Improved tracking of articles in a production system

Abstract

Tracking system (50) for a production system (10), for tracking articles (30) throughout their production and inspection in the production system (10). The production system (10) comprises a production stage (12, 20), a transfer stage (32, 34, 38, 40) and an inspection stage (42), the transfer stage (32, 34, 38, 40) having a first portion wherein the articles (30) are configured to be moved in an ordered manner and a second portion wherein the articles (30) are configured to be moved in a disordered manner. The tracking system (50) comprises: deterministic tracking means (62), configured to be operatively coupled to the transfer stage (32, 34, 38, 40) and to deterministically track the articles (30) across the first portion of the transfer stage (32, 34, 38, 40); optical tracking means (60), configured to be operatively coupled to the transfer stage (32, 34, 38, 40) and to optically track the articles (30) across the second portion of the transfer stage (32, 34, 38, 40); and a control unit (46), operatively coupled to the deterministic tracking means (62) and the optical tracking means (60) and configured to combine the deterministic tracking of the deterministic tracking means (62) and the optical tracking of the optical tracking means (60) to track the articles (30) throughout the transfer stage (32, 34, 38, 40).

Description

[0001] "IMPROVED TRACKING OF ARTICLES IN A PRODUCTION SYSTEM"

[0002] Cross-Reference to Related Applications

[0003] This Patent Application claims priority from Italian Patent Application No. 102024000023226 filed on October 18, 2024, the entire disclosure of which is incorporated herein by reference.

[0004] Technical Field

[0005] The present invention relates to an improved tracking of articles in a production system. In particular, it relates to a tracking system for a production system, to the production system comprising the tracking system and to a tracking method implemented by the tracking system.

[0006] Background of the Invention

[0007] As known, glass containers are made by means of a glass production system, namely comprising a batch house, a hot end and a cold end.

[0008] The batch house allows to prepare and mix into batches the raw materials required for glass production (typically sand, soda ash, limestone, feldspar, cullet and other raw materials) .

[0009] The hot end melts the batched materials into molten glass and produces segments of molten glass (referred to as glass "gobs") that are then molded into glass containers.

[0010] The cold end inspects the glass containers to ensure that they are of acceptable quality.

[0011] Typically, the hot end operations are performed by an Individual Section (IS) machine, which comprises a plurality of identical sections (e.g., between two and twenty) , each of which is adapted to produce one or more containers simultaneously (e.g., up to four) . The individual sections operate with the same operating cycles , i . e . the molded glass articles leave the sections always in the same sequence . From these sections , the glass articles pass onto a common conveyor belt , on which they are consequently transported in the same sequence .

[0012] The conveyor belt conveys the glass articles to a continuous cooling ( or annealing) oven, in which the glass articles are cooled and annealed ( or tempered) .

[0013] The glass articles are then conveyed via accumulation tables and conveyor belts to control machines that check the glass articles for defects , in conformity with various and known criteria .

[0014] However, the conveying of the glass articles via the accumulation tables happens in a manner which is no longer synchronous with respect to the original production process . In fact , in the accumulation tables the glass articles accumulate and mix together . In other words , the order of the glass articles entering the control machines is not deterministically related or relatable to the order of the glass articles exiting the sections .

[0015] After the production, it is often required to be able to determine from which of the sections or which mold the respective glass article originates . This may be critical for example in order to correctly reconstruct which mal functioning section originated defective glass articles , as well as to tune operating parameters of the sections in order to adj ust certain physical properties of the glass articles .

[0016] In fact , each of these sections is provided with independent mechanisms , such as a mold for the shaping of the glass article , which must be controlled, serviced, adj usted and possibly replaced when required . Nevertheless , due to the presence of the accumulation tables it is di f ficult to accurately reconstruct the speci fic sections originating the considered glass articles .

[0017] In a known solution, each mold has a di f ferent identi fying engraving ( e . g . , a dot code or a two-digit engraving) , also known as mold number . All of the glass articles from a given section that were produced with the same mold thus carry the same mold number engraving . After the manufacturing process , this mold number engraving can be recogni zed upon the hollow glass article either in script form or as a dot pattern . In this case , the control machines can be equipped with devices for reading the mold number in order to document which mold, and hence which section, produced which defected glass article .

[0018] However, it is not possible in this manner to assign or associate to a glass article the exact time of its production in the section and thus the concurrently prevailing operating conditions . Moreover, the engraving leaves a permanent and visible mark on the glass article , which is often not desired by the seller and final client .

[0019] According to known document EP2114834 , each glass item is provided, on passing through the conveying stage after between the glass-molding machine and the continuous annealing lehr, with a mark having an individual serial number with which data from the process of manufacture of the glass item in question are associated . The mark is applied by means of an automatic spraying machine which applies consecutive serial numbers , with fluorescent paint that can be detected via ultraviolet radiation . Even though such a mark is not visible under normal conditions , it is nonetheless a permanent and expensive alteration of the glass article , which could also cause safety issues for certain uses .

[0020] Another known alternative as disclosed in document EP2368861 Bl , that relates to a marking station that produces a marking on each obj ect by means of a laser beam, the marking station being positioned as close as possible to the exit of the forming machine and the marking giving a unique identi fication for each obj ect (which identi fication is obtained from at least one item of information on the mold number and / or forming cavity of said obj ect , and the date , time , minutes and seconds of manufacture of each one of said obj ects ) . Each marking can be produced alphanumerically or using a speci fic code that is directly legible or encrypted . For example , marking can be appl ied in the form of a data matrix code facilitating automatic re-reading operations . But this system, using laser marking solution, may be expensive to obtain and to maintain . It also lets a visible mark on the container that should be avoided on some kind of glass container for practical or aesthetic reasons , so it cannot be used for any kind of container .

