System and method for moving pieces

Abstract

A method for moving workpieces (50, 51, 52) to be machined and / or machined pieces (60, 61, 62) in a robotized work island (300), comprising an operating machine (250) for working sheet metals and a robot (100) for moving the workpieces (50, 51, 52) and machined pieces (60, 61, 62) and having an operating end (101) provided with gripping means (110) and an artificial vision apparatus (1), comprises the steps of positioning the operating end (101) above a first supporting plane (261) to acquire by means of a camera (2) of the vision apparatus (1) a first three-dimensional image of the first supporting plane (261) and of workpieces (50, 51, 52) and / or stacks of workpieces (55); processing the first three-dimensional image to determine position and orientation of the first supporting plane (261), number, geometry, position and orientation of each workpiece (50, 51, 52) and / or of each stack of workpieces (55, 56); identifying one or more workpieces (50, 51, 52) to be picked up and comparing its geometry with respective reference geometry to ascertain whether the workpieces (50, 51, 52) are compliant; picking up the workpiece (50, 51, 52) if compliant and moving it towards and a worktable (260) of the operating machine; releasing the workpiece (50, 51, 52) onto the worktable (260) so as to be machined and obtaining a corresponding machined piece (60, 61, 62); picking up the machined piece (60, 61, 62) from the worktable (260); arranging the operating end (101) with the vision apparatus (1) on the second supporting plane (262) to acquire a second three-dimensional image of the second supporting plane (261) and any machined pieces (60, 61, 62) and / or stacks of machined pieces (65, 66); processing the second image so as to determine position and orientation of the second supporting plane (262), number, position and orientation of any machined pieces (60, 61, 62) and / or stacks of machined pieces (65, 66); positioning and releasing the machined piece (60, 61, 62) on the second supporting plane (262).

Description

[0001] System and method for moving pieces

[0002] The invention relates to systems and methods for moving objects, pieces, material within cells or robotized work islands and, in particular, it relates to a system and a method for automatically moving workpieces and machined pieces or semi-finished pieces in a robotized work island for working sheet metals.

[0003] As is known, a cell or robotized work island or robotized island is a set of operating machines organized within a work area in which one or more programmable industrial robots are installed to speed up and simplify the entire production cycle and reach high degrees of repeatability of product quality.

[0004] More precisely, a robotized work island is a work area in which one or more operating machines or work units are positioned which are intended to perform machining on the workpieces, i.e. pieces, parts, material to be machined, and one or more programmable industrial robots capable of picking up the workpieces from a loading plane, for example a loading pallet, and supplying them to the operating machines and then picking up the machined or semi-finished pieces from the latter and depositing them in an orderly manner on an unloading plane, for example an unloading pallet. The operating machines may comprise machine tools, machines for working sheet metals, such as laser cutting machines, punching machines, combined cutting and punching machines, bending machines.

[0005] The industrial robots used in the work islands are generally known as anthropomorphic robots, that is, articulated robots having the shape of a human arm and generally provided with four or more degrees of freedom, typically six.

[0006] The use of vision systems in robotized work islands is known, which allow the robot or robots present to automatically identify and move the workpieces and machined or semifinished pieces. In particular, in the case of robotized islands for working metal sheets and / or entire metal plates or pieces, parts thereof, the known vision systems are able to identify the pieces or parts of sheets of metal sheets or metal plates to be worked and / or moved, so as to allow the control unit of the robot to perform the movement or manipulation of the aforesaid pieces autonomously and automatically.

[0007] The known artificial vision systems used for this purpose comprise one or more cameras capable of acquiring images of the piece or pieces to be moved. A processing unit of the artificial vision system processes the images acquired by the cameras by means of appropriate contour extraction algorithms so as to extract and extrapolate in a processed image the contour of the piece, i.e. the line or the set of lines that limit and circumscribe the piece. The camera(s) may be associated with laser emitters which project respective laser beams onto the pieces so as to allow the cameras to detect depth, height, thickness, vertical position (possible overlap or stacking) of the pieces based on the change of the lines drawn thereon by the respective laser beams on the pieces. In particular, as is known, the luminous line drawn on the pieces by the laser beam breaks or bends at a variation in depth or height of the piece and such a variation can be easily detected by the cameras.

