A line scanning image acquisition device and correction method for the outer surface of a cylindrical high-reflective part

Abstract

The present invention relates to a line scan image acquisition device and correction method for the outer surface of a cylindrical high-reflective part, which comprises the following steps: building a line scan image detection device and completing parameter setting; acquiring a line scan image of the outer surface of a cylindrical metal part; performing angle correction on the acquired line scan image of the outer surface of the cylindrical metal part; performing line scan image distortion correction on the outer bottom circular surface of the cylindrical metal part; and obtaining a corrected line scan image of the outer contour surface of the complete cylindrical metal part. By obtaining an accurate outer surface image of a cylindrical high-reflective metal thin-wall part, the defects of the outer surface of the cylindrical high-reflective metal thin-wall part can be more accurately detected and analyzed, the accuracy and reliability can be improved, and the needs of the industrial cylindrical high-reflective metal thin-wall part outer defect detection site can be better met.

Description

Technical Field

[0001] The present invention relates to the technical field of product surface quality defect detection, and in particular to a line scanning image acquisition device and a correction method for the outer surface of a cylindrical high-reflective part. Background Art

[0002] Cylindrical highly reflective thin-walled metal parts are widely used in the industrial field. The main body of the cookware is usually a stamped thin-walled metal part that is polished. However, due to factors such as material defects, transportation bumps, and improper operation, the outer surface of the processed cookware often has defects such as abrasions, dents, and scratches. Therefore, defect detection on the polished outer cylindrical surface of the cookware and the outer bottom circular surface is an important means to ensure the quality of the cookware. Due to the serious high reflectivity on the polished metal surface of the cookware, and the lack of effective technical means to complete high-resolution imaging of the outer surface of the cookware, the current production site still mainly uses manual visual methods for defect detection. Therefore, high-quality image acquisition and defect detection of the outer surface of the cookware is an important part of improving product quality.

[0003] Before the handle is installed, the metal pot stamping parts show the characteristics of highly reflective metal rotating bodies. The existing image acquisition methods are affected by the change of light when facing highly reflective metal rotating bodies, and the visual imaging quality in dynamic scenes loses a lot of image information, making it difficult to detect small defects. To this end, a circular multi-faceted array camera array system is introduced, and the target is driven by a turntable to achieve panoramic dynamic measurement. However, the multi-view area array camera system requires each camera to be calibrated separately, and because it is only applicable to scenes where the target is fixed and does not move, the information collected in a dynamic environment exceeds the required information, causing inconvenience and reduced efficiency in data processing, limiting its practicality in industrial production. In the industrial field, a line array camera is used to shoot the surface of highly reflective metal pots. By placing the appropriate light source position, the cylindrical surface of the outer wall of the rotating pot can be completely collected, avoiding redundant calculations and waste of resources. However, during the one-time imaging process of the outer surface of the pot by the line array camera, due to the shooting angle of the line array camera, the line scan image of the outer surface of the pot taken will face serious geometric distortion problems, which will be detrimental to the effective detection and quantitative analysis of defect features. Summary of the invention

[0004] The purpose of the present invention is to provide a line scan image acquisition device and correction method for the outer surface of a cylindrical high-reflective part, which is used to solve the problem that the existing technology cannot effectively detect and quantitatively analyze the defect characteristics existing on the cylindrical metal surface.

[0005] According to one aspect of the present invention, a method for correcting line scan images of the outer surface of a cylindrical high-reflective part is provided, which comprises the following steps:

[0006] Build the line scan image detection device and complete the parameter setting;

[0007] Line scan image acquisition of the outer surface of a cylindrical metal part;

[0008] Performing angle correction on the collected line scan image of the outer surface of the cylindrical metal part;

[0009] Perform line scan image distortion correction on the outer bottom circular surface of a cylindrical metal part;

[0010] Obtain the corrected complete line scan image of the outer contour of the cylindrical metal part.

