Light source unit, system and surface defect detection method based on photometric stereo

Abstract

The present invention provides a light source unit, a system and a surface defect detection method based on photometric stereo, comprising a lamp group composed of a plurality of lamp beads, a PCB board, a fixing part and an adjustment component, wherein the lamp group and the fixing part are respectively mounted on two opposite sides of the PCB board, and the adjustment component is connected to the fixing part to drive the angle adjustment of the lamp group. By adopting a structure of two adjusting screws, the angle between the LED lamp group and the center of the light source can be adjusted, thereby solving the adjustment pain point of a fixed photometric stereo light source, realizing the adjustment of the shooting angle of the lamp group, and realizing the application of illumination at more angles.

Description

Technical Field

[0001] The present invention relates to the technical field of optical equipment, and in particular to a light source unit, a system and a surface defect detection method based on photometric stereo. Background Art

[0002] Photometric stereo is a technology that restores three-dimensional structure based on changes in the intensity of reflected light on the surface of an object. Compared with methods such as structured light, triangulation, and shape from shading, photometric stereo has the advantages of low cost, simple structure, and greater sensitivity to defects. Photometric stereo has higher reconstruction accuracy and can restore detailed changes on continuous surfaces.

[0003] The existing patent document with publication number CN116399870A discloses a feature detection light source system, including an outer cover, having a mounting structure at its first end, and defining an outer edge at its second end and the first end. The outer cover includes an inner surface between the first end and the second end. There are multiple raised surfaces on the inner surface. Multiple light sources are coupled to the multiple raised surfaces on the inner surface of the outer cover, and power lines that provide power to the light sources are wired between the raised surfaces of the outer cover. A cutout can be set on the outer edge of the outer cover, and the detection object or a part of it can pass through the corresponding position of the cutout.

[0004] The light sources currently used by photometric stereo are basically fixed angles and levels, and the angles or number of light groups are limited. There are many limitations for photometric stereo detection with high accuracy or when shooting scenes require more radiation. The reason is that many shooting products do not meet the assumptions of photometric stereo for Lambert surfaces, so more lighting directions are needed to increase the robustness of the surface normal solution. However, with fewer light sources, some surface details may become blurred due to insufficient or excessive lighting, and fewer lighting conditions will lead to a lot of uncertainty in the detection details. Summary of the invention

[0005] In view of the defects in the prior art, an object of the present invention is to provide a light source unit, a system and a surface defect detection method based on photometric stereo.

[0006] According to a light source unit provided by the present invention, the light source unit comprises a lamp group consisting of a plurality of lamp beads, a PCB board, a fixing part and an adjustment component. The lamp group and the fixing part are respectively installed on two opposite sides of the PCB board, and the adjustment component is connected to the fixing part to drive the angle adjustment of the lamp group.

[0007] Preferably, the adjustment assembly comprises an adjustment member, an adjustment spring and an adjustment rod;

[0008] The adjusting member is connected to the fixing member;

[0009] The adjusting rods include two adjusting rods, which are movably mounted on both sides of the adjusting member, and the axes of the two adjusting rods are perpendicular to the plane where the PCB board is located;

[0010] The adjusting spring is installed between the two adjusting rods, and the adjusting spring is stretched or contracted along a direction perpendicular to the plane where the PCB board is located.

[0011] Preferably, the adjusting rod comprises an adjusting screw, and the adjusting screw is threadably connected to the adjusting member.

[0012] Preferably, the axis of the adjusting member and the axis of the fixing member intersect perpendicularly at the center of the PCB board;

[0013] The adjusting spring is installed at the center of the adjusting member, and the distances between the two adjusting rods and the adjusting spring are equal.

[0014] The present invention further provides a light source system, comprising a light source layer and a control interface, wherein the light source layer comprises one or more layers, and each light source layer is provided with a corresponding control interface;

[0015] Multiple light source layers are stacked, and the sizes of the multiple light source layers are reduced in a step-by-step manner;

[0016] The light source layer includes a plurality of light source units, and the plurality of light source units are connected end to end to form a light source opening.

