Control method and system for controlling integrity of articles made of compacted ceramic material

Abstract

A control method and system (100) for controlling the integrity of an article (8) made of compacted ceramic material; the control system (100) comprises: a feed surface (20); an illumination unit (21) for emitting at least one light beam towards the feed surface (20); a detection system (23) for capturing at least two images of at least two edge portions of two respective side edges (B1, B2) of the substantially flat article (8) illuminated by the illumination unit (21); and a processing unit (24) for processing the captured images in order to identify possible defects.

Description

Cross Reference to Related Applications

[0001] This patent application claims priority from Italian patent application No. 102023000010929 filed on May 30, 2023, the entire disclosure of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present invention relates to a control system and method for controlling the integrity of articles made of compacted ceramic material.

[0003] In particular, the present invention relates to a control system and method for controlling the integrity of substantially flat articles containing compacted ceramic powder which has not yet been subjected to heat treatment (for example drying and firing), in particular made of such compacted ceramic powder. More particularly, the present invention is advantageously, but not exclusively, applied in the field of production of slabs or tiles made of ceramic material. BACKGROUND

[0004] In the field of production of ceramic products, in particular slabs or tiles made of ceramic material, it is known to supply semi-dry ceramic powder (i.e. with a moisture content less than 10%, in particular in the range from 5% to 6%) along a given path through discontinuous compacting machines, commonly referred to as presses, or continuous compacting assemblies which subject the ceramic powder to a compacting pressure to obtain a layer of compacted ceramic powder which, at least when compacting occurs by means of continuous compacting machines, is cut to obtain a plurality of substantially flat articles made of compacted ceramic material, which are then dried, possibly subjected to decoration and / or finishing operations, and finally fired to obtain the final ceramic product.

[0005] In some cases, during the forming operation of the articles, surface defects such as, for example, surface swelling and / or cracks can occur, especially in the edge regions, due to, for example, different moisture of the ceramic powder, particle defects or air bubbles embedded in the ceramic material during compacting. Such defects, in addition to impairing the quality of the final ceramic product making it unusable, can also cause the articles to break or, in some cases, explode during drying or firing.

[0006] The importance of carrying out a complete control of the integrity of the articles before carrying out the drying and firing operations is therefore understood. In fact, in addition to determining the rejection of the articles and the consequent economic loss (the greater the size of the articles, the greater the overall economic loss that follows), the presence of such surface and / or edge defects also risks damaging or at least soiling the heat treatment machines in the event of breakage or explosion of the articles, thus requiring maintenance operations and the restoration of normal operating conditions, which can sometimes involve long machine downtimes.

[0007] To date, such control of the integrity of the articles is performed manually by an operator just downstream of the compacting station, who inspects the articles and, in order to identify possible surface and / or edge defects, which are often so small as to be difficult to see with the naked eye, makes use of contrast media, such as contrast liquids such as acetone or diesel, which are applied to the articles or in any case at least to some edge regions of such articles and are left to act so as to make such defects more visible.

[0008] Such a control method has some drawbacks in any case. First of all, the control operation implies the presence of an operator who is responsible for manually performing the inspection of the articles, with all the problems of precision, reliability and repeatability typical of manual operations.

[0009] Furthermore, such a control operation requires a certain time, in particular for the application of the contrast media mentioned above and for their action, with consequent increase in time and therefore reduction in productivity.

[0010] The object of the present application is to provide a control method and system for controlling the integrity of substantially flat articles made of compacted ceramic material which allows at least partially overcoming the drawbacks of the prior art. SUMMARY

[0011] According to the present application, a control method and system for controlling the integrity of articles made of compacted ceramic material are proposed according to what is claimed in the appended independent claims and preferably in any claim directly or indirectly dependent on any one of the mentioned independent claims.

[0012] The claims describe preferred embodiments of the application which form an integral part of the disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0013] The application is described below with reference to the accompanying drawings, which show some non-limiting example embodiments thereof, in which:

[0014] - Figure 1 a schematic view of a manufacturing plant for manufacturing ceramic products such as ceramic slabs and tiles according to the first aspect of the application is shown;

[0015] - Figure 2 a perspective view of a control system for detecting the integrity of an article, in this case a tile made of compacted ceramic material, according to an embodiment of the application is shown;

[0016] - Figure 3 a detail of the control of the integrity of a tile made of compacted ceramic material during one step of the control process is shown at an enlarged scale; Figure 2The control system shown has some parts removed to allow for a better view of the others;

[0017] - Figure 4 Shown at magnified scale Figure 3 The control system shown, but Figure 4 This is shown from another perspective and during subsequent steps in the process of controlling the integrity of tiles made from compacted ceramic materials; and

[0018] - Figure 5 and Figure 6 It shows Figure 2 Two side views of the control system, some parts of which have been removed to better view the others. Detailed Implementation

[0019] In the accompanying drawings, reference numeral 1 generally indicates the manufacturing equipment used to manufacture ceramic products 2 (e.g., ceramic slabs or tiles).

[0020] Special Reference Figure 1 Advantageously, the manufacturing equipment 1 for manufacturing ceramic product 2 includes: a supply assembly 3, which is advantageously provided with at least one supply device 4 (known per se and not specifically described herein), which is configured to supply ceramic powder CP, in particular a controlled amount of ceramic powder CP, at an input station 5 in a manner known per se; a forming assembly 6, which is arranged at a forming station 7 and is configured to form at least one substantially flat article 8, which comprises compacted ceramic material (in particular, made of compacted ceramic material); and a conveyor assembly 9, which extends from the input station 5 to the output station 10 along a given path PA in the feed direction A, which advantageously but not limitingly includes a plurality of conveyors 16, 18, 19 arranged in sequence (which will be better explained below), and the conveyor assembly 9 is configured to convey ceramic powder CP from the input station 5 to the forming station 7 and to convey the substantially flat article 2 from the forming station 7 to the kiln 11.

[0021] In this discussion, the expression “a substantially flat article 8 made of compacted ceramic material” or more simply “article 8” refers to a substantially (but not necessarily) flat article made of ceramic material (i.e., composed of the aforementioned compacted ceramic powder CP); more specifically, it refers to a base article intended for use in forming ceramic slabs or tiles, i.e., an intermediate article that has not yet undergone heat treatment (e.g., drying and firing), which will then lead to the manufacture of the actual ceramic product 2.