[0008] The cameras and laser emitters of the vision system are suitably fixed and positioned inside the work island by means of suitable support structures so as to detect the pieces in the various operating areas, i.e. at a loading area, where the robot picks up the workpieces from an input pallet or conveyor, a working area, where the robot supplies the workpieces to the operating machine and picks up the machined or semi-finished pieces from the latter, and an unloading area, where the robot positions and releases the machined or semi-finished pieces onto an output pallet or conveyor. The number of cameras and laser emitters and their arrangement therefore depends on the size of the work island and the position of the operating machine and the input and output pallets or conveyors.

[0009] A disadvantage of the known systems for moving pieces in a robotized work island lies in the fact that they are somewhat complex and expensive, as the related artificial vision systems require numerous cameras and laser emitters suitably positioned to detect the pieces in the different picking and release areas and a specific support structure for their support and positioning within the work island.

[0010] Another disadvantage of the known systems for moving pieces lies in the fact that, if the arrangement and / or the relative position of the operating machine and / or of the loading and unloading planes of the pieces must be modified, it is necessary to reconfigure the artificial vision system, in particular to modify the position and / or orientation of the cameras and / or of the laser emitters, this requiring time and therefore the need to interrupt production.

[0011] JP 2007-21634 discloses an automatic system for machining a piece, in which visual sensors acquire the image of the piece to detect the position and contour thereof. Based on the detected position, a robot automatically picks up the piece to be machined and selects a machining path based on the contour of the piece.

[0012] US 2020 / 0134860 discloses an artificial vision-based method and system for measuring the three-dimensional position of an object. The method includes providing a reference set of 3D voxels representing a reference surface of a reference object. By means of at least one hybrid 2D / 3D sensor, a measured set of 3D voxels representing a corresponding measured surface of an object to be measured is then acquired. The voxels of the reference and measured sets are processed by a matching algorithm to determine the position of the object to be measured.

[0013] An object of the present invention is to improve the known systems and methods for moving pieces inside a robotized work island.

[0014] Another object is to provide a system and a method for moving pieces inside a robotized work island comprising at least one machine for working sheet metals by means of a programmable industrial robot capable of automatically identifying and moving workpieces and machined or semi-finished pieces.

[0015] A further object is to provide a moving system and method that allows position, orientation, shape and size of workpieces and machined and / or semi-finished pieces to be detected in a precise, accurate and automatic manner.

[0016] A first aspect of the invention provides a method for moving pieces according to claim 1.

[0017] A second aspect of the invention provides a moving system according to claim 13.

[0018] The invention can be better understood and implemented with reference to the attached drawings which show exemplary and non-limiting embodiments, wherein:

[0019] Figure 1 is a schematic plan view of the moving system of the invention associated with a robotized work island and comprising a programmable industrial robot provided with an artificial vision apparatus and illustrated in various operating positions;

[0020] Figure 2 is a schematic plan view of the moving system of the invention associated with a variant of the robotized work island;

[0021] Figure 3 is a perspective view of the programmable industrial robot of Figure 1 provided with the vision apparatus mounted on an operating end thereof supporting gripping means and associated with a supporting plane for workpieces to be machined;

[0022] Figure 4 is a partial and perspective view of the operating end of the robot with the vision apparatus disassembled;

[0023] Figures 5 and 6 are respectively front and rear perspective views of the vision apparatus of Figure 1;

[0024] Figure 7 is an enlarged and exploded perspective view of the vision apparatus;

[0025] Figure 8 is a schematic front view of the vision apparatus of the invention associated with the supporting plane on which a workpiece is positioned.

[0026] With reference to Figures 1 and 2, the moving system 200 of the invention for moving pieces associated with a robotized work island or cell 300 is schematically illustrated, comprising, for example, an operating machine 250 for working sheet metals, provided with a worktable 260 on which the workpieces 50, 51, 52, i.e. the pieces to be processed, are arranged, a first supporting plane 261 for supporting one or more workpieces 50, 51, 52 in particular to be provided to the operating machine 250, a second supporting plane 262 for receiving and supporting one or more machined pieces 60, 60, 61 made by the operating machine 250 and a programmable industrial robot 100 adapted to move the workpieces 50, 51, 52 from the first supporting plane 261 to the worktable 260 and the machined pieces 60, 61, 62 from the worktable 260 to the second supporting plane 261 and provided with an artificial vision apparatus 1.

