Method for controlling the cutting process, in particular laser- cutting, of plate-like and similar objects and cutting machine operating with this method

Abstract

The present application relates to a method for controlling the cutting process of one or more components (5) from a sheet-like member (2) comprises the steps: - storing in a database the profiles of said one or more components (5) to be cut, each profile being defined by the succession of a plurality of points having respective coordinates in a reference system (Pxy), - applying to the sheet-like member (2) a mark which correlates with the reference system and which is suitable for identifying the position and orientation of said reference system (Pxy), - carrying out the cutting of said one or more components (5) along the respective profiles stored in the database, leaving at least part of said one or more components (5) connected to the sheet-like member (2) at at least one respective connection zone, - providing a vision device which is configured to acquire the image of said mark and providing a system for processing said image in order to recognise said reference system (Pxy) and the consequent positioning and orientation of said one or more components (5) connected to the sheet-like member (2) with respect to the recognised reference system, - identifying within the profile of each of said one or more components (5) connected to the sheet-like member (2) a region suitable for gripping the component via a gripping device, - carrying out the gripping of the respective component (5) connected to the sheet-like member (2) at said gripping region by means of said gripping device, - removing said at least one respective connection zone while the corresponding component (5) is being gripped in said gripping device, so as to separate the respective component (5) from the sheet-like member (2), and - moving the respective component (5) which is separated from said sheet-like member (2) in the direction of a discharge zone, keeping the component (5) gripped in said gripping device. A cutting machine operating with the above method is also described.

Description

[0001] Method for controlling the cutting process, in particular lasercutting, of plate-like and similar objects and cutting machine operating with this method

[0002] Technical area

[0003] The present invention relates to a method for controlling the cutting process, in particular laser-cutting of plate-like objects.

[0004] The invention further relates to a cutting machine, in particular for lasercutting plate-like objects, operating in accordance with the aforementioned method for controlling the cutting process.

[0005] Technological background

[0006] The invention can, in general, be applied in all technological fields in which a cutting process is envisaged of one or more components from a semifinished material, having in particular the shape of a sheet-like member.

[0007] These cutting processes are typically used in cutting metal or other materials, e.g., wood and the like, plastics, natural or artificial stone, in which one or more components of a chosen profile are separated by cutting from a generally plate-like material, i.e., in the form of a plate or sheet.

[0008] Examples of cutting technologies which can be used in the aforementioned fields include laser-cutting, plasma cutting, high-pressure water-jet cutting, punching and shearing.

[0009] In the following, the invention will specifically refer to the field of lasercutting metal plate-like objects from sheet-like members such as metal plates or sheets, without, however, losing generality.

[0010] As is known, machines for laser-cutting metal objects such as plates, sheets and the like, are provided with a support grid which is intended to be positioned, generally in a horizontal arrangement, within a suitably defined cutting zone.

[0011] The support grid generally consists of a lower frame, or counter grid, possibly removable, to which a bearing structure consisting of a plurality of vertically elongated support elements is constrained. The latter are arranged in a configuration such as to create a kind of grid or grating and have a shaping of their upper edges generally defined by an alternation of protrusions and recesses, which are configured according to the thicknesses to be cut as well as according to the shape and size of the pieces to be obtained from the object being cut.

[0012] The plate to be cut then rests on the protrusions of the support grid, and generally the arrangement and density of said protrusions is such as to support the majority of the pieces (normally of medium and large size) separated from the starting plate via the cutting process.

[0013] The removal and handling operations of the cut pieces towards unloading and / or storage stations are generally carried out manually by the operators, possibly assisted in some cases by robotic picking and unloading systems. If it is necessary to obtain one or more small pieces by cutting the plate, any excessive distance between the two consecutive protrusions of the grid could cause the piece, once cut, to fall, with possible damage thereto, if not to the machine, as well as difficulties in its recovery. In such cases, this is remedied by leaving, in the cutting step, the small piece connected to the plate via one or more micro-junctions, which are then removed later, once the plate has been distanced from the cutting zone of the machine. The offline movement and removal of the micro-junctions as well as the unloading and eventual storage of small parts are all activities involving significant manual intervention by skilled personnel, which can therefore lead to longer overall production times as well as increased costs related to human intervention in the aforementioned operations.

