A digital twin visual inspection device and inspection method for complex three-dimensional multi-through-hole parts

Abstract

The present invention relates to the field of visual inspection technology, specifically to a digital twin visual inspection device for complex three-dimensional multi-through-hole parts, comprising an annular device box with an opening arranged upward, a first drive motor, a second drive motor, a third drive motor, and a zoom camera; the first drive motor is used to drive the top plate to move 360° along the side wall of the annular device box; the second drive motor is used to drive the storage plate to move up and down along the vertical guide rail; the third drive motor is installed on the storage plate, and a rotating plate is installed on the output shaft of the third drive motor, and the zoom camera is installed on the rotating plate. The present invention also provides a detection method for the digital twin visual inspection device to perform complex three-dimensional multi-through-hole part detection. The visual inspection device and the detection method can realize 360° viewing angle shooting of the parts to be tested placed in the annular device box, adapt to the visual inspection of parts of different sizes, and improve the detection efficiency of complex three-dimensional multi-through-hole parts.

Description

Technical Field

[0001] The present invention relates to the field of visual inspection technology, and in particular to a digital twin visual inspection device for complex three-dimensional parts with multiple through holes. Background Art

[0002] With the development of industry, many components are being manufactured in a single process to improve overall rigidity and equipment performance. An increasing number of parts are becoming complex and porous. These components are often critical force-transmitting components within the equipment, requiring strict machining accuracy. Beyond diameter, through-hole measurements on complex parts also require precise positioning and angle, which directly impacts part assembly quality.

[0003] However, due to its complex structure, the hole position and hole orientation form a complex three-dimensional vector. When the part's orientation changes, the hole's orientation vector also changes. In actual measurement, it is difficult to visually inspect a part within a 360° sphere. Therefore, the visual inspection process inevitably requires flipping the part and measuring it from multiple angles. This process is extremely complex during automated inspection. Based solely on image recognition and calculation, the part is photographed from various angles, which is both inefficient and prone to omissions. Therefore, it is difficult to directly apply currently used visual inspection techniques for parts. During the measurement process, the camera must change multiple positions and angles in three-dimensional space to accurately observe the part's holes and measure their diameter, spatial position, and hole orientation. Current visual inspection techniques typically only perform simple diameter measurements at fixed angles, without strictly considering orientation information or hole orientation. In light of this, we propose a digital twin visual inspection device and method for complex three-dimensional parts with multiple through holes. Summary of the Invention

[0004] The purpose of the present invention is to provide a digital twin visual inspection device and an inspection method for complex three-dimensional multi-through-hole parts to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A digital twin visual inspection device for complex three-dimensional multi-through-hole parts includes an annular device case with an upward opening, a first drive motor, a second drive motor, a third drive motor, and a zoom camera; a top connecting plate is provided in the annular device case, a vertical guide rail is fixed to the bottom surface of the top connecting plate, and a storage plate is provided on the vertical guide rail; the first drive motor is installed on the top connecting plate, and is used to drive the top connecting plate to move 360° along the side wall of the annular device case; the second drive motor is installed on the bottom wall of the annular device case, and is used to drive the storage plate to move up and down along the vertical guide rail; the third drive motor is installed on the storage plate, and a rotating plate is installed on the output shaft of the third drive motor, and the zoom camera is installed on the rotating plate.

[0007] Preferably, a guide groove is provided on the side wall of the annular device housing, a slider is connected to the output end of the first drive motor, and the slider is slidably connected in the guide groove.

[0008] Preferably, the placement plate is provided with a through hole for passing the vertical guide rail, and the placement plate is also provided with a screw hole, the output end of the second drive motor is connected to a screw rod, and the screw rod is screwed onto the placement plate through the screw hole.

[0009] Preferably, a measuring platform for placing parts to be measured is further provided in the middle of the bottom wall of the annular equipment box.

[0010] The present invention also provides a detection method for detecting complex three-dimensional multi-through-hole parts using the digital twin visual inspection device, comprising the following steps:

[0011] Step 1:

[0012] Step 11: Use a zoom camera to take photos of the actual part from multiple angles, and search the database for matching part models based on a neural network.

[0013] Step 12: Automatically open the 3D CAD software to load the part model, and use OpenCV image matching to rotate and move the part model to the same 3D coordinate system as the actual part;

[0014] Step 2:

[0015] Step 21: Set the 3D CAD software background to white and the part to black. Based on the VTK coordinate system, focus on the part center point and position the zoom camera 3-5 times the longest side distance from the part center. Acquire images of the 3D digital model at intervals of 10°-30°.

