Standard plate for detecting concave-convex quantity of structured light nail head and manufacturing method of standard plate

Abstract

The invention discloses a standard plate for detecting the concave-convex amount of a structured light nail head and a manufacturing method thereof, and belongs to the technical field of three-dimensional measurement, the standard plate comprises a flat plate, and is characterized in that the flat plate comprises a front half part for simulating a concave nail head and a rear half part for simulating a convex nail head, the front half part and the rear half part are integrally formed, and the front half part and the rear half part are integrally formed. And the height of the front half part is the same as that of the rear half part. The prepared standard plate can accurately simulate nail head protrusion and nail head sinking, is simple in structure and easy to operate, and has good applicability.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional measurement technology, and particularly to a reference plate for detecting the unevenness of structural light nail heads and a manufacturing method thereof. Background Art

[0002] The unevenness of the nail head refers to the degree of depression or protrusion of the nail head compared to the surface of the connected object around it during the riveting process, that is, the height difference between the two.

[0003] Structured light technology is a flexible optical three-dimensional measurement technology. By projecting a modulated stripe image onto the surface of the object to be measured and capturing and analyzing it with a camera, the three-dimensional shape information of the surface of the object to be measured is obtained. Since the unevenness of the nail head is usually small and not easily distinguishable in the point cloud data, when using structured light technology to measure the unevenness of the nail head, it is usually necessary to first perform image segmentation on the two-dimensional image based on the different reflection conditions of the nail head and the connected object, then generate three-dimensional point cloud data in the segmented nail head and connected object areas respectively, and then compare the two pieces of point cloud to calculate the height difference.

[0004] The nail head generated by actual riveting is usually not parallel to the surface of the connected object, that is, one side is relatively sunken and the other side is relatively protruding. Therefore, when obtaining the reference value through contact measurement methods such as coordinate measuring machines, it is easy to cause differences in the calculation results of the unevenness due to differences in the sampling positions. When the sampling point is closer to the relatively sunken side, the reference value is smaller, and vice versa, when the sampling position is closer to the relatively protruding side, the reference value is larger.

[0005] To evaluate a structured light device for measuring the unevenness, a reference plate formed by actual riveting is usually used. Due to the large error in obtaining the reference value, it is difficult to objectively evaluate the accuracy of the device, and only the ability of the device to identify bright and dark nail heads and the repeatability of the measurement can be evaluated.

[0006] Chinese patent document with the publication number CN116358449A and the publication date of June 30, 2023 discloses a method for measuring the unevenness of aircraft rivets based on binocular structured light, including using a binocular camera to collect the structured light projection image on the aircraft skin; identifying the rivets from the image, extracting the region of interest centered on the rivets and resolving the phase; performing region segmentation according to the rivet contour to generate the point cloud of the relevant region; and calculating the unevenness of the rivets according to the point cloud.

[0007] The method for measuring the unevenness of aircraft rivets based on binocular structured light disclosed in this patent document is more simple and fast to operate compared to the traditional measurement methods using a depth gauge or a feeler gauge. However, it cannot accurately simulate the protrusion and depression of the nail head, and its applicability is poor. Summary of the Invention

[0008] In order to overcome the defects of the above-mentioned prior art, the present invention provides a standard plate for detecting the unevenness of a structured light nail head and a manufacturing method thereof. The standard plate prepared by the present invention can accurately simulate the protrusion and depression of the nail head, has a simple structure, is easy to operate, and has good applicability.

[0009] The present invention is realized through the following technical solutions: A standard plate for detecting the unevenness of a structured light nail head, including a flat plate, characterized in that: the flat plate includes a first half for simulating a sunken nail head and a second half for simulating a protruding nail head, the first half and the second half are integrally formed, and the height of the first half is the same as the height of the second half.

[0010] Eight grooves are formed on the first half, and the distance between any two adjacent grooves is 30 mm.

[0011] Eight bosses are provided on the second half, and the distance between any two adjacent bosses is 30 mm.

[0012] The flat plate is an aluminum alloy plate.

