Automated coplanarity inspection system and method for bottom support structure

Abstract

Disclosed are an automated coplanarity inspection system and method for a bottom support structure. The system comprises: an optical probe, a camera, and a flat glass, wherein the optical probe and the camera each are arranged below the flat glass; the movement direction of the optical probe is parallel to the flat glass; a workpiece under inspection is placed on the flat glass; an image of the bottom of said workpiece is collected by means of the camera and position coordinates of a region under inspection are marked; the optical probe is driven by a two-dimensional displacement mechanism to measure, in real time, the distances between all inspection points on the bottom of a support structure under inspection of said workpiece and the upper surface of the flat glass, thereby achieving automated coplanarity inspection. In the present invention, a transparent flat glass is used as a stage, so that the coplanarity of a bottom support structure of a workpiece under inspection can be directly measured from below, and it is not necessary to invert or suspend said workpiece, thereby satisfying the requirements for measurement under natural gravity conditions in actual production; moreover, the present invention is not limited by the workpiece material and provides high-stability and high-reliability inspection results, making it suitable for online automated inspection of mass-produced products.

Description

A bottom surface support structure coplanarity automatic detection system and method TECHNICAL FIELD

[0001] The present application belongs to the technical field of coplanarity / flatness detection, and particularly relates to a bottom surface support structure coplanarity automatic detection system and method. BACKGROUND

[0002] In the field of 3C manufacturing, the coplanarity / flatness of a structural part directly affects the quality of finished products and consumer experience, and strict detection of the coplanarity / flatness on the production line is a key link in product quality control. Optical detection methods, such as stereovision, laser scanning, and structured light 3D measurement methods, acquire three-dimensional data of the surface to be detected, combine detection and analysis software to discover size deviations in a timely manner and mark them, and have the advantages of non-contact, high precision, and high efficiency, and are widely used in online detection in 3C manufacturing.

[0003] However, for coplanarity detection of the bottom structure of a workpiece, such as the bottom surface support structure of a notebook computer, the product is required to be placed on a flat table, and the coplanarity of the bottom surface support structure is detected under the condition of natural gravity. At present, the coplanarity detection of the above-mentioned bottom support structure still relies on the traditional feeler gauge gap detection method, which has low detection efficiency and detection reliability depends on manual experience. For coplanarity detection of the above-mentioned bottom support structure, since the workpiece to be detected cannot be turned over or hung, there is currently no effective automatic online detection method. SUMMARY

[0004] To solve the technical problems existing in the prior art, the purpose of the present application is to provide a bottom surface support structure coplanarity automatic detection system and method.

[0005] To achieve the above-mentioned purposes and achieve the above-mentioned technical effects, the technical solution adopted by the present application is as follows:

[0006] A bottom surface support structure coplanarity automatic detection system, comprising:

[0007] an optical probe;

[0008] a camera;

[0009] a flat glass;

[0010] a two-dimensional displacement mechanism;

[0011] The optical probe and the camera are respectively arranged below the flat glass, the movement direction of the optical probe is parallel to the flat glass, the workpiece to be detected is placed on the flat glass, the camera is used to acquire an image of the bottom surface of the workpiece to be detected and mark the position coordinates of the detection area, the two-dimensional displacement mechanism is used to drive the optical probe to measure the distance between all bottom surface support structure bottom surface measurement points of the workpiece to be detected and the upper surface of the flat glass in real time, and coplanarity automatic detection is realized.

[0012] Furthermore, the system also includes a control module, to which the optical probe and camera are respectively connected.

[0013] Furthermore, the two-dimensional displacement mechanism includes an X-axis displacement mechanism and a Y-axis displacement mechanism. The optical probe is mounted on the X-axis displacement mechanism and the Y-axis displacement mechanism. The movement directions of the X-axis displacement mechanism and the Y-axis displacement mechanism are parallel to the flat glass. The optical probe can follow the X-axis displacement mechanism to achieve reciprocating motion in the X-axis direction, and the optical probe can follow the Y-axis displacement mechanism to achieve reciprocating motion in the Y-axis direction.