[0022] More advantageously but not limitingly, the article 8 includes (in particular) a plate made of compacted ceramic material having two larger surfaces S parallel to each other and opposite each other, and at least four side surfaces L, 2 by 2, perpendicular to the larger surfaces S and parallel to each other and opposite each other.

[0023] Advantageously, but not limitingly, the forming component 6 includes at least one continuous or discontinuous compaction device 12 configured to apply compaction pressure to the ceramic powder CP.

[0024] More specifically, according to some advantageous but non-limiting embodiments, for example Figure 1 In the embodiment shown, the forming assembly 6 includes: a continuous compaction device 12 (known in itself and not specifically described herein) arranged at a compaction station 13 (part of the forming station 7) positioned downstream of the supply assembly 3 along a given path PA and configured to apply compaction pressure to the ceramic powder CP to obtain strips of compacted ceramic powder KP; and a cutting device 14 located at a cutting station 15 (part of the forming station 7) arranged downstream of the compaction station 13 along a given path PA and configured to cut layers of compacted ceramic powder KP to obtain a plurality of substantially flat articles 8 made of compacted ceramic material, which are conveyed by means of a conveyor assembly 9 (e.g., ...). Figure 1 As shown, the material is supplied to the output of the forming station 7 by means of a belt conveyor 16.

[0025] According to other advantageous but non-limiting embodiments not shown, the forming component 6 includes a discontinuous compaction device (generally referred to as a discontinuous press, which is known in itself and not specifically described herein) (in particular, consisting of the discontinuous compaction device), which is configured to apply a defined compaction pressure to the ceramic powder CP layer and obtain at least one substantially flat article 8 made of compacted ceramic material.

[0026] Advantageously, the manufacturing equipment 1 also includes the aforementioned kiln 11, which is arranged downstream of the forming station 7 along a given path PA and is configured to fire substantially flat articles 8 made of compacted ceramic material at a firing temperature of at least about 1000°C (in particular, at a firing temperature in the range of about 1000°C to about 1400°C) in order to obtain ceramic product 2.

[0027] According to some advantageous but non-limiting implementations, for example Figure 1In the embodiment shown, the manufacturing apparatus 1 further includes at least one dryer 17 arranged along a given path PA downstream of the forming station 7 and upstream of the kiln 11 for drying substantially flat articles 8 made of ceramic material.

[0028] Advantageously, the manufacturing equipment 1 for manufacturing ceramic product 2 also includes a control system 100 arranged downstream of forming station 7 along a given path PA, which is used to control the integrity of the substantially flat article 8 made of compacted ceramic material.

[0029] In particular, according to one aspect of the invention, a control system 100 is actually proposed, which is particularly suitable for controlling (especially inspecting) a substantially flat article 8 made of compacted ceramic material formed by the above-described forming component 6 in order to identify possible surface defects (e.g., due to air embedding during the compaction step) and / or edge defects (e.g., cracks or damage).

[0030] Special Reference Figure 1 Advantageously, the control system 100 is arranged upstream of the kiln 11 along a given path PA.

[0031] Alternatively or in combination, when dryer 17 is also provided (such as in...) Figure 1 In the embodiment shown, more advantageously but not limitingly, the control system 100 is arranged upstream of the dryer 17 along a given path PA.

[0032] In particular, according to some advantageous but non-limiting embodiments, the control system 100 is arranged downstream of the forming station 7.

[0033] More advantageously, but not limitingly, the control system 100 is arranged immediately downstream of the forming station 7 (without the insertion of other stations).

[0034] Alternatively or additionally, according to other advantageous but non-limiting embodiments, the control system 100 is arranged at the forming station 7, particularly downstream of the compaction device 12 (more particularly, downstream of the compaction station 13 along a given path PA). More advantageously but non-limitingly, the control system 100 is arranged between the compaction device 12 and the cutting device 14 (particularly, between the compaction station 13 and the cutting station 15 along a given path PA).

[0035] Advantageously, but not limitingly, the conveyor assembly 9 includes: the aforementioned belt conveyor 16 on which the supplied ceramic powder CP is laid, and which is configured to supply the ceramic powder CP through the forming assembly 6; and an additional conveying device 18, such as a belt conveyor or alternatively a roller conveyor in the case shown, which is arranged downstream of the belt conveyor 16 along a given path PA and is part of the control system 100; and an additional conveyor 19, such as a roller conveyor in the case shown, for supplying the controlled, substantially flat articles 8 through subsequent stations, in the case shown, through the dryer 17 and the kiln 11.

[0036] It should be understood that the manufacturing equipment 1 may include any number of intermediate stations between the control system 100 and the kiln 11, such as a decoration and / or surface treatment station for the product 8.

[0037] Advantageously, the control system 100 includes a feed surface 20 for receiving at least one substantially flat article 8 containing compacted ceramic material (in particular, made of compacted ceramic material) and conveying the article along a feed path P in the aforementioned feed direction A, which is advantageously but not limitingly a part of the aforementioned given path PA (in particular, coinciding with a part of the given path).

[0038] More advantageously, but not limitingly, according to some advantageous but not limiting embodiments, such as those shown in the figures, the control system 100 includes the aforementioned conveying device 18, and the feed surface 20 is defined by the upper branch of such conveying device 18 (see, for example...). Figure 2 It should be understood that, according to other non-limiting embodiments not shown, the control system 100 may include other types of feeding devices, such as roller conveyors or any other movable plane.

[0039] Special Reference Figures 3 to 6 Advantageously, the control system 100 also includes an illumination unit 21, which comprises at least one LED strip 22 extending along a direction B substantially transverse to the feed direction A, and is configured to emit at least one light beam toward the feed surface 20 to illuminate at least one region Z of the feed surface 20 (see [link to relevant documentation]). Figure 3 The extension of region Z in direction B is at least equal to the extension of feed surface 20. In other words, advantageously, illumination unit 21 is configured to illuminate at least one entire transverse band of feed surface 20.

[0040] Advantageously, the control system 100 also includes an optical inspection system 23 for inspecting the substantially flat article 8 at least when the substantially flat article 8 is at least partially located in the area Z illuminated by the illumination unit 21; particularly when the substantially flat article 8 is at least partially illuminated by the illumination unit 21.

