Method for labelling objects and installation for processing objects that is equipped with a labelling device

Abstract

The invention relates to an installation (1) for processing objects (2), comprising a conveyor (3) intended to convey the objects in a certain conveying direction (D1), a labelling device (4) designed to apply a label (5) to an object being conveyed on the basis of at least certain information visible on the surface of the object, the labelling device comprising a labeller (7) designed to print a label and a label applicator robot (8) designed to apply the label to an object being conveyed. The robot comprises a label gripping surface (11) and is designed to keep the label pressed against the gripping surface during the movement of the robot.

Description

Method for labeling objects and object processing installation equipped with a labeling device

[0001] The invention falls within the field of object processing adapted for processing objects particularly in parcel sorting centers or logistics centers.

[0002] Some parcel sorting facilities, such as the one described in documents EP3538290, US2023 / 050326, and US11370575, are equipped with label-applying robots capable of applying labels to objects being conveyed. These robots are designed to operate in conjunction with conveyor systems and can be programmed to apply labels to objects of various shapes and sizes.

[0003] Using label-applying robots for parcel labeling offers numerous advantages over manual labeling. First, robots can operate at much higher speeds than human operators, increasing sorting throughput and reducing operating costs. Furthermore, robots can apply labels with high precision, minimizing labeling errors and improving the parcel sorting process.

[0004] Today's label-applying robots are equipped with various advanced technologies to improve their performance. Some robots, for example, are equipped with cameras to detect the position and orientation of objects on the conveyor, allowing for highly accurate label application.

[0005] However, the current trend is towards increased package heterogeneity and faster package conveying speeds, making labeling less and less reliable. Furthermore, there is now a need to minimize the rejection of packages whose labels were not recognized later in the sorting process.

[0006] The objective of the invention is therefore to solve the aforementioned problems.

[0007] To this end, the invention relates to a method for labeling objects in which the objects are conveyed on a conveyor in a certain conveying direction and in which a central unit is configured to identify at least some information associated with an object in at least one digital image of said object being conveyed and to create in return a digital data representing a certain processing indication of the object, and a labeling device designed to print the processing indication in the form of a label and to apply it to the object being conveyed, the central unit being configured to determine in said at least one digital image of the object, at least one label application surface specific to the object on which the label is to be applied,said application area corresponding to the total surface area of ​​the object in said at least one digital image of the object less a certain exclusion area of ​​said object in said digital image of the object on which the label is not to be applied, the central unit being configured to identify visual criteria specific to the object identified during the conveyance of the object and to delimit said exclusion area so that the visual criteria are contained within the exclusion area, characterized in that the visual criteria correspond to digital data representative of the surface of the object in three dimensions.

[0008] The idea behind the invention is to avoid applying a label to an object's surface that could hinder the object's processing, or even prevent its processing altogether if it were not recognized downstream. The invention thus makes it possible to ensure reliable object labeling without slowing down the downstream processing.

[0009] The invention consists more particularly of excluding, from the label application surface, an exclusion area, or zone, on the object that is not suitable for label application. This exclusion area is determined by the central processing unit, which is configured to take into account the total surface area of ​​the object in the digital image, corresponding to the object's surface in a plane, and to subtract the exclusion area from this total surface area. The remaining application area thus ensures a surface suitable for label application and for the subsequent processing of the object.

[0010] More specifically, the 3D surface data of the objects allows us to assess the heterogeneity of the object's surface, and in particular to determine the height of the object's surface relative to the conveyor. This makes it possible, for example, to exclude object surfaces that are too high or too low for label application.

[0011] The method according to the invention may also have the following characteristics:

[0012] - the visual criteria include at least some of the aforementioned information;

[0013] - visual criteria include the non-planar surfaces of the object;

[0014] - the central unit is configured to identify the absence or presence of a first label on the label application surface of the object in said digital image of the object, and in the presence of a first label; to command the labeling device to apply a second label on the first label;

[0015] - the central unit is configured to determine at least one label application area on each visible face of the object being conveyed on the conveyor;

[0016] -the central unit is configured to choose the fastest application surface to label from among the determined application surfaces;

[0017] - the central unit is parameterized to control N labeling devices, where N > 1, arranged in series along the conveyor, so that each labeling device labels one object out of X objects in series in the conveying direction, where X = Ne.