[0014] Furthermore, the X-axis displacement mechanism is mounted on the Y-axis displacement mechanism, and the X-axis displacement mechanism and the optical probe thereon can follow the Y-axis displacement mechanism to achieve reciprocating motion in the Y-axis direction.

[0015] Furthermore, the X-axis displacement mechanism is connected to drive motor one and then to the control module, and the Y-axis displacement mechanism is connected to drive motor two and then to the control module. The control module controls drive motor one and drive motor two to move the X-axis displacement mechanism and the Y-axis displacement mechanism to a suitable position.

[0016] Furthermore, the working distance of the optical probe is greater than the thickness of the flat glass, and the measuring range of the optical probe is greater than the height difference between the highest and lowest bottom support structures.

[0017] Furthermore, the optical probe is a spectral confocal probe.

[0018] This invention also discloses an automated method for detecting the coplanarity of a bottom support structure, comprising the following steps:

[0019] (1) Use a calibration board to calibrate the camera and establish the transformation relationship between the X and Y displacement mechanism coordinate system and the camera coordinate system by using markers at known positions;

[0020] (2) Place the test piece on a flat glass plate and use a camera to capture a complete bottom image of the test piece, including the boundary of the test piece. Based on the coordinate system transformation relationship established in step (1), obtain the position coordinates of the test piece in the X and Y displacement mechanism coordinate system.

[0021] (3) Rotate and scale the collected complete bottom surface image of the test piece, match it with the CAD design drawing, and mark the scanning area coordinates of the bottom support structure of the test piece according to the position coordinates of the test piece obtained in step (2).

[0022] (4) Based on the marked scanning area coordinates, the X-axis displacement mechanism and the Y-axis displacement mechanism drive the optical probe to measure the distance between all the bottom surface measuring points of the bottom support structure to be measured and the upper surface of the flat glass.

[0023] (5) Based on the distances between the bottom surface measuring points of all the bottom support structures to be tested and the upper surface of the flat glass, the coplanarity of all the bottom support structures is evaluated using the upper surface of the flat glass as the reference surface.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1) This invention uses a transparent flat glass as a stage, which can directly measure the bottom support structure of the test piece from below without flipping or suspending the test piece. This meets the measurement requirements under natural gravity conditions in actual production. Compared with conventional feeler gauge testing or other methods of detecting gaps from the side, this invention can directly measure the coplanarity of the bottom support structure, and the test results have higher stability and reliability.

[0026] 2) This invention employs a relative position measurement method, using the upper surface of the flat glass as a reference plane or datum plane, to directly measure the distances of all the measuring points on the bottom support structure of the test object relative to the upper surface of the flat glass. This not only reduces the accuracy requirements of the motion mechanism, but also, compared to conventional optical methods which are easily affected by glass surface reflection, refraction, and the material of the measured surface, resulting in measurement errors, this invention is not limited by the material of the test object, does not require complex data post-processing, and has higher accuracy and better real-time performance.

[0027] 3) This invention uses a camera to capture images of the bottom surface of the part under test, obtains the two-dimensional pose coordinates of the part under test, and further matches them with the CAD design drawing to automatically determine the scanning area coordinates of the bottom support structure. This then guides the X and Y axis displacement mechanism to drive the optical probe for automatic detection, making it suitable for online automated detection of mass products. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the structure of the present invention;

[0029] Figures 2-3 are schematic diagrams of the coplanarity measurement of the present invention. Detailed Implementation

[0030] The present invention will now be described in detail so that its advantages and features can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0031] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0032] As shown in Figures 1-3, the present invention discloses an automated detection system for the coplanarity of a bottom support structure, comprising: an optical probe 1, an X-axis displacement mechanism 2, a Y-axis displacement mechanism 3, a camera 4, and a flat glass 5.