[0021] Therefore , the need is felt to find a reliable and cheap way to track the glass articles throughout their production and inspection, without apporting permanent modi fications to the glass articles .

[0022] Moreover, this issue is felt independently from the type of article that is produced and thus applies also to other types of production lines ( e . g . , plastic articles , metal articles , PET articles ) .

[0023] Document US 2016 / 109380 Al relates generally to machines that inspect glass containers (bottles ) for defects , and more particularly to an glass container inspection system and method having a graphic user interface that may be used to review and obtain extensive information on defects identi fied by the glass container inspection system .

[0024] Document EP 0 847 563 Bl relates to methods and apparatus for inspecting food products and other products or items whose quality can be visually ascertained : for sorting such products with automated optical sorters ; and for setting sorting parameters for a food sorting machine having an application-speci fic graphical user interface .

[0025] Document EP 1 026 080 Bl relates generally to the field of manufacturing ophthalmic lenses , especially molded, hydrophilic contact lenses , and more speci fically to an automated apparatus for consolidating contact lenses for packaging after inspection thereof .

[0026] Document US 2019 / 155264 Al relates generally to sorting products using conveyors and, in particular, to systems and methods for sorting products using conveyors having multiple sensors .

[0027] Summary of the Invention

[0028] The aim of the present invention is to provide a tracking system, a production system and a tracking method that overcome the issues mentioned above .

[0029] According to the present invention, a tracking system, a production system and a tracking method are provided, as defined in the annexed claims that are integral part of the present description .

[0030] Brief Description of Drawings

[0031] For a better understanding of the present invention, preferred embodiments thereof are now described, purely by way of non-limiting example and with reference to the attached drawings, wherein:

[0032] - Figures 1-3 schematically show a production system for producing articles, comprising a tracking system for tracking the articles, according to respective embodiments of the tracking system.

[0033] In the following, elements common to the different embodiments have been indicated with the same reference numbers .

[0034] Detailed Description of the Invention

[0035] Figure 1 shows a glass production system 10 for the production of glass articles, in particular glass bottles or glass containers.

[0036] The glass production system 10 comprises a batch house 12, a hot end 14 and a cold end 16.

[0037] The batch house 12 is of known type and allows to prepare and mix into batches the raw materials required for glass production (typically sand, soda ash, limestone, feldspar, cullet and other raw materials) .

[0038] The hot end 14, of per se known type, melts the batched materials 18 from the batch house 12 into molten glass streams and produces segments of molten glass (referred to as glass "gobs") that are then molded into glass articles.

[0039] In particular, the hot end 14 comprises an Individual Section (IS) machine 20 receiving the batched materials 18 from the batch house 12.

[0040] As known, the IS machine 20 comprises a molten glass supply 22, a gob forming system 24, a gob distribution arrangement 26 and plurality of individual sections 28 (e.g., between two and twenty) , each of which is adapted to produce one or more glass articles 30 simultaneously (e.g., up to four) .

[0041] In the molten glass supply 22, the batched materials 18 are melted into molten glass through a furnace and supplied to the gob forming system 24.

[0042] In the gob forming system 24, streams of molten glass flow from a feeder bowl through respective and multiple outlets, towards the sections 28 of the IS machine 20. Each of the streams of molten glass is cut by a shearing mechanism, located below the feeder bowl, into roughly cylindrical segments of glass (i.e., the gobs) , which fall by gravity.

[0043] The falling glass gobs are guided by means of the gob distribution arrangement 26 (e.g., comprising scoops, troughs and deflectors) into their respective sections 28 of the IS machine 20.

[0044] The sections 28 perform molding operations to produce the hot glass articles 30 starting from the glass gobs, according to per se known techniques.

[0045] Each section 28 can have a plurality of sets of molds which can operate simultaneously, a correspondent number of cut molten glass streams can be simultaneously supplied to these respective sets of molds.

[0046] The sections 28 can operate with the same operating cycles, i.e. the molded glass articles 28 can leave the sections 28 always in the same sequence.

[0047] From these sections 28, the glass articles 30 pass onto a common conveyor unit (in the following a common conveyor belt, also called hot end conveyor) 32 of the hot end 14, on which they are consequently transported in the same sequence (i.e., according to the order of their production) .

[0048] The hot end conveyor 32 conveys the glass articles 30 to an entry of a continuous cooling oven ( or anneal ing lehr ) 34 of the hot end 14 . The glass articles 30 are cooled and annealed ( or tempered) in the cooling oven 34 .

[0049] In particular, the cooling oven 34 comprises multiple and parallel conveyors ( also called oven conveyors ) 36 that are placed so as to be orthogonal to the hot end conveyor 32 ( i . e . , their conveying directions are parallel between each other and are perpendicular to the conveying direction of the hot end conveyor 32 ) . The oven conveyors 36 take the glass articles 30 from the hot end conveyor 32 and arrange them into respective multiple arrays ( i . e . , one for each oven conveyor 36 ) . The glass articles 30 progressively slide onto the respective oven conveyors 36 , each glass article 30 being carried along its respective array path from the entry of the cooling oven 34 to its exit and without mixing with the glass articles 30 of the other arrays . This allows to progressively cool and anneal a higher number of glass articles 30 in a lower amount of time with respect to the case of a single array of glass articles 30 .

[0050] At the exit of the cooling oven 34 , the glass articles 30 are accumulated onto an accumulation region 38 of the cold end 16 , wherein the glass articles 30 can mix among them thus losing the synchrony and order previously due to the sequence of their production .

