ADAPTABLE GRAZING ILLUMINATING IMAGE CAPTURE DEVICE

Abstract

Image capture device with adaptable grazing illumination that allows the illumination to be adapted to a surface, comprising a base plate, a support plate, a camera, a light fixed on the support plate with its light in the camera's capture field, a control unit to coordinate the camera with the fixed light, two actuators fixed to the base plate, each actuator connected to a first end of a rod to impart a translational movement, each rod with a second end, at the second ends an extendable beam is rotatably fixed which can adapt its length, a movable light fixed to it to provide transverse illumination, the movable light is connected to the control unit, when said extendable beam is close to or rests on a piece the movable light provides grazing illumination with respect to the surface of said piece.

Description

IMAGE CAPTURE DEVICE WITH GRAZING ILLUMINATION ADAPTABLE TECHNICAL FIELD OF THE INVENTION The present invention falls within the field of detecting surface defects in objects using images, specifically, using grazing illumination. BACKGROUND OF THE INVENTION One technique for detecting shallow surface defects or relief in parts or objects is shape-from-shading, which extracts three-dimensional information by creating shadows that highlight the relief. This technique relies on acquiring images of the same scene illuminated from different directions. To achieve this, multidirectional illumination is synchronized with image acquisition. Currently, several products on the market allow synchronizing image capture with the lighting system, changing the direction of illumination with each capture and subsequently combining the images. Two well-known products are: Trevista (https: / / www.sac-vision.de / en / products / trevista) and Cognex In-Sight (https: / / www.cognex.com / es-es?utm_campaign=7014W000000rYddQAE&gclid=CjwKCAjwwbólBhBJEiwAbuVUSunxharrtqq 5ZnhF4noeloXp8KfP8HYqhGcJIQv-Dxzhc4cXkh0Vmxo CjmMQAvD_BwE). To create shadows in each image, grazing light is highly recommended. Grazing light is tangential lighting, or lighting at an acute angle (typically between 5° and 20°) to the surface of the illuminated object, highlighting irregularities, deformations, texture, and so on. The design of current systems provides a fixed lighting arrangement; the lighting system elements are all on the same plane, and the product being inspected is on a parallel plane close to that lighting plane. This means they can only analyze defects on flat surfaces; otherwise, changes in the inclination of the inspection surface would mean that the lighting would not be equal in all directions, and the algorithms would not produce the same results. When there are no restrictions on the parts to be inspected, such as on a production line where different parts of different shapes and sizes are passing through, it is not possible to establish an optimal lighting configuration that is valid for the variety of parts because the surface on which the detection is performed is not flat and / or is not parallel to the lighting. The patent with publication number WO202334585A1 is known, which shows an inspection device, with scanning means such as a camera, and with positioning means that allow adaptation to the surface being inspected; however, said positioning means are mere supports, without including lights or any other element related to the inspection. Therefore, there is a need for surface defect detection that is adaptable to different types of parts, which implies a change in the surface on which the detection is applied and, therefore, a change in the lighting of that surface. DESCRIPTION OF THE INVENTION The present invention is set forth and characterized in the independent claim, while the dependent claims describe other features thereof. The object of the invention is an image capture device with adaptable grazing illumination. The technical problem to be solved is configuring said system in such a way as to adapt the illumination to the surface on which the inspection is carried out, that is, to adapt the particularity of the application and the specific needs of the products, which allows maintaining a very similar grazing illumination in all the captures of the scene. In view of the foregoing, the present invention relates to an image-capturing device with adaptable grazing illumination comprising a base plate, a support plate connected to the base plate by connecting elements, a camera, a fixed light arranged on the support plate such that the light projected by the fixed light is in the camera's capture field, and a control unit configured to coordinate the image capture by the camera with the fixed light, whereby the control unit is connected to the camera and the fixed light to manage their operation, as known in the prior art. The term "plate" is meant to signify a structural element, in principle of any thickness, although preferably of a thickness less than its other dimensions, without this in itself being a limitation to other possible structural elements, such as, for example, a cast element of a certain thickness, an assembly of several elements that give rise to a certain thickness, etc. The device is characterized by the fact that it also comprises two actuators fixed to the support plate, as a minimum configuration, although a greater number is possible as cited in the example of the detailed explanation below, each actuator connected to a first end of a rod so that it can impart a translational movement to the rod to move it away from or closer to the support plate, each rod has a second end opposite to the first end, at the second ends an extendable beam is rotatably fixed so that it can adapt its length to the position of each second end, a movable light is fixed to the extendable beam so that it can provide transverse illumination with respect to that which can be provided by the fixed light, the movable light is connected to the control unit, so the control unit also manages the illumination of said movable light,Therefore, when the extendable beam is close to or resting on a piece, the movable light can provide grazing illumination of the surface of that piece. "Fixed light" and "moving light" refer to light positioned on an element that is stationary and capable of movement, respectively. Similarly, "light" refers to any light source. For the sake of simplicity, fixed light is used to illuminate the camera's field of view, while moving light illuminates the area perpendicular to the fixed light. This avoids using specific optical or similar elements, which can make the description more complex and less clear. Thus, in use, when you want to capture an image of a piece, the extendable beam is placed or brought close to the surface of said piece, providing by its own configuration a fixed illumination and a grazing illumination, which coordinated with the