[0033] In this invention, the optical probe 1 is positioned below the horizontally placed flat glass 5. The optical probe 1 is mounted on the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3. The movement directions of the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3 are parallel to the flat glass 5. The optical probe 1 can achieve two-dimensional movement in the horizontal direction. Specifically, the optical probe 1 can follow the X-axis displacement mechanism 2 to achieve reciprocating movement in the X-axis direction, and the optical probe 1 can follow the Y-axis displacement mechanism 3 to achieve reciprocating movement in the Y-axis direction.

[0034] Camera 4 is located below the flat glass 5 and does not interfere with the optical probe 1 and the X and Y axis displacement mechanism. It is used to capture an overall image of the bottom surface of the part under test 7.

[0035] The test piece 7 is placed on the flat glass plate 5. During measurement, the optical probe 1 is moved sequentially to the position of the bottom support structure 6 of the test piece 7 by the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3. The light beam emitted by the optical probe 1 passes through the flat glass plate 5 and hits the bottom surface of the test piece 7 from bottom to top. The optical probe 1 can measure the distance between the bottom surface of the bottom support structure 6 of the test piece 7 and the upper surface of the flat glass plate 5 in real time through the flat glass plate 5, so as to realize the coplanarity evaluation.

[0036] In some embodiments, the X-axis displacement mechanism 2 is disposed on the Y-axis displacement mechanism 3, so that the X-axis displacement mechanism 2 and the optical probe 1 thereon can follow the Y-axis displacement mechanism 3 to achieve reciprocating motion in the Y-axis direction.

[0037] The working distance of the optical probe 1 is greater than the thickness of the flat glass 5, and the measuring range of the optical probe 1 is greater than the height difference between the highest and lowest bottom support structures.

[0038] In some embodiments, to achieve automated movement, the present invention connects the optical probe 1 and the camera 4 to the control module respectively. At the same time, the X-axis displacement mechanism 2 is connected to the first drive motor and then to the control module, and the Y-axis displacement mechanism 3 is connected to the second drive motor and then to the control module. The image data collected by the camera 4 is transmitted to the control module for processing. The control module controls the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3 to move to the appropriate position by controlling the first drive motor and the second drive motor.

[0039] In some implementations, the control module is a conventional controller such as a microcontroller or PLC.

[0040] This invention also discloses an automated method for detecting the coplanarity of a bottom support structure, comprising the following steps:

[0041] (1) Use a calibration board to calibrate camera 4, and establish the transformation relationship between the coordinate systems of X-axis displacement mechanism 2 and Y-axis displacement mechanism 3 and the camera coordinate system by using markers at known positions;

[0042] (2) Place the test piece 7 on the flat glass 5, and use the camera 4 to capture a complete bottom image of the test piece 7 including its boundary from below. Based on the coordinate system transformation relationship established in step (1), obtain the position coordinates of the test piece 7 in the coordinate systems of the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3.

[0043] (3) Rotate and scale the collected complete bottom surface image of the test piece, match it with the CAD design drawing, and mark the scanning area coordinates of the bottom support structure 6 of the test piece 7 according to the position coordinates of the test piece 7 in step (2).

[0044] (4) According to the marked scanning area coordinates, the optical probe 1 can follow the X-axis displacement mechanism 2 to realize the reciprocating motion in the X-axis direction under the control of the control module and the drive motor 1. The optical probe 1 can follow the Y-axis displacement mechanism 3 to realize the reciprocating motion in the Y-axis direction under the control of the control module and the drive motor 1. The X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3 drive the optical probe 1 to measure the distance between all the bottom surface measurement points of the bottom support structure to be measured and the upper surface of the flat glass 5.

[0045] (5) Based on the distances between the bottom surface measuring points of all the bottom support structures to be tested and the upper surface of the flat glass 5, the coplanarity of all bottom support structures is evaluated using the upper surface of the flat glass 5 as the reference surface. Among them, the minimum distance between the bottom surface of the bottom support structure 6 to be tested and the upper surface of the flat glass 5 is used as the gap value for determining the gap value.

[0046] The optical probe 1 used in this invention, which can directly measure the distance between the upper surface of the flat glass 5 and the bottom surface of the bottom support structure 6, is a spectral confocal probe or a probe based on other optical principles.

