Automatic detection system and method for coplanarity of bottom surface supporting structure

Abstract

The invention discloses an automatic detection system and method for the coplanarity of a bottom surface supporting structure. The system comprises an optical measuring head; a camera; plate glass; the optical measuring head and the camera are respectively arranged below the plate glass, the moving direction of the optical measuring head is parallel to the plate glass, a to-be-measured piece is placed on the plate glass, and the camera collects a bottom surface image of the to-be-measured piece and marks position coordinates of a to-be-measured area; the two-dimensional displacement mechanism drives the optical measuring head to measure the distance between the bottom surface measuring points of all the to-be-measured supporting structures of the to-be-measured piece and the upper surface of the plate glass in real time, and automatic coplanarity detection is achieved. Transparent plate glass is adopted as the objective table, the coplanarity of the bottom supporting structure of the to-be-measured piece can be directly measured from the lower portion, the to-be-measured piece does not need to be overturned or suspended, the measurement requirement under the natural gravity condition in actual production is met, limitation of the material of the to-be-measured piece is avoided, and the detection result has higher stability and reliability; and the method is suitable for online automatic detection of large-batch products.

Description

Technical Field

[0001] The present invention belongs to the technical field of coplanarity / flatness detection, and in particular relates to an automatic detection system and method for the coplanarity of a bottom surface support structure. Background Art

[0002] In the field of 3C manufacturing, the coplanarity / flatness of structural parts directly affects the quality of finished products and consumer experience. Strict inspection on the production line is a key link in product quality control. Optical inspection methods, such as stereoscopic vision, laser scanning, structured light and other 3D measurement methods, obtain three-dimensional data of the surface to be measured, and combine with inspection and analysis software to timely detect and mark dimensional deviations. They have the advantages of non-contact, high precision, and high efficiency, and are widely used in 3C manufacturing online inspection.

[0003] However, for the coplanarity detection of the bottom structure of the workpiece, such as the bottom support structure of a laptop computer, it is required to place the product on a flat table and detect the coplanarity of the bottom support structure under natural gravity. At present, the coplanarity detection of the above bottom support structure still relies on the traditional feeler gauge gap measurement method, which has low detection efficiency and the detection reliability depends on manual experience. For the coplanarity detection of the above bottom support structure, since the workpiece to be tested cannot be turned over or suspended in the air, there is currently no effective automated online detection method. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a system and method for automatically detecting the coplanarity of a bottom support structure.

[0005] In order to achieve the above purpose and the above technical effect, the technical solution adopted by the present invention is:

[0006] An automatic detection system for the coplanarity of a bottom support structure, comprising:

[0007] Optical probe;

[0008] Camera;

[0009] plate glass;

[0010] 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 object to be tested is placed on the flat glass. The camera collects the bottom surface image of the object to be tested and marks the position coordinates of the area to be tested. The optical probe is driven by the two-dimensional displacement mechanism to measure the distance between the bottom surface measuring points of all the bottom surface supporting structures to be tested of the object to be tested and the upper surface of the flat glass in real time, so as to realize the automatic detection of coplanarity.

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

[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 arranged 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 realize reciprocating motion in the Y-axis direction.

[0015] Furthermore, the X-axis displacement mechanism is connected to drive motor 1 and then to the control module, and the Y-axis displacement mechanism is connected to drive motor 2 and then to the control module. The control module controls the X-axis displacement mechanism and the Y-axis displacement mechanism to move to a suitable position by controlling drive motor 1 and drive motor 2.

[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 surface support structures.

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

[0018] The present invention also discloses a method for automatically detecting the coplanarity of a bottom support structure, comprising the following steps:

[0019] (1) Use the calibration plate to calibrate the camera, and establish the transformation relationship between the X, Y displacement mechanism coordinate system and the camera coordinate system through markers with known positions;

[0020] (2) placing the object to be tested on a flat glass plate, and using a camera to capture a complete bottom surface image of the object to be tested including the boundary of the object to be tested from below, and obtaining the position coordinates of the object to be tested in the X, Y displacement mechanism coordinate system according to the coordinate system conversion relationship established in step (1);

[0021] (3) rotating and resizing the collected complete bottom surface image of the test piece, performing template matching with the CAD design drawing, and marking the scanning area coordinates of the bottom support structure of the bottom of the test piece according to the position coordinates of the test piece obtained in step (2);

[0022] (4) According to 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 the bottom surface measuring points of all the bottom surface support structures 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 measured and the upper surface of the flat glass, the upper surface of the flat glass is used as a reference plane to evaluate the coplanarity of all the bottom support structures.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

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

[0026] 2) The present invention adopts a relative position measurement method, taking the upper surface of the flat glass as the reference plane or reference plane, and directly measures the distances of all the bottom surface measuring points of the bottom surface support structure of the object to be measured relative to the upper surface of the flat glass. This not only reduces the accuracy requirements for the motion mechanism, but also is more susceptible to the influence of glass surface reflection, refraction and the material of the measured surface, which may cause measurement errors. Compared with conventional optical methods, the present invention is not limited by the material of the object to be measured, does not require complex data post-processing, and has higher accuracy and better real-time performance.