[0014] Description of the invention

[0015] The main aim of the invention is to provide a method for controlling the cutting process and a cutting machine operating with such a method, structurally and functionally designed to overcome the limitations indicated with reference to the known solutions.

[0016] This and other aims which will clearly appear in the following are achieved by the invention by means of a method for controlling the cutting process and a cutting machine made in accordance with the enclosed independent claims 1 and 17, respectively.

[0017] The features defined in the dependent claims refer to preferred examples of the invention.

[0018] In accordance with a first aspect, the invention relates to a method for controlling the cutting process of one or more components from a sheet-like member.

[0019] Preferably, the method comprises the step of storing in a database the profiles of said one or more components to be cut, each profile being defined by the succession of a plurality of points having respective coordinates in a reference system.

[0020] Preferably, the method comprises the step of applying to the sheet-like member a mark which correlates with the reference system and is suitable for identifying the position and orientation of said reference system. Preferably, the method comprises the step of carrying out the cutting of said one or more components along the respective profiles stored in the database, leaving at least part of said one or more components connected to the sheet-like member at at least one respective connection zone.

[0021] Preferably, the method comprises the step of providing a vision device which is configured to acquire the image of said mark and providing a system for processing said image in order to recognise said reference system and the consequent positioning and orientation of said one or more components connected to the sheet-like member with respect to the recognised reference system.

[0022] Preferably, the method comprises the step of identifying within the profile of each of said one or more components which are connected to the sheet-like member a region suitable for gripping the component via a gripping device. Preferably, the method comprises the step of carrying out the gripping of the respective component connected to the sheet-like member at said gripping region by means of said gripping device.

[0023] Preferably, the method comprises the step of removing said at least one respective connection zone while the corresponding component is being gripped in said gripping device, so as to separate the respective component from the sheet-like member.

[0024] Preferably, the method comprises the step of moving the respective component which is separated from said sheet-like member in the direction of a discharge zone, keeping the component gripped in said gripping device. In accordance with a second aspect, the invention relates to a machine for cutting one or more components from a sheet-like member. Preferably, the machine comprises a cutting unit which is configured to cut said one or more components along respective profiles of the components, each profile being defined by the succession of a plurality of points having respective coordinates with reference to a reference system, at least part of said components being cut while remaining connected to the sheet-like member at at least one respective connection zone with the sheet-like member.

[0025] Preferably, the machine comprises means for applying to the sheet-like member a mark which correlates with said reference system and which is suitable for identifying the position and orientation of the reference system, and the consequent positioning and orientation of said components which are connected to the sheet-like member with respect to the recognised reference system,

[0026] Preferably the machine comprises a vision device which is configured to acquire the image of said mark.

[0027] Preferably the machine comprises a system for processing said image in order to recognise said reference system and the consequent positioning and orientation of said one or more components connected to the sheet-like member with respect to the recognised reference system.

[0028] Preferably, the machine comprises a gripping device which is configured to carry out the gripping of each of said one or more components which are connected to the sheet-like member at a gripping region identified inside the profile of the corresponding component which is connected to the sheet-like member.

[0029] Preferably, the machine comprises cutting means which are configured to remove said at least one respective connection zone while the corresponding component is being gripped in said gripping device, so as to separate the component from the sheet-like member.

[0030] Preferably, the machine comprises means for moving the respective component which is separated from said sheet-like member in the direction of a discharge zone, while said separated component is gripped in said gripping device.

[0031] The present invention in at least one of the aspects mentioned above may have at least one of the preferred features set out below.

[0032] In a preferred embodiment, said reference system is a Cartesian reference system.

[0033] Preferably said reference system is defined in a Cartesian plane.

[0034] Preferably said sheet-like member is in the form of a plate-like object.

[0035] Preferably, said mark which correlates with the reference system is applied to one of the opposite surfaces defining the thickness of said plate-like object.

[0036] Preferably, said mark which correlates with the reference system is applied to said plate-like object by means of laser incision.

[0037] In a preferred embodiment, said vision device is a camera.

[0038] In a preferred embodiment, said vision device is mounted on a first robotic system.

[0039] In a preferred embodiment, said gripping device is mounted on said first robotic system.