[0018] The invention also extends to an object processing installation comprising a conveyor for conveying objects in a certain conveying direction, a labeling device designed to apply a label to an object being conveyed according to at least some information visible on the surface of the object, the labeling device comprising a labeler designed to print a label and a label applicator robot designed to apply the label to an object being conveyed, characterized in that the robot comprises a label gripping surface and in that the robot is designed to keep the label pressed against said gripping surface during the movement of the robot.

[0019] The object processing installation according to the invention may also have the following features:

[0020] - The robot's gripping surface includes a shock absorber designed to cushion the impact between the robot and the object when the label is applied to the object.

[0021] - the robot is connected to an air circulation device designed to suck or exhale air into the robot and the central unit is set to control the suction into the air circulation device to hold the label against the gripping surface during the movement of the robot and then to control the exhalation of air when the robot is in contact with the object to apply the label;

[0022] - the conveyor is a PD double tray conveyor and in that the central unit is configured to assign labeling devices to objects statically when the labeling devices used are in even number;

[0023] - the conveyor is a PD double tray conveyor and in that the central unit is configured to dynamically assign labeling devices to objects when the number of labeling devices used is odd. Brief presentation of the drawings

[0024] The present invention will be better understood and other advantages will become apparent upon reading the detailed description of an embodiment taken by way of non-limiting example and illustrated by the accompanying drawings, in which:

[0025] This is a schematic representation of an object processing installation according to the invention;

[0026] Laest is a schematic representation of a labeling device according to the invention when the robot retrieves a label directly from the labeler;

[0027] This is a schematic representation of a labeling device according to the invention when the robot applies a label to an object being conveyed on a conveyor;

[0028] Laest is a schematic representation of two labeling devices according to the invention in series along a conveyor;

[0029] Laest is a schematic representation of a digital image including an object being conveyed on a conveyor;

[0030] Laest is a diagram showing the steps of the process according to the invention;

[0031] Laest is a schematic representation of a double-tray conveyor according to the invention with four labeling devices;

[0032] Laest is a schematic representation of a double tray conveyor according to the invention with three labeling devices when all trays are carrying an object;

[0033] Laest is a schematic representation of a double tray conveyor according to the invention with three labeling devices in the case where some trays do not carry an object;

[0034] Laest is a schematic representation of a digital image of an object in which the visual criteria are identified by the central unit according to the invention. Description of a method of implementation

[0035] The invention relates to an object processing installation 1 of objects 2 visible on the and particularly well suited for use in a distribution center, a sorting center or a logistics center.

[0036] Object 2 refers to any type of object such as parcels, PPIs (Personal Protective Equipment), or postal mail. Object 2 may be heterogeneous in size, shape, and material.

[0037] The object processing installation 1 of objects 2 according to the invention typically includes a conveyor 3 for conveying objects 2 in a certain conveying direction D1 and a labeling device 4 designed to print and then apply a label 5 to an object 2 during conveying based on at least some information 6 visible on the surface of the object 2.

[0038] As an example, conveyor 3 could be either a single-platform PS conveyor or a double-platform PD conveyor. The single-platform conveyor has a succession of platforms one after the other in the conveying direction, while the double-platform conveyor has two rows of two single platforms following one another in the conveying direction, with the platforms in both rows extending side by side, forming pairs of platforms across the width of the conveyor. Each platform is designed to receive an object and transport it in the conveying direction D1.

[0039] The labeling device 4, also visible in Figures 2 to 4, according to the invention comprises a labeler 7 designed to print a label 5 and a label applicator robot 8 designed to apply the printed label 5 to an object 2 being conveyed.

