5 is blue, a 590nm yellow high-transmittance film should be added to the rotating color wheel 12; if the object to be tested 5 is a red object, a 520nm green should be added). In this embodiment, by setting commonly used colors on the rotating color wheel 12 as the basic colors of the rotating color wheel 12, other multi-color rotating color wheels 12 can be replaced as needed, so that the cost of the rotating color wheel 12 can be saved according to actual needs (the more single-wavelength transmission films on the rotating color wheel 12, the higher the cost); at the same time, the rotating color wheel 12 can meet both basic needs and special color needs: transparent color (can be applied to commonly used black and gray objects to be tested 5), 660nm red (can meet the detection of thin rods or slits), the setting of two preferred colors can meet most of the scenes in actual detection applications, and corresponding complementary colors can also be added for special scenes to increase image contrast and improve measurement accuracy.

[0044] Further, see Figure 1 As shown, in some embodiments, the adjustable light source module 1 may further include a collimator 13 and an aperture 14, wherein the collimator 13 and the aperture 14 are located between the rotating color wheel 12 and the fixture module 2, and the aperture 14 is located between the collimator 13 and the fixture module 2. In this embodiment, the aperture 14 is preferably an adjustable circular aperture 14, and the aperture 14 is provided with a plurality of holes of different sizes along its circumferential direction. When the measuring device is used to detect a coarser object 5 to be measured, the aperture 14 may be adjusted to have a larger hole aligned with the light source 11, so that the light emitted by the light source 11 may pass through the larger hole to irradiate the object 5 to be measured; when the measuring device is used to detect a finer object 5 to be measured, the aperture 14 may be adjusted to have a smaller hole aligned with the light source 11, so that the light emitted by the light source 11 may pass through the smaller hole to irradiate the object 5 to be measured, thereby enabling the measuring device to be applicable to the detection of objects 5 to be measured of various sizes. In this embodiment, the light source 11 may be placed at the object focus of the collimator 13, so that the light source 11 can form parallel light, thereby improving the detection accuracy.

[0045] Furthermore, in some optional embodiments, the minimum light-through diameter of the aperture 14 is greater than 0.5 mm. This embodiment limits the minimum light-through diameter of the aperture 14 to greater than 0.5 mm, thereby preventing the light spot from being too small and insufficiently bright and directly passing through the slit, making it impossible to perform accurate detection. At the same time, the maximum light-through diameter of the aperture 14 is smaller than the aperture of the collimator 13, thereby preventing the aperture 14 from being too large and causing light leakage.

[0046] Further, in some optional embodiments, see Figure 2 As shown, the fixture module 2 includes a fixed rail 21, and two clamps 22 are slidably mounted on the fixed rail 21, and the two clamps 22 are used to fix the object to be tested 5. In this embodiment, the fixed rail 21 extends in the front-to-back direction, and the two clamps 22 can move on the fixed rail 21 in the front-to-back direction, so that the gap between the two clamps 22 can be adjusted, so that the two clamps 22 can clamp the objects to be tested 5 of different sizes. In this embodiment, the number of clamps 22 on the fixed rail 21 can be two or more, and can be set according to actual needs, and there is no limitation here. In this embodiment, the bottom of each clamp 22 has a fixing screw, and when the clamp 22 is moved to a suitable position on the fixed rail 21, it can be fixed to the fixed rail 21 by a fixing screw.

[0047] Based on the above technical solution, see Figure 1 and Figure 2 As shown, in one embodiment, the high-precision dimension measuring device may further include a precision controllable slide rail 4; the fixture module 2 may further include a fixed plate 23, the fixed plate 23 is mounted on the precision controllable slide rail 4, and the fixed rail 21 is fixed to the fixed plate 23. In this embodiment, the fixture module 2 is integrally mounted on the precision controllable slide rail 4, so that the precision controllable slide rail 4 can drive the fixture module 2 to move along the x, y and z axes, so as to accurately adjust the position of the fixture module 2 in the x, y and z axis directions, and then adjust the distance between the object to be measured 5 in the fixture module 2 and the aperture 14 and the imaging module 3. The precision controllable slide rail 4 can also drive the fixture module 2 to rotate around the x, y and z axes, and adjust the object to be measured 5 to the required detection state, for example, adjust the object to be measured 5 so that the light spot of the light source 11 is symmetrical about the object to be measured 5, or the light source 11 and the object to be measured 5 are in a coaxial state. This embodiment uses a precision controllable slide rail 4 to adjust the position of the fixture module 2, which can achieve precise adjustment of the position of the fixture module 2 and provide a basis for subsequent precise detection.