[0017] Preferably, the light source layer is covered with a light source shell, an adjustment hole is provided in the light source shell, and the adjustment hole is provided above the adjustment component.

[0018] Preferably, an adjustment hole cap is provided on the light source housing, and the adjustment hole cap matches the adjustment hole.

[0019] The present invention also provides a surface defect detection method based on photometric stereo, the detection system includes a collection device and a light source system, and the method includes:

[0020] Step 1: Use the acquisition device and the light source system to acquire the image of the surface of the object to be measured;

[0021] Step 2: Process the acquired images using a photometric stereo algorithm to detect defects on the surface of the object to be tested.

[0022] Preferably, the step one comprises:

[0023] The surface of the object to be measured required for the focusing of the angle of view of the acquisition device remains unchanged;

[0024] Light up one or more light source layers in the light source system to illuminate the surface of the object to be measured, and adjust the angle between one or more light source layers and the center of the light source system to form a variety of different angles;

[0025] The acquisition device is used to collect images of the surface of the object to be measured irradiated by the light source system at different angles.

[0026] Preferably, the step 2 comprises:

[0027] The images collected by the light source system at different angles to illuminate the surface of the object to be tested are processed using the photometric stereo algorithm.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention adopts a structure of two adjustment screws (such as loose screws) to adjust the angle between the LED light group and the center of the light source, thereby solving the adjustment pain point of the fixed photometric stereo light source, and can freely adjust the shooting angle of the light group ±45°, thus realizing more angle illumination applications. More light source angles provide more illumination modes, which means that more information about the surface reflection characteristics can be captured, which is particularly important for reconstructing objects with complex surface structures or non-uniform materials;

[0030] 2. The present invention adopts a polygonal design (such as an octagonal design) to increase the number of illumination points of a single-layer light source to multiple (such as 8). Compared with the traditional four-partition strip light, ring light and arch light design, it solves the problem of fewer illumination directions and improves the accuracy and stability of photometric stereo technology applications. Increasing the direction of the light source helps to "illuminate" the details of the detection from multiple perspectives and reduce the uncertainty caused by insufficient lighting conditions;

[0031] 3. The present invention adopts a design of multi-layer light source layer combination and superposition (one or more layers are freely combined and superimposed) to support more application scenarios of product shooting, and solves the problem of poor adaptability of photometric stereo light sources in shooting in different industries or processes. In the photometric stereo method, a linear system called the photometric stereo equation is usually used to estimate the surface normal vector. Increasing the number of light source layers will increase more illumination directions, which is equivalent to adding constraints to the set of equations, making the solution more stable and reliable, and maintaining a high level of accuracy even in the presence of noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0033] Figure 1 A schematic diagram mainly showing the structure of the lamp assembly of the present invention;

[0034] Figure 2 A schematic diagram mainly showing the fixing method of the adjustment component of the present invention;

[0035] Figure 3A schematic diagram mainly showing the structure of the regulating assembly of the present invention;

[0036] Figure 4 A schematic diagram showing a top view of a single light source layer of the present invention;

[0037] Figure 5 A schematic diagram of the side view structure of a single light source layer of the present invention is mainly shown;

[0038] Figure 6 A schematic diagram of the side view structure of the light source system of the present invention is mainly embodied;

[0039] Figure 7 A schematic diagram of the three-dimensional structure of the light source system of the present invention is mainly embodied;

[0040] Figure 8 A schematic diagram mainly showing the light source system of the present invention detecting the surface of the object to be tested;

[0041] Fig. 9 A schematic diagram mainly showing the light source of the present invention detecting the surface of the object to be tested;

[0042] Fig.10 A schematic diagram mainly showing the results of the multi-layer light source layer detecting the surface of the object to be tested according to the present invention;

[0043] Fig.11 A schematic diagram mainly showing the result of the single-layer light source layer detecting the surface of the object to be tested of the present invention;

[0044] Fig.12 It mainly embodies the schematic diagram of the multi-layer light source layer detecting the surface of the object to be tested of the present invention.