[0051] In detail , the accumulation region 38 can comprise a resorting zone 38 ' and an accumulation table 38" , o f per se known type . In further details , the resorting zone 38 ' can have a tapered shape at its exit that allows the glass articles 30 , coming in parallel rows from the cooling oven 34 , to be re-arranged in a single array on a common conveyor belt 40 . The accumulation table 38" is coupled to the resorting zone 38 ' by means of a selective barrier that is controllable by the control unit 46 in an opened position, wherein the resorting zone 38 ' and the accumulation table 38" are in reciprocal communication so that the glass articles 30 in the resorting zone 38 ' can access the accumulation table 38" , or in a closed position, wherein the resorting zone 38 ' and the accumulation table 38" are not in reciprocal communication so that the glass articles 30 in the resorting zone 38 ' are prevented from accessing the accumulation table 38" . In fact , typically the resorting zone 38 ' is not an accumulation point for the glass articles 30 during normal functioning of the glass production system 10 ; however, it can become filled with glass articles 30 during an anomalous functioning of the glass production system 10 , for example when there is a stoppage in the cold end 16 that causes the lack of flowing of the glass articles 30 downstream while the glass articles 30 continue flowing from the cooling oven 34 . In the first case of correct and normal functioning of the glass production system 10 , the glass articles 30 move through the resorting zone 38 ' without accessing the accumulation table 38" ; on the other hand, in the second case of anomalous functioning of the glass production system 10 , the accumulation table 38" can be put in communication with the resorting zone 38 ' so that the glass articles 30 can accumulate therein, thus providing suf ficient time for correcting the functioning of the glass production system 10 before the resorting zone 38 ' becomes completely full of glass articles 30 . The accumulation table 38" can also be used for re-insertion of the glass articles 30 in the inspection flow ( i . e . , toward the cold end 16 ) or as a buf fer ( e . g . , i f the cold end 16 is partially blocked, for example for maintenance) .

[0052] In particular, the accumulation region 38 has an entry end (e.g., corresponding to an entry of the resorting zone 38' ) coupled to the exit of the cooling oven 34, and an exit end (e.g., corresponding to an exit of the resorting zone 38' ) opposite with respect to the entry end. The entry end receives the glass articles 30 coming in parallel rows from the cooling oven 34, whereas the exit end is coupled to a further common conveyor unit (in the following a further conveyor belt, also called cold end conveyor) 40 of the cold end 16.

[0053] The cold end conveyor belt 40 couples the accumulation region 38 and the control machines 42, thus conveying the glass articles 30 from the accumulation region 38 to control machines 42 of the cold end 16.

[0054] The control machines 42 check the glass articles 30 for defects in conformity with various and known criteria, to ensure that they are of acceptable quality. For example, the control machines 42 can comprise control cameras 44 for acquiring images or videos of the glass articles 30, to optically inspect their quality. Moreover and without being shown in Figure 1, the control machines 42 can comprise known selection means for selecting the defective glass articles 30, if any, and remove them from the final set of glass articles 30.

[0055] As evident from the above, the glass articles 30 are conveyed in an ordered manner up to the exit of the cooling oven 34 and, again, from the cold end conveyor 40 on. Therefore, in these areas of the glass production system 10 the movements of the glass articles 30 can be accurately tracked and predicted through deterministic calculations. On the other hand, on the accumulation region 38 the glass articles 30 are moved in a disordered manner (i.e., randomly) and their movements cannot be tracked and predicted through deterministic calculations.

[0056] In other words, the glass production system 10 has, in succession between them, a first portion (i.e., before the exit of the cooling oven 34) wherein the glass articles 30 are conveyed in an ordered manner, a second portion (i.e., the accumulation region 38) wherein the glass articles 30 are moved in a disordered manner and a third portion (i.e., from the cold end conveyor 40) wherein the glass articles 30 are conveyed again in an ordered manner.

[0057] Here, the wording ordered movements means movements that are directly due to the functioning of the components of the glass production system 10 (e.g., the functioning of the conveyors 32 and 36 and of the sections 28) and that are not influenced by the reciprocal interactions of the glass articles 30, so that their movements can be deterministically tracked based on design parameters of the components of the glass production system 10 (e.g., the lengths of the conveyors 32 and 36) and operating parameters of the components of the glass production system 10 (e.g., the conveyor speeds of the conveyors 32 and 36 and the outputting rate and order of the glass articles 30 by the sections 28) . On the other hand, the wording disordered movements means movements that are influenced by (even mainly due to) the reciprocal interactions of the glass articles 30 and that do not depend directly on the design and functioning of the components of the glass production system 10, so that their movements cannot be deterministically tracked.

[0058] Therefore, whereas the movements of the glass articles 30 in the first and third portion of the glass production system 10 are directly correlated to the design and functioning of the components of the glass production system 10, the movements of the glass articles 30 in the second portion of the glass production system 10 are not directly correlated to the design and functioning of the components of the glass production system 10. This also implies that the movements of the glass articles 30 on and after the cold end conveyor 40 are not directly and deterministically correlated to the movements before the exit of the cooling oven 34, due to the presence of the accumulation region 38.

[0059] The glass production system 10 also comprises a control unit 46, in particular an electronic control unit such as a dedicated processor. The control unit 46 is operatively coupled to the batch house 12, the hot end 14 and the cold end 16, to control such components of the glass production system 10 based on per se known criteria.

[0060] Additional known components of the glass production system 10 can be present, even if not described here because per se known and not part of the present invention.

[0061] In general thus, the glass production system 10 comprises a production stage (i.e., comprising the batch house 12 and the IS machine 20) , a transfer stage (i.e., comprising the hot end conveyor 32, the cooling oven 34 with the oven conveyors 36, the accumulation region 38 and the cold end conveyor 40) and an inspection stage (i.e., comprising the control machines 42) . The transfer stage has said first, second and third portions.