[0040] The labeling device 4 can be controlled using a central unit 9 configured to retrieve information about the object 2 to be labeled, such as its length, width, and height dimensions and / or its relative position on the conveyor 3 and / or its speed on the conveyor, as well as information visible on the surface of the object 2 specific to that object. Apart from the speed of the object 2 on the conveyor 3, this information can be obtained from at least one digital image taken by a camera 10 upstream of the labeling device 4 on the conveyor 3. Thus, based on this information, the central unit 9 can be configured to determine the information to be printed on the label 5 and the position on the surface of the object 2 to which the label 5 should be applied.

[0041] The processing installation 1 according to the invention may be equipped with a plurality of labeling devices 4, the number, distribution along the conveyor and their assignment to apply the labels will depend first of all on the configuration of the conveyor, i.e. a conveyor with single trays or with double trays.

[0042] For use on a single-tray conveyor, the labeling devices are positioned alternately along the conveyor for alternating assignment to objects. The number of labeling devices used will depend on the working range of the robots for each labeling device and the conveyor speed.

[0043] For use on a double tray conveyor, as shown in Figures 7, 8 and 9, each labeling device may be assigned to a maximum of one tray of the same pair of trays.

[0044] In the case of an even number of labeling devices used, the assignment by the central unit will be static; that is, each device is pre-assigned to a tray, regardless of whether an object is present. In an example with four labeling devices, a first labeling device 1DE and a second labeling device 2DE will be positioned on one side of the conveyor, while a third labeling device 3DE and a fourth labeling device 4DE will be positioned opposite each other on the other side of the conveyor. Thus, at each conveyor start, the first and second labeling devices are assigned to the first pair of trays in the conveying direction, and the third and fourth labeling devices are assigned to the next pair of trays upstream in the conveying direction.Next, each labeling device is assigned to every other pair of trays from its starting position, and each labeling device is alternately assigned to a tray on one side of the conveyor and then to a tray on the other side. This configuration optimizes the working ranges of the labeling device robots.

[0045] There is also a variant according to the invention using an odd number of labeling devices on a double-tray conveyor. For example, three labeling devices could be arranged on the same side of the conveyor. In this variant, the assignment is not static but dynamic and depends on the actual presence of objects on the conveyor. The central processing unit is then configured to: if all pairs of trays are occupied, assign a labeling device to two successive pairs out of three, alternating each time between a tray on one side of the conveyor and a tray on the other side; if a pair contains only one item to be labeled,

[0046] Assign a labeling device to item N, the assigned labeling device being the one that was not assigned to the previous pair of trays, N-1. The labeling devices assigned to the next pair, N+1, are those not assigned to pair N, following the same alternating pattern on both sides of the conveyor. The labeling device assigned to N is also assigned to an item in pair N+2.

[0047] To facilitate the application of label 5 to object 2, robot 8 can be configured as a delta robot capable of moving along three axes x, y, z and rotating around the z-axis. The axes of robot 8 allow it to reach any position on the object, potentially rotating to orient label 5 onto object 2.

[0048] More specifically, the robot 8 may include a gripping surface 11 at a certain distal end of the robot 8 designed to retrieve a label 5, as shown in the figure. The robot 8 will then be designed to hold the label 5 against the gripping surface 11 during the movement of the robot 8. The labeler 7, for its part, may be designed to print a label 5 and make it available in a certain position facilitating its grasping by the gripping surface of the robot 8. For example, the labeler may be designed to orient a label horizontally with the adhesive surface of the label facing downwards.

[0049] The robot 8 will, for example, include a shock absorber 12 extending from the gripping surface 11, designed to cushion the impact between the robot 8 and the object 2 when the label 5 is applied to the object 2, as shown in the figure. The shock absorber 12 also serves to compensate for any uncertainties in the measurement of the height of the object 2 and any irregularities in the surface of the object 2.

[0050] The shock absorber 12 may be in the form of a bellows-type suction cup, the damping effect of which is provided by the folding of the bellows. The suction cup may be made of an elastic material to improve its damping capacity.