[0045] As shown in the figure:

[0046] Light set 101 Second light source housing 208 Second control interface 210 PCB board 102 Third light source housing 308 Third control interface 310

[0047] Fixing member 103 Fourth light source housing 408 Fourth control interface 410

[0048] Adjustment member 104 Fifth light source housing 508 Fifth control interface 510

[0049] Adjusting spring 105 Sixth light source housing 608 Sixth control interface 610

[0050] Adjusting screw 106 Second adjusting hole cap 209 Sixth light source opening 611

[0051] Adjustment hole 107 Third adjustment hole cap 309 Camera 710

[0052] Light source housing 108 Fourth adjustment hole cap 409 Lens 711

[0053] Adjustment hole cap 109 Fifth adjustment hole cap 509 Object to be tested 712

[0054] Control interface 110 Sixth adjustment hole cap 609

[0055] Light source opening 111 DETAILED DESCRIPTION

[0056] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0057] like Figures 1 to 3 As shown, a light source unit provided according to the present invention includes a lamp group 101 composed of a plurality of lamp beads, a PCB board 102, a fixing member 103 and an adjusting component. The lamp group 101 and the fixing member 103 are respectively installed on two opposite sides of the PCB board 102, and the adjusting component is connected to the fixing member 103 to drive the angle adjustment of the lamp group 101.

[0058] Specifically, the adjustment assembly includes an adjustment member 104, an adjustment spring 105, and an adjustment rod. The adjustment member 104 is connected to the fixing member 103, and the adjustment rod includes two adjustment rods, which are movably mounted on both sides of the adjustment member 104, and the axes of the two adjustment rods are perpendicular to the plane where the PCB board 102 is located. The adjustment spring 106 is installed between the two adjustment rods, and the adjustment spring 105 stretches or contracts in a direction perpendicular to the plane where the PCB board 102 is located. A preferred embodiment is: the adjustment rod includes an adjustment screw 106, the adjustment screw 105 is threadedly connected to the adjustment member 104, the axis of the adjustment member 104 and the axis of the fixing member intersect perpendicularly at the center of the PCB board 102, the adjustment spring 105 is installed at the center of the adjustment member 104, and the two adjustment rods are equidistant from the adjustment spring 105.

[0059] like Figure 1 The figure shows an implementation of the lamp group setting. The lamp beads are evenly arranged in three rows to form a lamp group 101. The lamp beads are preferably LED lamps. The LED lamp group 101 is welded on a PCB board 102, supporting the application of lamp beads in multiple spectral bands such as R\G\B\W\UV\IR. Each PCB board 102 is connected using a single line to form a single light source. The PCB board 102 is compactly fixed using a PCB fixing part 103. The fixing part is attached to the middle position of the back of the PCB board 102 and is slightly shorter than the length of the PCB board 102. The adjusting part 104 is installed close to the PCB fixing part 103. Figure 2 As shown, the axis of the adjusting member 104 and the axis of the fixing member 103 intersect perpendicularly at the center of the PCB board 102, and such a setting can more conveniently adjust the angle of the lamp assembly 101. The height of the adjusting member 104 is greater than that of the fixing member 103, so it is more convenient to contact the adjusting screw, and the width and thickness of the adjusting member 104 are also greater, so it can receive greater adjustment pressure, thereby protecting the PCB board 102 from being damaged by the adjustment pressure.

[0060] like Figure 3 As shown, for the angle adjustment design of the lamp group 101, the adjustment member 104 is connected to the adjustment screw 106 and the adjustment spring 105 at the same time. The two adjustment screws 106 are movably installed on the left and right sides of the adjustment member 104, respectively. The axes of the two adjustment screws 106 are perpendicular to the plane where the PCB board 102 is located. The adjustment spring 105 is installed between the two adjustment screws 106, and the adjustment spring 105 stretches or contracts in a direction perpendicular to the plane where the PCB board 102 is located. The adjustment spring 105 is a tension spring, which provides a backward pulling force for the adjustment member 104 and is installed at the center of the adjustment member 104. The two adjustment screws 106 are at an equal distance from the adjustment spring 105. The rotation of the adjustment member 104 is controlled by adjusting the height of the left and right adjustment screws 106, thereby driving the angle adjustment of the LED lamp group 101, and realizing the application of adjustable light source irradiation angle.

