Automobile part surface defect detection method and system based on three-dimensional scanning
By using three-dimensional scanning technology and automated mechanical means in the automotive parts detection system, the problem that existing detection technology is difficult to detect surface defects of complex curved parts is solved, and efficient and accurate detection results are achieved.
Patent Information
- Application Number
- CN202411936395.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-03-28
AI Technical Summary
Existing automotive parts detection technology is difficult to quickly and accurately detect surface defects of complex curved parts, and lacks automated and visual inspection methods, resulting in low detection efficiency and accuracy.
A detection system based on three-dimensional scanning is adopted, including a detection box, a rotary board, a clamping board, a three-axis robotic arm and a control box, and data processing and comparison are carried out through a three-dimensional scanner.
It realizes automated, fast and accurate detection of surface defects of automobile parts, and can conduct comprehensive data acquisition on the front and back sides, improve detection accuracy, and generate detailed data comparison reports.
Smart Images
Figure CN119715560A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of automobile parts detection, and in particular to a method and system for detecting surface defects of automobile parts based on three-dimensional scanning. Background Art
[0002] In the production and manufacturing of automobile parts, quality control is always the top priority. There are many types of automobile parts, and they are characterized by complex shapes, multiple curved surfaces, and many hole details. Batch testing plays a vital role in the design, mold manufacturing, stamping, welding, first-piece inspection, series inspection and other links. High-precision, high-efficiency, and intuitive quality control methods are required to ensure the accuracy of automobile assembly. The traditional inspection method is to use traditional measuring tools to detect size and position. However, the traditional method has obvious disadvantages: it is difficult to achieve fast and accurate measurement of complex curved surfaces, and it is impossible to fully evaluate the error after processing. In addition, there is a lack of visual inspection means, resulting in low inspection efficiency and poor inspection accuracy. The automated inspection device does not have a flipping device, which results in only data collection and comparison on the front side of the part, reducing the inspection effect. Therefore, a surface defect detection method and system for automobile parts based on three-dimensional scanning are proposed to solve the above problems. Summary of the invention
[0003] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method and system for detecting surface defects of automobile parts based on three-dimensional scanning, which has the advantage of automatically performing data collection and comparison.
[0004] (II) Technical solution To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a method and system for detecting surface defects of automobile parts based on three-dimensional scanning adopts the following technical solutions: comprising a detection box, an adjustment groove is arranged on the right side of the inner cavity of the detection box, the inner cavity of the adjustment groove is fixedly connected to the adjustment box, a first motor is fixedly connected to the bottom of the inner cavity of the adjustment box, an active bevel gear is fixedly connected to the output end of the first motor, a driven bevel gear is meshed on the surface of the active bevel gear, a first rotating rod is fixedly connected to the inner cavity of the driven bevel gear, a rotating plate is fixedly connected to the top of the first rotating rod, first hydraulic cylinders are fixedly connected to both sides of the inner cavity of the adjustment groove, a movable vertical plate is fixedly connected to the output end of the first hydraulic cylinder, and a second hydraulic cylinder is fixedly connected to one side of the movable vertical plate. cylinder, the output end of the second hydraulic cylinder is fixedly connected to a rotating box, the inner cavity wall of the rotating box is fixedly connected to a second motor, the output end of the second motor is fixedly connected to a driving gear, the surface of the driving gear is meshed with a driven gear, the inner cavity of the driven gear is fixedly connected to a second rotating rod, the end of the second rotating rod away from the rotating box is fixedly connected to a clamping plate, the left side of the top of the detection box is fixedly connected to a three-axis mechanical arm, the rotating end of the three-axis mechanical arm is fixedly connected to a scanning device, the top of the left side of the detection box is fixedly connected to an extension plate, a display screen is placed on the top of the extension plate, and a control box is placed on the bottom of the extension plate, and the control box includes a component control system, an image preprocessing system, a feature extraction system, a three-dimensional modeling system, a size comparison system and a report generation system.
[0005] As a preferred solution, the surfaces of the rotating plate and the clamping plate are both provided with detection grooves, and the inner cavity of the detection groove is provided with an angle sensor.
[0006] As a preferred solution, a contact sensor is fixedly connected to a side of the clamping plate away from the second rotating rod, and the number of the first hydraulic cylinder, the second hydraulic cylinder, the rotating box and the clamping plate are two.