[0011] In one of the embodiments, the step of building a line scan image detection device specifically includes setting the angle of the line array camera and the distance between the line array camera and the cylindrical metal part, so that the line array camera can completely capture the outer surface image of the cylindrical metal part; and making the upper boundary of the line scan image correspond to the center of the outer bottom circular surface of the cylindrical metal part, and the lower boundary corresponds to the lowest end of the cylindrical surface of the outer wall of the cylindrical metal part.

[0012] In one embodiment, in the step of building the line scan image detection device, the rotation speed of the rotating platform is specifically set to match the line frequency of the line array camera:

[0013] R=2πr·v T / (α·C) (1)

[0014] Where r is the radius of the cylindrical metal part, v T is the rotation speed of the rotating platform, α is the pixel accuracy, and C is the number of turns of the rotating platform.

[0015] In one of the embodiments, the step of building the line scan image detection device specifically includes adjusting the irradiation angle of the industrial line light source so that the industrial line light source adopts a low-angle irradiation method; a total of four industrial line light sources are set, two of which are vertically arranged and the remaining two are horizontally arranged; wherein the incident angle of the vertically arranged industrial line light source and the angle between the cross-section of the side of the cylindrical metal part is 30°, and the incident angle of the horizontally arranged industrial line light source and the angle between the bottom of the cylindrical metal part is 25°.

[0016] In one embodiment, in the step of performing angle correction on the collected line scan image of the outer surface of the cylindrical metal part, a mathematical formula for the angle between the line scan image and the ideal image plane is obtained as follows:

[0017]

[0018] In the formula, h c is the height of the linear array camera from the plane, l c is the actual distance from the linear array camera lens to the outer surface of the cylindrical metal part;

[0019] The mathematical relationship between the pixel size of the line scan image of the outer surface of a cylindrical metal part and the optical axis of the line scan camera can be inferred:

[0020]

[0021] Where w' is the ideal pixel width of the line scan image, h 1 ' is the ideal pixel height of the bottom circular surface line scan image, h 1 is the actual pixel height of the bottom circular surface line scan image, h 2 ' is the ideal pixel height of the line scan image of the outer cylindrical surface, h 2 is the actual pixel height of the line scan image of the outer cylindrical surface, p is the pixel size, R is the line frequency of the linear array camera, H is the field of view, and f is the length of the linear photosensitive element.

[0022] In one of the embodiments, in the step of performing line scan image distortion correction on the outer bottom circular surface of the cylindrical metal part, the line scan image of the bottom surface of the cylindrical metal part is corrected to a real outer bottom circular surface image of the cylindrical metal part;

[0023] First, a Cartesian coordinate system with the upper left corner of the line scan image as the origin is established, the horizontal axis is defined as the center of the cylindrical metal part, the opposite side is used as the outer contour of the cylindrical metal part, and the arrangement order of the image pixels is specified; in the Cartesian coordinate system, the horizontal coordinate of the line scan image is used to determine the angle of the pixel point in the polar coordinate system, and the vertical coordinate determines its radius, so that each pixel point is mapped to the corresponding position;

[0024] Use the following formula to map the angle-corrected bottom image of the cylindrical metal part from the Cartesian coordinate system to the polar coordinate system:

[0025]

[0026] Where r is the radius of the circle, θ is the angle of the polar coordinate system, and w is the width of the line scan image in pixels;

[0027] Secondly, when the origins of the two polar coordinates and the Cartesian coordinate system coincide, the polar coordinate system is converted to the Cartesian coordinate system by the following formula to establish the mapping relationship between the coordinates of the corresponding points in the two coordinate systems:

[0028]

[0029] Wherein, x' is the abscissa of the Cartesian coordinate system after polar coordinate mapping, and y' is the ordinate of the Cartesian coordinate system after polar coordinate mapping;

[0030] Finally, the pixel resampling method is used to fill the grayscale values ​​of the corresponding pixels in the line scan image of the bottom circular surface of the cylindrical metal part into the corrected image:

[0031]

[0032] In the formula, η=(xx 1 ) / (x 2 -x 1 ) and μ=(yy 1 ) / (y 2 -y 1 ) is a relative position parameter, (x, y) represents the relative position of (x 1 ,y 1 ) and (x 2 ,y 2 )’s horizontal and vertical distances.