[0062] In addition to the above, the glass production system 10 also comprises a tracking system 50 for tracking the glass articles 30 throughout their production and inspection, i.e. from the hot end 14 to the cold end 16 .

[0063] The tracking system 50 comprises the previously mentioned control unit 46 .

[0064] The tracking system 50 also comprises optical tracking means ( also called a optical tracking module ) 60 that are operatively coupled to the control unit 46 and optically detect the glass articles 30 during their movements in the glass production system 10 .

[0065] In the embodiment of Figure 1 , the optical tracking means 60 comprise at least a first image acquisition device 52 . Figure 1 exemplarily shows a single first image acquisition device 52 , even though a plurality of them may be present .

[0066] In the following, the first image acquisition device 52 is considered to be a camera configured to acquire images or video frames of the glass articles 30 passing through its field of view .

[0067] The first camera 52 is placed at the second portion of the trans fer stage , to detect the glass articles 30 being moved therein . In particular, the first camera 52 is placed so that its field of view covers the whole second portion ( i . e . , the whole accumulation region 38 ) , so that the glass articles 30 are detected from when exiting the cooling oven 34 up to when entering the cold end conveyor 40 .

[0068] The first camera 52 is operatively coupled to the control unit 46 , which in use receives from the first camera 52 the images of the glass articles 30 present on the accumulation region 38 and tracks them across the accumulation region 38 , according to known obj ect recognition and tracking techniques .

[0069] For example , the most commonly used tracking methods may comprise two connected parts: a detection block, which identifies a relevant object in a frame, and a recognition block, which either assigns a new identity to that object or matches it with an existing one.

[0070] The first step in tracking an object is its detection; in this step, various algorithms are used to identify objects within a frame. Detection and segmentation algorithms, such as YOLO, DETR, Mask R-CNN, and U-Net, identify objects in each frame and then locate them using bounding boxes or at the pixel level. The goal of a detection step is to recognize a specific object, predefined by the algorithm, under a range of conditions, such as low image resolution or changes in brightness .

[0071] Tracking algorithms are applied sequentially to identify the detected objects across multiple frames, assigning a unique label to each object in every frame. The purpose of the tracking step is to generate a trajectory for each relevant object that appears in a series of frames, which is a collection of the object's positions over time. Techniques commonly used for tracking include Kalman filters (which model object position, velocity, and other dynamics based on linear motion) , optical flow, and deep learning-based methods .

[0072] Deep learning-based methods extend classical tracking approaches by incorporating deep learning features to improve tracking robustness, especially when objects are occluded or change their appearance; this can be done by incorporating visual appearance features (object descriptors) .

[0073] After detecting the object in a frame, an association step is needed to link the position of the detected object with the identities tracked by the algorithm. Various methods, such as the Hungarian matching algorithm, can be used. These algorithms solve the association problem by matching the detected objects, identified by the detection algorithm, with the identities defined by the tracking algorithm. This can be done, for example, by maximizing the overlap of bounding boxes using Intersection over Union (ToU) or by minimizing the Euclidean distance (L2) between their positions .

[0074] This tracking step aims to associate detections to identities handling complex situations such as occlusions, false positives or objects leaving the scene, generating identities accordingly. Whenever a new object is detected in a position that does not match an existing track, a new track is created for that object. Each new track is assigned to a unique ID that uniquely identifies the object over time, and the ID is maintained if the object is tracked. For each new track, the motion model used (e.g., Kalman filter) is initialized to begin predicting the future positions of the object. The track is updated after the association step, including updating the motion model, the object coordinates, and the age of the detected object, representing the number of frames it has been tracked.

[0075] Each identity tracked by the tracking algorithm has a "time to live" counter, that indicates how many frames an identity can exists without being associated with an object: this is important because a detection can be missed due to an error in the detection algorithm, that can be caused by occlusion, motion blur or other factors. On the other hand, in the case of false positives, a "warm-up" period can be introduced to confirm a new track only after a certain number of consecutive detections. If an identity is not detected for a certain number of consecutive frames, or if the number of missed detections exceeds a predefined threshold (e.g., 5 or 10 frames) , the track associated with that identity is deleted, and the identity is terminated.

[0076] In view of the above, it is evident that the optical tracking means 60 are configured to optically track the glass articles 30 in the second portion of the transfer stage (i.e., in the accumulation region 38, so that the glass articles 30 are detected from when exiting the cooling oven 34 up to when entering the cold end conveyor 40) .

[0077] Here, optical tracking corresponds to monitoring the motion of each glass article 30 in the one or more portions of the transfer stage that are identified by disordered motion of the glass articles 30 (in the considered example, the second portion of the transfer stage) , in particular as time passes. In detail, the motion monitoring comprises monitoring the position (and possibly also the speed) of each glass article 30 in the second portion of the transfer stage .

[0078] In other words, by optical tracking it is meant here the determination of the position (and possibly also the speed) of each glass article 30 through the second portion of the transfer stage, at each time instant.

[0079] As better discussed previously, the optical tracking is made possible by automatic visual inspection of the glass articles 30 during their disordered motion in the second portion of the transfer stage, that allows to determine the motion data of the glass articles 30 (i.e., position and possibly also the speed) based on said automatic visual inspection . Therefore, the optical tracking allows to determine the position (possibly also the speed) and timing of each glass article 30 entering and exiting the second portion of the transfer stage.

[0080] The optical tracking means 60 correspond to the means (e.g., sensors) that are used to carry out the optical tracking and thus to determine the motion data (and possibly also the timing) of each glass article 30 in the second portion of the transfer stage.