[0007] As a preferred solution, the first rotating rod is movably connected to the adjustment box via a bearing, and the second rotating rod is movably connected to the rotation box via a bearing.
[0008] As a preferred solution, the scanning device includes a blue light three-dimensional scanner, an ultrasonic detector and a CCD camera. The blue light three-dimensional scanner is fixedly connected to the top of the right side of the three-axis robotic arm, the ultrasonic detector is fixedly connected to the bottom of the right side of the three-axis robotic arm, and the CCD camera is fixedly connected to the front side of the right side of the three-axis robotic arm.
[0009] As a preferred solution, a third hydraulic cylinder is fixedly connected to the bottom of the inner cavity of the rotating plate, a push plate is fixedly connected to the output end of the third hydraulic cylinder, and a lifting block is fixedly connected to the top of the push plate.
[0010] As a preferred solution, vertical rods are fixedly connected to both sides of the inner cavity of the rotating plate, a sliding groove is provided in the inner cavity of the pushing plate, and the vertical rods are located in the inner cavity of the sliding groove.
[0011] A method for detecting surface defects of automobile parts based on three-dimensional scanning comprises the following steps: A. Place the auto parts to be inspected on the top of the lifting block, the third hydraulic cylinder contracts to drive the push plate to move downward, the push plate drives the auto parts to move downward, place the auto parts on the top of the rotating plate, the three-axis mechanical arm drives the scanning device to move toward the auto parts, at this time the blue light three-dimensional scanner on the scanning device performs data scanning on the auto parts, and the scanning data is transmitted to the image preprocessing system, then the ultrasonic detector performs ultrasonic scanning on the auto parts again, the blue light three-dimensional scanning performs data collection on the outside of the auto parts, the ultrasonic detector performs data collection on the wall thickness of the auto parts and whether there are cracks, the CCD camera performs image collection on the auto parts, during the data collection process the first motor drives the active bevel gear to rotate, the active bevel gear drives the driven bevel gear to rotate, the driven bevel gear drives the first rotating rod to rotate, the first rotating rod drives the rotating plate to rotate, adjust the angle of the auto parts, so that the scanning device can perform a comprehensive inspection on the front of the auto parts; B. After the front data detection of the automobile part is completed, the third hydraulic cylinder extends to drive the push plate to move upward, and the push plate drives the automobile part to move upward. At the same time, the first hydraulic cylinder drives the moving vertical plate to move upward, and the moving vertical plate drives the clamping plate to move upward. Then the second hydraulic cylinder drives the clamping plate to move toward the automobile part. The left and right clamping plates clamp the automobile part. Then the first hydraulic cylinder continues to move upward. After reaching a sufficient flipping height, the first hydraulic cylinder stops, and then the second motor is started. The second motor drives the driving gear to rotate, the driving gear drives the driven gear to rotate, the driven gear drives the second rotating rod to rotate, the second rotating rod drives the clamping plate to rotate, and the clamping plate drives the automobile part to flip. After flipping the automobile part, repeat the above steps to place the automobile part on the top of the rotating plate again, and use the scanning device again to collect data on the back of the automobile part; C. The data collected from the front and back sides of the auto parts are transmitted to the image preprocessing system. After the image preprocessing system performs image denoising, enhancement, grayscale and binarization processing steps on the image, the feature extraction system systematically classifies the preprocessed image by features such as color, texture and shape. The 3D modeling system performs 3D modeling on the data collected by the blue light 3D scanner and the ultrasonic detector, that is, two 3D models are established for one auto part. The size comparison system compares the correct size set in the system with the established 3D model. Finally, the report generation system generates a data comparison report.
[0012] (III) Beneficial effects Compared with the prior art, the present invention provides a method and system for detecting surface defects of automobile parts based on three-dimensional scanning, which has the following beneficial effects.
[0013] 1. By setting the rotating plate and the clamping plate, the rotating plate can drive the automobile parts to rotate in a circle and adjust the direction of the automobile parts, so as to collect data at different positions on the front of the automobile parts. After the front data collection is completed, the clamping plate can flip the automobile parts, so as to collect data on the back of the automobile parts. By collecting data on the front and back, the detection accuracy of automobile parts can be improved.