[0048] Further, see Figure 2As shown, in some optional embodiments, each of the clamping members 22 is provided with a mounting hole 221, and the mounting hole 221 penetrates the clamping member 22 along the extension direction of the fixed rail 21. In this embodiment, the mounting hole 221 penetrates the clamping member 22 along the front-to-back direction, and the mounting holes 221 on the two clamping members 22 are coaxially arranged. When measuring the outer diameter of the rod or the inner diameter of the hole, the object to be measured 5 can be horizontally inserted into the mounting holes 221 of the two clamping members 22, so that the axis of the rod or the hole is horizontal along the front-to-back direction, and the light emitted by the light source 11 is irradiated to the object to be measured 5, and the end surface of the rod or the hole can be photographed by the imaging module 3, and the outer diameter of the rod or the inner diameter of the hole can be calculated based on the photographed image. At the same time, the clamping members 22 are slidably installed on the fixed rail 21. By adjusting the relative positions of the two clamping members 22, after the piece to be tested is passed through the two clamping members 22, the length of the piece to be tested between the two clamping members 22 is moderate, and the length of the piece to be tested in front of the two clamping members 22 is consistent with the length behind the two clamping members 22, ensuring that the piece to be tested is in a horizontal state.

[0049] Further, in some embodiments, see Figure 2 As shown, the sides of the two clamping members 22 that are close to each other are both provided with a flexible anti-injury layer 24. In this embodiment, the sides of the two clamping members 22 that face each other are used to clamp the object to be tested 5. The flexible anti-injury layer 24 is provided on the side that clamps the object to be tested 5, which can prevent the clamping members 22 from causing damage to the object to be tested 5 when clamping the object to be tested 5.

[0050] Further, see Figure 3 As shown, in one embodiment, the imaging module 3 and the adjustable light source module 1 are located on the same side of the fixture module 2, and the axis of the imaging module 3 and the axis of the adjustable light source module 1 are arranged symmetrically about the symmetry plane passing through the center of the mounting hole 221. In this embodiment, the imaging module 3 and the adjustable light source module 1 can be both arranged in front of the fixture module 2, and the adjustable light source module 1 and the imaging module 3 can be arranged up and down or left and right. When the adjustable light source module 1 and the imaging module 3 are arranged up and down, the symmetry plane is a horizontal plane passing through the center of the mounting hole 221; when the adjustable light source module 1 and the imaging module 3 are arranged left and right, the symmetry plane is a vertical plane passing through the center of the mounting hole 221. The light emitted by the light source 11 is irradiated to the object to be tested 5, and the reflected light of the object to be tested 5 can enter the imaging module 3 for imaging. In this embodiment, the imaging module 3 and the adjustable light source module 1 are placed on the same side of the fixture module 2, so that a larger area can be left behind the fixture module 2, so that the fixture module 2 can be suitable for a horizontally placed and relatively long object to be tested 5. Of course, this solution is also suitable for a short object to be tested 5.

[0051] Based on the above technical solution, preferably, see Figure 3As shown, the value range of the angle α between the axis of the imaging module 3 and the symmetry plane is: α<=arctan(V / 2H); wherein V is the inner diameter of the mounting hole 221; and H is the distance between the outer side surfaces 222 of the two clamping members 22 along the axis direction of the mounting hole 221 when the object to be measured 5 is mounted on the two clamping members 22. In this embodiment, the angle α between the axis of the imaging module 3 and the symmetry plane is limited to this range, so that no matter whether the size of the area to be measured on the object to be measured 5 is large or small, the collimated light can cover the area to be measured; at the same time, the angle α between the adjustable light source module 1 and the symmetry plane is also within this range. The adjustable light source module 1 of this angle is symmetrically arranged with the imaging module 3, so that a bright field image of the area to be measured can be obtained, which can better highlight the contour feature information of the area to be measured.

[0052] See also Figure 1 As shown, in some optional embodiments, the imaging module 3 includes an imaging lens 31 and a camera 32 spaced apart from the imaging lens 31, the imaging lens 31 is located between the fixture module 2 and the camera 32, and the focal plane of the imaging lens 31 coincides with the imaging surface of the camera 32. In this embodiment, the imaging lens 31 and the camera 32 are spaced apart by a distance, and such a setting can highlight the long back focal length, the aberration of the long back focal lens will be smaller, and the imaging will be clearer; at the same time, in response to higher precision requirements or larger target surface requirements, the camera 32 with smaller pixels or larger target surface can be replaced, thereby meeting the complex requirements of higher precision and larger imaging surface.