[0047] Example 1

[0048] As shown in Figures 1-3, an automated detection system for the coplanarity of a bottom support structure includes: an optical probe 1, an X-axis displacement mechanism 2, a Y-axis displacement mechanism 3, a camera 4, and a flat glass plate 5. The optical probe 1 is a spectral confocal probe, positioned below the horizontally placed flat glass plate 5 and mounted on the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3. The X-axis displacement mechanism 2 is mounted on the Y-axis displacement mechanism 3. The movement directions of the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3 are parallel to the flat glass plate 5, and the position of the flat glass plate 5 in the two-dimensional coordinate system of the X and Y axes is known. The optical probe 1 can reciprocate along the X-axis direction following the X-axis displacement mechanism 2, and the X-axis displacement mechanism 2 and the optical probe 1 on it can reciprocate along the Y-axis direction following the Y-axis displacement mechanism 3. The camera 4 is located below the flat glass plate 5 and does not interfere with the optical probe 1 or the X and Y axis displacement mechanisms; it is used to capture an overall image of the bottom surface of the part under test 7.

[0049] The working distance of the optical probe 1 is greater than the thickness of the flat glass 5, and the measuring range of the optical probe 1 is greater than the height difference between the highest and lowest bottom support structures.

[0050] During measurement, the test piece 7 is placed on the flat glass plate 5, and the bottom surface image of the test piece is captured by the camera 4. The optical probe 1 is moved sequentially to the position of the bottom support structure 6 of the test piece by the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3. The light beam emitted by the optical probe 1 passes through the flat glass plate 5 and hits the bottom surface of the test piece 7 from bottom to top. The optical probe 1 can measure the distance between the bottom surface of the bottom support structure 6 of the test piece 7 and the upper surface of the flat glass plate 5 in real time through the flat glass plate 5, so as to realize the coplanarity evaluation.

[0051] To achieve automated movement, optical probe 1 and camera 4 are connected to the control module. At the same time, X-axis displacement mechanism 2 is connected to drive motor 1 and then to the control module, and Y-axis displacement mechanism 3 is connected to drive motor 2 and then to the control module. The control module is a microcontroller. The image data collected by camera 4 is transmitted to the control module for processing. The control module controls drive motor 1 and drive motor 2 to move X-axis displacement mechanism 2 and Y-axis displacement mechanism 3 to the appropriate position.

[0052] An automated method for detecting the coplanarity of a bottom support structure includes the following steps:

[0053] (1) Use a calibration board to calibrate camera 4. Establish the transformation relationship between the coordinate systems of X-axis displacement mechanism 2 and Y-axis displacement mechanism 3 and the camera coordinate system by using markers at known positions. Existing conventional techniques can be used, and will not be elaborated here.

[0054] (2) Place the test piece 7 on the flat glass 5, and use the camera 4 to capture a complete bottom image of the test piece 7 including its boundary from below. Based on the coordinate system transformation relationship established in step (1), obtain the position coordinates of the test piece 7 in the coordinate systems of the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3.

[0055] (3) Rotate and scale the collected complete bottom surface image of the test piece, match it with the CAD design drawing, and mark the scanning area coordinates of the bottom support structure 6 at the bottom of the test piece 7 according to the position coordinates of the test piece 7 in step (2).

[0056] (4) According to the marked scanning area coordinates, the optical probe 1 can follow the X-axis displacement mechanism 2 to realize the reciprocating motion in the X-axis direction under the control of the control module and the drive motor 1. The optical probe 1 can follow the Y-axis displacement mechanism 3 to realize the reciprocating motion in the Y-axis direction under the control of the control module and the drive motor 1. The X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3 drive the optical probe 1 to measure the distance between all the bottom surface measurement points of the bottom support structure to be measured and the upper surface of the flat glass 5.