[0014] 2. The three-axis robotic arm can flexibly adjust the position of the scanning device. The scanning device can be used to collect data and images of automobile parts. The control box can process the collected data and perform three-dimensional modeling, and compare the modeling information with the pre-stored information. The third hydraulic cylinder, push plate and lifting block can be used to lift and lower automobile parts. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a cross-sectional schematic diagram of the detection box of the present invention; Figure 3 It is a schematic diagram of the internal structure of the rotary box of the present invention; Figure 4 It is a schematic diagram of the internal structure of the regulating box of the present invention; Figure 5 It is a schematic diagram of the internal structure of the rotating plate of the present invention; Figure 6 It is a schematic diagram of the system principle of the present invention.
[0016] In the figure: 1, detection box; 2, adjustment groove; 3, adjustment box; 4, first motor; 5, active bevel gear; 6, driven bevel gear; 7, first rotating rod; 8, rotating plate; 9, first hydraulic cylinder; 10, moving vertical plate; 11, second hydraulic cylinder; 12, rotating box; 13, second motor; 14, driving gear; 15, driven gear; 16, second rotating rod; 17, clamping plate; 18, three-axis mechanical arm; 19, scanning device; 191, blue light 3D scanning Instrument; 192, ultrasonic detector; 193, CCD camera; 20, extension plate; 21, display screen; 22, control box; 221, component control system; 222, image preprocessing system; 223, feature extraction system; 224, three-dimensional modeling system; 225, size comparison system; 226, report generation system; 23, angle sensor; 24, contact sensor; 25, third hydraulic cylinder; 26, push plate; 27, lifting block; 28, vertical rod. DETAILED DESCRIPTION
[0017] The following will disclose multiple embodiments of the present invention with drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these practical details are not necessary. In addition, for the purpose of simplifying the drawings, some conventional structures and components will be depicted in a simple schematic manner in the drawings.
[0018] Embodiment 1: See also Figure 1-6 In order to achieve the purpose of rotating parts, the present embodiment provides the following technical solutions, which specifically disclose: comprising a detection box 1, an adjusting groove 2 is arranged on the right side of the inner cavity of the detection box 1, an adjusting box 3 is fixedly connected to the inner cavity of the adjusting groove 2, a first motor 4 is fixedly connected to the bottom of the inner cavity of the adjusting box 3, an active bevel gear 5 is fixedly connected to the output end of the first motor 4, a driven bevel gear 6 is meshed on the surface of the active bevel gear 5, a first rotating rod 7 is fixedly connected to the inner cavity of the driven bevel gear 6, a rotating plate 8 is fixedly connected to the top of the first rotating rod 7, a first hydraulic cylinder 9 is fixedly connected to both sides of the inner cavity of the adjusting groove 2, a moving vertical plate 10 is fixedly connected to the output end of the first hydraulic cylinder 9, a second hydraulic cylinder 11 is fixedly connected to one side of the moving vertical plate 10, a rotating box 12 is fixedly connected to the output end of the second hydraulic cylinder 11, a second motor 13 is fixedly connected to the inner cavity wall of the rotating box 12, a driving gear 14 is fixedly connected to the output end of the second motor 13, and a driven gear 15 is meshed on the surface of the driving gear 14 , the inner cavity of the driven gear 15 is fixedly connected with a second rotating rod 16, and the end of the second rotating rod 16 away from the rotating box 12 is fixedly connected with a clamping plate 17, and the surfaces of the rotating plate 8 and the clamping plate 17 are both provided with detection grooves, and the inner cavity of the detection groove is provided with an angle sensor 23, and the side of the clamping plate 17 away from the second rotating rod 16 is fixedly connected with a contact sensor 24, and the number of the first hydraulic cylinder 9, the second hydraulic cylinder 11, the rotating box 12 and the clamping plate 17 is two, the first rotating rod 7 is movably connected to the adjustment box 3 through a bearing, and the second rotating rod 16 is movably connected to the rotating box 12 through a bearing. Through the provided rotating plate 8 and the clamping plate 17, the rotating plate 8 can drive the automobile parts to rotate in a circle and adjust the direction of the automobile parts, so as to collect data at different positions on the front of the automobile parts, and after the front data collection is completed, the clamping plate 17 can flip the automobile parts, so as to collect data on the back of the automobile parts, and the detection accuracy of the automobile parts can be improved by collecting data on the front and back sides.