[0040] In a preferred embodiment, said first robotic system comprises a first anthropomorphic robot. In a preferred embodiment, the removal of said connection zones is carried out by a laser-cutting device.

[0041] In a preferred embodiment, said laser-cutting device is configured to functionally cooperate with said first robotic system in cutting said connection zones.

[0042] In a preferred embodiment, said laser-cutting device is mounted on a respective second robotic system comprising a second anthropomorphic robot.

[0043] In a preferred embodiment, said connection zones comprise respective micro-junctions for connecting said one or more components to the sheetlike member.

[0044] In a preferred embodiment, said cutting process is a laser-cutting process.

[0045] In a preferred embodiment, said cutting process is carried out by means of punching or shearing or by means of a pressurised waterjet or by means of plasma-cutting.

[0046] In a preferred embodiment, said machine comprises a first robotic system including a first anthropomorphic robot with an operating head on which said vision device and said gripping device are mounted.

[0047] In a preferred embodiment, said cutting means for removing said connection zones of the components with the sheet-like member comprise a cutting device mounted on a second robotic system.

[0048] In a preferred embodiment, said first and second robotic systems are functionally independent.

[0049] In a preferred embodiment, said second robotic system comprises a respective second anthropomorphic robot. In a preferred embodiment, such a cutting unit is configured to carry out laser-cutting or plasma-cutting or pressurised waterjet cutting or cutting by means of punching or by means of shearing.

[0050] In a preferred embodiment, said cutting head is configured as a lasercutting head.

[0051] In a preferred embodiment, said cutting unit is configured to carry out the laser-cutting of components from a sheet of metallic material.

[0052] Brief description of the drawings

[0053] Further features and advantages of the invention will become clearer from the detailed description which follows of some of its preferred embodiment examples illustrated, by way of non-limiting example, with reference to the appended drawings, wherein :

[0054] Figure 1 is a schematic perspective view of an example of a lasercutting machine made in accordance with the invention,

[0055] Figure 2 is a side elevation and partial section view of the lasercutting machine of Figure 1,

[0056] Figure 3 is a schematic view in plan and partial section of the lasercutting machine of the previous figures,

[0057] Figure 4 is a plan view of an example of a sheet-like member including a plurality of components obtained by laser-cutting the same,

[0058] Figure 5 is a partial plan view, and in enlarged scale, of a further example of a sheet-like member from which a plurality of components can be obtained,

[0059] Figure 6 is a schematic side elevation view of a detail of the laser- cutting machine in accordance with the invention,

[0060] - Figure 7 is a partial perspective view, and in enlarged scale, of a detail of the laser-cutting machine in accordance with the invention, shown in a step of the method for controlling the cutting process of the invention.

[0061] Preferred embodiments of the invention

[0062] With initial reference to Figures 1 to 3, an example of a machine for lasercutting plate-like objects, preferably shaped as sheet-like members, made in accordance with the invention, is denoted with 1 and only schematically depicted.

[0063] The example described refers to objects in the form of plates 2, in particular metallic plates, although this conformation of objects is not limiting to the application prerogatives of the cutting machine of the invention, the latter being capable of being designed, in more general terms, for cutting objects of any shape.

[0064] The machine 1 comprises a cutting unit 3 including a laser-cutting head 3a, which is movable within a working zone 4 to cut one or more components, all indicated with 5, along the peripheral profiles of the plate 2.

[0065] The machine 1 comprises a support structure of the plate 2 at the working zone 4, said structure comprising a grid 6 in itself conventional, which is provided with vertically extended and mutually spaced support elements 7, adapted to define a grid with alternating protrusions and recesses, for supporting the plate 2 at localised points. The arrangement and density of the support elements 7 are chosen according to the thicknesses to be cut as well as according to the shape and size of the pieces or components 5 to be obtained from the sheet 2 being cut.

[0066] The machine 1 is further provided with a handling device of the plate 2, denoted with 8, which is adapted to move from a slab picking zone 9 towards the working zone 4 for the correct positioning of the plate to be cut. The handling device can also be configured to move at least part of the cut components 5 towards a discharge zone (not shown) provided near the working zone 4.