[0013] A manufacturing method of a standard plate for detecting the unevenness of a structured light nail head, characterized by including the following steps: S1. Take a flat plate with a thickness of H for standby. The maximum protrusion amount of the simulated nail head is A, and the maximum depression amount of the simulated nail head is B. The H - A thickness of the flat plate is defined as the reference plane. The first half of the flat plate is used to simulate the sunken nail head, and the second half of the flat plate is used to simulate the protruding nail head; S2. Clamp the flat plate on a milling machine, and then mill the first half of the flat plate to the reference plane so that the height of the first half is lower than that of the second half; S3. Mill the second half of the flat plate to the reference plane, mill out seven bosses spaced 30 mm apart on the second half of the flat plate, remove the flat plate for polishing and anodizing to form a diffuse reflection surface on the outer surface of the flat plate, and then clamp the flat plate on the milling machine again to mill an additional boss; S4. Mill eight grooves on the first half of the flat plate, and the distance between any two adjacent grooves is 30 mm; S5. Obtain a standard plate for detecting the unevenness of a structured light nail head.

[0014] In the step S1, the area of the first half of the flat plate for simulating the sunken nail head is a machined bright surface, and the remaining area is a sprayed dark surface.

[0015] In the step S1, the area of the second half of the flat plate for simulating the protruding nail head is a sprayed dark surface, and the remaining area is a machined bright surface.

[0016] In the step S2, the height of the first half is 10 mm.

[0017] In the step S2, the height of the latter half is 11.5 mm.

[0018] In the step S5, the standard plate includes 16 simulated nail heads.

[0019] The beneficial effects of the present invention are mainly manifested in the following aspects: 1. In the present invention, the flat plate includes a first half for simulating a sunken nail head and a second half for simulating a protruding nail head. The first half and the second half are integrally formed, and the height of the first half is the same as that of the second half. Compared with the prior art, the prepared standard plate can accurately simulate the protrusion and depression of the nail head, has a simple structure, is easy to operate, and has good applicability.

[0020] 2. In the present invention, the area of the first half of the flat plate for simulating the sunken nail head is a machined bright surface, and the remaining area is a sprayed dark surface; the area of the second half of the flat plate for simulating the protruding nail head is a sprayed dark surface, and the remaining area is a machined bright surface, which can respectively simulate the situations where the nail head is brighter than the connected object and the nail head is darker than the connected object, and has good applicability.

[0021] 3. In the present invention, the entire manufacturing process only requires one global surface treatment, and there is no need to perform surface treatment on each simulated nail head one by one after machining is completed, and the preparation is simpler.

[0022] 4. In the present invention, it is convenient for a coordinate measuring machine to measure, and can simultaneously simulate four states of concave, convex, bright and dark of the nail head.

[0023] 5. In the present invention, the concave and convex states are realized by the height difference between the simulated nail head and the surrounding surface, and the bright and dark states are realized by the difference in the surface treatment method between the simulated nail head and its surrounding surface, which can better evaluate the structured light device for measuring the concave and convex amount.

[0024] 6. In the present invention, the entire manufacturing process of the standard plate is simple and efficient, which is conducive to reducing the manufacturing cost of the standard plate. Description of the Drawings

[0025] The present invention will be further specifically described below in conjunction with the drawings of the specification and the specific embodiments: Figure 1 It is a schematic structural diagram of the standard plate of the present invention; Figure 2 It is a flow block diagram for preparing the standard plate of the present invention; Markings in the figure: 1. Flat plate, 2. First half, 3. Second half, 4. Groove, 5. Boss. Specific Embodiments

[0026] Example 1 See Figure 1, A standard plate for detecting the concave-convex amount of structured light nail heads, including a flat plate 1, the flat plate 1 includes a first half 2 for simulating a concave nail head and a second half 3 for simulating a convex nail head, the first half 2 and the second half 3 are integrally formed, and the height of the first half 2 is the same as the height of the second half 3.

[0027] This embodiment is the most basic implementation method. The flat plate 1 includes a first half 2 for simulating a concave nail head and a second half 3 for simulating a convex nail head. The first half 2 and the second half 3 are integrally formed, and the height of the first half 2 is the same as the height of the second half 3. Compared with the prior art, the prepared standard plate can accurately simulate the protrusion and depression of the nail head, has a simple structure, is easy to operate, and has good applicability.

[0028] Embodiment 2 See Figure 1 , A standard plate for detecting the concave-convex amount of structured light nail heads, including a flat plate 1, the flat plate 1 includes a first half 2 for simulating a concave nail head and a second half 3 for simulating a convex nail head, the first half 2 and the second half 3 are integrally formed, and the height of the first half 2 is the same as the height of the second half 3.