[0053] See also Figure 1 As shown, in some embodiments, the imaging module 3 and the adjustable light source module 1 are located on opposite sides of the fixture module 2. In this embodiment, the adjustable light source module 1 is located in front of the fixture module 2, and the imaging module 3 is located behind the fixture module 2. The adjustable light source module 1, the fixture module 2 and the imaging module 3 are arranged in a front-to-back order. For thin rods or slits, when the cross-sectional diameter or spacing is calculated by collecting the contour information of the object to be measured by reflection, the measurement accuracy is affected by the environment (such as diffraction), etc., so that the measurement accuracy of thin rods or slits is low (the smaller the object, the more sensitive it is, and the diffraction effect cannot be formed for larger objects to be measured); in this embodiment, the adjustable light source module 1 and the imaging module 3 are arranged in front and behind the fixture module 2, respectively, so that the size of smaller objects can be measured using the diffraction principle. Diffraction is a wavelength-level accuracy (nm), which has higher reliability and measurement accuracy for measuring smaller objects.

[0054] Further, in some optional embodiments, the calculation of the size of the area to be tested of the object to be tested 5 based on the image acquired by the imaging module 3 may include: calculating the boundary of the area to be tested in the image; and calculating the cross-sectional diameter d of the area to be tested according to the pixel size P of the camera 32, the number of pixels N occupied by the cross-sectional diameter within the boundary of the area to be tested, and the magnification M of the lens in front of the camera 32; or calculating the seam spacing d of the object to be tested 5 according to the pixel size P of the camera 32, the number of pixels N occupied by the seam spacing within the boundary of the area to be tested, and the magnification M of the lens in front of the camera 32.

[0055] See also Figure 4 As shown in FIG. 1 , (a) is a schematic diagram of the detection result of a thick rod-shaped object to be detected 5 or a regular gap, and FIG. (b) is the processing result after boundary recognition. When the object to be detected 5 is a cylindrical rod, Figure 4 The distance between the upper and lower arrows in (b) is the cross-sectional diameter within the boundary of the test area, and the number of pixels between the upper and lower arrows is the number of pixels N occupied by the cross-sectional diameter within the boundary of the test area; when the test area of ​​the object 5 to be tested is a regular gap (the gap here is not a thin gap), Figure 4 The distance between the two arrows in (b) is the gap spacing within the boundary of the region to be tested, and the number of pixels between the two arrows is the number of pixels N occupied by the gap spacing within the boundary of the region to be tested. Figure 4 By calculating the number of cross-sectional pixels N at multiple locations in (b), the average of the cross-sectional diameter d or the slit spacing d can be obtained. The specific formula is:

[0056]

[0057] Among them, i is Figure 4 The number of locations selected in (b).

[0058] Figure 4 (c) is a schematic diagram of measuring the inner diameter of a regular hole or the end face of a thick rod-shaped object to be tested 5, and (d) is the processing result after boundary recognition in (c). At this time, the number of pixels occupied between the two arrows on the same diameter is the number of pixel data N occupied by the cross-sectional diameter within the boundary of the test area. Figure 4 The number of cross-sectional pixels N is calculated at multiple diameter positions in (d), and the average cross-sectional diameter d can be obtained. The specific formula is also:

[0059]

[0060] In this embodiment, when measuring the outer diameter of a thick rod-shaped object to be tested 5, the object to be tested 5 can be placed vertically to collect Figure 4 The image shown in (a) can also be collected by placing the object 5 horizontally. Figure 4(c) shows the end face image. Both methods can be used to calculate the outer diameter of the rod-shaped object to be tested 5, and the outer diameters obtained by the two methods can be verified with each other.

[0061] Furthermore, in some embodiments, calculating the boundary of the region to be detected in the image may include: dividing the image into binary values ​​and then calculating the boundary of the region to be detected in the image using an edge detection algorithm. In this embodiment, the edge detection algorithm may use a Canny operator, or other edge detection algorithms may be used.