[0081] Moreover, the tracking system 50 also comprises deterministic tracking means (also called a deterministic tracking module) 62, operatively coupled to the control unit 46 and configured to deterministically track the glass articles 30 across the first and third portions of the transfer stage.

[0082] In detail, in use the control unit 46 also tracks the glass articles 30 across the first and third portions of the transfer stage, according to deterministic techniques.

[0083] In particular, the tracking in the first and third portions is performed based on (predefined and fixed) design parameters (e.g., the lengths of the conveyors 32 and 36) and operating parameters of the components of, respectively, the first and third portions of the transfer stage (e.g., the conveyor speeds of the conveyors 32 and 36 and the outputting rate of the glass articles 30 by the sections 28) . For example, the operating parameters of the glass production system 10 can be known and fixed (e.g., manually or automatically set at the start of the glass production system 10) or can be detected in real time (e.g., through respective sensors of the glass production system 10, such as conveyor speed sensors coupled to the conveyors to be monitored) .

[0084] For example , by knowing the length and the conveying speed of the hot end conveyor 32 , it is possible to calculate the time interval required by the glass articles 30 to arrive at the entry of the cooling oven 34 from their exit from the sections 28 ; analogous calculation can be made for the oven conveyors 36 in the cooling oven 34 and for the cold end conveyor 40 .

[0085] According to an exemplary and non-limiting embodiment that is here described only for illustrative purposes , the deterministic tracking means 62 can comprise a data storage unit ( e . g . , a memory, not shown ) integrated in the control unit 46 or operatively coupled to it and configured to store the design parameters ( and possibly also the operating parameters ) of the glass production system 10 , as well as possibly also the sensors of the glass production system 10 configured to measure in real time the operating parameters of the glass production system 10 . For example , Figure 1 exemplarily shows conveyor speed sensors 58 of the deterministic tracking means 62 , operatively coupled to the hot end conveyor 32 and to the oven conveyors 36 to sense in real time their conveying speeds ; however, other sensors can be analogously considered in addition or in substitution to these cited sensors , as per se evident .

[0086] In view of the above , it is evident that the deterministic tracking means 62 are configured to deterministically track the glass articles 30 in the first and third portions of the trans fer stage ( i . e . , before the exit of the cooling oven 34 and from the cold end conveyor 40 , so that the glass articles 30 are detected up to when exiting the cooling oven 34 and again from when entering the cold end conveyor 40) .

[0087] Here, deterministic tracking corresponds to monitoring the motion of each glass article 30 in the one or more portions of the transfer stage that are identified by ordered motion of the glass articles 30 (in the considered example, the first and third portions of the transfer stage) , in particular as time passes. In detail, the motion monitoring comprises monitoring the position (and possibly also the speed) of each glass article 30 in the first and third portions of the transfer stage.

[0088] In other words, by deterministic tracking it is meant here the determination of the position (and possibly also the speed) of each glass article 30 through the first and third portion of the transfer stage, at each time instant.

[0089] As better discussed previously, the deterministic tracking is made possible by considering the ordered motion of the glass articles 30 in the first and third portions of the transfer stage, that allows to determine the motion data of the glass articles 30 (i.e., position and possibly also the speed) based on the design parameters and / or the operating parameters that have been stored or measured and that concern the first and third portions of the transfer stage .

[0090] Therefore, the deterministic tracking allows to determine the position (possibly also the speed) and timing of each glass article 30 entering and exiting the first and third portions of the transfer stage.

[0091] The deterministic tracking means 62 correspond to the means (e.g., sensors, elements, memories, etc.) that are used to carry out the deterministic tracking and thus to determine the motion data (and possibly also the timing) of each glass article 30 in the first and third portion of the transfer stage.

[0092] The control unit 46 combines the deterministic tracking in the first and third portions of the transfer stage with the optical tracking in the second portion of the transfer stage, in order to continuously identify and monitor the glass articles 30 moving across the different portions of the transfer stage.

[0093] In further detail, each glass article 30 exiting the first portion of the transfer stage (i.e., the cooling oven 34) is associated with a respective virtual identifier, determined via the deterministic tracking performed across the first region. Each virtual identifier is indicative of production data of the respective glass article 30, that allow to identify it. Examples of production data can comprise the section 28 that has generated the considered glass article 30, the mold used, the time of exit from the respective section 28, etc.

[0094] Then, each glass article 30 is optically tracked across the second portion of the transfer stage, so that it is possible to optically determine when it enters the cold end conveyor 40.

[0095] Therefore, by combining the deterministic tracking in the first and third portions of the transfer stage with the optical tracking in the second portion of the transfer stage, it is possible to keep track of each glass article 30 throughout its production and inspection and in particular to retrieve its production data at any step of the production line. This is relevant especially at the cold end stage in the control machines 42, since it allows for example to identify the malfunctioning sections 28 from the detection of the defective glass articles 30 and to identify which parameters lead to the defective articles.

[0096] Here, combining the deterministic tracking and the optical tracking means using the same virtual identifier to monitor the motion of the respective glass article 30 during both the deterministic tracking and the optical tracking, i.e. throughout all the portions of the transfer stage.

[0097] In other words, it means that the tracking in each portion takes charge of the virtual identifier of each glass article 30 tracked in the precedent portion of the transfer stage: in the present case, the virtual identifier associated to each glass article 30 by means of the deterministic tracking in the first portion of the transfer stage is used also during the optical tracking in the second portion of the transfer stage, as well as also during the deterministic tracking in the third portion of the transfer stage.