[0033] In another aspect of the present application, a collection device based on the above-mentioned line scan image correction method for the outer surface of a cylindrical high-reflective part is also proposed, which includes:

[0034] Fixed frame;

[0035] A line array camera, wherein the line array camera is arranged on the fixing frame;

[0036] A rotating platform, the rotating platform is arranged at intervals on the opposite side of the lens of the linear array camera, a driving motor is connected to the bottom of the rotating platform, and the rotating platform is used to load cylindrical metal parts;

[0037] An industrial bar light source, which is used to be arranged on the side of a cylindrical metal part;

[0038] A controller, the controller being electrically connected to the linear array camera, the drive motor and the industrial bar light source;

[0039] a power supply electrically connected to the controller; and

[0040] A computer is electrically connected to the controller.

[0041] Implementing the embodiments of the present invention will have the following beneficial effects:

[0042] When the line scan image correction method for the outer surface of a cylindrical high-reflective part of the present scheme is used to detect whether there are defects on the appearance surface of a cylindrical metal part, first, a line scan image detection device is built and the parameter setting is completed; in this way, the working parameters of the line scan image detection device are optimized according to the size, material, etc. of the cylindrical metal part to obtain a better detection effect; the highly reflective metal surface specifically includes the cylindrical outer surface of the cylindrical metal part and the outer bottom circular surface connected to the lower end of the cylindrical outer surface (for ease of understanding, the cylindrical metal part can be regarded as a cookware), then, a line scan image is collected on the outer surface of the cylindrical metal part, and then the angle of the line scan image of the outer surface of the cylindrical metal part is corrected; then, the cylindrical The outer bottom circular surface of the metal part is subjected to line scan image distortion correction, so that a corrected line scan image of the complete outer contour surface of the cylindrical metal part can be obtained; the line scan image detection device of this scheme proposes a corresponding line scan image distortion correction algorithm, thereby eliminating the geometric distortion in the overall line scan image of the outer wall cylindrical surface and the outer bottom circular surface of the cylindrical high-reflective metal thin-walled part, and obtaining a high-resolution distortion-free image of the outer surface of the cylindrical high-reflective metal thin-walled part; by obtaining an accurate image of the outer surface of the cylindrical high-reflective metal thin-walled part, the defects of the outer surface of the cylindrical high-reflective metal thin-walled part can be more accurately detected and analyzed, which can improve accuracy and reliability and can better meet the needs of on-site external defect detection of industrial cylindrical high-reflective metal thin-walled parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A flowchart of a method for correcting line scan images of the outer surface of a cylindrical high-reflective component according to an embodiment;

[0045] Figure 2 A diagram showing the position and angle of the line array camera relative to the pot;

[0046] Figure 3 This is the layout diagram of the industrial line light source and line array camera;

[0047] Figure 4 Schematic diagram of the mapping transformation of the line scan image coordinate system of the bottom surface of the cookware.

[0048] in:

[0049] 10. Line array camera; 20. Rotating platform; 30. Cookware; 40. Vertical industrial line light source; 50. Horizontal industrial line light source. DETAILED DESCRIPTION

[0050] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0051] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0053] Please refer to Figure 1 , is a method for correcting line scan images of the outer surface of a cylindrical high-reflective part according to an embodiment, which comprises the following steps:

[0054] S100: Build a line scan image detection device and complete parameter settings.

[0055] S200: performing line scan image acquisition on the outer surface of the cylindrical metal part.

[0056] S300: performing angle correction on the collected line scan image of the outer surface of the cylindrical metal part.

[0057] S400: performing line scan image distortion correction on the outer bottom circular surface of the cylindrical metal part.

[0058] S500: Obtain a corrected line scan image of the outer contour of a complete cylindrical metal part.

[0059] It is necessary to explain that, in order to facilitate understanding of the technical solution, the cylindrical metal part can be regarded as a pot 30 (such as a steamer, a milk pot, a soup pot, etc.). It can be understood that the pot 30 has a cylindrical outer surface and a circular bottom wall, and the outer bottom circular surface is connected between the cylindrical outer surface and the bottom wall. The combination of the three constitutes the complete outer contour surface of the pot 30. This solution is used to detect whether there are scratches, pits and other appearance defects on the outer contour surface of the pot 30.