[0029] Preferably, there are eight grooves 4 opened on the first half 2, and the distance between any two adjacent grooves 4 is 30 mm.

[0030] There are eight bosses 5 provided on the second half 3, and the distance between any two adjacent bosses 5 is 30 mm.

[0031] The flat plate 1 is an aluminum alloy plate.

[0032] This embodiment is a preferred implementation method. The area of the first half 2 of the plate for simulating the concave nail head is a machined bright surface, and the remaining area is a sprayed dark surface; the area of the second half 3 of the flat plate 1 for simulating the convex nail head is a sprayed dark surface, and the remaining area is a machined bright surface, which can respectively simulate the situations where the nail head is brighter than the connected object and the nail head is darker than the connected object, and has good applicability.

[0033] Embodiment 3 See Figure 1 and Figure 2 , A manufacturing method of a standard plate for detecting the concave-convex amount of structured light nail heads, including the following steps: S1. Take a flat plate 1 with a thickness of H for standby. The maximum protrusion amount of the simulated nail head is A, and the maximum depression amount of the simulated nail head is B. The H-A thickness of the flat plate 1 is defined as the reference plane. The first half 2 of the flat plate 1 is used to simulate the concave nail head, and the second half 3 of the flat plate 1 is used to simulate the convex nail head; S2. Clamp the flat plate 1 on a milling machine, and then mill the first half 2 of the flat plate 1 to the reference plane so that the height of the first half 2 is lower than that of the second half 3; S3. Mill the rear half 3 of the flat plate 1 to the reference plane, mill seven bosses 5 spaced 30 mm apart on the rear half 3 of the flat plate 1, remove the flat plate 1 for grinding and anodizing to form a diffuse reflection surface on the outer surface of the flat plate 1, and then clamp the flat plate 1 on the milling machine again to mill an additional boss 5; S4. Mill eight grooves 4 on the front half 2 of the flat plate 1, with a distance of 30 mm between any two adjacent grooves 4; S5. Prepare a standard plate for detecting the unevenness of the structured light nail head.

[0034] This embodiment is another preferred embodiment. The entire manufacturing process only requires one global surface treatment, without the need to individually simulate the nail head for surface treatment after machining is completed, making the preparation simpler.

[0035] Example 4 See Figure 1 and Figure 2 , a manufacturing method of a standard plate for detecting the unevenness of the structured light nail head, comprising the following steps: S1. Take a flat plate 1 with a thickness of H for standby. The maximum protrusion amount of the simulated nail head is A, and the maximum depression amount of the simulated nail head is B. The H - A thickness of the flat plate 1 is defined as the reference plane. The front half 2 of the flat plate 1 is used to simulate the depressed nail head, and the rear half 3 of the flat plate 1 is used to simulate the protruding nail head; S2. Clamp the flat plate 1 on the milling machine, and then mill the front half 2 of the flat plate 1 to the reference plane so that the height of the front half 2 is lower than that of the rear half 3; S3. Mill the rear half 3 of the flat plate 1 to the reference plane, mill seven bosses 5 spaced 30 mm apart on the rear half 3 of the flat plate 1, remove the flat plate 1 for grinding and anodizing to form a diffuse reflection surface on the outer surface of the flat plate 1, and then clamp the flat plate 1 on the milling machine again to mill an additional boss 5; S4. Mill eight grooves 4 on the front half 2 of the flat plate 1, with a distance of 30 mm between any two adjacent grooves 4; S5. Prepare a standard plate for detecting the unevenness of the structured light nail head.

[0036] Preferably, in step S1, the area of the front half 2 of the flat plate 1 for simulating the depressed nail head is a machined bright surface, and the remaining area is a sprayed dark surface.

[0037] This embodiment is another preferred embodiment, which is convenient for coordinate measuring machine metrology and can simultaneously simulate the four states of concave, convex, bright, and dark of the nail head.