[0067] The cutting process can involve cutting each component 5 along its entire profile to separate it from the plate 2. This mode is typically envisaged if that component 5, once separated from the plate 2, can remain supported by the support grid 6 (i.e., supported by a suitable number of support elements), so that it can be picked up and unloaded off-line once the cutting is complete.

[0068] In the case of small components 5, it can instead be envisaged that the component is not completely separated from the plate 2 in the cutting process, but remains connected to the plate at one or more connection zones, indicated with 2a, formed by respective micro-junctions which keep the component still connected to the plate, preventing it from falling if, due to its small size, it cannot be supported by the grid support elements. In this case, the final separation of the component, by means of removal of the connection zones 2a, is carried out at a later step of the cutting process, as will become clear in the following.

[0069] In an embodiment, it is envisaged that the profiles of the components 5 to be cut on a plate 2 are first stored in a database, said profiles being defined as a succession of a plurality of points having respective coordinates referring to a reference system Pxy.

[0070] In more detail, said reference system Pxy is a Cartesian reference system defined in a Cartesian plane by a pair of Cartesian axes X,Y, with a prefixed origin 0, with respect to which the x,y coordinates of the successions of points defining the profiles of the components 5 are then identified and stored in the database. The coordinates of the profiles are transferred to the motion control logic of the cutting head 3a, to guide the latter along the appropriate cutting trajectories so as to separate each component 5 from the plate 2 during the cutting process.

[0071] It is understood that the reference system Pxy (with respect to which the coordinates of the profiles of the components 5 to be cut are identified) must be appropriately centred with respect to a fixed reference system with the machine 1 in which the cutting head 3a is moved to carry out the cutting trajectories.

[0072] In accordance with the method for controlling the cutting process of the invention, it is envisaged that a mark, denoted with 10, which correlates with the reference system Pxy is applied to the plate 2 (associated with the profiles to be cut) so that said mark is suitable for identifying the position (origin) and orientation (pair of axes x, y) of said reference system Pxy. The mark 10 can be conceived in the form of an image or figure or a geometric entity, viz., other similar sign or mark suitable for the purpose. In other words, the mark must be designed to contain sufficient references to allow the identification of the origin and the x, y axes of the Cartesian reference system Pxy.

[0073] For example, it can be envisaged that the mark 10 simply consists of a first point, identifying the origin 0, and a second and third point, which with the first origin point can respectively define the direction and orientation of the x, y axes.

[0074] Any other mark 10, which comprises sufficient graphical information to identify the position of the origin 0 and the directions of the x, y axes, may be used.

[0075] The mark 10 is preferably applied to the plate 2 by means of incision, although other ways of applying the mark are possible.

[0076] The image of the mark 10 is also intended to be acquired by a capturer 12, for example configured as a vision device, such as a camera or video camera. This vision device 12, which will also be referred to in the following for simplicity with the term "camera", is preferably mounted on a robotic system, as will become clear in the following of the description.

[0077] The camera 12 is operatively associated with an image processing system configured to recognise, via the image analysis of the mark 10, the reference system Pxy, and consequently to enable identifying the positioning and orientation of the profiles of the components 5 associated with the respective plate.

[0078] It should be noted that, whether the plate 2 remains on the cutting machine or is moved outside the working zone 4 of the machine, the recognition of the reference system Px,y, via the analysis of the image of the mark 10, makes it possible to know and reach all the coordinates of the profile points of each component 5.

[0079] In accordance with the invention, the machine 1 comprises a gripping device 13 configured to carry out the gripping of the components 5, in particular the gripping of the small components 5 which, following the main cutting step, remain connected to the plate 2 via the connection zones 2a.

[0080] Based on knowledge of the profile of the component 5, it can be envisaged that a preferred gripping zone, e.g. barycentric, will be identified within the profile of the component by means of the use of suitable calculation algorithms.

[0081] Once the gripping zone has been identified, the gripping device 13, e.g., including suction cups or other suitable gripping systems, can be brought at the component 5 to carry out the gripping.

[0082] In a preferred embodiment, the gripping device 13 is mounted on a robotic system, and preferably the gripping device 13 is mounted in combination with the camera 12 on the same robotic system. Said robotic system can comprise an anthropomorphic robot 15 on whose operating cuff 15a the camera 12 and gripping device 13 are mounted, as schematically depicted in Figure 6.