[0051] The labeling device 4 can also be connected to an air circulation device 13 designed to draw in or expel air into the robot 8.

[0052] In this case, the central unit 9 will be configured to control the suction in the air circulation device 13 to hold the label 5 against the gripping surface 11 during the movement of the robot 8 and then to control the expiration of the air when the robot 8 is in contact with the object 2 to apply the label 5.

[0053] In the case of a bellows-type suction cup shock absorber, air will flow through the suction cup so that label 5 is pressed against the end of the suction cup.

[0054] During label pickup, the air circulation device 13 generates a vacuum at the outlet of the gripping surface using the Venturi effect. This vacuum forces the label onto the gripper by suction and is maintained throughout the robot's movement to position the label precisely on the object.

[0055] When the label is applied, a solenoid valve integrated into the air circulation device 13 is activated by the central unit 9 to cancel the Venturi effect and direct the compressed air directly to the gripping surface and thus to the label. This generates a blowing action that presses the label onto the object.

[0056] More specifically, the central unit is configured to control the air circulation device 13 in response to numerical data representing the pressure inside the air circulation device 13, obtained, for example, using a pressure sensor. A reference pressure of, for example, 1 bar, means that no vacuum is being created and that the circulation device is not obstructed by a label. Conversely, when the pressure is less than 400 mm bar, it means that the end of the gripping surface is obstructed and that a vacuum is being created, and therefore that a label is correctly positioned at the end of the gripping surface.

[0057] The central unit is then configured to stop the suction and start the blowing when the gripping surface is sufficiently close to the object, for example, between 1 and 10 millimeters from the object's application surface. To do this, the central unit 9 uses numerical data representing the height of the label application area on the object relative to the conveyor surface on which the object is conveyed, and the real-time position of the robot's gripping surface.

[0058] The blowing is then stopped once the gripping surface is sufficiently far from the object, here for example between 2 and 10 millimeters from the application surface of the object.

[0059] By way of non-limiting example, and within the context of using the processing unit 1 in a sorting process for objects 2, the conveyor 3 may be in the form of a sorting conveyor equipped with sorting outlets 14 into which the objects 2 are sorted, as shown in the figure. The printed label 5 will in this case be a sorting label recognized by a label recognition device 15 on the sorting conveyor. The sorting label will advantageously bear a sorting indication enabling the sorting of the object 2 into a suitable sorting outlet 14. The sorting indication is determined by the central unit 9 based on certain information visible on the surface of the object 2 and a certain sorting plan for the objects 2 into the sorting outlets 14.

[0060] The invention also relates to a method for labeling objects particularly well-suited for implementation in a processing plant 1 as described above, but not limited to it. The object labeling method 2 according to the invention makes it possible to label all types of objects 2, and in particular heterogeneous objects as defined above.

[0061] A non-limiting embodiment of the object labeling method 2 according to the invention is shown in the diagram. The method as shown here consists of conveying objects on a conveyor in a step 100 along a certain conveying direction D1, then, using a central unit 9, identifying in a step 200 certain information associated with an object 2 in at least one digital image IN of the object being conveyed and, in return, creating in a step 300 a digital data representing a certain processing indication for the object 2. A labeling device is then used to print the processing indication in the form of a label in a step 400 and to apply it in a step 500 to the object 2 being conveyed.

[0062] The central unit 9 can also retrieve other information about the object 2 to be labeled, such as its three dimensions (length, width, height) and / or its relative position on conveyor 3 and / or its speed V1 on conveyor 3. Apart from the speed V1 of object 2 on conveyor 3, this other information can be obtained from at least one digital image. The central unit 9 can then be configured to determine the total surface area ST of object 2 visible from a certain viewing angle and to determine the object's position during its transport on the conveyor based on the conveying speed.