[0027] In particular, the robot 100, for example of anthropomorphic type with several degrees of freedom, comprises an operating end 101 configured to support gripping means 110 adapted to grip and move the workpieces 50, 51, 52 and the machined pieces 60, 61, 62 and on which the artificial vision apparatus 1 is fixed, in particular in a removable or reversible manner, comprising a three-dimensional camera 2 and a laser emitter 3 arranged to generate a laser beam L on an emission plane E. More precisely, the operating end 101, called a wrist, is provided with an attachment flange 102 for the gripping means 110, also of known type and comprising for example a plurality of suction cups and / or gripping magnets.

[0028] The operating machine 250 for working sheet metals is, for example, one among a bending machine, a panelling machine, a laser cutting machine, a punching machine, a combined cutting and punching machine, and the workpieces are typically metal sheets 50, metal plates, semi-finished elements 51, 52, scraps of sheet metal or metal plate, etc. The machined pieces 60, 61, 62 are fully machined pieces 60, 62 and semi-finished pieces 61.

[0029] The first supporting plane 261 is, for example, the supporting plane of a pallet or a table or a loading or input conveyor, while the second supporting plane 262 is, for example, the supporting plane of a pallet or a table or an unloading or output conveyor.

[0030] The moving system 200 further comprises a processing unit 210 connected to the artificial vision apparatus 1 and configured to process respective three-dimensional images of the first supporting plane 261 and the second supporting plane 262 acquired by the camera 2 in cooperation with the laser emitter 3 so as to detect at least position and orientation of the first supporting plane 261, number, geometry, position and orientation of each workpiece 50, 51, 52 arranged on the first supporting plane 261 and / or number, position, orientation, height and number of pieces of each stack of workpieces 55, 56 arranged on the first supporting plane, and position and orientation of the second supporting plane 262, number, position and orientation of any machined pieces 60, 61, 62 positioned on the second supporting plane 262 and / or number, position, orientation, height and number of pieces of any stacks of machined pieces 65, 66 positioned on the second supporting plane 262. More precisely, with reference to Figure 1, the artificial vision apparatus 1 is able to detect a first stack 55 of metal sheets 50 and two second stacks 56 of semi-finished elements 51 arranged on the first supporting plane 261 and two first stacks 65 of machined pieces 60 and a second stack 66 of semi-finished pieces 61 arranged on the second supporting plane 262.

[0031] The geometry of the workpiece 50, 51, 52 refers to the shape of the outer contour of the piece and that of any openings or internal processing and the relative dimensions. For example, in Figure 1, the workpiece 50 is a rectangular metal sheet, the flat-shaped semifinished element 51 is rectangular- shaped with a rectangular- shaped appendage, and the further semi-finished element 52 of Figure 2 is a rectangular plate provided with a row of circular holes.

[0032] The processing unit 210 is further configured to process at least one respective three- dimensional image of the worktable 260 acquired by the camera 2, in particular, in cooperation with the laser emitter 3, so as to detect the presence on the worktable 260 of any workpieces 50, 51, 52 and / or machined pieces 60, 61, 62.

[0033] The processing unit 210 by means of appropriate image recognition algorithms is able to determine the position of each piece and its orientation on the supporting plane 261, 262 or on the worktable 260 with reference to an X, Y, Z reference system of the robot 100. The position of the piece means, for example, a distance of a reference point of the piece from the origin of the X, Y, Z reference system of the robot 100 along two orthogonal axes X, Y, of the aforesaid reference system, while the orientation of the piece means an angle formed by a reference stretch of the contour of the piece with one of the two axes of the X, Y, Z reference system.

[0034] The processing unit 210 is also able to calculate a thickness or a height of the piece, i.e. its dimension along the third orthogonal axis Z of the reference system S and its position along such third orthogonal axis Z, for example in the case of superimposed or stacked pieces.

[0035] The processing unit 210 is an autonomous unit dedicated to the control of the vision apparatus 1 and image processing or is integrated in a control unit of the robot 100 or in a control unit of the operating machine 250.

[0036] With particular reference to Figures 5 to 8, the artificial vision apparatus 1 comprises a three- dimensional or 3D camera 2, of a known type, capable of acquiring three-dimensional images of one or more pieces to be picked up and moved and a laser emitter 3, also of a known type, arranged to generate a laser beam L on an emission plane E. As known, the flat laser beam L projected on the piece or pieces arranged on a supporting plane or worktable allows the 3D camera to detect the depth, height, thickness, vertical position (possible overlapping or stacking) of the aforesaid pieces. More precisely, the luminous line LI drawn on the piece or pieces by the laser beam breaks or bends at a variation in depth or height of the piece and such a variation can be easily detected by the camera (Fig. 3).