[0062] In this embodiment, for the measurement of the thicker rod-shaped object to be tested 5, regular gaps, and the inner diameter of regular holes, the color of the light output by the light source 11 can be adjusted by rotating the color wheel 12 so that the color of the output light forms a complementary color with the object to be tested 5; then the object to be tested 5 is placed in the fixture module 2, and the object to be tested 5 is adjusted to be coaxial with the light source 11 or the light spot of the light source 11 is symmetrical about the area to be tested; then, by adjusting the distance between the imaging lens 31 and the camera 32, a corresponding clear image (that is, Figure 4 (a) or (c)); then the image is binary segmented and the Canny operator is used to calculate the boundary of the object 5 to be measured; finally, the cross-sectional diameter d or the slit spacing d is calculated.

[0063] Furthermore, in some optional embodiments, the calculation of the cross-sectional size of the object to be measured 5 based on the image acquired by the imaging module 3 may also include: extracting the intensity distribution and distance relationship distribution curve of the effective area in the horizontal direction of the image; and calculating the size of the area to be measured of the object to be measured 5 based on the intensity distribution and distance relationship distribution curve.

[0064] In this embodiment, for a thinner rod-shaped object to be tested 5 or a regular slit, it can be known from Babinet's theorem that a thin rod or a slit has the same diffraction phenomenon. If the size of the test area of ​​the object to be tested 5 is smaller than the set size (i.e., the thin rod or the slit), the object to be tested 5 is vertically fixed on the fixture module 2, and the image of the test area of ​​the object to be tested 5 is collected as a diffraction image ( Figure 5 (a)), and the intensity distribution and distance relationship distribution curve of the horizontal direction of the effective area in the middle of the image can be extracted according to the collected diffraction image. The intensity distribution diagram is shown in Figure 5 For the measurement of the inner diameter of a relatively thin regular hole, a thin rod with a hollow inner diameter is extracted and fixed horizontally on the fixture module 2, and the thin rod is adjusted to be coaxial with the light source 11, and the corresponding diffraction image is taken, as shown in FIG. Figure 6 As shown in (a), the relationship between the intensity distribution and distance in the horizontal direction through the center is as follows Figure 6 Then, based on the intensity distribution and distance relationship distribution curve, the outer diameter of the thin rod, the spacing of the regular thin slits, or the inner diameter of the thin hole can be calculated.

[0065] This embodiment can take diffraction into consideration when measuring thin slits and thin rods of a few millimeters or even smaller, and can accurately measure the cross-sectional diameters of the thin slits and thin rods.

[0066] On the basis of the above technical solution, in one embodiment, the calculation of the size of the test area of ​​the test object 5 based on the intensity distribution and distance relationship distribution curve may include: calculating the distance x from each level of dark pattern to the central main maximum point in the intensity distribution and distance relationship distribution curve k ; and according to the dark fringe level k, the distance x from the kth dark fringe to the central main maximum point k , the light wavelength λ and the focal length f of the front lens of the camera 32 are used to calculate the cross-sectional diameter of the area to be measured or the slit spacing d of the object to be measured 5.

[0067] In this embodiment, for a thinner rod-shaped object to be tested 5 or a regular slit, when measuring the outer diameter of the rod-shaped object to be tested 5 (that is, the cross-sectional diameter d of the area to be tested) or the slit spacing d of the regular slit, according to Figure 5 The intensity distribution and distance relationship distribution curve (b) in the image can be used to calculate the distance x from each level of dark pattern to the central main maximum point through pixel calibration. k , where the central principal maximum point is Figure 5 (b) The point with the highest peak value; then according to the dark fringe level k, the distance x from the kth dark fringe to the central main maximum point k , the wavelength λ of light and the focal length f of the front lens of the camera 32 are used to calculate the cross-sectional diameter of the area to be measured or the slit spacing d of the object to be measured 5, and the calculation formula is:

[0068]

[0069] On the basis of the above technical solution, in one embodiment, the calculation of the size of the area to be measured of the object 5 to be measured based on the intensity distribution and distance relationship distribution curve may include: obtaining the central Airy disk diameter x0 in the intensity distribution and distance relationship distribution curve; and calculating the cross-sectional diameter d of the area to be measured based on the light wavelength λ, the focal length f of the front lens of the camera 32 and the central Airy disk diameter x0.

