CN-121994805-A - Surface defect detection device and detection method for cylindrical member

CN121994805ACN 121994805 ACN121994805 ACN 121994805ACN-121994805-A

Abstract

The application discloses a surface defect detection device and a detection method for a cylindrical member, wherein the surface defect detection device comprises a support structure, a driving mechanism, a first image acquisition unit, a second image acquisition unit and a third image acquisition unit, wherein the support structure is used for supporting the cylindrical member to be detected, the driving mechanism is connected with a butt joint section of the cylindrical member and used for driving the cylindrical member to rotate around the central axis of the cylindrical member, the first image acquisition unit comprises a surface scanning camera and an annular light source, the optical axis of the surface scanning camera is coaxially arranged with the central axis of the annular light source, the optical axis of the surface scanning camera is parallel to and spaced from the central axis of the cylindrical member, the second image acquisition unit comprises a line scanning camera and a line light source, the line scanning camera and the line light source are arranged towards the circumferential surface of the cylindrical member, the first image acquisition unit is provided with two groups and is respectively used for acquiring images of two end surfaces of the main body section, and the second image acquisition unit is used for acquiring images of the circumferential surface of the cylindrical member. By the method and the device, the detection efficiency and the detection precision can be improved, and the detection cost can be reduced.

Inventors

LIU DONG
LI XIYUAN
WANG ZEDONG
WANG SHILING
ZHANG FENGWEI
LIU CHONG

Assignees

浙江大学

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (12)

1. A surface defect detecting device for a cylindrical member including at least a main body section and a butt section formed at both ends of the main body section and coaxial with the main body section, the surface defect detecting device comprising: a support structure for supporting the cylindrical member to be inspected; The output end of the driving mechanism is connected with the butt joint section of the cylindrical member and is used for driving the cylindrical member to rotate around the central axis of the driving mechanism; a first image acquisition unit including a facial scanning camera and an annular light source, an optical axis of the facial scanning camera being arranged coaxially with a central axis of the annular light source, and the optical axis of the facial scanning camera being arranged parallel to and at intervals from a central axis of the cylindrical member; a second image acquisition unit including a line scan camera and a line light source, both of which are arranged toward a circumferential surface of the cylindrical member; the first image acquisition units are provided with two groups and are respectively used for acquiring images of the end faces of the two ends of the main body section in the cylindrical member, and the second image acquisition units are used for acquiring images of the circumferential face of the cylindrical member.
2. The surface defect detection apparatus of claim 1, wherein an optical axis of the facial scan camera is configured to have a first set pitch with a central axis of the cylindrical member, and a lens end face of the facial scan camera has a second set pitch with an end face of the body section in the cylindrical member.
3. The surface defect inspection apparatus of claim 1, further comprising a housing comprising a base and a mount disposed on the base, wherein the support structure, the drive mechanism, the first image acquisition unit, and the line scan camera are all disposed on the base, wherein the line light source is disposed on the mount, and wherein the line light source is configured to swing relative to the mount to adjust an illumination angle of the line light source relative to the cylindrical member.
4. The surface defect detection apparatus of claim 1, wherein the line scan camera is a time-sharing strobe line scan camera, the line light sources are provided in groups, and the groups of line light sources are configured to have different illumination angles with respect to the cylindrical member.
5. The surface defect detection apparatus of claim 1, wherein the line scan cameras are provided in two groups, the two groups being spaced apart along the axial direction of the cylindrical member.
6. The surface defect detection apparatus as claimed in any one of claims 1 to 5, wherein the drive mechanism comprises a drive motor and a clamp capable of being driven to rotate by the drive motor, the clamp being for clamping and fixing the butt section in the cylindrical member.
7. The surface defect detection apparatus as claimed in any one of claims 1 to 5, wherein the support structure comprises two sets of support seats for supporting respective ends of the body section in the cylindrical member.
8. The surface defect inspection apparatus of claim 7, further comprising two sets of lifting and positioning mechanisms, wherein the two sets of lifting and positioning mechanisms are disposed in one-to-one correspondence with the two sets of supporting seats and are respectively used for driving the corresponding supporting seats to lift so as to adjust the height position of the central axis of the cylindrical member placed on the supporting seats.
9. The surface defect inspection apparatus of claim 7, further comprising a horizontal positioning mechanism disposed on both sides of the cylindrical member opposite to the driving mechanism, wherein the horizontal positioning mechanism is connected to the support base and the first image capturing unit on the side and is used for driving the support base and the first image capturing unit to translate synchronously so as to adjust the distance between the two groups of support bases and the two groups of first image capturing units.
10. The surface defect detecting apparatus according to claim 7, wherein the support base is provided with a placement groove and a contact structure provided to an inner wall of the placement groove, the contact structure being provided with an arc surface for abutting against a main body section in the cylindrical member.
11. A surface defect detection method for a cylindrical member, implemented using the surface defect detection apparatus according to any one of claims 1 to 10, characterized in that the surface defect detection method comprises: The driving mechanism is controlled to drive the cylindrical member arranged on the supporting structure to rotate successively at a set angle and a set interval time until the number of the cylindrical member is not less than one circle; Controlling the first image acquisition unit to acquire a first partial image of a part, located in the field of view of the facial scanning camera, on the end face of the main body section in the cylindrical member within the set interval duration each time; in the process of rotating the cylindrical member by a set angle each time, controlling the second image acquisition unit to acquire a second partial image of a part, located in the field of view of the line scanning camera, on the circumferential surface of the cylindrical member; And splicing the acquired first partial images to obtain an end face image of the main body section, and splicing the acquired second partial images to obtain a circumferential face image of the cylindrical member.
12. The method of claim 11, wherein stitching the acquired first partial image information to obtain the end image information of the main body segment comprises: Determining the number N of the first partial images according to the set angle and numbering the first partial images as (1, 2, & gtN) according to the acquisition sequence; intercepting each first partial image by using three coordinates of A, B and C in a camera view field to obtain an ROI region image, wherein the coordinates of A points are (m, N), the coordinates of B points are (m+ rcos α, n+ rsin α), the coordinates of C points are ((m+ rcos (α+θ), n+ rsin (α+θ)), wherein the A point is the center of an end face of a main body section, r is the radius of the end face of the main body section, θ is the set angle, n×θ=2pi, and 0≤α≤2pi; converting camera coordinates (X, Y) of each ROI area image into global coordinates (X, Y) through coordinate mapping, wherein the mapping relation between the camera coordinates (X, Y) and the global coordinates (X, Y) is as follows: ; and extracting the actual contour of each ROI region image by adopting a contour detection algorithm, and sequentially splicing N ROI region images according to global coordinates (X, Y) to obtain an end face image of the main body section.