[0098] Therefore, the combination of the deterministic tracking and the optical tracking allows monitoring each glass article 30 throughout the entire transfer stage without interruptions, i.e. following the virtual identifier of each glass article 30 across all the portions of the transfer stage (thus from its generation at the beginning of the first portion up to the end of the third portion of the transfer stage) .

[0099] Based on such combined tracking of the glass articles 30, the control unit 46 may also automatically control one or more functionalities of the glass production system 10. For example, it is possible to adjust the functioning of the malfunctioning sections 28 (e.g., the mold) in order to correct the production of the defective glass articles 30. This can be done according to per se known criteria of correlations between the control parameters of the glass production system 10 and the consequent physical properties of the glass articles 30 obtained from the control machines 42 .

[0100] Even though Figure 1 shows only one first camera 52 , it is evident that the optical tracking means 60 can comprise a plurality of first cameras 52 , imaging the second portion of the trans fer stage . In particular, the fields of view of the first cameras 52 overlap among them and cover the entire second portion of the trans fer stage , so that no part of the accumulation region 38 remains unmonitored, including the accumulation table 38" . Thus , the robustness of detection increases .

[0101] In particular, as previously described, in certain tracking conditions , a single camera may not be sufficient to cover a large area, making it necessary to use a technique involving multiple cameras . Multi-camera obj ect detection and tracking utili zes several cameras with overlapping fields of view ( FOV) to detect and track obj ects across a wider area of observation .

[0102] In this scenario , the tracking information between cameras are synchroni zed and shared to ensure that an obj ect tracked in one camera ' s field of view can be seamlessly trans ferred to another camera as it moves across the scene , without losing its identity . In particular, the camera systems are synchroni zed both temporally and spatially .

[0103] Temporal synchroni zation can be achieved through hardware solutions or network-based protocols like NTP, while spatial synchronization requires calibrating the cameras so that the 2D or 3D positions of obj ects in one camera can be accurately mapped to other cameras . Once synchronization is established, the system can transfer tracking information, such as object ID, position, and appearance, from one camera to another to maintain continuous tracking.

[0104] Spatial tracking can be done using a shared coordinate system between cameras, meaning that the position of the object detected in one camera can be transformed into the space of the other camera using the position and orientation of the cameras relative to each other. When an object is about to leave the view of one camera, its last known position can be projected into the FOV of the neighboring camera. Track Handoff via Appearance Features is used especially in the case of objects with different shapes, colors, textures, etc.; these features are encoded in an appearance feature vector that can be used to match the same object when it enters the second camera's FOV, at which point the system can confidently say that the object is the same as the one being tracked in the first camera.

[0105] To maintain a globally unique tracking ID, two main methods can be used: Centralized Tracker or Distributed Track Management. In the former, the central system receives data from all cameras (e.g., object detections, appearance features, positions) and assigns or updates global track IDs based on the information from each camera. In the latter case, each camera may have its own local tracker, but the cameras communicate with each other to share information about tracked objects.

[0106] Another alternative is to create a unique scene by merging the FOVs of all the different cameras into a single image, and then apply the detection, association, and tracking algorithms to this single image.

[0107] In the embodiment of Figure 2, the optical tracking means 60 , here exemplarily comprising two first image acquisition devices 52 ' and 52" , also includes a second image acquisition device 54 . In the following, the second image acquisition device 54 is also considered to be a camera configured to acquire images or video frames of the glass articles 30 passing through its field of view .

[0108] The second camera 54 is placed at the second portion of the trans fer stage , to detect the glass articles 30 exiting from the first portion ( i . e . , exiting from the cooling oven 34 ) . For example , the second camera 54 is placed at the entry end of the accumulation region 38 . Therefore , the second camera 54 images the glass articles 30 when they are still moving in an ordered manner , j ust before they start to mix and interact among themselves .

[0109] The second camera 54 is operatively coupled to the control unit 46 and allows to label each glass article 30 exiting from the cooling oven 34 with the respective virtual identi fier indicative of the production data, for example through data fusion techniques . In other words , based on the deterministic tracking across the first portion of the trans fer stage , it is possible to associate to the glass articles 30 imaged by the second camera 54 the respective virtual identi fiers .

[0110] As evident , a plurality of second cameras 54 can be present , with overlapping fields o f view observing the exit of the cooling oven 34 .

[0111] In the embodiment of Figure 3 , the optical tracking means 60 also comprise a third image acquisition device 56 . In the following, the third image acquisition device 56 is also considered to be a camera configured to acquire images or video frames o f the glass articles 30 passing through its field of view .

[0112] The third camera 56 is placed at the first portion of the trans fer stage , to detect the glass articles 30 conveyed in an ordered manner through the first portion . For example , the third camera 56 is placed at the entry of the cooling oven 34 , to detect the glass articles 30 conveyed from the hot end conveyor 32 to the oven conveyors 36 .

[0113] The third camera 56 is operatively coupled to the control unit 46 and allows to optically inspect the glass articles 30 in the first portion of the trans fer stage .

[0114] This optical detection can be used, together with the deterministic tracking of the glass articles 30 , to increase the robustness and reliability of detection through data fusion . In detail , the sequence of glass articles 30 entering the cooling oven 34 and tracked through the third camera 56 can be compared with the sequence of glass articles 30 exiting the cooling oven 34 and tracked through the second camera 56 , so as to detect any conveying error that may occur when entering the cooling oven 34 or in the cooling oven 34 itsel f . Knowing the annealing time required for the glass articles 30 to travel through the cooling oven 34 , the control unit 46 can match the patterns at the entry and at the end of the cooling oven 34 , so that the hot end-cold end correlation feature relies not only on the calculated annealing time but also on a visual inspection of these patterns .