[0016] Step 22: Analyze each obtained image based on OpenCV to see if there are features that appear to be holes. If so, it is a suspected through hole.

[0017] Step 23: Since each image is obtained based on the VTK coordinate system, it is easy to locate the zoom camera position, focus, and positive normal direction corresponding to the image; keep the zoom camera position and positive normal direction fixed, and search and move the focus position within the coordinate range of the part at a certain step length. Save an image of a certain resolution at each step, and process the image to analyze whether the exposed white area is getting larger and whether there is a trend of showing an arc edge line; if a suspected arc edge line is found, the search step length is reduced and the camera position is gradually moved closer; when the exposed white area is a perfect circle, the through hole is found; the Python script simulates the mouse operation of some CAD software functions to automatically obtain the center point coordinates of the hole. Combined with the camera position and OpenCV, the diameter of the hole can be obtained. The line connecting the camera position and the center point coordinates of the hole is the normal direction of the hole;

[0018] Step 24: Through the above cycle, the system automatically obtains the position, direction and size of each through hole;

[0019] Step 3:

[0020] Step 31: Based on the obtained position, direction, and size of each through hole, the camera is driven to move to the corresponding position, and the shooting range is changed by the zoom lens to take pictures;

[0021] Step 32: Combine OpenCV to measure the size of the hole and determine the roundness of the hole, and give a detection conclusion.

[0022] Compared with the existing technology, the beneficial effects of the present invention are: the digital twin visual inspection equipment for complex three-dimensional multi-through-hole parts can realize 360-degree viewing angle shooting of the parts to be tested placed in the ring-shaped equipment box. At the same time, the shooting height and pitch angle of the zoom camera can be adjusted to adapt to the visual inspection of parts of different sizes, thereby improving the inspection efficiency of complex three-dimensional multi-through-hole parts;

[0023] At the same time, the detection method provided by the present invention uses a zoom camera 5 to take photos of actual parts at multiple angles, searches for matching part digital models in the database based on a neural network, and then uses three-dimensional software and OpenCV for image processing to determine the hole size and roundness of complex three-dimensional multi-through-hole parts, and gives a detection conclusion. Different parts can be measured and inspected in batches without changing the system program, which is beneficial to part assembly. After a group of parts that need to be assembled are inspected, simulated assembly can be performed to improve assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2It is a cross-sectional view of the overall structure of the present invention;

[0026] Figure 3 For the present invention Figure 2 A magnified view of the structure at center A;

[0027] Figure 4 This is a schematic diagram of the installation structure of the first drive motor, the second drive motor, and the third drive motor in the present invention;

[0028] Figure 5 Schematic diagram of the structure of the storage plate of the present invention.

[0029] In the figure: 1. Annular equipment box; 11. Top plate; 12. Vertical guide rail; 13. Storage plate; 131. Through hole; 132. Screw hole; 14. Guide groove; 2. First drive motor; 21. Slider; 3. Second drive motor; 31. Screw; 4. Third drive motor; 41. Rotating plate; 5. Zoom camera; 6. Measuring platform. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to 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 invention 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 should not be understood as limiting the present invention.

[0032] In the description of this patent, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "set" should be understood in a broad sense. For example, they can refer to fixed connection or set, detachable connection or set, or integral connection or set. Those skilled in the art will understand the specific meanings of the above terms in this patent based on the specific circumstances.

[0033] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, a feature identified as "first," "second," or "third" may explicitly or implicitly include one or more of the features.

[0034] Example 1

[0035] See also Figure 1-Figure 5 As shown, the present invention provides a technical solution:

[0036] A digital twin visual inspection device for complex three-dimensional multi-through-hole parts includes an annular device case 1 with an opening upward, a first drive motor 2, a second drive motor 3, a third drive motor 4, and a zoom camera 5; a top connecting plate 11 is provided in the annular device case 1, a vertical guide rail 12 is fixed to the bottom surface of the top connecting plate 11, and a storage plate 13 is provided on the vertical guide rail 12; the first drive motor 2 is installed on the top connecting plate 11, and is used to drive the top connecting plate 11 to move 360° along the side wall of the annular device case 1; the second drive motor 3 is installed on the bottom wall of the annular device case 1, and is used to drive the storage plate 13 to move up and down along the vertical guide rail 12; the third drive motor 4 is installed on the storage plate 13, and a rotating plate 41 is installed on the output shaft of the third drive motor 4, and the zoom camera 5 is installed on the rotating plate 41. Therefore, the visual inspection equipment can realize 360° viewing angle shooting of the parts to be tested placed in the annular equipment box 1. At the same time, the shooting height and shooting pitch angle of the zoom camera 5 can be adjusted so that it can adapt to parts of different sizes for visual inspection, thereby improving the inspection efficiency of complex three-dimensional multi-through-hole parts.