[0037] The vision apparatus 1 further comprises a supporting element 5 configured to support the camera 2 and the laser emitter 3, which are positioned relative to each other in such a way that an optical axis K of the camera 2 forms with the laser beam L, i.e. with the emission plane E, of the aforesaid laser beam L, a detection angle a between 20° and 40°, in particular between 25° and 35°.

[0038] The camera 2 and the laser emitter 3 are also positioned with respect to each other such that an intersection point P between the optical axis K and the laser beam L is at a predefined detection distance h from the camera 2 and / or the laser emitter 3 along a direction parallel to the laser beam L (Fig. 7).

[0039] The optical axis K of the camera 2 means the optical axis of the lenses of such camera, i.e. the imaginary line along which there is a rotation symmetry for the aforesaid lenses and which defines the trajectory of the light through them.

[0040] Such detection distance h is, for example, between 400 and 600 mm.

[0041] The optics of the camera 2 are in any case able to frame and capture images of objects contained within a predefined solid vision angle whose 0 dimensions depend on the technical characteristics of the camera 2 itself. The camera 2 and the laser emitter 3 are mutually positioned angularly with the aforesaid detection angle a such that the luminous line LI drawn or made on the piece by the laser beam L is contained within the solid vision angle 0 of the camera 2.

[0042] The supporting element 5 comprises an external seat 9 that allows the connection or coupling or engagement of the vision apparatus 1 to the operating end 101 of the robot 100.

[0043] More precisely, the supporting element 5 comprises an enclosure 6 provided with a first internal seat 7 adapted to house the camera 2 or the emitter 3 and a second internal seat 8 adapted to house the emitter 3 or the camera 2. In the embodiment illustrated in the figures, the camera 2 is housed in the first internal seat 7 while the laser emitter 3 is housed in the second internal seat 8. Appropriate openings 7a, 8a are provided in the enclosure 6 at the internal seats 7, 8 to allow the camera 2 to detect the images and the laser emitter 3 to emit the laser beam L outwards.

[0044] The external seat 9 of the supporting element 5 is arranged between the two internal seats 7, 8 and is configured to engage an external portion of the operating end 101 of the robot 100, and more precisely to abut an external wall of the connection flange 102 of the operating end 101.

[0045] The enclosure 6, for example made of metal alloy or composite and / or plastic material, comprises a bottom wall 11 shaped almost like a "C" and a peripheral side wall 12 perpendicular to the bottom wall 11 and in particular connected to a peripheral edge I la thereof so as to form with the aforesaid bottom wall 11 the internal seats 7, 8 and the external seat 9.

[0046] In particular, in the illustrated embodiment the enclosure 6 in addition to the two internal seats 7, 8 separated from the external seat 9 comprises a hollow-shaped and elongated and straight junction portion 10 that connects the two internal seats 7, 8 to each other.

[0047] The external seat 9 comprises, in particular, two first flat portions or faces 12a and a second flat portion or face 12b belonging to the peripheral side wall 12; the first flat portions 12a are parallel, opposite and spaced from each other and the second flat portion 12b is orthogonal to, and adjoining, the first flat portions 12a.

[0048] As evident in Figure 2, the flat portions 12a, 12b are arranged to abut respective flat sectors 102a, 102b made on the connection flange 102 of the operating end 101 of the robot 100.

[0049] The vision apparatus 1 can be reversibly fixed to the connection flange 102 by means of fixing means of known type and not illustrated in the figures.

[0050] The supporting element 5 further comprises a cover 13 having a shape almost equal to that of the bottom wall 11 of the enclosure 6 and adapted to abut the peripheral side wall 12 on the side opposite the bottom wall 11 so as to close the enclosure 6. The cover 13 is reversibly fixed to the enclosure 6, for example by means of a plurality of screws.

[0051] The vision apparatus 1 may also comprise a lighting unit 4 arranged to illuminate a work zone framed by the camera 2 and crossed by the laser beam L, in particular in the case of low-light conditions of the work environment in which the robot 100 operates. The lighting unit 4 is, for example, housed in the second internal seat 7, next to the laser emitter 3. Alternatively, the lighting unit 4 can be housed inside the second internal seat 8.