[0038] Example 5 See Figure 1 and Figure 2, A manufacturing method of a standard plate for detecting the unevenness of a structured light nail head, comprising the following steps: S1. Prepare a flat plate 1 with a thickness of H. The maximum protrusion amount of the simulated nail head is A, and the maximum depression amount of the simulated nail head is B. The H - A thickness of the flat plate 1 is defined as the reference plane. The first half 2 of the flat plate 1 is used to simulate the depressed nail head, and the second half 3 of the flat plate 1 is used to simulate the protruding nail head; S2. Clamp the flat plate 1 on a milling machine, and then mill the first half 2 of the flat plate 1 to the reference plane so that the height of the first half 2 is lower than that of the second half 3; S3. Mill the second half 3 of the flat plate 1 to the reference plane, mill seven bosses 5 with a spacing of 30 mm from each other on the second half 3 of the flat plate 1, remove the flat plate 1 for polishing and anodizing so that the outer surface of the flat plate 1 forms a diffuse reflection surface, and then clamp the flat plate 1 on the milling machine again to mill an additional boss 5; S4. Mill eight grooves 4 on the first half 2 of the flat plate 1, and the distance between any two adjacent grooves 4 is 30 mm; S5. Obtain a standard plate for detecting the unevenness of a structured light nail head.

[0039] In the step S1, the area of the first half 2 of the flat plate 1 for simulating the depressed nail head is a machined bright surface, and the remaining area is a sprayed dark surface.

[0040] In the step S1, the area of the second half 3 of the flat plate 1 for simulating the protruding nail head is a sprayed dark surface, and the remaining area is a machined bright surface.

[0041] This embodiment is another preferred embodiment. The concave - convex state is realized by the height difference between the simulated nail head and the surrounding surface, and the bright - dark state is realized by the difference in the surface treatment method between the simulated nail head and its surrounding surface, which can better evaluate the structured light device for measuring the concave - convex amount.

[0042] Example 6 See Figure 1 and Figure 2 , A manufacturing method of a standard plate for detecting the unevenness of a structured light nail head, comprising the following steps: S1. Prepare a flat plate 1 with a thickness of H. The maximum protrusion amount of the simulated nail head is A, and the maximum depression amount of the simulated nail head is B. The H - A thickness of the flat plate 1 is defined as the reference plane. The first half 2 of the flat plate 1 is used to simulate the depressed nail head, and the second half 3 of the flat plate 1 is used to simulate the protruding nail head; S2. Clamp the flat plate 1 on a milling machine, and then mill the first half 2 of the flat plate 1 to the reference plane so that the height of the first half 2 is lower than that of the second half 3; S3. Mill the rear half 3 of the flat plate 1 to the reference plane, mill seven bosses 5 spaced 30 mm apart from each other on the rear half 3 of the flat plate 1, remove the flat plate 1 for grinding and anodic oxidation so that the outer surface of the flat plate 1 forms a diffuse reflection surface, and then clamp the flat plate 1 on the milling machine again to mill an additional boss 5. S4. Mill eight grooves 4 on the front half 2 of the flat plate 1, and the distance between any two adjacent grooves 4 is 30 mm. S5. Prepare a standard plate for detecting the unevenness of the structured light nail head.

[0043] In the step S1, the area of the front half 2 of the flat plate 1 for simulating the sunken nail head is a machined bright surface, and the remaining area is a sprayed dark surface.

[0044] In the step S1, the area of the rear half 3 of the flat plate 1 for simulating the protruding nail head is a sprayed dark surface, and the remaining area is a machined bright surface.

[0045] In the step S2, the height of the front half 2 is 10 mm.

[0046] In the step S2, the height of the rear half 3 is 11.5 mm.

[0047] In the step S5, the standard plate includes 16 simulated nail heads.

[0048] This embodiment is the best implementation mode. The entire manufacturing process of the standard plate is simple and efficient, which is conducive to reducing the manufacturing cost of the standard plate.

[0049] The specific preparation process of the standard plate of the present invention is as follows: Take an aluminum alloy blank of 150 mm * 150 mm * 20 mm, clamp it on the milling machine, make the bottom surface of the 150 mm * 150 mm aluminum alloy blank fit with the milling machine tabletop, calculate the height based on the fitting surface, and then mill the aluminum alloy blank to a height of 11.5 mm. Divide the upper surface into equal front half 2 and rear half 3, and both the front half 2 and the rear half 3 are 150 mm * 75 mm. The front half 2 is used to simulate the sunken nail head, and the rear half 3 is used to simulate the protruding nail head.