[0061] The light source unit provided by the present invention uses a structure of adjusting two left and right adjustment screws 106 (such as loose screws) to adjust the illumination angle of the lamp group 101, which can freely adjust the shooting angle of the lamp group ±45°, and realize more angle illumination applications. The multi-angle lamp group 101 and the multi-layer combination lamp group 101 are more effectively adapted to various detection lighting and multi-light-point luminous stereoscopic illumination requirements.

[0062] The present invention also provides a light source system, including a light source layer and a control interface 110, wherein the light source layer includes one or more layers, and each light source layer is provided with a corresponding control interface 110. The multiple light source layers are superimposed, and the size of the multiple light source layers is reduced in a step-by-step manner; the light source layer includes a plurality of the above-mentioned light source units, and the plurality of light source units are connected end to end to form a light source opening 111. The light source layer is covered with a light source housing 108, and an adjustment hole 107 is provided in the light source housing 108, and the adjustment hole 107 is provided above the adjustment component. An adjustment hole cap 109 is provided on the light source housing 108, and the adjustment hole cap 109 matches the adjustment hole 107.

[0063] like Figures 4 to 5The figure shows an implementation method of the light source layer setting. Each light source layer is octagonal in design. Each side of each light source layer has an independent light source housing 108 and an adjustment module. The eight control lines are all controlled by the serial port control interface 110 to realize power supply and brightness control. Therefore, the interface controls the power supply, brightness adjustment and on / off time control of the light group 101 on the PCB board 102 through each circuit. The serial port design is more firmly installed to avoid poor contact or control signal interference during long mobile shooting. Each light source layer has an independent light source opening, such as Figure 4 The light source opening 111 shown can support the smooth passage of light from the upper light source. An adjustment hole 107 is arranged above the adjustment component of each light source unit, and an adjustment hole cap 109 is arranged on the light source housing 108. The design of an adjustment hole cap 109 is added behind the adjustment hole 107 to prevent foreign matter from entering the adjustment hole 107 and causing blockage. The material of the adjustment hole cap 109 is preferably rubber material, which is not easy to damage. The eight light sources are all illuminated using a flash mode, and the lamp beads can dissipate heat through the air without the need for an external fan. The adjustment hole 107 is designed at the adjustment position to reserve adjustment space for convenient use of the conventional adjustment screw 106. The light source housing 108 is designed with a large space, mainly to support the passage of multiple light sources and the heat dissipation of the PCB board 102. Heat dissipation will affect the service life of the lamp beads. Therefore, the space of the light source housing 108 is increased, which can effectively solve the integration and heat dissipation problems of multiple wiring materials.

[0064] The light source system provided by the present invention adopts an octagonal design in which the light source layer increases the number of illumination points of a single layer of light source to 8. Compared with the traditional four-zone strip light, ring light and arch light design, it solves the problem of fewer illumination directions and improves the accuracy and stability of photometric stereo technology applications. Increasing the light source direction helps to "illuminate" the details of the detection from multiple perspectives and reduce the uncertainty caused by insufficient lighting conditions.