[0041] This optical inspection system 23 is advantageously configured to capture at least two images of at least two edge portions of at least two corresponding side edges B1 and B2 of a substantially flat article 8 illuminated by the illumination unit 21.

[0042] Advantageously, but not limitingly, the aforementioned edge portions respectively include (in particular, are) a region of the article 8 at a side edge B1 of the article 8 (in particular, including at least a portion of the side edge B1) and another region of the article 8 that is substantially flat at another side edge B2 of the article 8 parallel to and opposite to the side edge B2 (in particular, including at least a portion of the other side edge B2) (see See Figure 3 and Figure 4 ).

[0043] According to some advantageous but non-limiting embodiments, such as the one shown in the figures, the optical inspection system 23 includes a pair of side optical capture devices 27 (in particular, consisting of a pair of side optical capture devices 27), each side optical capture device being configured to capture one of the aforementioned at least two additional images of the edge portion of the article 8.

[0044] Advantageously, but not limitingly, this optical detection system 23 is configured to also detect additional images of at least one transverse band of the substantially flat article 8 illuminated by the illumination unit 21.

[0045] Specifically, in this case, advantageously but not limitingly, the optical inspection system 23 also includes at least one central optical capturing device 26, which is arranged between the optical capturing devices 27 and configured to capture the image of the aforementioned at least one transverse band of the article 8.

[0046] Advantageously, the control system 100 also includes a processing unit 24 configured to process (in particular all) the images captured by the optical inspection system 23 in order to identify surface defects and / or edge defects present respectively in such transverse bands and / or such at least two edge portions of the article 8 (see...). Figures 2 to 6 ).

[0047] According to some advantageous but non-limiting embodiments, such as the appendix Figure 3 To be continued Figure 6In the embodiment shown, the lighting unit 21 includes at least a pair of LED strips 22, which consist of two parallel LED strips 22. Each LED strip 22 extends along direction B over the feed surface 20 to cover the entire extension of the feed surface 20, and more specifically, the entire width of the feed surface 20. More advantageously, but not limitingly, such LED strips 22 are spaced apart from each other along the feed direction A, and each of such LED strips 22 includes a plurality of LEDs oriented toward the opposing LED strip 22 to provide optimal illumination of the aforementioned region Z.

[0048] In particular, according to some advantageous but non-limiting embodiments, the LED strip 22 or (when a pair of LED strips 22 are provided) a pair of LED strips 22 are configured to illuminate the region Z comprising the aforementioned transverse strip of the article 8 and the aforementioned side portion of the article 8, such that they can be captured by the optical detection system 23.

[0049] More advantageously, but not limitingly, the LED strip 22 or each such LED strip 22 includes a plurality of white LEDs having a luminous power of at least about 1,100 lumens; particularly, at least about 1,200 lumens; and more particularly, the luminous power is in the range of about 1,260 to about 20,000 lumens.

[0050] Alternatively or in combination, according to some advantageous but non-limiting implementations, such as Figure 3 , Figure 4 and Figure 6 In the embodiment shown, the lighting unit 21 further includes at least two additional LED strips 25, each extending along direction B to emit at least one light beam toward the feed surface 20 to illuminate a corresponding side region ZL of the feed surface 20, thereby illuminating the aforementioned edge portion of the article 8. In other words, advantageously but not limitingly, such additional LED strips 25 are arranged such that, in use, the substantially flat side edges B1, B2 of the article 8 are each located at the corresponding side region ZL illuminated by such LED strips 25.

[0051] More advantageously, but not limitingly, the lighting unit 21 includes: a first pair of LED strips 25 extending along direction B, arranged parallel to each other and facing each other, and spaced apart from each other along feed direction A, so as to illuminate (in use) at least one side region ZL of the feed surface 20 located near the side edge B1 of the article 8; and another pair of LED strips 25 extending along direction B, arranged parallel to each other and facing each other, and spaced apart from each other along feed direction A, so as to illuminate (in use) another side region ZL of the feed surface 20 located near another side edge B2 of the substantially flat article 8.

[0052] Advantageously but not limitingly, the side region ZL extends less in direction B than the region Z illuminated by LED strip 22 extends less in direction B.

[0053] Advantageously but not limitingly, each of the LED strips 25 also includes a plurality of white LEDs (in particular, composed of a plurality of white LEDs) having a luminous power of at least about 1,100 lumens; in particular, at least about 1,200 lumens; and more particularly, the luminous power is in the range of about 1,260 to about 20,000 lumens.

[0054] Alternatively or in combination, more advantageously but not limitingly, at least LED strip 25 (more advantageously, LED strip 22) is configured to emit the aforementioned light beam intermittently, with its emission frequency in phase (i.e., balanced) with the capture frequency of the optical detection system 23. In other words, advantageously but not limitingly, LED strip 25 comprises LEDs with intermittent light (i.e., stroboscopic light) (particularly composed of LEDs with intermittent light (i.e., stroboscopic light) whose emission frequency is in phase (i.e., in phase) with the capture frequency of the detection system 23. This allows for further improvement in the illumination of at least the side region ZL, thereby also improving the system's ability to detect even smaller defects. Furthermore, the use of intermittent light advantageously allows for illumination of the side region ZL of the feed surface 20 (particularly, also the region Z) at a high luminous power, for example, approximately 20,000 lumens, without causing LED strip 25 (more advantageously, also LED strip 22) to overheat, and therefore eliminates the need for a specially designed cooling device.

[0055] According to some advantageous but non-limiting implementations, for example Figures 3 to 6 In the embodiment shown, the control system 100, particularly the optical inspection system 23, includes at least one guide 28 extending along direction B above the feed surface 20 and slidably carrying each side optical capturing device 27. The processing unit 24 is configured to determine at least one first dimension (specifically, width) of the article 8 in direction B based on the aforementioned image of the transverse strip of the article 8, and thus adjust the relative positions of these side optical capturing devices 27. Specifically, each side optical capturing device 27 is slidably connected to the guide 29 so that it can move along the guide 28. In this way, the relative distance between the side optical capturing devices 27 can be adjusted according to the specifications of the article 8.