[0070] In this embodiment, for measuring the inner diameter of a relatively fine regular hole, according to Figure 6 The intensity distribution and distance relationship distribution curve in (b) can be used to obtain the central Airy disk diameter x0. According to the light wavelength λ, the focal length f of the front lens of the camera 32 and the central Airy disk diameter x0, the size of the inner diameter d can be calculated as:

[0071]

[0072] Furthermore, in some embodiments, before the imaging module 3 acquires the image of the object to be tested 5, the position of the object to be tested 5 can be adjusted so that the light spot of the light source 11 is symmetrical about the area to be tested; and the distance between the lens behind the object to be tested 5 and the camera 32 is adjusted so that the focal plane of the lens coincides with the imaging plane of the camera 32. In this embodiment, when the object to be tested 5 is vertically fixed to the fixture module 2, the object to be tested 5 can be adjusted so that the light spot of the light source 11 is symmetrical about the area to be tested, so that the area to be tested captured is in the middle of the image, and the focal plane of the lens coincides with the imaging plane of the camera 32, thereby ensuring the clarity of the captured image.

[0073] The present application proposes a high-precision dimension measuring device, which can form complementary colors with the color of the object to be measured 5 through color control in the measurement of thicker rods, slits and inner diameter cross-section diameters, and further improve contrast and measurement accuracy in combination with image processing; in the measurement of thin slits, thin rods and inner diameters of several millimeters or even smaller, it can take diffraction into account and accurately measure the cross-sectional diameters of thin slits and thin rods, and can simultaneously take into account the unified measurement of multiple objects such as thick outer diameters, thin outer diameters and hollow inner diameters through a simple system and measurement method.

[0074] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0075] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0076] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A high-precision dimension measuring device, It is characterized in that It includes: An adjustable light source module (1), wherein the color of output light of the adjustable light source module (1) is adjustable; A fixture module (2), the fixture module (2) being located on one side of the adjustable light source module (1), and the fixture module (2) being used to fix the object to be tested (5); An imaging module (3), the imaging module (3) being located on one side of the fixture module (2); and a calculation module, which is used to calculate the size of the area to be measured of the object to be measured (5) based on the image acquired by the imaging module (3).

2. The high-precision dimension measuring device according to claim 1, It is characterized in that The adjustable light source module (1) comprises a light source (11) and a rotating color wheel (12); the light source (11) and the fixture module (2) are located on opposite sides of the rotating color wheel (12).

3. The high-precision dimension measuring device according to claim 2, It is characterized in that The adjustable light source module (1) further comprises a collimator (13) and an aperture (14); the collimator (13) and the aperture (14) are located between the rotating color wheel (12) and the fixture module (2); and the aperture (14) is located between the collimator (13) and the fixture module (2).

4. The high-precision dimension measuring device according to claim 3, It is characterized in that The minimum light-passing diameter of the aperture (14) is greater than 0.5 mm.

5. The high-precision dimension measuring device according to claim 1, It is characterized in that The fixture module (2) comprises a fixed rail (21), on which two clamping members (22) are slidably mounted, and the two clamping members (22) are used to fix the object to be tested (5).

6. The high-precision dimension measuring device according to claim 5, It is characterized in that The high-precision dimension measuring device further comprises a precision controllable slide rail (4); The fixture module (2) further comprises a fixing plate (23), wherein the fixing plate (23) is mounted on the precision controllable slide rail (4), and the fixing rail (21) is fixed to the fixing plate (23).

7. The high-precision dimension measuring device according to claim 5, It is characterized in that Each of the clamping members (22) is provided with a mounting hole (221), and the mounting hole (221) penetrates the clamping member (22) along the extension direction of the fixing rail (21).

8. The high-precision dimension measuring device according to claim 7, It is characterized in that The imaging module (3) and the adjustable light source module (1) are located on the same side of the fixture module (2), and the axis of the imaging module (3) and the axis of the adjustable light source module (1) are arranged symmetrically about a symmetry plane passing through the center of the mounting hole (221); or, The imaging module (3) and the adjustable light source module (1) are located on opposite sides of the fixture module (2).

9. The high-precision dimension measuring device according to claim 8, It is characterized in that The value range of the angle α between the axis of the imaging module (3) and the symmetry plane is: α<=arctan(V / 2H); Wherein, V is the inner diameter of the mounting hole (221); and H is the distance between the outer side surfaces (222) of the two clamping members (22) along the axial direction of the mounting hole (221) when the object to be measured (5) is mounted on the two clamping members (22).

10. The high-precision dimension measuring device according to claim 1, It is characterized in that The imaging module (3) comprises an imaging lens (31) and a camera (32) spaced apart from the imaging lens (31); the imaging lens (31) is located between the fixture module (2) and the camera (32), and the focal plane of the imaging lens (31) coincides with the imaging plane of the camera (32).

Images