[0052] Electrical connection means, of known type and not illustrated in the figures, are provided for electrically connecting the camera 2, the laser emitter 3 and, if present, the lighting unit 4, to electrical supply means and to the processing unit 210.

[0053] The operation of the moving system 200 of the invention provides a step of picking up one or more pieces 50, 51, 52 to be machined by the robot 100 provided with suitable gripping means 110. To allow the detection of the pieces 50, 51, 52 arranged on the first supporting plane 261 by the artificial vision apparatus 1 mounted on the operating end 101, the latter is initially positioned by the robot 100 above the pieces at the predefined detection distance h. More precisely, the vision apparatus 1 is positioned above the first supporting plane 261 at the predefined detection distance h to acquire at least a first three-dimensional image of the first supporting plane 261 and of one or more workpieces 50, 51, 52 and / or of one or more stacks or piles of workpieces 55, 56 positioned thereon.

[0054] The operating end 101 with the vision apparatus 1 can also be moved, for example parallel to the aforesaid first supporting plane 261, to allow the laser beam L emitted by the laser emitter 3 to project a luminous line LI progressively over the entire surface of the first supporting plane 261 and over that of the workpiece(s) 50, 51, 52.

[0055] The processing unit 210 is configured to process the aforesaid first three-dimensional image so as to detect and determine position and orientation of the first supporting plane 261, number, geometry, position and orientation of each workpiece 50, 51, 52 and / or number, position, orientation, height and number of pieces of each stack of workpieces 55, 56.

[0056] Based on the information obtained from the analysis of the first three-dimensional image, it is then possible to identify the workpiece(s) 50, 51, 52 to be picked up and compare a respective detected geometry thereof with a corresponding reference geometry, for example a respective CAD drawing stored in a database associated with the processing unit 210, to determine whether the workpiece(s) 50, 51, 52 are compliant and suitable for processing.

[0057] For example, Figure 2 shows a first supporting plane 261 on which two compliant workpieces 52 are positioned (because they are provided with a complete row of holes) and a non-compliant workpiece 52’ (because it is provided with an incomplete row of holes).

[0058] If the identified workpiece 50, 51, 52 is compliant, the gripping means 110 are positioned by the robot 100 so as to optimally retract and grasp such a workpiece 50, 51, 52 to allow the subsequent movement thereof up to the worktable 260 of the operating machine 250.

[0059] If, on the contrary, the identified workpiece 52’ is not compliant, it is picked up from the first supporting plane 261 by the gripping means 110 of the robot 100 and transferred and released on a third reject supporting plane 263.

[0060] The robot 100 releases the (compliant) workpiece(s) 50, 51, 52 onto the worktable 260 in a defined release position B, i.e. with a defined position and orientation, for subsequent machining.

[0061] Before depositing the (compliant) workpiece(s) 50, 51, 52 on the worktable 260, the vision system 1 can acquire with the camera 2 and in cooperation with the laser emitter 3 a third three-dimensional image of the worktable 260 and the processing unit 210 can process the aforesaid third three-dimensional image to detect the position and orientation of the worktable 260 and / or to verify the possible presence on the worktable 260 of workpieces 50, 51, 52 and / or machined pieces 60, 61, 62, for example not picked up by the robot 100 itself at the end of their processing.

[0062] If the worktable 260 supports at least one workpiece 50, 51, 52 and / or machined piece 60, 61, 62 the robot 100 can be stopped and the presence of pieces on the worktable 260 can be signalled.

[0063] At the end of the machining, the robot 100 picks up the machined piece or pieces 60, 61, 62, obtained from the machining of the respective workpieces 50, 51, 52, positioning the gripping means 110 in the same release position B.

[0064] Alternatively, the vision apparatus 1 of the invention, preliminarily arranged by the robot 100 at the predefined detection distance h on the worktable 260 and on the machined pieces 60 or semi-finished pieces 61, may be activated to allow the camera 2 to detect the position and orientation thereof.

[0065] The machined piece(s) 60, once grasped by the gripping means 110 are transferred to the second supporting plane 262. In particular, the operating end 101 of the robot 100 and the vision apparatus 1 are arranged above the second supporting plane 262 at the predefined detection distance h to acquire by means of the camera 2, in cooperation with the laser emitter 3, one or more second three-dimensional images of the second supporting plane 262 and of any machined pieces 60, 61, 62 and / or stacks of machined pieces 65, 66 positioned thereon.