[0056] In this configuration, advantageously but not limitingly, the processing unit 24 is configured to determine at least one first dimension (specifically, width) of the article 8 in direction B based on the aforementioned image of the transverse strip of the article 8, and to move the side optical capturing devices 27 along the guide 28 based on the evaluated dimension, such that the distance between the side optical capturing devices 27 is substantially equal to the width of the article 8. In this way, advantageously, each of these side optical capturing devices 27 is located at one of the side edges B1, B2 of the article 8 during use, for capturing images of the substantially flat edge portion of the article 8.

[0057] More advantageously, but not limitingly, the control system 100, particularly the optical detection system 23, also includes a linear actuation component 29 (known in itself), which can be actuated by the processing unit 24 to adjust the relative distance between such side optical capturing devices 27 (see in particular). Figures 3 to 6 Specifically, according to some advantageous but non-limiting embodiments not shown, the linear actuation assembly 29 includes two independent actuation motors (in particular, consisting of two independent actuation motors), one actuation motor for each side optical capture device 27, each actuation motor being actuated to move the corresponding side optical capture device 27 in a manner independent of the other side optical capture device.

[0058] Advantageously, but not limitingly, in this case, when an additional LED strip 25 is provided, the additional LED strip 25 is integrated with the side optical capturing device 27. More advantageously, but not limitingly, when the aforementioned additional LED strip 25 is provided, such additional LED strip 25 and side optical device 27 are arranged relative to each other such that in use (i.e., when the control system 100 is actuated to detect possible surface and / or edge defects of the article 8), each of the aforementioned side regions ZL coincides with one of the two edge portions of the two corresponding side edges B1, B2 of the article 8 illuminated by the lighting unit 21.

[0059] More specifically, according to some advantageous but non-limiting implementations, for example Figures 3 to 6 In the illustrated embodiment, the control system 100, particularly the optical detection system 23, includes two trolleys 30 slidably connected to the guide 28. These two trolleys 30 can be translated and actuated along the guide 28, particularly in the illustrated example by the aforementioned linear actuation component 29. Each trolley 30 is configured to carry one of the aforementioned side optical capture devices 27 and one or a pair of the aforementioned LED strips 25.

[0060] Alternatively or in combination, according to some advantageous but non-limiting embodiments, such as the embodiments shown, each side optical capture device 27 and / or each LED strip 25, 22 can also move along a direction C perpendicular to the feed surface 20 (in particular, vertically) to allow adjustment of the distance between the side optical capture device 27 and the feed surface 20 and / or between the LED strip 25 and the feed surface 20 according to the specifications of the substantially flat article 8 to be controlled.

[0061] Advantageously, but not limitingly, in this case, the processing unit 24 is configured to move the side optical capturing device 27 along direction C according to the thickness of the article 8, so as to ensure that the distance between the side optical capturing device 27 and the article 8 to be inspected is at most approximately 150 mm, particularly in the range of approximately 100 mm to approximately 150 mm, and / or ensure that the distance between the LED strips 22, 25 and the article 8 to be inspected is at most approximately 28 mm. In this way, it is also possible to ensure that the aforementioned image of the edge portion of the article 8 is correctly captured.

[0062] Alternatively or additionally, advantageously but not limitingly, the central optical capturing device 26 is movable along the aforementioned direction C to allow adjustment of the distance between such optical capturing device 26 and the feed surface 20 (specifically, the upper surface of the substantially flat article 8) according to the specifications of the article 8 to be controlled. Again, more advantageously but not limitingly, in this case, the processing unit 24 is configured to move the central optical capturing device 26 along direction C between a first position and a second position at least 15 mm away from the first position, according to the thickness of the article 8; in other words, advantageously but not limitingly, the position of the optical capturing device 26 is adjustable along direction C to ensure that the distance between the optical capturing device 26 and the article 8 to be inspected is at most approximately 1500 mm and at least 500 mm.

[0063] Advantageously, but not limitingly, each of the aforementioned optical capturing devices 26 and 27 has a resolution of at least 1 μm; particularly, in the range of about 1 μm to about 20 μm; more advantageously, equal to about 3.5 μm. Alternatively or additionally, advantageously but not limitingly, the field depth of each of the aforementioned optical capturing devices 26 and 27 is in the range of about 0.5 mm to about 8 mm; more particularly, in the range of about 1 mm to about 5 mm.

[0064] More advantageously, but not limitingly, each of the aforementioned optical capturing devices 26 and 27 includes a camera (in particular, consists of a camera).

[0065] More specifically, advantageously but not limitingly, each of the optical capturing devices 26 and 27 includes a matrix camera (specifically composed of the matrix camera) with a resolution ranging from about 5 MP; particularly from about 12 MP to about 50 MP.

[0066] According to some advantageous but non-limiting embodiments, the optical capturing device 27 includes at least two cameras of the type described above (in particular, consists of at least two cameras of the type described above).

[0067] According to some advantageous but non-limiting embodiments, the processing unit 24 includes a memory (not visible in the drawings) and a processor (of a known type), the memory being used to store a library containing a plurality of known defects (particularly known surface and / or edge defects), and the processor being advantageously but non-limitingly aligned with the processing unit 24 and configured to process images detected by the optical inspection system 23 and identify possible shadows present in such images, and compare such possible shadows with data stored in the memory in order to check whether the article 8 has one or more defects stored in such a library.

[0068] More specifically, according to some advantageous but non-limiting embodiments, the processing unit 24 is configured to process the image detected by the optical detection system 23 using pattern matching techniques.

[0069] In particular, according to some advantageous but non-limiting embodiments, the processing unit 24 is configured to analyze such an image captured by the optical detection system 23 using a pattern matching algorithm of a known type.

[0070] According to some advantageous but non-limiting embodiments, this pattern matching algorithm is based on the Hough transform, which enables the identification of segments on an image, allowing the processing unit 24 to identify possible surface and / or edge defects by comparing such segments with known defects stored in the aforementioned memory.