[0027] 3) The present invention uses a camera to capture the bottom surface image of the test piece to obtain the two-dimensional posture coordinates of the test piece, and further performs template matching with the CAD design drawing. It can automatically determine the scanning area coordinates of the bottom support structure, and then guide the X- and Y-axis displacement mechanism to drive the optical probe to perform automatic detection, which is suitable for online automated detection of large-scale products. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0029] Figure 2-3 They are respectively schematic diagrams of coplanarity measurement of the present invention. DETAILED DESCRIPTION

[0030] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0031] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0032] like Figure 1-3 As shown, the present invention discloses an automatic 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 the present invention, the optical probe 1 is arranged below the horizontally placed flat glass 5, and 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 realize two-dimensional movement in the horizontal direction. Specifically, the optical probe 1 can follow the X-axis displacement mechanism 2 to realize reciprocating movement in the X-axis direction, and the optical probe 1 can follow the Y-axis displacement mechanism 3 to realize reciprocating movement in the Y-axis direction.

[0034] The camera 4 is located below the flat glass 5 and does not interfere with the optical probe 1 and the X-axis and Y-axis displacement mechanisms, and is used to capture the overall image of the bottom surface of the object to be measured 7 .

[0035] The workpiece 7 to be measured is placed on the flat glass 5. During measurement, the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3 drive the optical probe 1 to move to the position of the bottom support structure 6 to be measured in sequence. The light beam emitted by the optical probe 1 passes through the flat glass 5 from bottom to top and hits the bottom surface of the workpiece 7 to be measured. The optical probe 1 can measure the distance between the bottom surface of the bottom support structure 6 at the bottom of the workpiece 7 to be measured and the upper surface of the flat glass 5 in real time through the flat glass 5 to achieve 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 realize 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 surface support structures.

[0038] In some embodiments, in order to realize automated movement, the present invention connects the optical probe 1 and the camera 4 to the control module respectively, and at the same time connects the X-axis displacement mechanism 2 to the drive motor 1 and then to the control module, and connects the Y-axis displacement mechanism 3 to the drive motor 2 and then to the control module. The image data collected by the camera 4 is transmitted to the control module for processing, and 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 drive motor 1 and the drive motor 2.

[0039] In some embodiments, the control module is a conventional controller such as a single chip microcomputer, a PLC, etc.

[0040] The present invention also discloses a method for automatically detecting the coplanarity of a bottom support structure, comprising the following steps:

[0041] (1) Calibrate the camera 4 using a calibration plate, and establish the conversion relationship between the coordinate system of the X-axis displacement mechanism 2, the Y-axis displacement mechanism 3 and the camera coordinate system through markers with known positions;

[0042] (2) The test piece 7 is placed on the flat glass 5, and a camera 4 is used to capture a complete bottom surface image of the test piece 7 including the boundary of the test piece 7 from below. According to the coordinate system conversion relationship established in step (1), 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 are obtained;

[0043] (3) rotating and resizing the collected complete bottom surface image of the test piece, performing template matching with the CAD design drawing, and marking the scanning area coordinates of the bottom surface support structure 6 to be tested at the bottom 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 reciprocating motion in the X-axis direction under the control of the control module and the drive motor 1, and the optical probe 1 can follow the Y-axis displacement mechanism 3 to realize 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 the bottom surface measuring points of all the bottom surface support structures to be measured and the upper surface of the flat glass 5;

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

[0046] The optical probe 1 used in the present invention to 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] like Figure 1-3As shown, an automatic coplanarity detection system for 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 5. The optical probe 1 is a spectral confocal probe, which is arranged below the horizontally placed flat glass 5 and is mounted on the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3. The X-axis displacement mechanism 2 is arranged 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 5, and the position of the flat glass 5 in the two-dimensional coordinate system of the X-axis and Y-axis displacement mechanisms is known. The optical probe 1 can follow the X-axis displacement mechanism 2 to achieve reciprocating motion in the X-axis direction, and 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. The camera 4 is located below the flat glass 5 and does not interfere with the optical probe 1 and the X-axis and Y-axis displacement mechanisms, and is used to capture the overall image of the bottom surface of the test piece 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 surface support structures.