[0037] It is worth noting that a guide groove 14 is provided on the side wall of the annular device housing 1. A slider 21 is connected to the output end of the first drive motor 2, and the slider 21 is slidably connected within the guide groove 14. Since the top plate 11 is fixed in a vertical position within the annular device housing 1, when the first drive motor 2 is in operation, the slider 21 slides along the guide groove 14, thereby pulling the zoom camera 5 to achieve 360° photography.

[0038] Furthermore, the storage plate 13 is provided with a through hole 131 for passing through the vertical guide rail 12, and the storage plate 13 is also provided with a screw hole 132. The output end of the second drive motor 3 is connected to a screw rod 31, and the screw rod 31 is screwed to the storage plate 13 through the screw hole 132. Since the vertical guide rail 12 positions the storage plate 13, when the second drive motor 3 is in operation, the screw rod 31 on its output end rotates in the screw hole 132, converting its power output into a linear motion of the storage plate 13 along the vertical guide rail 12. In this embodiment, as shown in FIG. Figure 4 As shown, the vertical guide rail 12 can be symmetrically provided with two counter-plates 13 for limiting the position.

[0039] In addition, a measuring platform 6 for placing parts to be measured is also provided in the middle of the bottom wall of the annular device box 1. It is convenient to place the parts to be measured on the measuring platform 6 and to facilitate the taking of parts.

[0040] Example 2

[0041] The present invention also provides a detection method for using the digital twin visual inspection device to detect complex three-dimensional multi-through-hole parts, comprising the following steps:

[0042] Step 1:

[0043] Step 11: Use the zoom camera 5 to take photos of the actual part at multiple angles, and search for matching part digital models in the database based on the neural network;

[0044] Step 12: Automatically open the 3D CAD software (which can be UG, CATIA or other 3D software) to load the part digital model, and use OpenCV image matching to rotate and move the part digital model to the same 3D coordinate system as the actual part;

[0045] Step 2:

[0046] Step 21: Set the 3D CAD software background to white and the part to black. Based on the VTK coordinate system, focus on the part center point and position the zoom camera 5 at a distance 3-5 times the longest side distance from the part center. Obtain images of the 3D model at a certain resolution at intervals of 10°-30°. Depending on the part structure and hole size, the resolution range is 500x500 to 3000x3000.

[0047] Step 22: Analyze each obtained image based on OpenCV to see if there are features that appear to be holes. If so, it is a suspected through hole.

[0048] Step 23: Since each image is obtained based on the VTK coordinate system, it is easy to locate the zoom camera 5 position, focus and positive normal direction corresponding to the image; keep the zoom camera 5 position and positive normal direction fixed, and search and move the focus position within the coordinate range of the part at a certain step length. Save a picture of a certain resolution at each step, and process and analyze the picture to see whether the exposed white area is getting larger and whether there is a trend of showing an arc edge line; if a suspected arc edge line is found, the search step length is reduced and the camera position is gradually moved closer; when the exposed white area is a perfect circle, the through hole is found; the Python script simulates the mouse operation of some CAD software functions to automatically obtain the center point coordinates of the hole. Combined with the camera position and OpenCV, the diameter of the hole can be obtained. The line connecting the camera position and the center point coordinates of the hole is the normal direction of the hole;

[0049] Step 24: Through the above cycle, the system automatically obtains the position, direction and size of each through hole;

[0050] Step 3:

[0051] Step 31: Based on the obtained position, direction, and size of each through hole, the camera is driven to move to the corresponding position, and the shooting range is changed by the zoom lens to take pictures;

[0052] Step 32: Combine OpenCV to measure the size of the hole and determine the roundness of the hole, and give a detection conclusion.

[0053] When the digital twin visual inspection device for complex three-dimensional multi-through-hole parts of this embodiment is in use, since the top plate 11 is fixed in a vertical position in the annular device housing 1, when the first drive motor 2 is in operation, the slider 21 slides along the guide groove 14, thereby pulling the zoom camera 5 to perform 360° shooting. Since the vertical guide rail 12 positions the storage plate 13, when the second drive motor 3 is in operation, the screw 31 on its output end rotates in the screw hole 132, converting its power output into a linear motion of the storage plate 13 along the vertical guide rail 12. At the same time, when the output end of the third drive motor 4 is in operation, it can drive the zoom camera 5 on the rotating plate 41 to flip, thereby changing its shooting pitch angle. Therefore, the visual inspection device can realize 360° shooting of the part to be tested placed in the annular device housing 1. At the same time, the shooting height and shooting pitch angle of the zoom camera 5 can be adjusted so that it can adapt to parts of different sizes for visual inspection, thereby improving the inspection efficiency of complex three-dimensional multi-through-hole parts.