[0063] More specifically, the central unit 9 will be parameterized to determine at a step 250, carried out after step 200 and before step 300, in said at least one digital image IN of the object 2, at least one application surface SA of label 5 specific to the object 2 on which the label is to be applied, said application surface SA corresponding to the total surface ST of the object 2 in said at least one digital image IN of the object 2 less a certain exclusion surface SE of said object 2 in said digital image IN of the object 2 on which the label 5 is not to be applied, as seen on the.

[0064] The determination of the exclusion surface SE can also be carried out by the central unit 9.

[0065] More specifically, the central unit 9 can be configured to identify visual criteria specific to the object 2 during its transport on the conveyor 3 and to delimit said exclusion area SE so that the visual criteria are contained within the exclusion area SE.

[0066] Visual criteria refer, for example, to numerical data representing the surface of object 2 in two and / or three dimensions. In the case of the two-dimensional surface, the numerical data corresponds to an image of the object as seen in a plane. The numerical data representing the three-dimensional surface of object 2 allows for the assessment of the heterogeneity of the object's surface, or even the height of the object's surface relative to conveyor 3. This makes it possible, for example, to exclude the surface of object 2 that would be too high or too low for the application of label 5. If the total surface ST of the object consists only of exclusion surfaces SE, that is, no application surfaces, the central unit does not command the labeling of the object, which continues its conveyor journey in the direction of travel D1.Manual labeling of the object could be considered downstream in the direction of conveying.

[0067] Visual criteria also include, for example, numerical data representing an internal margin (IM) on each object, visible on the label, for example, 10mm of margin from each edge of the object. This margin is defined to prevent the application of labels too close to the edges of the object.

[0068] As an example, if several application surfaces are identified by the central unit, the central unit will choose the application surface closest to a zero point PZ of the object 2, also called here the origin of the object's coordinate system and visible in, which is a point defined in space relative to a zero point on the conveyor tray on which it is conveyed.

[0069] Digital data representing the three-dimensional surface of object 2 can be obtained using a vision sensor, such as a profilometer. This data can be in the form of point clouds, each representing a three-dimensional package and allowing the determination of the height of each point on the object's surface relative to the conveyor. This data also allows the central processing unit 9 to determine the inclination of object 2's surface and, in turn, whether this inclination exceeds a threshold that prevents the gripping surface 11, which is a horizontal surface, from applying the label. The threshold can also be determined based on a certain compensation capacity of the gripping surface up to a certain inclination of object 2's surface. The use of a flexible suction cup as the gripping surface, in particular, allows for compensation of a certain inclination of the object's surface.

[0070] By way of non-limiting example, said certain information associated with object 2 in said at least one digital image IN of said object 2 during transport may also be considered as one of the visual criteria.

[0071] The said certain information according to the invention may, for example, correspond to sorting information previously affixed to object 2.

[0072] As an example, visual criteria also include the non-planar surfaces of object 2. The non-planar surfaces of the object can be determined from digital images representing the surface of object 2 in three dimensions or from other digital images obtained for example by shadow area detection, clipping, etc.

[0073] It is understood that the visual criteria mentioned may be considered alone or in combination depending on the needs.

[0074] The central unit 9 can also be configured to identify, at step 225, after step 200 and before steps 250 and 300, a first label 5a on the label application surface of object 2 in the digital image IN of object 2, and to then command the labeling device 4 to apply a second label 5b over the first label 5a. This function prevents overloading the label application surface SA with a second label 5b in addition to the first label 5a, thus avoiding label 5 recognition errors downstream in the processing. This function also allows step 250 to be skipped and the process to proceed directly to step 300.

[0075] The central unit 9 can also be configured to determine at least one label application surface (SA) on each visible face of the object 2 being conveyed on the conveyor 3. This functionality allows, in particular, the selection of the face of the object 2 with the most suitable label application surface (SA) for the application of label 5.

[0076] The central unit 9 will, for example, be configured to choose the fastest application surface to be labeled by the labeling device 4 from among the determined SA application surfaces.