[0060] See also Figure 2 and Figure 3 In addition, the present application also proposes a collection device based on the above-mentioned line scan image correction method for the outer surface of a cylindrical highly reflective part, which includes a fixed frame, a linear array camera 10, a rotating platform 20, an industrial strip light source, a controller, a power supply and a computer.

[0061] The line array camera 10 is arranged on a fixing frame, so that installation and positioning can be achieved through the fixing frame.

[0062] The fixing frame may be fixedly installed or equipped with casters for easy movement to change the work site. Furthermore, the fixing frame is also provided with a horizontal telescopic mechanism and / or a height lifting mechanism, so as to facilitate flexible adjustment of the horizontal and / or height position of the line array camera 10, so that the field of view of the line array camera 10 can cover the outer contour surface of the entire pot 30, meeting the detection needs of pots 30 of different sizes.

[0063] The line scan camera 10 is a camera that uses a line scan image sensor. Typical applications of the line scan camera 10 are the detection of continuous materials, such as metals, plastics, paper, and fibers. The object being detected usually moves at a constant speed and is scanned line by line by one or more cameras to achieve uniform detection of the entire surface. The image can be processed line by line, or a surface image consisting of multiple lines can be processed. In addition, the line scan camera 10 is very suitable for measurement applications, thanks to the high resolution of the sensor, which can accurately measure to microns.

[0064] The rotating platform 20 is disposed at intervals on the opposite side of the lens of the linear array camera 10 . A driving motor is connected to the bottom of the rotating platform 20 . The rotating platform 20 is used to load cylindrical metal parts.

[0065] During the inspection, the linear array camera 10 is fixed, and the driving motor drives the rotating platform 20 to rotate horizontally at a uniform speed, thereby driving the cookware 30 to display its entire outer wheel contour in the field of view of the linear array camera 10, so that the linear array camera 10 can capture the complete outer contour surface image of the cookware 30.

[0066] To prevent the cookware 30 from shifting or even falling on the rotating platform 20 during rotation, the top surface of the rotating platform 20 may be provided with positioning components or mechanisms such as slots, blocks, clamps, magnets, etc. to limit and fix the cookware 30 placed on the rotating platform 20.

[0067] The industrial bar light source is used to be arranged on the side of the cylindrical metal part; the controller is electrically connected to the linear array camera 10, the drive motor and the industrial bar light source; the power supply is electrically connected to the controller; and the computer is electrically connected to the controller.

[0068] During the inspection, the industrial bar light source cooperates with the linear array camera 10 to capture images, which can effectively curb the problem of overexposure of the high-luminous surface of the metal parts, and with the fill light of the industrial bar light source, it is helpful to obtain images with higher brightness and clarity. The controller is used to control the automatic coordination of various functional components, eliminating human intervention, improving inspection efficiency and result accuracy. The image data obtained by the inspection can be transmitted to the computer by the controller, which is convenient for the inspector to analyze in real time to determine whether there are quality defects.

[0069] Furthermore, in the step of building a line scan image detection device, it specifically includes setting the angle of the line array camera 10 and the distance between the line array camera 10 and the cylindrical metal part, so that the line array camera 10 can completely capture the outer surface image of the cylindrical metal part. In addition, the upper boundary of the line scan image corresponds to the center of the outer bottom circular surface of the cylindrical metal part, and the lower boundary corresponds to the lowest end of the cylindrical surface of the outer wall of the cylindrical metal part. In this way, after the rotating platform 20 drives the pot 30 to rotate one circle, the line array camera 10 can completely obtain the contour image of the entire outer peripheral surface of the pot 30, without the need for continuous rotation for supplementary shooting, resulting in image redundancy and energy waste, and increasing the subsequent film reading time of the inspection personnel.