[0071] Alternatively or additionally, advantageously but not limitingly, processing unit 24 is configured to: extract sub-images from the image detected by optical detection system 23, including regions where shadows (which may correspond to potential defects) exist, using pattern matching techniques known per se; analyze such sub-images using an analytical algorithm, a so-called skeleton algorithm, to reconstruct the edges of such potential defects, for example by labeling each pixel based on the distance and / or intensity between each pixel of the image and its nearest neighbor, so that they can be combined to define a representation or skeleton of the potential defect; and assign a score to each of such sub-images. The higher the score, i.e., the better the skeleton algorithm preserves the potential defect, the greater the probability that it is actually a defect (e.g., a crack). Therefore, in this case, advantageously but not limitingly, processing unit 24 is configured to also identify potential defects based on what is inferred by means of the skeleton algorithm; more specifically, based on the value of such a score.

[0072] In particular, advantageously but not limitingly, the processing unit 24 is configured to process / analyze the images captured by the side optical capturing device 27 in order to identify possible edge defects, such as cracks or fissures; and to process / analyze the images captured by the center optical capturing device 26 in order to identify possible surface defects, such as bubble inclusions.

[0073] According to some advantageous but non-limiting embodiments of the invention, the processing unit 24 is also configured to determine the specifications of the substantially flat article 8 by analyzing the image of the transverse band of the article 8 captured by the central optical capturing device 26, more particularly at least determining the width and thickness, so as to adjust the position of the side optical capturing devices 27 and / or the LED strips 22, 25 along direction B and along direction C, and when the optical capturing device 26 is provided, also adjust the position of the optical capturing device 26 along direction C, as described above.

[0074] Alternatively or in combination, according to some advantageous but non-limiting embodiments, the control system 100 includes a user interface 31 through which an operator can input setting data, such as the specifications of the substantially flat article 8 made of ceramic material to be controlled. For example, in Figure 2 In the illustrated embodiment, such a user interface 31 includes a screen and a keyboard (in particular, it consists of a screen and a keyboard).

[0075] According to other embodiments, the control system 100, particularly the processing unit 24, communicates with other components of the manufacturing equipment 1 for manufacturing the ceramic product 2. The control system 100 is configured to receive data from these other components of the manufacturing equipment 1, which is at least approximately the specifications of the substantially flat article 8. Specifically, according to some advantageous but non-limiting embodiments, the processing unit 24 communicates with the forming assembly 6 to receive such data regarding the specifications of the article 8.

[0076] Furthermore, according to some advantageous but non-limiting embodiments, in this case (i.e., when the control system 100—more particularly, the processing unit 24—communicates with other components of the manufacturing equipment 1), the data on the integrity of the article 8 processed by the processing unit 24 can also be used, for example, to feedback adjust the operation of the supply assembly 3 and / or the forming assembly 6 by modifying one or more operating parameters according to the type of detected surface and / or edge defects. Specifically, advantageously but non-limitingly, the data on the integrity of the article 8 processed by the processing unit 24 can be used to change the density of the substantially flat article 2, for example, by locally increasing the amount of ceramic powder CP supplied by the supply assembly 3, appropriately adjusting the position and operation of the supply device 4, or by adjusting the operation of the compaction device 12.

[0077] According to some advantageous but non-limiting embodiments not shown, the control system 100 further includes at least one detector, such as an encoder arranged along the feed path P, configured to detect the presence and / or position of a substantially flat article 8 on the feed surface 20 (in particular, the area of ​​operation of the optical inspection system 23), and the processing unit 24 is configured to control the actuation of the optical inspection system 23 and / or the illumination unit 21 based on the data detected by such detector. More advantageously but non-limitingly, the control system 100 includes two detectors, such as two encoders connected to the conveyor assembly 9 (i.e., fixed to the conveyor 18), arranged sequentially along the feed path P and spaced apart from each other, such that the detector (one detector further upstream along the feed path P) detects the presence and / or position of a substantially flat article 8 at the input point on the feed surface 20 (in particular, within the area of ​​operation of the optical inspection system 23), and the other detector arranged downstream of the first detector along the given path P detects the presence and / or position of a substantially flat article 8 at the optical inspection system 23. More specifically, advantageously but not limitingly, the distance between the two detectors along the feed path P is variable between approximately 200 mm and approximately 600 mm. This allows for improved accuracy in detecting the article 8, which is fed substantially flat along the feed path P. In this case, the processing unit 24 is configured to control the actuation of the optical detection system 23 and / or the illumination unit 21 based on the detection data from the two detectors.

[0078] Special Reference Figure 2 According to some advantageous but non-limiting embodiments, the control system 100 includes a support structure 32 configured to at least support the lighting unit 21 and the optical detection system 23. More specifically, advantageously but non-limitingly, this support structure 32 includes a gantry (particularly composed of gantry frames) configured to extend over a belt conveyor 18 defining the aforementioned feed surface 20. More advantageously but non-limitingly, the support structure 32 has a beam 33 and two supports 34, the beam 33 being sized to accommodate and protect the lighting unit 21 and the optical detection system 23 from external influences, and the two supports 34 holding the beam 33 and at least supporting the processing unit 24.

[0079] Advantageously but not limitingly, the beam 33 is open at the bottom on the side of the feed surface 20 to allow the illumination unit 21 to illuminate the substantially flat article 8 moving on the feed surface 20, as described above, and to allow the optical inspection system 23 to capture an image of such article 8, as described above.

[0080] The presence of this support structure 32 allows for the simple and cost-effective protection of the more delicate and expensive components of the control system 100 (such as the lighting unit 21 and the optical detection system 23) from dust and / or other substances that may damage them.

[0081] According to some advantageous but non-limiting embodiments not shown, the control system 100 also includes a warning unit, such as an indicator light or a sound transmitter, which can be actuated to issue an alarm signal when surface and / or edge defects are detected. Alternatively, the alarm signal can be displayed, for example, via the user interface 31 described above, or can be transmitted by the processing unit 24 to a control station of the manufacturing equipment 1 in which the control system 100 is installed, which may be located in a remote station.

[0082] According to another aspect of the invention, a control method is provided for controlling the integrity of articles 8 (such as those described above) made of compacted ceramic materials. Advantageously, but not limitingly, this control method is actuated by the control system 100 described above.