[0019] Embodiment 2: See also Figure 1-6In order to achieve the purpose of data collection and comparison, the present embodiment provides the following technical solutions, which specifically disclose: a three-axis mechanical arm 18 is fixedly connected to the left side of the top of the detection box 1, and a scanning device 19 is fixedly connected to the rotating end of the three-axis mechanical arm 18. An extension plate 20 is fixedly connected to the top of the left side of the detection box 1, a display screen 21 is placed on the top of the extension plate 20, and a control box 22 is placed on the bottom of the extension plate 20. The control box 22 includes a component control system 221, an image preprocessing system 222, a feature extraction system 223, a three-dimensional modeling system 224, a size comparison system 225 and a report generation system 226. The scanning device 19 includes a blue light three-dimensional scanner 191, an ultrasonic detector 192 and a CCD camera 193. The blue light three-dimensional scanner 191 is fixedly connected to the top of the right side of the three-axis mechanical arm 18, and the ultrasonic detector 192 is fixedly connected to the three-axis mechanical arm 18. At the bottom of the right side, the CCD camera 193 is fixedly connected to the front side of the right side of the three-axis mechanical arm 18, and the bottom of the inner cavity of the rotating plate 8 is fixedly connected to the third hydraulic cylinder 25, and the output end of the third hydraulic cylinder 25 is fixedly connected to the push plate 26, and the top of the push plate 26 is fixedly connected to the lifting block 27. Vertical rods 28 are fixedly connected to both sides of the inner cavity of the rotating plate 8, and the inner cavity of the push plate 26 is provided with a slide groove, and the vertical rod 28 is located in the inner cavity of the slide groove. Through the set three-axis mechanical arm 18, the position of the scanning device 19 can be flexibly adjusted, and through the set scanning device 19, data acquisition and image acquisition of automobile parts can be performed, and through the set control box 22, data processing and three-dimensional modeling of the collected data can be performed, and the modeling information can be compared with the pre-stored information, and through the set third hydraulic cylinder 25, the push plate 26 and the lifting block 27, the automobile parts can be lifted upward and placed downward.
[0020] Embodiment three: See also Figure 1-6 In order to achieve the purpose of data collection and comparison, this embodiment provides the following technical solutions, specifically disclosing: a method for detecting surface defects of automobile parts based on three-dimensional scanning, comprising the following steps: A. Place the automobile parts to be inspected on the top of the lifting block 27, the third hydraulic cylinder 25 contracts and drives the push plate 26 to move downward, the push plate 26 drives the automobile parts to move downward, and the automobile parts are placed on the top of the rotating plate 8. The three-axis mechanical arm 18 drives the scanning device 19 to move toward the automobile parts. At this time, the blue light three-dimensional scanner 191 on the scanning device 19 performs data scanning on the automobile parts, and the scanning data is transmitted to the image preprocessing system 222. Then the ultrasonic detector 192 performs ultrasonic scanning on the automobile parts again, the blue light three-dimensional scanning collects data on the outside of the automobile parts, the ultrasonic detector 192 collects data on the wall thickness of the automobile parts and whether there are cracks, and the CCD camera 193 collects images of the automobile parts. During the data collection process, the first motor 4 drives the active bevel gear 5 to rotate, the active bevel gear 5 drives the driven bevel gear 6 to rotate, the driven bevel gear 6 drives the first rotating rod 7 to rotate, and the first rotating rod 7 drives the rotating plate 8 to rotate, and adjusts the angle of the automobile parts so that the scanning device 19 can perform a comprehensive inspection on the front of the automobile parts; B. After the front data detection of the automobile part is completed, the third hydraulic cylinder 25 extends to drive the push plate 26 to move upward, and the push plate 26 drives the automobile part to move upward. At the same time, the first hydraulic cylinder 9 drives the moving vertical plate 10 to move upward, and the moving vertical plate 10 drives the clamping plate 17 to move upward, and then the second hydraulic cylinder 11 drives the clamping plate 17 to move toward the automobile part, and the left and right clamping plates 17 clamp the automobile part, and then the first hydraulic cylinder 9 continues to move upward. After reaching a sufficient flipping height, the first hydraulic cylinder 9 is stopped, and then the second motor 13 is started, and the second motor 13 drives the driving gear 14 to rotate, and the driving gear 14 drives the driven gear 15 to rotate, and the driven gear 15 drives the second rotating rod 16 to rotate, and the second rotating rod 16 drives the clamping plate 17 to rotate, and the clamping plate 17 drives the automobile part to flip, and after the automobile part is flipped, the above steps are repeated to place the automobile part on the top of the rotating plate 8 again, and the scanning device 19 is used again to collect data on the back of the automobile part; C. The data collected from the front and back sides of the automobile parts are transmitted to the image preprocessing system 222. After the image preprocessing system 222 performs image denoising, enhancement, grayscale and binarization processing steps on the image, the feature extraction system 223 systematically classifies the preprocessed image by features such as color, texture and shape. The three-dimensional modeling system 224 performs three-dimensional modeling on the data collected by the blue light three-dimensional scanner 191 and the ultrasonic detector 192, that is, two three-dimensional models are established for one automobile part. The size comparison system 225 compares the correct size set in the system with the established three-dimensional model. Finally, the report generation system 226 generates a data comparison report.