[0054] At the same time, the detection method provided by the present invention uses a zoom camera 5 to take photos of actual parts at multiple angles, searches for matching part digital models in the database based on a neural network, and then uses three-dimensional software and OpenCV for image processing to determine the hole size and roundness of complex three-dimensional multi-through-hole parts, and gives a detection conclusion. Different parts can be measured and inspected in batches without changing the system program, which is beneficial to part assembly. After a group of parts that need to be assembled are inspected, simulated assembly can be performed to improve assembly efficiency.

[0055] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A digital twin visual inspection method for complex three-dimensional multi-through-hole parts, used for digital twin visual inspection equipment to inspect complex three-dimensional multi-through-hole parts, characterized in that: The digital twin visual inspection device comprises: an annular device box (1) with an opening arranged upward, a first drive motor (2), a second drive motor (3), a third drive motor (4), and a zoom camera (5); A top connecting plate (11) is provided in the annular device box (1), a vertical guide rail (12) is fixed to the bottom surface of the top connecting plate (11), and a storage plate (13) is provided on the vertical guide rail (12); The first drive motor (2) is mounted on the top connecting plate (11) and is used to drive the top connecting plate (11) to move 360° along the side wall of the annular device housing (1); The second drive motor (3) is mounted on the bottom wall of the annular device housing (1) and is used to drive the storage plate (13) to move up and down along the vertical guide rail (12); The third drive motor (4) is mounted on the storage plate (13), and a rotating plate (41) is mounted on the output shaft of the third drive motor (4), and the zoom camera (5) is mounted on the rotating plate (41); The detection method comprises the following steps: Step 1: Step 11: Use the zoom camera (5) to take photos of the actual part at multiple angles, and search for matching part models in the database based on the neural network; Step 12: Automatically open the 3D CAD software to load the part model, and use OpenCV image matching to rotate and move the part model to the same 3D coordinate system as the actual part; Step 2: Step 21: Set the 3D CAD software background to white and the part to black. Based on the VTK coordinate system, with the center point of the part as the focus, the zoom camera (5) is positioned 3-5 times the longest side distance from the center of the part; and obtain images of the 3D digital model at intervals of 10°-30°. Step 22: Analyze each obtained image based on OpenCV to see if there are features that appear to be holes. If so, it is a suspected through hole. Step 23: Since each image is obtained based on the VTK coordinate system, the zoom camera (5) position, focus and positive normal direction corresponding to the image can be located; the zoom camera (5) position and positive normal direction are kept stationary, and the focus position is searched and moved at a certain step length within the coordinate range of the part, and a picture of a certain resolution is saved at each step. The picture is processed and analyzed to see whether the exposed white area becomes larger and whether there is a trend of showing an arc edge line; if a suspected arc edge line is found, the search step length is reduced and the camera position is gradually moved in; when the exposed white area is a perfect circle, the through hole is found; the coordinates of the center point of the hole can be automatically obtained by simulating the mouse operation of some functions of the CAD software through a python script, and the diameter of the hole can be obtained by combining the camera position and OpenCV. The line connecting the camera position and the coordinates of the center point of the hole is the normal direction of the hole; Step 24: Through the above cycle, the system automatically obtains the position, direction and size of each through hole; Step 3: Step 31: Based on the obtained position, direction, and size of each through hole, the camera is driven to move to the corresponding position, and the shooting range is changed by the zoom lens to take pictures; Step 32: Combine OpenCV to measure the size of the hole and determine the roundness of the hole, and give a detection conclusion.

2. The digital twin visual inspection method for complex three-dimensional multi-through-hole parts according to claim 1 is characterized by: A guide groove (14) is provided on the side wall of the annular device housing (1); a slider (21) is connected to the output end of the first drive motor (2), and the slider (21) is slidably connected in the guide groove (14).

3. The digital twin visual inspection method for complex three-dimensional multi-through-hole parts according to claim 1 is characterized by: The storage plate (13) is provided with a through hole (131) for passing the vertical guide rail (12), and the storage plate (13) is also provided with a screw hole (132). The output end of the second drive motor (3) is connected to a screw rod (31), and the screw rod (31) is screwed onto the storage plate (13) through the screw hole (132).

4. The digital twin visual inspection method for complex three-dimensional multi-through-hole parts according to claim 1 is characterized by: A measuring platform (6) for placing parts to be measured is also provided in the middle of the bottom wall of the annular device box (1).

Images