ES1258130U - Failure inspection system in product manufacturing processes (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Failure inspection system in product manufacturing processes intended to be arranged in at least one of the stations through which the products pass one by one in the manufacturing process, the system comprising at least one chamber (1), a position or presence sensor (2), a processing unit (3) and a lighting unit (4), all of them electronically linked, as well as a support structure (5) to support at least said camera (1), position or presence sensor (2) and/or the lighting unit (4), the system being characterized in that the processing unit (3), in an initial commissioning phase of the system, is configured to: A) generate a master image (a) for each camera (1), each master image (a) being defined according to the type of product to be inspected, B) select one or more reference marks (b) in each pattern image (a), defining the reference mark (b) as the set of pixels (p) of a section of a pattern image (a), C) define a search region (c) where the reference marks (b) will be searched in the image of the product to be acquired by each camera (1), D) determine one or more sections (d) of each pattern image (a), defining the sections (d) as the characteristics to be detected in the images of the products (e), these characteristics corresponding to contours, edges, areas or figures geometric, said processing unit (3) being, in a failure inspection phase to be carried out for each product, configured to: E) acquire an image of the product (e) with each camera (1) when the position sensor (2) detects that the product is in the position that corresponds to the field of view of each camera (1), F) modify the search region (c) of the product image (e) or the reference brand (b'), either by repositioning it, varying its size and/or performing a perspective transformation, to search and match at least one mark (f) that matches the corresponding reference mark (b'), G) apply the modification needed in the previous stage to each section (d') of the master image (a) or to the product image (e'), while adjusting the product image (e') through the application of filters, H) find each section modified (d') or not (d) in the modified and/or adjusted product image (e'), and I) issue a signal, classify the product as defective and/or stop the manufacturing process if these sections are not found (d, d'). (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Failure inspection system in product manufacturing processes

OBJECT OF THE INVENTION

The object of the present invention application is the registration of an inspection system capable of detecting faults that may occur in product manufacturing processes, incorporating notable innovations and advantages over the techniques used up to now.

More specifically, the invention proposes the development of a system that makes it possible to inspect products in very diverse manufacturing processes and at a very low investment cost.

BACKGROUND OF THE INVENTION

In the current state of the art, various techniques for the inspection of defects in manufacturing processes are known with the intention of reducing defective products, such as, for example, fabrics with holes or electronic circuits with absence of components. Thanks to these techniques, a reduction in manufacturing costs is achieved, by avoiding the fatigue of the worker who performs the visual inspection, by reducing the inspection time and by avoiding possible human errors, while at the same time acquiring knowledge for the implementation of future manufacturing processes.

Many failures inspection system implementations use automated optical systems whereby an image of the product to be inspected is acquired and compared to a reference image in order to discover unwanted patterns or errors in the product. Unlike other automatic systems, the main advantage of optical systems is that the inspection can be done instantly and at any distance, without interfering with the manufacturing process.

However, these systems based on the comparison of the images of the products with a pattern image are not very effective when not all the products arrive at the different stations of the manufacturing process in exactly the same position. If the product image has been acquired from a different point of view than the master image, the system is not able to properly inspect the product.

Therefore, there is still a need for a failure inspection system capable of inspecting a product regardless of its position, which is both inexpensive to implement and robust in use. The present invention contributes to solving the existing deficiency.

DESCRIPTION OF THE INVENTION

The object of the present invention corresponds to the development of an inspection system for failures in product manufacturing processes, which can be adapted to the needs of the process according to the type of element to be inspected, such as welds, strands of sealing for joints or parts that do not tolerate displacements in their positioning.

The present failure inspection system is intended to be installed at a station in the manufacturing process through which products pass one by one. The components that the system comprises are at least a camera, a position or presence sensor, a lighting unit and a processing unit, as well as a support structure for at least said camera, sensor and / or lighting unit.

In particular, within the system of the invention, the processing unit, in an initial commissioning phase of said system, is configured to:

A) define a master image for each camera, each master image defined according to the type of product to be inspected,

B) select one or more reference marks in each pattern image, defining a mark as the set of pixels in a section of an image,

C) define a search region where the reference marks in the image of each product to be purchased by each camera will be searched, and

D) define the characteristics of one or more sections of each pattern image to be detected in the image to be captured by each camera, said characteristics corresponding to contours, edges, areas or geometric figures to be inspected in the product.

In this first phase of commissioning, the involvement of a technician or user is necessary. To define the pattern image for each camera, it is necessary to acquire an image corresponding to each area to be inspected in the objects with one of the cameras and then apply filters and a lens calibration to improve its quality and highlight the relevant details. The technician can adjust the corresponding camera, the position of the product and / or lighting unit until each pattern image generated meets the appropriate requirements. The technician can configure these requirements manually, based on analysis of the results and personal experience, or through an established parameter setting protocol executable by the processing unit. Regarding the application of filters, both in the previous and in the next phase, preferably the images are processed through filters collected from libraries with free software license of the BSD type.