[0050] Mill the area of the front half 2 for simulating the sunken nail head to a thickness of 10 mm as a whole. A 1.5 mm step is formed between the front half 2 and the rear half 3. Then mill the area of the rear half 3 for simulating the protruding nail head, mill seven bosses 5 spaced 30 mm apart from each other on the aluminum alloy plate, and mill the area outside the bosses 5 to a thickness of 10.1 mm. Then mill the seven bosses 5 to heights of 10.2 mm, 10.3 mm, 10.4 mm, 11.1 mm, 11.2 mm, 11.3 mm, and 11.4 mm respectively.

[0051] Remove the aluminum alloy plate, grind and anodize it to make the outer surface a diffuse reflection surface with a lower reflectivity. Then, clamp the aluminum alloy plate on the milling machine again and perform secondary milling on the area simulating the protruding nail head to form a boss 5 with a height of 10.1 mm. The area outside the boss 5 is milled to a height of 10 mm, and at this time, 8 bosses 5 are produced. Finally, mill the grooves 4 in the area simulating the sunken nail head, milling grooves 4 with depths of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 1.1 mm, 1.2 mm, 1.3 mm, and 1.4 mm respectively to obtain a standard plate.

Claims

1. A standard plate for structured light nail head concave-convex quantity detection, comprising a flat plate (1), characterized in that: The plate (1) comprises a front half (2) for simulating a recessed nail head and a rear half (3) for simulating a protruding nail head, the front half (2) and the rear half (3) being integrally formed, and the height of the front half (2) is the same as the height of the rear half (3).

2. The standard plate for structured light nail head concave-convex detection according to claim 1, characterized in that: The front half (2) is provided with grooves (4), there are eight grooves (4), and the distance between any two adjacent grooves (4) is 30 mm.

3. The standard plate for structured light nail head concave-convex detection according to claim 1, characterized in that: The rear half (3) is provided with eight bosses (5), and the distance between any two adjacent bosses (5) is 30 mm.

4. The standard plate for structured light nail head concave-convex detection according to claim 1, characterized in that: The flat plate (1) is an aluminum alloy plate.

5. A method for manufacturing a standard plate for structured light nail head concave-convex detection, characterized in that: The following steps are involved: S1. Take a plate (1) with a thickness of H for use, the maximum protrusion of the simulated nail head is A, the maximum depression of the simulated nail head is B, the thickness HA of the plate (1) is defined as a reference plane, the front half (2) of the plate (1) is used to simulate a depressed nail head, and the rear half (3) of the plate (1) is used to simulate a protruding nail head; S2, clamping the plate (1) on a milling machine, and then milling the front half (2) of the plate (1) to the reference plane, so that the height of the front half (2) is lower than that of the rear half (3); S3, milling the rear half (3) of the plate (1) to the reference plane, milling seven bosses (5) spaced 30 mm apart from each other on the rear half (3) of the plate (1), removing the plate (1) for grinding and anodizing to form a diffuse reflection surface on the outer surface of the plate (1), clamping the plate (1) on the milling machine again, and milling an additional boss (5); S4. Mill eight grooves (4) on the front half (2) of the plate (1), and the distance between any two adjacent grooves (4) is 30 mm; S5. Prepare a standard plate for structured light nail head bump detection.

6. The method for manufacturing a standard plate for structured light nail head concave-convex detection according to claim 5, characterized in that: In the step S1, the area of ​​the front half (2) of the plate (1) used to simulate the recessed nail head is a machined bright surface, and the remaining area is a sprayed dark surface.

7. The method for manufacturing a standard plate for structured light nail head concave-convex detection according to claim 5, characterized in that: In the step S1, the area of ​​the rear half (3) of the plate (1) used to simulate the protruding nail head is a spray-painted dark surface, and the remaining area is a machine-painted bright surface.

8. The method for manufacturing a standard plate for structured light nail head concave-convex detection according to claim 5, characterized in that: In step S2, the height of the front half (2) is 10 mm.

9. The method for manufacturing a standard plate for structured light nail head concave-convex detection according to claim 5, characterized in that: In step S2, the height of the rear half (3) is 11.5 mm.

10. The method for manufacturing a standard plate for structured light nail head concave-convex detection according to claim 5, characterized in that: In step S5, the standard board includes 16 simulated nail heads.

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