[0083] The control method includes the following steps: a supply step, during which at least one substantially flat article 8 comprising compacted ceramic material (particularly made of compacted ceramic material) is fed along a feed path P in a feed direction A onto a feed surface 20 (advantageously, but not limited to, the type described above); an illumination step, during which an illumination unit 21 (advantageously, but not limited to, the type described above) comprising at least one LED strip 22 extending substantially transversely to the feed direction A emits at least one light beam toward the feed surface 20 and illuminates at least one region Z of the feed surface 20, the extension of region Z in direction B being at least equal to the extension of the feed surface 20; and a detection step (at least partially) performed simultaneously with the illumination step, during which an optical detection system 23 comprising a pair of optical capturing devices 27 captures at least two images of two edge portions of the substantially flat article 8 illuminated by the illumination unit 21. Specifically, as better explained with respect to the control system 100, during such a detection step, each of the aforementioned pair of optical capturing devices 27 captures an image of the corresponding edge portion of the substantially flat article 8.

[0084] As already explained in detail with respect to the control system 100 (and for the sake of brevity, will not be repeated here), according to some advantageous but non-limiting embodiments, the lighting unit 21 includes a pair of LED strips 22, and during such an lighting step, the two LED strips 22 emit light beams for illuminating the region Z, which is advantageously, but not limited to, the type described above. Alternatively or in combination, the lighting unit 21 also includes at least two additional LED strips 25 (more specifically, a pair of LED strips 25), and during the aforementioned lighting step, each LED strip 25 emits a light beam toward the feed surface 20 to illuminate the side region ZL of the article 8, which extends near (in particular, includes) the side edges B1 and B2 of the article 8, as already described in detail with respect to the control system 100.

[0085] The control method also includes (at least in part) an image processing step following the illumination step, during which the processing unit 24 processes the image captured during the detection step in order to identify defects present in the two edge portions of the two corresponding side edges B1, B2 of the article 8.

[0086] According to some advantageous but non-limiting embodiments, during the detection step of the control method, the optical detection system 23 captures at least one additional image of the transverse band of the substantially flat article 8 illuminated by the illumination unit 21, and during the image processing step, the processing unit 24 also processes such additional images captured during the detection step in order to identify possible defects (in particular, surface defects) present in such transverse bands of the substantially flat article (8).

[0087] According to some advantageous but non-limiting embodiments, the control method also includes (at least in part) a warning step following the processing step, during which a warning unit (not visible in the figures) emits an alarm signal, such as by an indicator light, an acoustic signal, or a message, upon detection of surface and / or edge defects. This alarm signal may be displayed via a user interface 31 (e.g., part of the control system 100 for the actuation method) or may be automatically sent to a control station in a remote station.

[0088] Advantageously but not limitingly, the lighting and testing steps (at least in part) are performed simultaneously with the supply step.

[0089] According to some advantageous but non-limiting embodiments, the detection steps include: a first detection sub-step, during which a pair of side optical capturing devices 27 (advantageously but not limited, as described above with respect to control system 100) as part of optical detection system 23 capture the aforementioned image of the edge portion of article 8; and (at least in part) another detection sub-step following the already mentioned detection sub-step, during which a central optical capturing device 26 (advantageously but not limited, as described above with respect to control system 100) as part of optical detection system 23 captures the aforementioned image of the transverse band of article 8.

[0090] In particular, advantageously but not limitingly, during the aforementioned detection sub-step, each side optical device 27 captures one of the aforementioned two additional images of the edge portion of the substantially flat article 8 made of compacted ceramic material.

[0091] According to some advantageous but non-limiting embodiments, the control method further includes: (at least partially) an identification step following the detection step, during which the processing unit 24 determines at least one first dimension of the article 8 in direction B (in particular, at least the width of the article 8) based on additional images of the transverse strip of the article 8 captured during the detection step; and an adjustment step, during which the position of each side optical capturing device 27 is adjusted based on the data determined in such an identification step, such that each such side optical capturing device 27 is located at one of the side edges B1 or B2 of the substantially flat article 8, so as to be able to capture the aforementioned additional images of the aforementioned edge portion of the substantially flat article 8. Alternatively or additionally, during the adjustment step, the position of the LED strip 25 is adjusted based on the data determined in such an identification step, so as to illuminate the edge portion region of the substantially flat article 8 in a suitable manner.

[0092] Specifically, advantageously but not limitingly, in this case, the adjustment step includes a lateral adjustment sub-step during which the side optical capturing devices 27 and / or LED strips 25 are moved in direction B (advantageously but not limitingly, along a guide 28 extending above the feed surface 20, as better described with respect to the control system 100), such that the distance between such side optical capturing devices 27 along direction B is substantially equal to the dimension of the article 8 in such direction B (i.e., equal to the width of the article 8). Alternatively or in combination, the adjustment step provides a vertical adjustment sub-step during which the side optical capturing devices 27 and / or LED strips 25 are moved in direction C perpendicular to the feed surface 20 to adjust the distance between the side optical capturing devices 27 and the substantially flat article 8 fed on the feed surface 20 in use, according to the specifications of the article 8, particularly at least according to the thickness of the article 8.

[0093] Alternatively or additionally, advantageously but not limitingly, the method also provides a step of adjusting the position of the central optical capturing device 26, during which the position of the central optical capturing device 26 is also adjusted at least along direction C based on the specifications of the article 8.

[0094] As already specifically explained with respect to the control system 100, according to some embodiments, the specifications of the article 8 are determined during the above-described processing steps. According to other advantageous but non-limiting embodiments, the control method also provides an initial setup step, during which data related to the specifications of the article 8 to be controlled is input, for example, via a user interface 31.

[0095] According to a final aspect of the invention, a method for manufacturing ceramic products 2, such as ceramic slabs or tiles, is provided, which is advantageously but not limitingly actuated by the aforementioned manufacturing equipment 1.

[0096] Specifically, advantageously, the manufacturing method includes: a supply step, during which a supply component 6 supplies a quantity (particularly a given / controlled amount) of ceramic powder CP at an input station 5; a forming step, during which a forming component 6, arranged at a forming station 7 (and advantageously, but not limitingly, as described above with respect to manufacturing equipment 1), applies at least one compaction pressure to the ceramic powder CP and forms at least one substantially flat article 8 comprising compacted ceramic material (particularly, made of compacted ceramic material); and a firing step, during which such substantially flat article 8 made of compacted ceramic material is fired in a kiln 11 to obtain ceramic product 2. According to some advantageous but not limiting embodiments, the method further includes a drying step, during which the article 8 is dried in a dryer 17; and / or possibly further finishing and decorative steps.