Regarding the two or more reference marks to be selected in each pattern image, they can be selected by the technician according to the ones he considers most appropriate based on his experience or they can be selected by means of a computational analysis that detects those areas of pixels that are easier. to identify digitally. In the same way, defining a search region can be carried out by the technician manually or through an automated protocol executable by the processing unit, just like the stage of defining the characteristics of the sections of each pattern image to be detected in the images of the products captured by each camera.

The processing unit, in a second and final phase of inspection of failures to be carried out for each product, is also configured to:

E) acquire an image with each camera of the product to be inspected when the position sensor detects that the product is in the position that corresponds to the field of view of the cameras,

F) modify the search region of the product image or the reference brand, either by repositioning it, varying its size and / or performing a perspective transformation, to search and match at least one brand that matches the corresponding brand reference,

G) apply the modification of the search region of the product image or the reference mark to each section of the master image or to the product image, while adjusting the product image by applying filters,

H) find each section modified or not in the modified and / or adjusted product image,

I) issue a signal, qualify the product as defective and / or stop the manufacturing process in the event that these sections are not found because it is considered a manufacturing failure.

The novelty of this system resides in the particular configuration of the processing unit which is prepared to modify the image of the product or the reference brand to make the brands coincide, obviously in combination with the configuration of said processing unit to previously define some reference marks in the pattern image and having located them in the product image. Given that not all products have to be in exactly the same position with respect to the cameras, the system includes this stage in which the image of the product is modified so that its comparison with the standard image is more effective. The modification can consist of a repositioning or displacement in the plane of the image to make a first mark coincide, a variation of the size in case at least one second mark does not coincide or even a transformation of its perspective so that more than one mark coincide. . Image modification can be carried out using overlapping algorithms or control criteria, which modify the image automatically or with the help of a technician.

Thanks to this novelty, the detection of failures in optical inspection systems is more effective. At the same time, the entire second phase of fault inspection, when carried out by the processing unit, is carried out at very high speed, so that the efficiency of the manufacturing process increases considerably.

As it has been seen, in the failure inspection phase, the processing unit is configured to acquire an image of the product with each camera, and this task occurs when the position sensor detects that a product is in the position it needs. corresponds to the field of view of the cameras. As an optional embodiment, the system can comprise a waiting time window in which, in the failure inspection phase, the position sensor must detect that one product has been replaced by the next one in the camera's field of view, If not, the processing unit will issue a warning signal. This time window is preferably established in the initial commissioning phase.

Another aspect of the invention consists in searching, by the processing unit, at least one section that corresponds to a reference mark is carried out by means of a comparison by means of a mathematical function or algorithm.

Optionally, the system can comprise more than one position sensor with which, when detecting whether the product is in the camera's field of view, the processing unit is further configured to detect whether the product is in an orientation Similar enough to that of the master image, for example, to select the appropriate camera with which to take the image. In turn, the processing unit is configured to regulate the intensity and direction of the light from the source, for example, in the event that said processing unit detects that the ambient light reflected in the images of the product has changed or that an item to be inspected requires different lighting to another item to inspect. In the same way, the system can comprise at least one light reflector or a light filter, where the processing unit is configured to regulate the intensity and direction of the light that reaches the product by regulating or controlling said light. reflector or filter.

The support structure of the system is made up of two vertical posts joined by a horizontal beam that is adjustable in height, and comprises at least one holding element for cameras or sensors, which can be rotated and moved around the structure, so that it can be adjusted both the visual field of the supported cameras and / or sensors and the lighting, depending on the type of product to be inspected.

These and other characteristics and advantages of the system object of the present invention will be apparent from the description of a preferred, but not exclusive, embodiment, which is illustrated by way of non-limiting example in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1.- Illustrates a schematic view of an example embodiment of the present fault detection system.

Figure 2.- Illustrates an application example of the failure detection system of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

As can be seen in Fig. 1, the exemplary embodiment of the fault inspection system of the invention comprises at least one camera (1), a position or presence sensor (2), a lighting unit (4) and a processing unit (3), all of them electronically linked. In this schematic view, the link has been represented by means of cables (dotted lines), although the link can also be wireless. The system also comprises a support structure (5) made up of two vertical posts (51) joined by a horizontal beam (52) adjustable in height. The structure (5) comprises at least one fastening element (53) for cameras, sensors and / or lighting units, which can be rotated and moved in relation to the structure (5), so that the field can be regulated. visual of the cameras (1) and / or the sensors (2) supported, depending on the type of products to be inspected.