[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.
Claims
1. A system for detecting surface defects of automobile parts based on three-dimensional scanning, comprising a detection box (1), characterized in that: An adjustment groove (2) is provided on the right side of the inner cavity of the detection box (1); the inner cavity of the adjustment groove (2) is fixedly connected to an adjustment box (3); the bottom of the inner cavity of the adjustment box (3) is fixedly connected to a first motor (4); the output end of the first motor (4) is fixedly connected to an active bevel gear (5); the surface of the active bevel gear (5) is meshed with a driven bevel gear (6); the inner cavity of the driven bevel gear (6) is fixedly connected to a first rotating rod (7); the top of the first rotating rod (7) is fixedly connected to a rotating plate (8); both sides of the inner cavity of the adjustment groove (2) are fixedly connected to a first hydraulic cylinder (9); the output end of the first hydraulic cylinder (9) is fixedly connected to a movable vertical plate (10); one side of the movable vertical plate (10) is fixedly connected to a second hydraulic cylinder (11); the output end of the second hydraulic cylinder (11) is fixedly connected to a rotating box (12); the inner cavity wall of the rotating box (12) is fixedly connected to a second motor (13); The output end of the motor (13) is fixedly connected to a driving gear (14), the surface of the driving gear (14) is meshed with a driven gear (15), the inner cavity of the driven gear (15) is fixedly connected to a second rotating rod (16), the end of the second rotating rod (16) away from the rotating box (12) is fixedly connected to a clamping plate (17), the left side of the top of the detection box (1) is fixedly connected to a three-axis mechanical arm (18), the rotating end of the three-axis mechanical arm (18) is fixedly connected to a scanning device (19), the top of the left side of the detection box (1) is fixedly connected to an extension plate (20), the top of the extension plate (20) is provided with a display screen (21), the bottom of the extension plate (20) is provided with a control box (22), and the control box (22) comprises a component control system (221), an image preprocessing system (222), a feature extraction system (223), a three-dimensional modeling system (224), a size comparison system (225) and a report generation system (226).
2. The automobile parts surface defect detection system based on three-dimensional scanning according to claim 1 is characterized in that: The surfaces of the rotating plate (8) and the clamping plate (17) are both provided with detection grooves, and the inner cavity of the detection groove is provided with an angle sensor (23).
3. The automobile parts surface defect detection system based on three-dimensional scanning according to claim 1 is characterized in that: A contact sensor (24) is fixedly connected to a side of the clamping plate (17) away from the second rotating rod (16), and the number of the first hydraulic cylinder (9), the second hydraulic cylinder (11), the rotating box (12) and the clamping plate (17) are all two.
4. The automobile parts surface defect detection system based on three-dimensional scanning according to claim 1 is characterized in that: The first rotating rod (7) is movably connected to the adjustment box (3) via a bearing, and the second rotating rod (16) is movably connected to the rotation box (12) via a bearing.