[0065] like Figure 6 to Figure 7The figure shows an implementation of a multi-layer, multi-angle, photometric stereo light source design: the light source system includes a multi-layer light source unit, wherein each light source layer includes a plurality of light source units, the light source unit includes a lamp group 101 (composed of a plurality of lamp beads arranged), the lamp beads are respectively welded on a PCB board 102, a fixing member 103, an adjusting member 104, an adjusting spring 105 and an adjusting screw 106, and the angle of the PCB board 102 can be adjusted by adjusting the up and down deflection of the adjusting member 104. The adjusting spring 105 is a tension spring, which provides a backward pulling force for the PCB board 102 and the lamp group 101, and the two adjusting screws 106 move up and down to cooperate with the adjustment, providing an upward or downward force to rotate the adjusting member 104 and adjust the angle of the lamp group 101. The housing space of the light source housing 108 is designed to be relatively large, and the line of the octagonal lamp group 101 can pass through. The adjusting hole cap 109 is mainly designed to prevent foreign objects from blocking the adjusting hole design, and the control interface 110 is designed as a serial port, which is mainly for the lamp bead power supply and brightness adjustment control. The multi-layer light source layer includes multiple light source housings, multiple control interfaces, multiple adjustment hole caps and multiple light source openings. For example, the six-layer light source layer includes, in addition to the first light source housing, the first adjustment hole cap and the first controller interface, the second light source housing 208, the second adjustment hole cap 209, the second controller interface 210, the third light source housing 308, the third adjustment hole cap 309, the third control interface 310, the fourth light source housing 408, the fourth adjustment hole cap 409, the fourth control interface 410, the fifth light source housing 508, the fifth adjustment hole cap 509, the fifth control interface 510, the sixth light source housing 608, the sixth adjustment hole cap 609, the sixth control interface 610 and the sixth light source opening 611. The composition and structural design of each layer is consistent to ensure the friendliness of installation, adjustment and application.

[0066] like Figure 6 The figure shows an implementation method of designing the number of light source layers in a multi-layer, multi-angle photometric stereo light source system, using six layers of octagonal light sources stacked in combination, each layer of light sources has a separate control interface 110, such as: a second control interface 210, a third control interface 310, an independent adjustment device and an independent light source housing 108. The size of each layer of light sources decreases in a step-by-step manner until it reaches the smallest layer of light sources. The six-layer octagonal photometric stereo light source has a total of forty-eight light source units, each of which can support angle adjustment of ±45°, and supports multiple band applications such as R\G\B\W\UV\IR and brightness adjustment levels of 0-255 levels (i.e., 256 levels). The light source opening 111 superimposed on the smallest layer of light sources is designed to be a circular opening to support lens applications, such as the sixth light source opening 611. Figures 7 and 8 As shown, the multi-layer, multi-angle, and multi-luminosity stereo light source design can also use one or more layers of light sources to overlap according to shooting requirements. The overall combination is more convenient and is used to support the shooting of different types of products.

[0067] The light source system provided by the present invention can support more application scenarios for product shooting by adopting a design of multi-layer light source layer combination and superposition (one or more layers are freely combined and superimposed), thereby solving the problem of poor adaptability of photometric stereo light sources in shooting in different industries or processes. In the photometric stereo method, a linear system called the photometric stereo equation is usually used to estimate the surface normal vector. Increasing the number of light source layers will increase more illumination directions, which is equivalent to adding constraints to the set of equations, making the solution more stable and reliable, and maintaining a high level of accuracy even in the presence of noise.

[0068] The present invention also provides a surface defect detection method based on photometric stereo, the detection system includes a collection device and a light source system, and the method includes:

[0069] Step 1: Use the acquisition device and the light source system to acquire the image of the surface of the object to be measured;

[0070] Step 2: Process the acquired images using a photometric stereo algorithm to detect defects on the surface of the object to be tested.

[0071] Specifically, step one includes:

[0072] The surface of the object to be measured required for the focusing of the angle of view of the acquisition device remains unchanged;

[0073] Light up one or more light source layers in the light source system to illuminate the surface of the object to be measured, and adjust the angle between one or more light source layers and the center of the light source system to form a variety of different angles;

[0074] The acquisition device is used to collect images of the surface of the object to be measured irradiated by the light source system at different angles.

[0075] Step 2 includes:

[0076] The images collected by the light source system at different angles to illuminate the surface of the object to be tested are processed using the photometric stereo algorithm.