camera through the control unit allows taking images with said illuminations, adding that with the same device you can change to a different surface, of the same piece or of another piece, to which the extendable beam can be adapted providing in the same way a fixed illumination and a grazing illumination to take an image with the same quality, and so on the device can be adapted to different surfaces. An advantage in line with the object of the invention is that it allows the lighting to be adapted to the surface of the part being inspected, so that the images taken are of equal quality when the surface of the part changes. Another advantage is that the control unit allows independent control of both the fixed and moving lights, adjusting any of their operating parameters, such as intensity, on / off time, etc., and to any degree. This means that any light can be switched on or off at any interval or time, providing complete control over the lighting on the subject and the timing of image capture. Therefore, images can be taken under any lighting requirements. In other words, the device provides dynamic and programmed lighting configuration for each capture, resulting in a reconfigurable and multifunctional acquisition system. This allows for different lighting to be applied to the same part, adapting at all times to the needs of the product being inspected, and in real time—that is, at the moment each image is taken. Other advantages related to dependent claims are cited below in the detailed exposition. BRIEF DESCRIPTION OF THE FIGURES This descriptive report is complemented by a set of figures, illustrative of the preferred example, and never limiting the invention. Figure 1 represents a perspective view of the device of the invention. Figure 2 represents an elevation view of the device in Figure 1. DETAILED EXPLANATION OF THE INVENTION Figure 1 shows an image-capturing device with adaptable grazing illumination comprising: a base plate (2), in the embodiment shown having a quadrangular shape and a first opening (2.1) as a through hole; a support plate (3), in the embodiment shown having a cross shape and a second opening (3.1) as a through hole, connected to the base plate (2) by connecting elements (5), in the embodiment shown eight threaded rods with nuts; a camera (8), arranged on the support plate (3) in the embodiment shown; a fixed light (9), also arranged on the support plate (3), in the embodiment shown four LED strips arranged around the camera (8), so that the light projected by the fixed light (9), represented by dashed arrows, is in the field of view of the camera (8); a control unit (14) configured to coordinate the taking of images by the camera (8) and the fixed light (9); in the embodiment shown four actuators (6) fixed to the support plate (3), arranged one at each corner of the base plate (2), the minimum being two; each actuator (6) connected to a first end (7).1) of a stem (7) so that it can impart a translational movement to the stem (7) to move it away from or closer to the support plate (3); each stem (7) has a second end (7.2) opposite the first end (7.1); at the second ends (7.2) an extendable beam (10) is rotatably fixed so that it can adapt its length to the position of each second end (7.2), in the embodiment shown the extendable beams (10) are linear guides. Following the embodiment shown in Figure 1, a movable light (11) is fixed to the extendable beam (10) so that it can provide transverse illumination, represented by dashed arrows, with respect to that which can be provided by the fixed light (9); the movable light is connected to the control unit (14), so that when said extendable beam (10) is close to or resting on a piece, not shown in the figures, the movable light (11) can provide grazing illumination with respect to the surface of said piece. Figure 1 schematically shows the projection directions of the light beams emitted by the fixed light (9) and the moving light (11) using dashed arrows. Figure 2 only shows the beams of the fixed light (9), as those of the moving light (11) would be transverse, usually perpendicular, to the plane of the figure. Double thick arrows in Figures 1 and 2 represent the translational movements of the rods (7) and the extendable beams (10). The moving light (11) adapts to changes in the length of the extendable beams (10), for example, by means of an extendable LED strip, two LED strips with movement between them, or any other known configuration. In Figure 1, the left-hand stem (7) is shown retracted, while the others are extended. This retraction of the stem (7) causes the two extendable rails (10) connected to it to be longer than the other stems (7). In the representation of Figures 1 and 2, the connection between the second ends (7.2) of the stems (7) and the extendable rails (10) is made by means of L-shaped connectors (13). This is a specific embodiment, and any other that allows for a rotating connection would be equally valid. For clarity, the figures do not indicate with arrows the rotation that takes place in the rotating fixings (12), represented as hexagonal-headed bolts, in these connectors (13). One option, as shown, is that the actuators (6) are four, forming a quadrilateral, and the extendable beams (10) are four, connected to the second ends (7.2) of the rods (7), also forming a quadrilateral. This provides a configuration that is easy to manufacture as it is made up of quadrilaterals, and is also robust against bending and torsion. Another option is to include an intermediate plate (4) with a third opening (4.1) in the form of a through-hole, located after the base plate (2) and on the side where the actuators (6) are connected. This provides the advantage of intermediate structural reinforcement. Advantageously, the connecting elements (5) extend to the intermediate plate (4), thus forming a robust structure with the fewest possible elements. Another option is to include a mounting plate (1) on the opposite side of the base plate (2) where the actuators (6) are connected. This provides simple mounting, such as to the end of a robotic arm. Advantageously, the connecting elements (5) extend to the mounting plate (1), thus forming a robust structure with the fewest possible components. With the above, it is possible to create a device with a very convenient positioning and image capture time, less than one second, which can be highly resistant, depending on the structural options chosen as explained, being able to withstand loads of one thousand kilograms, and, similarly, relatively large inspection surfaces, greater than 20 cm², can be obtained. The camera (8) can be arranged on any element that makes up the device. In the embodiment shown, it is fixed to the support plate (3), centered on it and with the lens facing different openings, which is a specific embodiment without limiting the invention, as explained throughout this description.