[0083] The machine 1 is also provided with a further laser-cutting device 16, which is configured specifically to remove the connection zones 2a to the plate 2 in the components 5.

[0084] The laser-cutting device 16 is preferably mounted on a second robotic system. Said second robotic system is also preferably configured as an anthropomorphic robot 17 bearing an end operating cuff 17a, on which said laser-cutting device 16 is mounted.

[0085] In the cutting process, with particular reference to the small components 5, where micro-junctions are left in the main cutting step to connect with the plate 2, the removal of said micro-junctions is carried out by leading the laser-cutting device 16 at the respective connection zone and removing said connection zone while the component 5 is being gripped in the gripping device 13. Once the component 5 has been separated from the plate 2, said component is carried by the gripping device in the direction of a discharge zone.

[0086] The trajectories travelled by the laser-cutting 16 and gripping 13 devices are also determined so that no interference occurs in their respective movements.

[0087] With reference to Figure 4, for reasons of process optimisation, it can be envisaged that the smaller components 5 are placed and confined within a sub-area 18 of the plate 2. In this case, the mark 10 which correlates with the reference system Pxy is applied at the sub-area 18 so that it remains united to said sub-area even if it is separated from the plate 2 to be carried off-line, in a zone in which to carry out the removal of the connection zones of the components to the plate. This operation carried out off-line has the advantage of not interfering with the processing cycles of the main lasercutting unit. Thanks to the recognition of the reference system Pxy of the invention, by means of analysis of the mark 10, the profiles of the components 5 and their connection zones 2a are advantageously identifiable in order to be able to effectively identify the most suitable trajectories along which to conduct the cutting devices 16 and gripping devices 13 in the respective operations of removing the connection zones 2a and gripping the component 5, as described in detail above.

[0088] It is understood that the laser-cutting devices 16 and gripping devices 13 can act in combination with each other, in the manner described, even if the plate 2 is kept in the working zone 4 of the machine and it is necessary to separate small components 5 connected to the plate 2 via micro-junctions suitably envisaged in the main cutting step.

[0089] The invention thus achieves the proposed aims, achieving numerous advantages with respect to the known solutions.

[0090] A major advantage lies in the fact that thanks to the invention, it is possible to automate certain steps of cutting, sorting and unloading components separated by cutting from plate-like objects, thus not requiring human intervention to carry out certain operating steps. Envisaging carrying out the aforementioned operations by means of robotic systems with the prerogatives of the invention advantageously allows for significant cost reductions and enables productivity gains in cutting equipment, in particular in the use of laser-cutting machines.

[0091] Another advantage lies in the fact that thanks to the invention it is possible to carry out certain cutting operations automatically, even off-line, with the consequent improvement of processing cycles.

Claims

CLAIMS1. A method for controlling the cutting process of one or more components (5) from a sheet-like member (2), comprising the steps:- storing in a database the profiles of said one or more components (5) to be cut, each profile being defined by the succession of a plurality of points having respective coordinates in a reference system (Pxy),- applying to the sheet-like member (2) a mark (10) which correlates with the reference system and which is suitable for identifying the position and orientation of said reference system (Pxy),- carrying out the cutting of said one or more components (5) along the respective profiles stored in the database, leaving at least part of said one or more components (5) connected to the sheet-like member (2) at at least one respective connection zone (2a), providing a vision device (12) which is configured to acquire the image of said mark (10) and providing a system for processing said image in order to recognise said reference system (Pxy) and the consequent positioning and orientation of said one or more components (5) connected to the sheet-like member (2) with respect to the recognised reference system, identifying within the profile of each of said one or more components (5) connected to the sheet-like member (2) a region suitable for gripping the component via a gripping device (13),- carrying out the gripping of the respective component (5) connected to the sheet-like member (2) at said gripping region by means of saidgripping device (13), removing said at least one respective connection zone (2a) while the corresponding component (5) is being gripped in said gripping device (13), so as to separate the respective component (5) from the sheetlike member (2), moving the respective component (5) which is separated from said sheet-like member (2) in the direction of a discharge zone, keeping the component (5) gripped in said gripping device (13).