[0077] The multi-layer and multi-angle photometric stereo light source design uses one or more layers of light sources to be superimposed according to the shooting requirements. The overall combination is relatively convenient and is used to support the shooting of different types of products. Photometric stereo is a three-dimensional surface shape reconstruction method based on multi-view imaging technology. Photometric stereo uses multiple images to restore the three-dimensional structure of the object surface. It requires that the relative position of the object to be measured and the acquisition device remain unchanged, and then uses light sources in different directions to illuminate the object, thereby producing different light and dark effects, and calculates and synthesizes three-dimensional images based on images taken from multiple angles. This method infers the normal vector of the object surface by illuminating the object from different angles and capturing the changes in the reflected light on the object surface, thereby reconstructing the geometric shape of the object.

[0078] like Figure 8As shown, the acquisition device preferably includes a camera 710 and a lens 711, which acquire images of the surface of the object to be measured 712. During the acquisition process, the relative positions of the object to be measured and the camera are kept unchanged, and the angle of each light source unit in each light source layer is changed to obtain light sources in different directions to illuminate the object, thereby producing different light and dark effects. The images of the object surface acquired at various different angles are processed using a photometric stereo algorithm to obtain surface features of the object to be measured, including concave and convex defects.

[0079] like Fig. 9 As shown, t = ρ (N * L) * l

[0080] in:

[0081] t: represents the measured pixel intensity (pixel value)

[0082] 1: Indicates the light source intensity (radiation intensity)

[0083] ρ: represents the diffuse reflectance of the surface of the object to be measured

[0084] L: represents the three-dimensional light source unit position vector

[0085] N: represents the three-dimensional surface normal vector

[0086] Both N and L are vectors in three-dimensional space, and the intensity of the light source can be represented by a constant 1. The pixel value t can be obtained directly from the image, and the direction of the light source on the right can be calibrated in advance. Then, when the object to be tested and the camera are both stationary, at least three non-coplanar light rays can be used to illuminate the surface of the object to solve N and ρ: let the three light source direction vectors form the matrix L = [L1, L2, L3] T, and the corresponding three pixel values ​​form the vector t i , then there is ρ i =|L -1 t i |

[0087]

[0088] When light sources illuminate the surface of an object, shadows may be generated, so the area that cannot be illuminated by three light sources at the same time will not be able to be solved. Therefore, more light sources can usually be used to illuminate the object from different directions and form an image to solve this problem.

[0089] Assuming n>=3, then we have:

[0090] L = [L1, L2, L3, ..., L n ] T

[0091] t i =[t i1 , t i2, t i3 ,...,t in ] T =ρ i LN i

[0092] So:

[0093] ρ i =|(L T L)w 1 L T t i |

[0094]

[0095] in:

[0096] t i : represents the pixel value at position i

[0097] t in : represents n pixel values

[0098] l: indicates the light source intensity (radiation intensity)

[0099] ρ i : represents the diffuse reflectance at position i

[0100] L n : represents the position vector of n light source units

[0101] N i : represents the surface unit normal vector

[0102] Therefore, photometric stereo actually uses multiple light source directions to illuminate the object. Theoretically, photometric stereo only needs more than three light source directions, but the model in the actual test may not meet the assumption of photometric stereo for Lambert surface, so more lighting directions are needed to increase the robustness of the surface normal solution. The lighting directions in the data sets widely used to test photometric stereo are basically far more than three (8, 16, 48, etc.). When shooting slight concave and convex defects (such as: bruises, indentations, scratches, etc.), Fig.10 As shown in the figure, when high resolution accuracy is required, it is necessary to flash the light sources of 48 groups of lights at all angles one by one to shoot, and then calculate the image of light from all directions to improve the accuracy of detection. If it is for ordinary concave-convex defects (such as convex spots, deformation, defects, etc.), it is only necessary to light up a circle of lights (4 or 8 groups) one by one to shoot. Fig.11 As shown in Figure 1, the advantage of lighting up some light sources is that fewer images are taken, the calculation is fast, and the detection efficiency is higher. The light source is designed as a six-layer octagon. Even if multiple layers are combined, the normal vector N will remain unchanged, such as Fig.12As shown, each of the six light source layers is closed 360° for shooting, ensuring that the object to be tested is illuminated by light in all directions. If multiple columns of light source units are combined, multiple spatial normal vectors N will appear, and they will be separated from the camera shooting center, making it impossible to perform photometric stereo calculation.