[0115] As evident from the present description, the tracking system 50 implements in use a tracking method for tracking the glass articles 30 , based on the combination of the deterministic tracking and the optical tracking . The steps of the tracking method are not here described in detail , since they are evident in view of the previous description of the tracking system 50 .

[0116] From what has been described and illustrated previously, the advantages of the present invention are evident .

[0117] In particular, the glass production system 10 allows to accurately track and recognize the glass articles 30 throughout their production line , i . e . both when they are conveyed in an ordered manner and when they move in a disordered manner . Therefore , it i s possible to exactly track the glass articles 30 and, i f required, to reconstruct the errors in the production line that lead to defective glass articles 30 and to correct them .

[0118] In general , the tracking system 50 allows to follow any glass article 30 ( i . e . , individual container ) from its forming to its inspection, even i f they do not bear any readable and physical identi fier .

[0119] In the present description, the wording production data is used to indicate one or more process parameters like mold number, time of forming, settings of the IS machine sequencer, feeder parameters , glass temperature and so on . Moreover, the wording inspection data is used to indicate the presence of any kind of defect in the glass article 30 like bubble , unfi lled finish, checks and so on . The wording measurements is used to indicate any kind of measurement useful for the present solution, for instance thickness distribution container heigh, lean, diameters and so on . Furthermore , the wording identi fication is used to indicate the action of providing an identity to each glass article 30 and it is made by associating to each glass article 30 a respective virtual identi fier, which is unique . Based on this tracking, the production data, the inspection data and the measurements can be associated through the di f ferent steps of the process to each individual glass article 30 . This provides accurate , complete and coherent data to determine the relationships between process parameters and quality results , between causes and ef fects . In detail , data analysis , statistics , modelling and learning methods provide for : a better knowledge to improve the process ; data to build models of the process ; data for automatic control of the forming process , using for instance inspections results and measurements in the closed loops .

[0120] Finally, it is clear that modi fications and variations may be made to what has been described and illustrated herein, without thereby departing from the scope of the present invention, as defined in the annexed claims . For example , the di f ferent embodiments described can be combined with each other to provide further solutions .

[0121] As evident , other numbers and disposition of the cameras of the optical tracking means 60 can be used, provided that they allow to obtain the same detection that was previously discussed .

[0122] Moreover, even i f the present discussion mentions the presence of only one second region wherein the glass articles 30 move in a di sordered manner, it is evident that the previously discussed tracking strategy can be applied also when several regions of disordered movements are present . In this case , this combined tracking strategy can be repeated for each region wherein the articles move in a disordered manner .

[0123] The region wherein the articles move in a disordered manner could also comprise a region which is accessible to operators (e.g., expert staff supervising the glass production system 10) or which can be influenced by external factors that can change the order of the glass articles 30 (e.g., an operator that intentionally moves some glass articles 30 in a certain region) .

[0124] Moreover, the third portion of the transfer stage may be absent, thus leaving only the first and second portions. In this case, the deterministic tracking is carried out in the first portion and the optical tracking is carried out in the second portion of the transfer stage.

[0125] Furthermore, the previously discussed tracking strategy can be applied also to other fields of application, such as to the production lines of plastic containers, PET containers, metal containers (e.g., aluminum containers) , metal boxes, etc. Therefore, the previously discussed field of application of glass articles has been used only for exemplary and illustrative purposes, but not in a limiting way .

[0126] Moreover, it is also possible that the cameras do not have an overlapping FOV. In this case, a deterministic motion tracking system could be applied to allow track handoff between non-overlapping cameras, under the assumption that objects in the frame follow a deterministic path, so the system can predict when an object will leave the FOV of one camera and enter the FOV of the next camera. In some cases, the object position can be predicted using a motion model, typically when the path is non-deterministic but the chances of one object interfering with the other are close to zero. An object can also be removed from or reinserted into the flow. This can happen due to human interaction, line malfunction, or simply for retooling purposes. In fact, in a deterministic system, the expected position and time of the object's movement is known or can be predicted based on past observations. By continuously monitoring these predictions, the system can detect anomalies when an object is removed. For example, if the object does not arrive within a certain time threshold of the predicted arrival time, the object can be considered removed from the flow and the system flags the object as missing. If the deterministic path requires it, proximity or motion sensors can be installed along the path to detect when an object is physically removed or deviates from the expected path. Another option, in the case of human interaction with the flow, is to place a camera or other tracking device in the areas where human intervention may occur to flag those items that have been removed and may be returned to the flow.

Claims

CLAIMS1. Tracking system (50) for a production system (10) , for tracking articles (30) throughout their production and inspection in the production system (10) , the production system (10) comprising a production stage (12, 20) for producing the articles (30) , an inspection stage (42) for inspecting the articles (30) and a transfer stage (32, 34, 38, 40) for transferring the articles (30) from the production stage (12, 20) to the inspection stage (42) , the transfer stage (32, 34, 38, 40) having a first portion wherein the articles (30) are configured to be moved in an ordered manner and a second portion wherein the articles (30) are configured to be moved in a disordered manner, the tracking system (50) comprising:- deterministic tracking means (62) , configured to be operatively coupled to the transfer stage (32, 34, 38, 40) and to deterministically track the articles (30) across the first portion of the transfer stage (32, 34, 38, 40) ; optical tracking means (60) , configured to be operatively coupled to the transfer stage (32, 34, 38, 40) and to optically track the articles (30) across the second portion of the transfer stage (32, 34, 38, 40) ; and a control unit (46) , operatively coupled to the deterministic tracking means (62) and the optical tracking means (60) and configured to combine the deterministic tracking of the deterministic tracking means (62) and the optical tracking of the optical tracking means (60) to track the articles (30) throughout the transfer stage (32, 34, 38, 40) .