[0050] During measurement, the workpiece 7 to be measured is placed on the flat glass 5, and the bottom surface image of the workpiece to be measured is collected by the camera 4. The optical probe 1 is driven by the X-axis displacement mechanism 2 and the Y-axis displacement mechanism 3 to move to the position of the bottom surface support structure 6 to be measured in sequence. The light beam emitted by the optical probe 1 passes through the flat glass 5 from bottom to top and hits the bottom surface of the workpiece 7 to be measured. The optical probe 1 can measure the distance between the bottom surface of the bottom support structure 6 at the bottom of the workpiece 7 to be measured and the upper surface of the flat glass 5 in real time through the flat glass 5 to achieve coplanarity evaluation.

[0051] To realize automatic movement, the optical probe 1 and the camera 4 are connected to the control module respectively, and the X-axis displacement mechanism 2 is connected to the drive motor 1 and then connected to the control module, and the Y-axis displacement mechanism 3 is connected to the drive motor 2 and then connected to the control module. The control module is a single-chip microcomputer. 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 drive motor 1 and the drive motor 2.

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

[0053] (1) Calibrate the camera 4 using a calibration plate, and establish the conversion relationship between the coordinate system of the X-axis displacement mechanism 2, the Y-axis displacement mechanism 3 and the camera coordinate system through markers with known positions. Existing conventional technologies can be used, which will not be elaborated here;

[0054] (2) The test piece 7 is placed on the flat glass 5, and a camera 4 is used to capture a complete bottom surface image of the test piece 7 including the boundary of the test piece 7 from below. According to the coordinate system conversion relationship established in step (1), 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 are obtained;

[0055] (3) rotating and resizing the collected complete bottom surface image of the test piece, performing template matching with the CAD design drawing, and marking 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 reciprocating motion in the X-axis direction under the control of the control module and the drive motor 1, and the optical probe 1 can follow the Y-axis displacement mechanism 3 to realize 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 the bottom surface measuring points of all the bottom surface support structures to be measured and the upper surface of the flat glass 5;

[0057] (5) Based on the distances between all the bottom surface measuring points of the bottom support structures to be measured and the upper surface of the flat glass 5, the upper surface of the flat glass 5 is used as a reference plane to evaluate the coplanarity of all the bottom support structures. Among them, for determining the gap value, 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] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0059] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An automated coplanarity detection system for a bottom support structure, characterized in that: include: Optical probe; Camera; plate glass; Two-dimensional displacement mechanism; 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 object to be tested is placed on the flat glass. The camera collects the bottom surface image of the object to be tested and marks the position coordinates of the area to be tested. The optical probe is driven by the two-dimensional displacement mechanism to measure the distance between the bottom surface measuring points of all the bottom surface supporting structures to be tested of the object to be tested and the upper surface of the flat glass in real time, so as to realize the automatic detection of coplanarity.

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

3. The bottom support structure coplanarity automatic detection system 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 bottom support structure coplanarity automatic detection system according to claim 3, characterized in that: The X-axis displacement mechanism is arranged 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 realize reciprocating motion in the Y-axis direction.

5. The bottom support structure coplanarity automatic detection system according to claim 3, characterized in that: The X-axis displacement mechanism is connected to the driving motor 1 and then to the control module, and the Y-axis displacement mechanism is connected to the driving motor 2 and then to the control module. The control module controls the X-axis displacement mechanism and the Y-axis displacement mechanism to move to a suitable position by controlling the driving motor 1 and the driving motor 2.

6. The bottom support structure coplanarity automatic detection system 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 surface support structures.

7. The bottom support structure coplanarity automatic detection system according to claim 1, characterized in that: The optical probe is a spectral confocal probe.

8. A method for automatically detecting the coplanarity of a bottom support structure, characterized in that: The following steps are involved: (1) Use the calibration plate to calibrate the camera, and establish the transformation relationship between the X, Y displacement mechanism coordinate system and the camera coordinate system through markers with known positions; (2) placing the object to be tested on a flat glass plate, and using a camera to capture a complete bottom surface image of the object to be tested including the boundary of the object to be tested from below, and obtaining the position coordinates of the object to be tested in the X, Y displacement mechanism coordinate system according to the coordinate system conversion relationship established in step (1); (3) rotating and resizing the collected complete bottom surface image of the test piece, performing template matching with the CAD design drawing, and marking the scanning area coordinates of the bottom support structure of the bottom of the test piece according to the position coordinates of the test piece obtained in step (2); (4) According to 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 the bottom surface measuring points of all the bottom surface support structures 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 measured and the upper surface of the flat glass, the upper surface of the flat glass is used as a reference plane to evaluate the coplanarity of all the bottom support structures.

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