[0057] (5) Based on the distances between the bottom surface measuring points of all the bottom support structures to be tested and the upper surface of the flat glass 5, the coplanarity of all bottom support structures is evaluated using the upper surface of the flat glass 5 as the reference surface. Among them, the minimum distance between the bottom surface of the bottom support structure 6 and the upper surface of the flat glass 5 among all the measuring points is used as the gap value.

[0058] Any parts or structures not specifically described in this invention can be made using existing technologies or products, and will not be elaborated upon here.

[0059] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An automated detection system for the coplanarity of a bottom support structure, characterized in that, include: Optical probe; Camera; plate glass; Two-dimensional displacement mechanism; The optical probe and camera are respectively positioned below the flat glass. The optical probe moves in a direction parallel to the flat glass. The part to be tested is placed on the flat glass. The camera captures images of the bottom surface of the part to be tested and marks the coordinates of the area to be tested. A two-dimensional displacement mechanism drives the optical probe to measure the distance between all the bottom surface measurement points of the bottom support structure of the part to be tested and the upper surface of the flat glass in real time, thereby realizing automated detection of coplanarity.

2. The automated detection system for the coplanarity of a bottom support structure according to claim 1, characterized in that, It also includes a control module, to which the optical probe and camera are respectively connected.

3. The automated detection system for the coplanarity of a bottom support structure according to claim 1, characterized in that, The two-dimensional displacement mechanism includes an X-axis displacement mechanism and a Y-axis displacement mechanism. The optical probe is mounted on the X-axis displacement mechanism and the Y-axis displacement mechanism. The movement directions of the X-axis displacement mechanism and the Y-axis displacement mechanism are parallel to the flat glass. The optical probe can follow the X-axis displacement mechanism to achieve reciprocating motion in the X-axis direction, and the optical probe can follow the Y-axis displacement mechanism to achieve reciprocating motion in the Y-axis direction.

4. The automated detection system for the coplanarity of a bottom support structure according to claim 3, characterized in that, The X-axis displacement mechanism is mounted on the Y-axis displacement mechanism, and the X-axis displacement mechanism and the optical probe on it can follow the Y-axis displacement mechanism to achieve reciprocating motion in the Y-axis direction.

5. The automated detection system for the coplanarity of a bottom support structure according to claim 3, characterized in that, The X-axis displacement mechanism is connected to drive motor one and then to the control module. The Y-axis displacement mechanism is connected to drive motor two and then to the control module. The control module controls drive motor one and drive motor two to move the X-axis displacement mechanism and the Y-axis displacement mechanism to a suitable position.

6. The automated detection system for the coplanarity of a bottom support structure according to claim 1, characterized in that, The working distance of the optical probe is greater than the thickness of the flat glass, and the measuring range of the optical probe is greater than the height difference between the highest and lowest bottom support structures.

7. The automated detection system for the coplanarity of a bottom support structure according to claim 1, characterized in that, The optical probe is a spectral confocal probe.

8. An automated method for detecting the coplanarity of a bottom support structure, characterized in that, Includes the following steps: (1) Use a calibration board to calibrate the camera and establish the transformation relationship between the X and Y displacement mechanism coordinate system and the camera coordinate system by using markers at known positions; (2) Place the test piece on a flat glass plate and use a camera to capture a complete bottom image of the test piece, including the boundary of the test piece. Based on the coordinate system transformation relationship established in step (1), obtain the position coordinates of the test piece in the X and Y displacement mechanism coordinate system. (3) Rotate and scale the collected complete bottom surface image of the test piece, match it with the CAD design drawing, and mark the scanning area coordinates of the bottom support structure of the test piece according to the position coordinates of the test piece obtained in step (2). (4) Based on the marked scanning area coordinates, the X-axis displacement mechanism and the Y-axis displacement mechanism drive the optical probe to measure the distance between all the bottom surface measuring points of the bottom support structure to be measured and the upper surface of the flat glass. (5) Based on the distances between the bottom surface measuring points of all the bottom support structures to be tested and the upper surface of the flat glass, the coplanarity of all the bottom support structures is evaluated using the upper surface of the flat glass as the reference surface.

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