[0103] In photometric stereo, the direction of the light source is crucial, because illumination from different directions will produce different shadow and highlight effects on the image, thus providing the depth information required for reconstruction. Therefore, increasing the number of light source directions can improve the accuracy and robustness of reconstruction. However, increasing the number of light source directions is not without cost. It will increase the time for data acquisition and processing, and may also introduce additional noise and computational complexity. Therefore, in practical applications, reconstruction accuracy and efficiency are usually weighed, and an appropriate number of light groups (such as one layer of eight-sided illumination, two layers of eight-sided illumination, etc.) is selected according to the detection requirements and detection accuracy of the photographed object. In addition, the distribution of the light source also needs to be carefully designed to ensure that the illumination from all directions can evenly cover the entire surface of the object, so as to obtain the best reconstruction effect.

[0104] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0105] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A light source unit, characterized in that: The invention comprises a lamp group (101) composed of a plurality of arranged lamp beads, a PCB board (102), a fixing member (103) and an adjustment component, wherein the lamp group (101) and the fixing member (103) are respectively mounted on two opposite sides of the PCB board (102), and the adjustment component is connected to the fixing member (103) to drive the angle adjustment of the lamp group (101); The adjustment assembly comprises an adjustment member (104), an adjustment spring (105) and an adjustment rod; The adjusting member (104) is connected to the fixing member (103); The adjusting rods include two adjusting rods, which are movably mounted on both sides of the adjusting member (104), and the axes of the two adjusting rods are perpendicular to the plane where the PCB board (102) is located; The adjusting spring (105) is installed between the two adjusting rods, and the adjusting spring (105) stretches or contracts in a direction perpendicular to the plane where the PCB board (102) is located; The adjusting rod comprises an adjusting screw (106), and the adjusting screw (106) is threadedly connected to the adjusting member (104); The axis of the adjusting member (104) and the axis of the fixing member (103) intersect perpendicularly at the center of the PCB board (102); The adjusting spring (105) is installed at the center of the adjusting member (104), and the two adjusting rods are equidistant from the adjusting spring (105).

2. A light source system, characterized in that: It comprises a light source layer and a control interface (110), wherein the light source layer comprises one or more layers, and each light source layer is provided with a corresponding control interface (110); Multiple light source layers are stacked, and the sizes of the multiple light source layers are reduced in a step-by-step manner; The light source layer comprises a plurality of light source units as claimed in claim 1, and the plurality of light source units are connected end to end to form a light source opening (111).

3. The light source system according to claim 2, characterized in that: The light source layer is coated with a light source housing (108), an adjustment hole (107) is provided in the light source housing (108), and the adjustment hole (107) is arranged above the adjustment component.

4. The light source system according to claim 3, characterized in that: An adjustment hole cap (109) is provided on the light source housing (108), and the adjustment hole cap (109) matches the adjustment hole (107).

5. A surface defect detection method based on photometric stereo, characterized in that: The detection system comprises a collection device and a light source system according to any one of claims 2 to 4, and the method comprises: Step 1: Use the acquisition device and the light source system to acquire the image of the surface of the object to be measured; Step 2: Process the acquired images using a photometric stereo algorithm to detect defects on the surface of the object to be tested.

6. The surface defect detection method based on photometric stereo according to claim 5, characterized in that: The step one comprises: The surface of the object to be measured required for the focusing of the angle of view of the acquisition device remains unchanged; Light up one or more light source layers in the light source system to illuminate the surface of the object to be measured, and adjust the angle between one or more light source layers and the center of the light source system to form a variety of different angles; The acquisition device is used to collect images of the surface of the object to be measured irradiated by the light source system at different angles.

7. The surface defect detection method based on photometric stereo according to claim 6, characterized in that: The second step comprises: The images collected by the light source system at different angles to illuminate the surface of the object to be tested are processed using the photometric stereo algorithm.

Images