2. A method according to claim 1, wherein said reference system (Pxy) is a Cartesian reference system.

3. A method according to claim 2, wherein said reference system is defined in a Cartesian plane.

4. A method according to any one of the preceding claims, wherein said sheet-like member (2) is in the form of a plate-like object.

5. A method according to claim 4, wherein said mark (10) which correlates with the reference system is applied to one of the opposite surfaces defining the thickness of said plate-like object.

6. A method according to claim 4, wherein said mark (10) which correlates with the reference system (Pxy) is applied to said plate-like object (2) by means of laser incision.

7. A method according to any one of the preceding claims, wherein said vision device (12) is a camera.

8. A method according to any one of the preceding claims, wherein said vision device (12) is mounted on a first robotic system.

9. A method according to claim 8, wherein said gripping device (13) ismounted on said first robotic system.

10. A method according to claim 8 or 9, wherein said first robotic system comprises a first anthropomorphic robot (15).

11. A method according to any one of claims 8 to 10, wherein the removal of said connection zones (2a) is carried out by a laser-cutting device (16).

12. A method according to claim 11, wherein said laser-cutting device (16) is configured to functionally cooperate with said first robotic system in cutting said connection zones (2a).

13. A method according to claim 11 or 12, wherein said laser-cutting device (16) is mounted on a respective second robotic system comprising a second anthropomorphic robot (17).

14. A method according to any one of the preceding claims, wherein said connection zones (2a) comprise respective micro-junctions for connecting said one or more components (5) to the sheet-like member (2).

15. A method according to any one of the preceding claims, wherein said cutting process is a laser-cutting process.

16. A method according to any one of claims 1 to 14, wherein said cutting process is carried out by means of punching or shearing or by means of pressurised water jet or by means of plasma-cutting.

17. A machine for cutting one or more components (5) from a sheet-like member (2), comprising:- a cutting unit (3) which is configured to cut said one or more components (5) along respective profiles of the components, each profile being defined by the succession of a plurality of points having respective coordinates with reference to a reference system (Pxy), atleast part of said components (5) being cut while remaining connected to the sheet-like member (2) at at least one respective connection zone (2a) with the sheet-like member (2), means for applying to the sheet-like member (2) a mark (10) which correlates with said reference system (Pxy) and which is suitable for identifying the position and orientation of the reference system, and the consequent positioning and orientation of said components (5) which are connected to the sheet-like member (2) with respect to the recognised reference system,- a vision device (12) which is configured to acquire the image of said mark (10),- a system for processing said image in order to recognise said reference system and the consequent positioning and orientation of said one or more components (5) which are connected to the sheetlike member (2) with respect to the recognised reference system,- a gripping device (13) which is configured to carry out the gripping of each of said one or more components (5) which are connected to the sheet-like member (2) at a gripping region identified inside the profile of the corresponding component (5) which is connected to the sheetlike member (2),- cutting means which are configured to remove said at least one respective connection zone (2a) while the corresponding component (5) is being gripped in said gripping device (13), so as to separate the component (5) from the sheet-like member (2), means for moving the respective component (5) which is separatedfrom said sheet-like member (2) in the direction of a discharge zone, while said separated component (5) is gripped in said gripping device (13).

18. A machine according to claim 17, comprising a first robotic system including a first anthropomorphic robot (15) with an operating head on which said vision device (12) and said gripping device (13) are mounted.

19. A machine according to claim 17 or 18, wherein said cutting means for removing said connection zones (2a) of the components (5) with the sheetlike member (2) comprise a cutting device (16) which is mounted on a second robotic system.

20. A machine according to claim 19, wherein said first and second robotic systems are functionally independent.

21. A machine according to claim 19, wherein said second robotic system comprises a respective second anthropomorphic robot (17).

22. A machine according to any one of claims 17 to 21, wherein said cutting unit (3) is configured to carry out laser-cutting or plasma-cutting or pressurized water jet cutting or cutting by means of punching or by means of shearing.

23. A machine according to claim 19, wherein said cutting device (16) is configured as a laser-cutting device.

24. A machine according to any one of claims 17 to 21, wherein said cutting unit (3) is configured to carry out the laser-cutting of components (5) from a sheet (2) of metallic material.

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