2. Tracking system according to claim 1, wherein theoptical tracking means (60) comprise at least a first image acquisition device (52) configured to acquire images of the second portion of the transfer stage (32, 34, 38, 40) .

3. Tracking system according to claim 2, wherein the optical tracking means (60) comprise a plurality of said image acquisition devices (52) , having respective and overlapping fields of view that together cover the second portion of the transfer stage (32, 34, 38, 40) .

4. Tracking system according to claim 2 or 3, wherein the optical tracking means (60) further comprise at least a second image acquisition device (54) configured to acquire images of the articles (30) passing in an ordered manner from the first to the second portion of the transfer stage (32, 34, 38, 40) .

5. Tracking system according to claim 4, wherein the optical tracking means (60) further comprise at least a third image acquisition device (56) configured to acquire images of the articles (30) in the first portion of the transfer stage (32, 34, 38, 40) , and wherein the control unit (46) is configured to compare the images from the second image acquisition device (54) and the images from the third image acquisition device (56) to optically track the articles (30) also in the first portion of the transfer stage (32, 34, 38, 40) .

6. Tracking system according to anyone of the previous claims, wherein the deterministic tracking means (62) comprise means for storing design parameters of the production system (10) , in particular a data storage unit, and / or means for storing and / or acquiring in real time operative parameters of the production system (10) , in particular one or more conveyor speed sensors.. Tracking system according to anyone of the previous claims, wherein the control unit (46) is configured to assign a respective virtual identifier to each article (30) imaged by the optical tracking means (60) , said virtual identifier being indicative of production data of the respective article (30) and being determined based on the deterministic tracking .

8. Tracking system according to anyone of the previous claims, wherein the deterministic tracking means (62) comprise means configured to determine motion data, in particular a position at each time instant, of each article (30) in the first portion of the transfer stage, and wherein the optical tracking means (60) comprise means configured to determine the motion data of each article (30) in the second portion of the transfer stage.

9. Production system (10) for producing and inspecting articles ( 30 ) , the production system (10) comprising a production stage (12, 20) for producing the articles (30) , an inspection stage (42) for inspecting the articles (30) and a transfer stage (32, 34, 38, 40) for transferring the articles (30) from the production stage (12, 20) to the inspection stage (42) , the transfer stage (32, 34, 38, 40) having a first portion wherein the articles (30) are configured to be moved in an ordered manner and a second portion wherein the articles (30) are configured to be moved in a disordered manner, the production system (10) further comprising a tracking system (50) , according to anyone of the previous claims, for tracking the articles (30) throughout their production and inspection in the production system (10) ,the tracking system (50) comprising:- the deterministic tracking means (62) , operatively coupled to the transfer stage (32, 34, 38, 40) and configured to deterministically track the articles (30) across the first portion of the transfer stage (32, 34, 38, 40) ;- the optical tracking means (60) , operatively coupled to the transfer stage (32, 34, 38, 40) and configured to optically track the articles (30) across the second portion of the transfer stage (32, 34, 38, 40) ; and- the control unit (46) , operatively coupled to the deterministic tracking means (62) and the optical tracking means (60) and configured to combine the deterministic tracking of the deterministic tracking means (62) and the optical tracking of the optical tracking means (60) to track the articles (30) throughout the transfer stage (32, 34, 38, 40) .

10. Production system according to claim 9, wherein the control unit (46) is further configured to control one or more functionalities of the production system (10) based on the tracking of the articles (30) throughout the transfer stage (32, 34, 38, 40) and based on the inspection by the inspection stage (42) .

11. Production system according to claim 9 or 10, wherein the production system (10) is configured to produce one of the following articles (30) : glass articles; plastic articles; metal articles.

12. Production system according to claim 11, wherein the production system (10) is configured to produce the glass articles ( 30 ) , wherein the production stage (12, 20) comprises at least an individual section machine (20) ,wherein the transfer stage (32, 34, 38, 40) comprises at least a cooling oven (34) , a first conveyor unit (32) coupling the individual section machine (20) and an entry of the cooling oven (34) , an accumulation region (38) at an exit of the cooling oven (34) and a second conveyor unit (40) coupling an exit of the accumulation region (38) and the inspection stage (42) , wherein the inspection stage (42) comprises control machines (42) , and wherein the first portion of the transfer stage (32, 34, 38, 40) comprises at least the first conveyor unit (32) and the cooling oven (34) , whereas the second portion of the transfer stage (32, 34, 38, 40) comprises at least the accumulation region (38) .

13. Tracking method for tracking articles (30) throughout their production and inspection in a production system (10) , the production system (10) comprising a production stage (12, 20) for producing the articles (30) , an inspection stage (42) for inspecting the articles (30) and a transfer stage (32, 34, 38, 40) for transferring the articles (30) from the production stage (12, 20) to the inspection stage (42) , the transfer stage (32, 34, 38, 40) having a first portion wherein the articles (30) are configured to be moved in an ordered manner and a second portion wherein the articles (30) are configured to be moved in a disordered manner, the tracking method being implemented by a tracking system (50) of the production system (10) and comprising the steps of:- deterministically track, by means of deterministictracking means (62) of the tracking system (50) , the articles(30) across the first portion of the transfer stage (32, 34, 38, 40) ;- optically track, by means of optical tracking means (60) of the tracking system (50) , the articles (30) across the second portion of the transfer stage (32, 34, 38, 40) ; and- combining, by a control unit (46) operatively coupled to the deterministic tracking means (62) and the optical tracking means (60) , the deterministic tracking of the deterministic tracking means (62) and the optical tracking of the optical tracking means (60) to track the articles (30) throughout the transfer stage (32, 34, 38, 40) .

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