In Fig. 2 a graphic example is shown of how the particular operating configuration of the processing unit (3) of the system is used for fault detection. As can be seen in Fig. 2 (A), in an initial commissioning phase of the system, the processing unit (3) is configured to generate a pattern image (a) for each camera (1), being in this example only one. In this pattern image (a) a reference mark (b) is selected, in this example the set of pixels (p) marked in black from the grid of Fig. 2 (A). Likewise, a search region (c) is defined where the reference marks in the image of each product to be acquired by the camera (1) will be searched. Finally, this first phase comprises the determination of the characteristics of one or more sections (d) of the standard image (a) that must be detected in the images of the products. In this example embodiment, section (d) corresponds to the surface geometry of a component to check if the component has been installed, in this case comprising a monochromatic rhomboid area.

con la intención de encontrarla, tal y como se ejemplifica en la Fig. 2(D). En caso de no encontrarla, el sistema emitiría una señal, calificaría el producto como defectuoso y/o detendría el proceso de fabricación, por considerarse un fallo de fabricación al no estar instalado el componente. Once the commissioning phase is finished, the failure inspection phase continues, which is carried out for each product to be inspected. In this phase, the processing unit is configured to acquire the image of a product (e) and with the identification of the search region (c), as exemplified in Fig. 2 (B). Next, the search region (c) or the reference mark (b) is modified, either by repositioning it, varying its size and / or performing a perspective transformation, to find and match at least one mark of the search region (c) with at least one reference mark (b). As shown in Fig. 2 (C), in this example the reference mark (b) is modified. Once the modified reference mark (b ') is found that matches a mark in the search region (c), the same modifications are applied to section (d) to obtain a modified section (d'). Subsequently, this modified section (d ') is compared with the product image adjusted with filters

with the intention of finding it, as exemplified in Fig. 2 (D). If it is not found, the system will emit a signal, classify the product as defective and / or stop the manufacturing process, as it is considered a manufacturing failure as the component is not installed.

Claims (7)

1. Failure inspection system in product manufacturing processes intended to be arranged in at least one of the stations through which the products pass one by one in the manufacturing process, the system comprising at least one chamber (1) , a position or presence sensor (2), a processing unit (3) and a lighting unit (4), all of them electronically linked, as well as a support structure (5) to support at least said camera (1) , position or presence sensor (2) and / or the lighting unit (4), the system being characterized in that the processing unit (3), in an initial commissioning phase of the system, is configured to: A) generate a master image (a) for each camera (1), each master image (a) being defined according to the type of product to be inspected, B) select one or more reference marks (b) in each pattern image (a), defining the reference mark (b) as the set of pixels (p) of a section of a pattern image (a), C) define a search region (c) where the reference marks (b) will be searched in the image of the product to be purchased by each camera (1), D) determine one or more sections (d) of each pattern image (a), defining the sections (d) as the characteristics to be detected in the images of the products (e), these characteristics corresponding to contours, edges, areas or figures geometric, said processing unit (3) being, in a failure inspection phase to be carried out for each product, configured to: E) acquire an image of the product (e) with each camera (1) when the position sensor (2) detects that the product is in the position that corresponds to the field of view of each camera (1), F) modify the search region (c) of the product image (e) or the reference brand (b '), either by repositioning it, varying its size and / or performing a perspective transformation, to search and match at least one mark (f) that matches the corresponding reference mark (b '), G) apply the modification needed in the previous stage to each section (d ') of the master image (a) or to the product image (e'), while adjusting the product image

by applying filters, H) search for each section modified (d ') or not (d) in the modified and / or adjusted product image (e'), and I) issue a signal, classify the product as defective and / or stop the manufacturing process if these sections are not found (d, d '). System according to claim 1, wherein, in the initial commissioning phase, the processing unit (3) is further configured to establish a waiting time window in which, in the failure inspection phase, the position sensor (2) detects that one product has been replaced by the next in the field of view of the camera (1), and if not, the processing unit (4) is configured to emit a warning signal. System according to any of the preceding claims, wherein the processing unit (3) is configured to search for at least one mark (f) that corresponds to a reference mark (b) by means of a comparison by means of a mathematical function or algorithm . 4. System according to any of the preceding claims, wherein, when the processing unit (3) detects with the position sensor (2) whether the product is in the field of view of the camera (1), it is further configured to detect if the product is in an orientation similar enough to that of the standard image (a). System according to any of the preceding claims, wherein the processing unit (3) is additionally configured to control the lighting unit (3) to adjust the intensity and direction of the light. System according to any of the preceding claims, comprising at least one light reflector or a light filter, where the processing unit (3) is configured to adjust the intensity and direction of the light that reaches the product. System according to any of the preceding claims, comprising a support structure (5) made up of two vertical posts (51) joined by a horizontal beam (52) adjustable in height, said structure (5) comprising at least one fastening element (53) for cameras, sensors and / or lighting units, which can be rotated and moved in relation to the structure (5).