Description

Surface defect detection device and detection method for cylindrical member Technical Field The application relates to the technical field of surface defect detection, in particular to a surface defect detection device and method for a cylindrical member. Background The carbon fiber composite material has high specific strength, high specific modulus and excellent impact resistance, and the characteristics thereof lead the carbon fiber composite material to be widely applied to the field of industrial products which need to be compatible with high strength and light weight. For example, in the field of nuclear industry, carbon fiber composites can be used in uranium enriched centrifuge rotors. However, the surface defects such as bubbles, falling, inclusions, wrinkles, scratches and the like often occur in the production process of the parts made of the carbon fiber materials, and the surface defects may be seriously affected in practical application. Taking the nuclear industry field as an example, when a centrifuge device made of carbon fiber rotates at a high speed under high temperature and high pressure conditions, the surface defects can reduce the damage resistance of the material and even directly cause the burst of the device. At present, the surface defect detection is generally carried out on the parts made of carbon fiber materials by adopting an artificial visual method, and the problems of low efficiency, easiness in fatigue of workers, high omission rate, high false detection rate and the like exist. The curved surface structure of the cylindrical component also greatly improves the detection difficulty, and particularly for the large-caliber cylindrical component, the surface area required to be detected is larger, so that the problems of missed detection and false detection are more likely to occur. Disclosure of Invention The present application aims to solve one of the technical problems in the related art to a certain extent. To this end, the present application provides a surface defect detecting device and detecting method for a cylindrical member. In order to achieve the above object, the present application adopts the following technical scheme that a surface defect detecting device for a cylindrical member at least includes a main body section and a butt joint section formed at both ends of the main body section and coaxial with the main body section, the surface defect detecting device includes: a support structure for supporting the cylindrical member to be inspected; The output end of the driving mechanism is connected with the butt joint section of the cylindrical member and is used for driving the cylindrical member to rotate around the central axis of the driving mechanism; a first image acquisition unit including a facial scanning camera and an annular light source, an optical axis of the facial scanning camera being arranged coaxially with a central axis of the annular light source, and the optical axis of the facial scanning camera being arranged parallel to and at intervals from a central axis of the cylindrical member; a second image acquisition unit including a line scan camera and a line light source, both of which are arranged toward a circumferential surface of the cylindrical member; the first image acquisition units are provided with two groups and are respectively used for acquiring images of the end faces of the two ends of the main body section in the cylindrical member, and the second image acquisition units are used for acquiring images of the circumferential face of the cylindrical member. The application has the advantages that the images of the end surfaces of the two ends of the main body section in the cylindrical member of the first image acquisition unit are arranged, the images of the circumferential surface of the cylindrical member are acquired by the second image acquisition unit, and the acquired images are subjected to surface defect analysis by utilizing the existing mature machine vision-based surface defect detection technology, so that the detection result can be obtained. Therefore, the detection efficiency and the detection precision can be remarkably improved, the detection cost is reduced, the acquired image can be stored, and the traceability of the detection result is realized. Through setting up actuating mechanism to specific positions of camera, annular light source, line are swept to face and are swept camera and line light source are designed, at the in-process of driving cylindrical component rotation through actuating mechanism, can gather the partial image in the camera visual field through first image acquisition unit and second image acquisition unit respectively, and the image of the both ends terminal surface of required main part section and the image of the periphery of cylindrical component can be obtained through the image concatenation. Through the structural design and the position layout design, the shielding influence