[0070] In another embodiment, the step of building the line scan image detection device specifically includes setting the rotation speed of the rotating platform 20 to match the line frequency of the line array camera 10:

[0071] R=2πr·v T / (α·C) (1)

[0072] Where r is the radius of the cylindrical metal part, v T is the rotation speed of the rotating platform 20, α is the pixel accuracy, and C is the number of turns of the rotating platform 20. This ensures that when the pot 30 rotates continuously with the rotating platform 20, the line array camera 10 can continuously shoot the outer contour surface of the pot 30 in a block manner, thereby ensuring that the line array camera 10 obtains a complete image of the outer surface of the pot 30, preventing problems such as missing images from being captured, which affects the accuracy and efficiency of the detection results.

[0073] Furthermore, in another embodiment, in the step of building a line scan image detection device, it specifically includes adjusting the irradiation angle of the industrial line light source so that the industrial line light source adopts a low-angle irradiation method; a total of four industrial line light sources are arranged, two of which are vertically arranged, and the remaining two are horizontally arranged; wherein the incident angle of the vertically arranged industrial line light source 40 and the angle between the cross-section of the side surface of the cylindrical metal part is 30°, and the incident angle of the horizontally arranged industrial line light source 50 and the angle between the bottom surface of the cylindrical metal part is 25°.

[0074] Two vertically placed industrial line light sources and two horizontally placed industrial line light sources are arranged around the outer surface of the cookware 30, and the angle of the irradiated light is controlled, which can effectively curb the overexposure problem caused by the high reflectivity of the metal surface. In addition, multiple light sources simultaneously fill in the light for various parts of the cookware 30, effectively overcoming the problem that in dynamic shooting scenes with changing light intensity, the visual imaging quality loses a lot of image information, making it difficult to detect small defects.

[0075] In addition, in the step of performing angle correction on the collected line scan image of the outer surface of the cylindrical metal part, the mathematical relationship formula of the angle between the line scan image and the ideal image plane is obtained as follows:

[0076]

[0077] In the formula, h c is the height of the linear array camera 10 from the plane, l c is the actual distance from the lens of the linear array camera 10 to the outer surface of the cylindrical metal part;

[0078] The mathematical relationship between the pixel size of the line scan image of the outer surface of the cylindrical metal part and the optical axis of the line array camera 10 can be inferred:

[0079]

[0080] Where w' is the ideal pixel width of the line scan image, h 1 ' is the ideal pixel height of the bottom circular surface line scan image, h 1 is the actual pixel height of the bottom circular surface line scan image, h 2 ' is the ideal pixel height of the line scan image of the outer cylindrical surface, h 2 is the actual pixel height of the line scan image of the outer cylindrical surface, p is the pixel size, R is the line frequency of the linear array camera 10, H is the field of view, and f is the length of the linear photosensitive element. After the above mathematical calculation, the angle correction of the line scan image of the outer surface can be well supported, thereby helping to improve the clarity of the captured image.

[0081] See also Figure 4In another embodiment, in the step of performing line scan image distortion correction on the outer bottom circular surface of the cylindrical metal part, it is mainly necessary to correct the position of the image pixel points that have been offset. Specifically, the line scan image of the bottom surface of the cylindrical metal part is corrected to the real outer bottom circular surface image of the cylindrical metal part.

[0082] First, a Cartesian coordinate system with the upper left corner of the line scan image as the origin is established, the horizontal axis is defined as the center of the cylindrical metal part, the opposite side is used as the outer contour of the cylindrical metal part, and the arrangement order of the image pixels is specified; in the Cartesian coordinate system, the horizontal coordinate of the line scan image is used to determine the angle of the pixel point in the polar coordinate system, and the vertical coordinate determines its radius, so that each pixel point is mapped to the corresponding position;

[0083] Use the following formula to map the angle-corrected bottom image of the cylindrical metal part from the Cartesian coordinate system to the polar coordinate system:

[0084]

[0085] Where r is the radius of the circle, θ is the angle of the polar coordinate system, and w is the width of the line scan image in pixels;

[0086] Secondly, when the origins of the two polar coordinates and the Cartesian coordinate system coincide, the polar coordinate system is converted to the Cartesian coordinate system by the following formula to establish the mapping relationship between the coordinates of the corresponding points in the two coordinate systems:

[0087]

[0088] Wherein, x' is the abscissa of the Cartesian coordinate system after polar coordinate mapping, and y' is the ordinate of the Cartesian coordinate system after polar coordinate mapping;

[0089] Finally, the pixel resampling method is used to fill the grayscale values ​​of the corresponding pixels in the line scan image of the bottom circular surface of the cylindrical metal part into the corrected image:

[0090]

[0091] In the formula, η=(xx 1 ) / (x 2 -x 1 ) and μ=(yy 1 ) / (y 2 -y 1 ) is a relative position parameter, (x, y) represents the relative position of (x 1 ,y 1 ) and (x 2 ,y 2After such calculation, the line scan image of the bottom surface of the cylindrical metal part can be corrected into the real outer bottom circular surface image of the cylindrical metal part, eliminating the image distortion and aberration problems, which is conducive to the subsequent effective detection and quantitative analysis of the defect characteristics of the outer surface of the cookware 30.

[0092] The implementation of the embodiments of the present invention will have the following beneficial effects: when the line scan image correction method for the outer surface of a cylindrical high-reflective part of the present scheme is used to detect whether there are defects on the appearance surface of a cylindrical metal part, first, a line scan image detection device is built and the parameter setting is completed; in this way, the working parameters of the line scan image detection device are optimized according to the size, material, etc. of the cylindrical metal part to obtain a better detection effect; the highly reflective metal surface specifically includes the cylindrical outer surface of the cylindrical metal part and the outer bottom circular surface connected to the lower end of the cylindrical outer surface (for ease of understanding, the cylindrical metal part can be regarded as a cooker 30), and then, a line scan image is collected on the outer surface of the cylindrical metal part, and then the collected line scan image of the outer surface of the cylindrical metal part is angled. Correction; then, the line scan image distortion correction is performed on the outer bottom circular surface of the cylindrical metal part, so that the corrected line scan image of the outer contour surface of the complete cylindrical metal part can be obtained; the line scan image detection device of this scheme proposes a corresponding line scan image distortion correction algorithm, thereby eliminating the geometric distortion in the overall line scan image of the outer wall cylindrical surface and the outer bottom circular surface of the cylindrical high-reflective metal thin-walled part, and obtaining a high-resolution distortion-free image of the outer surface of the cylindrical high-reflective metal thin-walled part; by obtaining an accurate image of the outer surface of the cylindrical high-reflective metal thin-walled part, the defects of the outer surface of the cylindrical high-reflective metal thin-walled part can be more accurately detected and analyzed, which can improve accuracy and reliability, and can better meet the needs of the industrial cylindrical high-reflective metal thin-walled part external defect detection site. The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent application. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for this invention shall be based on the attached claims.

Claims

1. A method for correcting line scan images of the outer surface of a cylindrical high-reflective part, characterized in that: The steps include: Build the line scan image detection device and complete the parameter setting; Line scan image acquisition of the outer surface of a cylindrical metal part; Performing angle correction on the collected line scan image of the outer surface of the cylindrical metal part; Perform line scan image distortion correction on the outer bottom circular surface of a cylindrical metal part; Obtain a corrected line scan image of the outer contour of a complete cylindrical metal part; Among them, in the step of performing angle correction on the collected line scan image of the outer surface of the cylindrical metal part, the mathematical relationship formula of the angle between the line scan image and the ideal image plane is obtained as follows: Where α is the angle between the image plane and the bottom of the pot, β is the angle between the image plane and the side of the pot, and h c is the height of the linear array camera from the image plane, l c is the actual distance from the linear array camera lens to the outer surface of the cylindrical metal part; The mathematical relationship between the pixel size of the line scan image of the outer surface of a cylindrical metal part and the optical axis of the line scan camera can be inferred: Wherein, w' is the ideal pixel width of the line scan image, h1' is the ideal pixel height of the bottom circular surface line scan image, h1 is the actual pixel height of the bottom circular surface line scan image, h2' is the ideal pixel height of the outer wall cylindrical surface line scan image, h2 is the actual pixel height of the outer wall cylindrical surface line scan image, p is the pixel size, R is the line frequency of the linear array camera, H is the field of view, and f is the length of the linear photosensitive element.