[0077] The central unit 9 can also be configured to control the labeling device 4 so as to apply a label 5 according to a certain orientation defined according to the orientation of the object 2. For example, an object oriented in landscape format on the conveyor will have a label 5 applied that is also oriented in landscape format on the object 2.

[0078] Therefore, to increase the labeling throughput and thus the conveying speed of objects 2 on conveyor 3, the central unit 9 can be configured to control at least two labeling devices 4 arranged in series along conveyor 3, as shown in the figure, with the two labeling devices 4 being configured to label one out of every two objects 2 in the conveying direction D1. More generally, it can be provided that the central unit 9 controls N labeling devices, where N > 1, arranged in series along the conveyor, such that each labeling device labels one out of X objects in series in the conveying direction, where X = N.

[0079] Without restricting the scope of the invention, one or more features specific to the processing installation 1 according to the invention can be combined with one or more features specific to the labeling process according to the invention and vice versa, and in particular the parameters of the central unit 9.

Claims

A method for labeling objects in which the objects are conveyed (100) on a conveyor in a certain conveying direction and in which a central unit is configured to identify (200) at least some information associated with an object in at least one digital image (DI) of said object being conveyed and to create (300) in return a digital data representative of a certain processing indication of the object, and a labeling device designed to print (400) the processing indication in the form of a label and to apply it (500) to the object being conveyed, the central unit being configured to determine (250) in said at least one digital image of the object, at least one label application surface (SA) specific to the object onto which the label is to be applied,said application area corresponding to the total surface area (ST) of the object in said at least one digital image of the object less a certain exclusion area (SE) of said object in said digital image of the object on which the label is not to be applied, the central processing unit being configured to identify visual criteria specific to the object identified during the conveyance of the object and to delimit said exclusion area so that the visual criteria are contained within the exclusion area, characterized in that the visual criteria correspond to digital data representative of the surface of the object in three dimensions. A method for labeling objects according to claim 1, characterized in that the visual criteria include said at least some information. Method for labeling objects according to any one of claims 1 or 2, characterized in that the visual criteria include the non-planar surfaces of the object. A method for labeling objects according to any one of the preceding claims, characterized in that the central unit is parameterized to identify the absence or presence of a first label on the label application surface of the object in said digital image of the object, and in the presence of a first label; to command the labeling device to apply a second label on the first label. Method for labeling objects according to any one of the preceding claims, characterized in that the central unit is parameterized to determine at least one label application area on each visible face of the object being conveyed on the conveyor. A method for labeling objects according to any one of the preceding claims, characterized in that the central unit is parameterized to control N labeling devices, where N > 1, arranged in series along the conveyor, such that each labeling device labels one object out of X objects in series in the conveying direction, where X = N. An object processing installation (1) comprising a conveyor (3) for conveying objects in a certain conveying direction (D1), a labeling device (4) designed to apply a label (5) to an object being conveyed based on at least some information visible on the surface of the object, the labeling device comprising a labeler (7) designed to print a label and a label applicator robot (8) designed to apply the label to an object being conveyed, the robot comprising a label gripping surface (11) and is designed to hold the label against said gripping surface during the movement of the robot,characterized in that the robot is connected to an air circulation device designed to draw in or expel air into the robot, and in that the central unit is configured to control the intake of air from the air circulation device to hold the label against the gripping surface during the robot's movement, and then to control the expulsion of air when the robot is in contact with the object to apply the label. Object processing installation according to claim 7, characterized in that the robot's gripping surface includes a shock absorber (12) designed to cushion the shock between the robot and the object when the label is applied to the object. Object processing installation according to any one of claims 7 or 8, characterized in that the conveyor is a PD double tray conveyor and in that the central unit is parameterized to assign the labeling devices to the objects statically when the labeling devices used are in even number. Object processing installation according to any one of claims 7 or 8, characterized in that the conveyor is a PD double tray conveyor and in that the central unit is parameterized to dynamically assign labeling devices to objects when the labeling devices used are in odd number.

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