5. The automobile parts surface defect detection system based on three-dimensional scanning according to claim 1 is characterized in that: The scanning device (19) comprises a blue light three-dimensional scanner (191), an ultrasonic detector (192) and a CCD camera (193); the blue light three-dimensional scanner (191) is fixedly connected to the top of the right side of the three-axis mechanical arm (18); the ultrasonic detector (192) is fixedly connected to the bottom of the right side of the three-axis mechanical arm (18); and the CCD camera (193) is fixedly connected to the front side of the right side of the three-axis mechanical arm (18).
6. The automobile parts surface defect detection system based on three-dimensional scanning according to claim 1, characterized in that: A third hydraulic cylinder (25) is fixedly connected to the bottom of the inner cavity of the rotating plate (8), a push plate (26) is fixedly connected to the output end of the third hydraulic cylinder (25), and a lifting block (27) is fixedly connected to the top of the push plate (26).
7. The automobile parts surface defect detection system based on three-dimensional scanning according to claim 6 is characterized in that: Vertical rods (28) are fixedly connected to both sides of the inner cavity of the rotating plate (8), a sliding groove is provided in the inner cavity of the pushing plate (26), and the vertical rod (28) is located in the inner cavity of the sliding groove.
8. A method for detecting surface defects of automobile parts based on three-dimensional scanning, characterized in that: The following steps are involved: A. The automobile part to be inspected is placed on the top of the lifting block (27), the third hydraulic cylinder (25) contracts and drives the push plate (26) to move downward, the push plate (26) drives the automobile part to move downward, the automobile part is placed on the top of the rotating plate (8), the three-axis mechanical arm (18) drives the scanning device (19) to move toward the automobile part, at this time, the blue light three-dimensional scanner (191) on the scanning device (19) scans the automobile part, and the scanned data is transmitted to the image preprocessing system (222), and then the ultrasonic detector (192) performs ultrasonic scanning on the automobile part again, the blue light three-dimensional scanner (191) on the scanning device (19) scans the automobile part, and the scanned data is transmitted to the image preprocessing system (222). The optical three-dimensional scanning collects data on the exterior of the automobile part, the ultrasonic detector (192) collects data on the wall thickness of the automobile part and whether there are cracks, and the CCD camera (193) collects images of the automobile part. During the data collection process, the first motor (4) drives the active bevel gear (5) to rotate, the active bevel gear (5) drives the driven bevel gear (6) to rotate, the driven bevel gear (6) drives the first rotating rod (7) to rotate, and the first rotating rod (7) drives the rotating plate (8) to rotate, and adjusts the angle of the automobile part so that the scanning device (19) can perform a comprehensive inspection on the front of the automobile part; B. After the front data detection of the automobile part is completed, the third hydraulic cylinder (25) extends to drive the push plate (26) to move upward, and the push plate (26) drives the automobile part to move upward. At the same time, the first hydraulic cylinder (9) drives the moving vertical plate (10) to move upward, and the moving vertical plate (10) drives the clamping plate (17) to move upward. Then, the second hydraulic cylinder (11) drives the clamping plate (17) to move toward the automobile part. The left and right clamping plates (17) clamp the automobile part. Then, the first hydraulic cylinder (9) continues to move upward and stops after reaching a sufficient turning height. The first hydraulic cylinder (9) then starts the second motor (13), the second motor (13) drives the driving gear (14) to rotate, the driving gear (14) drives the driven gear (15) to rotate, the driven gear (15) drives the second rotating rod (16) to rotate, the second rotating rod (16) drives the clamping plate (17) to rotate, the clamping plate (17) drives the automobile part to flip, after the automobile part is flipped, repeat the above steps to place the automobile part on the top of the rotating plate (8) again, and use the scanning device (19) again to collect data on the reverse side of the automobile part; C. The data collected from the front and back sides of the automobile parts are transmitted to the image preprocessing system (222). After the image preprocessing system (222) performs image denoising, enhancement, grayscale conversion and binarization processing steps on the image, the feature extraction system (223) systematically classifies the preprocessed image by features such as color, texture and shape. The three-dimensional modeling system (224) performs three-dimensional modeling on the data collected by the blue light three-dimensional scanner (191) and the ultrasonic detector (192), that is, two three-dimensional models are established for one automobile part. The size comparison system (225) compares the correct size set in the system with the established three-dimensional model. Finally, the report generation system (226) generates a data comparison report.