2. The method for correcting the line scan image of the outer surface of a cylindrical high-reflective part according to claim 1, characterized in that: The step of building the line scan image detection device specifically includes setting the angle of the line array camera and the distance between the line array camera and the cylindrical metal part so that the line array camera can completely capture the outer surface image of the cylindrical metal part; The upper boundary of the line scan image corresponds to the center of the outer bottom circular surface of the cylindrical metal part, and the lower boundary corresponds to the lowest end of the cylindrical surface of the outer wall of the cylindrical metal part.

3. The method for correcting the line scan image of the outer surface of a cylindrical high-reflective part according to claim 1, characterized in that: The step of building the line scan image detection device specifically includes setting the rotation speed of the rotating platform to match the line frequency of the line array camera: R=2πr·v T / (a·C) (3) Where r is the radius of the cylindrical metal part, v T is the rotation speed of the rotating platform, a is the pixel accuracy, and C is the number of turns of the rotating platform.

4. The method for correcting the line scan image of the outer surface of a cylindrical high-reflective part according to claim 1, characterized in that: The step of building the line scan image detection device specifically includes adjusting the irradiation angle of the industrial line light source so that the industrial line light source adopts a low-angle irradiation method; a total of four industrial line light sources are set, two of which are vertically arranged and the remaining two are horizontally arranged; the incident angle of the vertically arranged industrial line light source and the angle between the cross-section of the side of the cylindrical metal part are 30°, and the incident angle of the horizontally arranged industrial line light source and the angle between the bottom of the cylindrical metal part are 25°.

5. The method for correcting line scan images of the outer surface of a cylindrical high-reflective component according to claim 1, characterized in that: In the step of performing line scan image distortion correction on the outer bottom circular surface of the cylindrical metal part, the line scan image of the bottom surface of the cylindrical metal part is corrected into a real outer bottom circular surface image of the cylindrical metal part; Firstly, a Cartesian coordinate system with the upper left corner of the line scan image as the origin is established, the horizontal axis is defined as the center of the cylindrical metal part, the opposite side is defined as the outer contour of the cylindrical metal part, and the arrangement order of the image pixels is specified; In the Cartesian coordinate system, the horizontal coordinate of the line scan image is used to determine the angle of the pixel point in the polar coordinate system, while the vertical coordinate determines its radius, thereby mapping each pixel point to the corresponding position; Use the following formula to map the angle-corrected bottom image of the cylindrical metal part from the Cartesian coordinate system to the polar coordinate system: Where r is the radius of the circle, θ is the angle of the polar coordinate system, and w is the width of the line scan image in pixels; Secondly, when the origins of the two polar coordinates and the Cartesian coordinate system coincide, the polar coordinate system is converted to the Cartesian coordinate system by the following formula to establish the mapping relationship between the coordinates of the corresponding points in the two coordinate systems: Wherein, x' is the abscissa of the Cartesian coordinate system after polar coordinate mapping, and y' is the ordinate of the Cartesian coordinate system after polar coordinate mapping; Finally, the pixel resampling method is used to fill the grayscale values ​​of the corresponding pixels in the line scan image of the bottom circular surface of the cylindrical metal part into the corrected image: In the formula, η = (x-x1) / (x2-x1) and μ = (y-y1) / (y2-y1) are relative position parameters.

6. A collection device based on the line scan image correction method for the outer surface of a cylindrical high-reflective part according to any one of claims 1 to 5, characterized in that: include: Fixed frame; A line array camera, wherein the line array camera is arranged on the fixing frame; A rotating platform, the rotating platform is arranged at intervals on the opposite side of the lens of the linear array camera, a driving motor is connected to the bottom of the rotating platform, and the rotating platform is used to load cylindrical metal parts; An industrial bar light source, which is used to be arranged on the side of a cylindrical metal part; A controller, the controller being electrically connected to the linear array camera, the drive motor and the industrial bar light source; a power supply, the power supply being electrically connected to the controller; as well as A computer is electrically connected to the controller.

Images