[0097] Advantageously, the manufacturing method also includes a conveying step during which a conveyor assembly 9 (advantageously, but not limited to, the type described above with respect to manufacturing equipment 1) conveys ceramic powder CP from input station 5 to forming station 7 along a given path PA in feed direction A, and conveys the substantially flat article 8 from forming station 7 to kiln 11.

[0098] The manufacturing method for producing ceramic product 2 further includes an integrity control step for controlling the integrity of the substantially flat article 8, which (at least partially) occurs before the firing step and, when a drying step is provided, before the drying step, such that the integrity of article 8 is controlled before the heat treatment operation of article 8. Advantageously, such control step is actuated according to the above-described control method.

[0099] Advantageously but not limitingly, this integrity control step (at least in part) follows the forming step.

[0100] According to some advantageous but non-limiting embodiments, the manufacturing method for producing ceramic product 2 further includes (at least partially) a feedback control step following the processing step, during which the supply step and forming step are adjusted feedbackally based on the type of surface and / or edge defects detected during the integrity control step, for example by modifying one or more operating parameters of the apparatus intended to perform said steps. In detail, as explained above with respect to control system 100, according to some advantageous but non-limiting embodiments, during such a feedback control step, the amount of ceramic powder CP supplied by supply component 3 is locally altered and / or the actuation of forming component 6 is adjusted, for example, to change the density of the substantially flat article 2.

[0101] This invention has many advantages, among which the following advantages are mentioned.

[0102] The control method and system of the present invention allow for more precise and systematic control of the integrity of substantially flat articles 8 made of compacted ceramic material, thereby eliminating or significantly reducing in any way the risk of articles 8 with defects (particularly surface and / or edge defects) reaching the heat treatment system (e.g., dryer 17 and kiln 11). In this way, the risk of damage to such heat treatment systems 11, 17 is avoided, and the need for lengthy and complex maintenance or restoration operations is eliminated, thereby improving the efficiency and productivity of the method and manufacturing equipment 1 used to manufacture ceramic products 2.

[0103] Furthermore, compared to known control methods and systems, the control method and system 100 of the present invention allows for high-precision identification of potential surface or edge defects without the need for a comparison medium, thereby reducing the number of operations to be performed and thus lowering costs when the results are the same.

[0104] Another advantage is that the control method and system 100 of the present invention are perfectly and easily adapted to the methods and manufacturing equipment 1 used for manufacturing ceramic products 2, thereby improving their efficiency and reducing the need for labor.

Claims

1. A control system (100) for controlling the integrity of an article (8) made of compacted ceramic material; said control system (100) comprising: A feed surface (20) is used to receive at least one substantially flat article (8) and to convey the article along a feed path (P) in a feed direction (A), the article comprising compacted ceramic material (in particular, made of compacted ceramic material). The illumination unit (21) includes at least one LED strip (25) extending along a direction (B) substantially transverse to the feed direction (A) and is configured to emit at least one light beam toward the feed surface (20) to illuminate at least one region (Z) of the feed surface (20), the region (Z) extending in the direction (B) at least equal to the extension of the feed surface (20). An optical inspection system (23) for inspecting the substantially flat article (8); the optical inspection system (23) is configured to capture at least two images of at least two edge portions of at least two corresponding side edges (B1, B2) of the substantially flat article (8) illuminated by the illumination unit (21), and includes a pair of optical capturing devices (27) (in particular, consisting of a pair of optical capturing devices (27)), each optical capturing device being configured to capture one of the at least two images of the edge portions of the substantially flat article (8); as well as The processing unit (24) is configured to process the image captured by the optical inspection system (23) in order to identify possible defects present in the at least two edge portions of the substantially flat article (8).

2. The control system (100) according to claim 1, wherein: The optical inspection system (23) is configured to capture at least one additional image of at least one transverse band of the substantially flat article (8) illuminated by the illumination unit (21); and the processing unit (24) is configured to further process the additional image of at least one transverse band of the substantially flat article (8) in order to identify possible defects present in the at least one transverse band of the substantially flat article (8).

3. The control system (100) according to claim 2, wherein the optical detection system (23) includes an additional optical capturing device (26) (in particular, consisting of an additional optical capturing device (26)) arranged between the optical capturing devices (27) of the pair of optical capturing devices (27) and configured to capture the at least one additional image of the at least one transverse band of the substantially flat article (8).

4. The control system (100) according to any one of the preceding claims, wherein: The lighting unit (21) includes at least two additional LED strips (25), each of which extends along the direction (B) to emit at least one light beam toward the feed surface (20), thereby illuminating a corresponding side region (ZL) of the feed surface (20); and The additional LED strip (25) is arranged such that, in use, the side edges (B1, B2) of the substantially flat article (8) are each located at the corresponding side region (ZL).

5. The control system (100) according to any one of the preceding claims, wherein: The optical detection system (23) includes a guide (28) extending above the feed surface (20) along the direction (B); and each of the pair of optical capturing devices (27) is slidably connected to the guide (28); and The processing unit (24) is configured to determine at least one first dimension (particularly, width) of the substantially flat article (8) in the direction (B), and based on the first dimension, to move the optical capturing device (27) along the guide (28) such that the distance between the optical capturing devices (27) of the pair of optical capturing devices (27) is substantially equal to the dimension of the substantially flat article (8); In particular, the additional LED strip (25) is integrated with the optical side device (27).

6. The control system (100) according to claim 5, wherein each of the pair of optical capturing devices (27) is movable in a direction (C) perpendicular to the feed surface (20) to allow adjustment of the distance between the optical capturing device (27) and the feed surface (20) (in particular, the upper surface of the substantially flat article (8)) according to the specifications of the article (8); In particular, the additional optical capturing device (26) is also capable of moving along the direction (C) to change the distance relative to the feed surface (20) according to the specifications of the substantially flat article (8).

7. The control system (100) according to any one of the preceding claims, wherein the processing unit (24) includes a memory and a processor, the memory being configured to store a library containing a plurality of known defects, the processor being configured to process the images detected by the optical inspection system (23) and compare them with the contents of the memory in order to check whether the substantially flat article (8) has one or more of the plurality of known defects.