Claims

1. -Image-capturing device with adaptable grazing illumination comprising a base plate (2), a support plate (3) connected to the base plate (2) by connecting elements (5), a camera (8), a fixed light (9) arranged on the support plate (3) such that the light projected by the fixed light (9) is in the capture field of the camera (8), a control unit (14) configured to coordinate the image capture by the camera (8) with the fixed light (9), characterized in that it further comprises two actuators (6) fixed to the support plate (3), each actuator (6) connected to a first end (7.1) of a stem (7) so as to impart a translational movement to the stem (7) to move it away from or closer to the support plate (3), each stem (7) having a second end (7.2) opposite the first end (7.1), at the second ends (7.2) An extendable beam (10) is rotatably fixed so that its length can be adapted to the position of each second end (7.2). A movable light (11) is fixed to the extendable beam (10) so that it can provide transverse illumination relative to that provided by the fixed light (9). The movable light is connected to the control unit (14), so that when said extendable beam (10) is close to or resting on a piece, the movable light (11) can provide grazing illumination relative to the surface of said piece.

2. Device according to claim 1 in which the actuators (6) are four, forming a quadrilateral, and the extendable beams (10) are four, connected to the second ends (7.2) of the rods (7), also forming a quadrilateral. 3.-Device according to claim 1 in which an intermediate plate (4) with a third opening (4) is also included.1) as a through-hole arranged after the base plate (2) and on the side where the actuators (6) are connected.

4. Device according to claim 3 wherein the connecting elements (5) extend to the intermediate plate (4).

5. Device according to claim 1 wherein a fixing plate (1) is further included, arranged on the opposite side of the base plate (2) where the actuators (6) are connected.

6. Device according to claim 5 wherein the connecting elements (5) extend to the fixing plate (1).

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