8. The control system (100) according to any one of the preceding claims, wherein the at least one LED strip (25) of the lighting unit (21) (in particular, each LED strip (22, 25)) comprises a plurality of white LEDs, the plurality of white LEDs having a luminous power of at least about 1100 lumens; in particular, at least about 1200 lumens; more particularly, the luminous power being in the range of about 1260 lumens to about 20000 lumens.

9. The control system (100) according to any one of the preceding claims, wherein the at least one LED strip (25) of the lighting unit (21) (in particular, each LED strip (22, 25)) is configured to emit the light beam in an intermittent manner.

10. The control system (100) according to any one of claims 2 to 9, wherein each of the optical devices (26, 27) has a resolution of at least 1 μm; particularly, in the range of about 1 μm to about 20 μm; more advantageously, equal to about 3.5 μm.

11. A manufacturing apparatus (1) for manufacturing ceramic products, such as ceramic slabs and tiles, the manufacturing apparatus (1) comprising: Supply component (3), which is configured to supply ceramic powder (CP) at input station (5); A forming assembly (6) is arranged at a forming station (7) and configured to form at least one substantially flat article (8) comprising compacted ceramic material (particularly made of compacted ceramic material), the forming assembly (6) including at least one compaction device (12) configured to apply compaction pressure to the ceramic powder (CP); A kiln (11) configured to fire at least one substantially flat ceramic article (8) made of compacted ceramic material and obtain ceramic product (2). A conveyor assembly (9) for conveying the ceramic powder (CP) from the input station (5) to the forming station (7) along a given path (PA) in the feed direction (A) and for conveying the substantially flat article (8) from the forming station (7) to the kiln (11). as well as A control system (100) for controlling the integrity of a substantially flat article (8) made of compacted ceramic material, the control system (100) being arranged upstream of the kiln (11) along the given path (PA) and being a control system according to any one of claims 1 to 9.

12. A method for controlling the integrity of an article (8) made of compacted ceramic material; the method comprising the following steps: The supply step, during which at least one substantially flat article (8) is fed in the feed direction (A) along the feed path (P) on the feed surface (20), the article (8) comprising compacted ceramic material (in particular, made of compacted ceramic material). The illumination step, during which an illumination unit (21) comprising at least one LED strip (22) extending substantially transversely to the feed direction (A) emits at least one light beam toward the feed surface (20) and illuminates at least one region (Z) of the feed surface (20), the region (Z) extending in the direction (B) being at least equal to the extension of the feed surface (20); The detection step is performed at least partially concurrently with the illumination step, and during the detection step, an optical detection system (23) comprising a pair of optical capturing devices (27) (in particular, consisting of a pair of optical capturing devices (27)) captures at least two images of two edge portions of the substantially flat article (8) illuminated by the illumination unit (21); as well as An image processing step, which is at least partially following the illumination step, and during the image processing step, the processing unit (24) processes the image captured during the detection step in order to identify possible defects present in the at least two edge portions of the two corresponding side edges (B1, B2) of the substantially flat article (8).

13. The control method according to claim 12, wherein, During the inspection step, the optical inspection system (23) captures at least one additional image of the transverse band of the substantially flat article (8) illuminated by the illumination unit (21), and during the image processing step, the processing unit (24) also processes the additional image captured during the inspection step in order to identify possible defects present in the transverse band of the substantially flat article (8).

14. The control method according to claim 13, wherein the detection step comprises: In the first detection sub-step, during which the pair of optical capturing devices (27) capture the image of the edge portion of the substantially flat article (8); And a second detection sub-step, which is at least partially after the first detection sub-step, and during the second detection sub-step, an additional optical capturing device (26), as part of the optical detection system (23), captures the additional image of the at least one transverse band of the substantially flat article (8).

15. The control method according to claim 14, comprising: A first identification step, which is at least partially following the detection step, and during the first identification step, the processing unit (24) determines at least one first dimension (particularly, width) of the substantially flat article (8) in the direction (B) based on the at least one additional image. And an adjustment step, during which the position of each of the pair of optical capturing devices (27) is adjusted based on the data determined in the identification step, such that each of the optical capturing devices (27) is located at one of the side edges (B1, B2) of the substantially flat article (8) so as to be able to capture the image of at least the edge portion.

16. The control method according to claim 15, wherein the adjustment step includes a lateral adjustment sub-step and / or a vertical adjustment sub-step, during which the optical capturing device (27) moves in the direction (B) such that the distance between them is substantially equal to the size of the substantially flat article (8), and during the vertical adjustment sub-step, the optical capturing device (27) moves in the direction (C) perpendicular to the feed surface (20) to adjust the distance between the optical capturing device (27) and the substantially flat article (8) according to the specifications of the substantially flat article (8); In particular, during the vertical adjustment sub-step, the position of the additional optical capturing device (26) along the direction (C) is also adjusted.

17. The control method according to any one of claims 12 to 16, comprising a warning step, said warning step being at least partially after said processing step, and during said warning step, a warning unit issuing an alarm signal upon detecting a defect.

18. A method for manufacturing ceramic products, such as ceramic slabs and tiles, the method comprising: During the supply step, the supply component (3) supplies (in particular, a given / controlled amount) of ceramic powder (CP) at the input station (5). In the forming step, during the forming step, a forming component (6) arranged at the forming station (7) applies at least a compaction pressure to the ceramic powder (CP) and forms at least one substantially flat article (8) containing compacted ceramic material (in particular, made of compacted ceramic material). The firing step, during which the at least one substantially flat article (8) made of compacted ceramic material is fired in a kiln (11). During the conveying step, the conveyor assembly (9) conveys the ceramic powder (CP) from the input station (5) to the forming station (7) along a given path (PA) in the feed direction (A), and conveys the substantially flat article (8) from the forming station (7) to the kiln (11). as well as An integrity control step, which is at least partially prior to the firing step, is used to control the integrity of the substantially flat article (8) prior to the firing step, the article (8) comprising compacted ceramic material (particularly made of compacted ceramic material); the control step is actuated by the control method according to any one of claims 12 to 17.

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