[0066] The second image is processed by the processing unit 210 so as to detect and determine position and orientation of the second supporting plane 262, number, position and orientation of the machined pieces 60, 61, 62 possibly present on the second supporting plane 262 and / or number, position, orientation, height and number of stacks of machined pieces 65, 66 possibly present on the second supporting plane 262.

[0067] In particular, the processing unit 210 processing the second image verifies, before the gripping means 110 position and release the machined piece 60, 61, 62 on the second supporting plane 262, that the second supporting plane 262 is at least partially free, i.e. capable of receiving and supporting the machined piece(s) 60, 61, 62 moved by the gripping means 110.

[0068] It should be noted that since the artificial vision apparatus 1 of the invention is fixed to the operating end 101 of the robot 100, the workpieces 50, 51, 52 and machined pieces 60, 61, 62 can always be correctly detected, acquiring a three-dimensional image thereof, regardless of their arrangement within the working space of the robot, in particular when arranged on the first supporting plane 261 of the input pallet and on the worktable 260 of the operating machine 250. Similarly, the artificial vision apparatus 1 also allows to detect the position and dimensions of the first and second supporting plane 261, 262 and of the worktable 260 of the operating machine 250.

[0069] Thereby, even by modifying the position of the first and second supporting planes 261, 262 with respect to the robot 100, as well as the position of the pieces on the aforesaid supporting planes, the moving system 200 of the invention is always able to detect the pieces and pick them up and move them correctly since the vision apparatus 1 can be positioned by the robot 100 in the most appropriate detection position, in particular at the predefined detection distance h and so that the pieces, the supporting planes and worktable are contained within the solid vision angle 0 of the camera 2.

[0070] The invention further comprises a method for moving workpieces 50, 51, 52 and / or machined pieces 60, 61, 62 in a robotized work island 300, comprising at least one operating machine 250 for working sheet metals provided with a worktable 260, a first supporting plane 261 for supporting at least one workpiece 50, 51, 52, a second supporting plane 262 for supporting at least one machined piece 60, 61, 62 and a programmable industrial robot 100 adapted to pick up and move the workpieces 50, 51, 52 and machined pieces 60, 61, 62 and having an operating end 101 provided with gripping means 110 and an artificial vision apparatus 1 comprising a three-dimensional camera 2 and a laser emitter 3 arranged to generate a laser beam L.

[0071] The method of the invention comprises the following steps: arranging the operating end 101 of the robot 100 with the vision apparatus 1 above the first supporting plane 261 at a predefined detection distance h to acquire by means of the camera 2 and in cooperation with the laser emitter 3 at least a first three-dimensional image of the first supporting plane 261 and of at least one workpiece 50, 51, 52 and / or of at least one stack of workpieces 55, 56 positioned thereon (step 1); processing the first three-dimensional image so as to detect and determine at least position and orientation of the first supporting plane 261, number, geometry, position and orientation of each workpiece 50, 51, 52 and / or number, position, orientation, height and number of pieces of each stack of workpieces 55, 56 (step 2); identifying at least one workpiece 50, 51, 52 to be picked up and comparing a geometry thereof with a respective reference geometry to determine if said workpiece 50, 51, 52 is compliant and suitable for processing (step 3); picking up the workpiece 50, 51, 52, if compliant, by means of the gripping means 110 of the robot 100 and moving it towards and onto the worktable 260 (step 4); releasing the workpiece 50, 51, 52 onto the worktable 260 to be processed by the operating machine 250 and obtaining a corresponding machined piece 60, 61, 62 (step 5); picking up the machined piece 60, 61, 62 from the worktable 260 of the operating machine 250 by means of the gripping means 110 (step 6); arranging the operating end 101 and the vision apparatus 1 above the second supporting plane 262 at the predefined detection distance h to acquire, by means of the camera 2 and in cooperation with the laser emitter 3, at least a second three-dimensional image of the second supporting plane 261 and of any machined pieces 60, 61, 62 and / or stacks of machined pieces 65, 66 positioned thereon (step 7); processing the second image so as to detect and determine at least position and orientation of the second supporting plane 262, number, position and orientation of said possible machined pieces 60, 61, 62 and / or number, position, orientation, height and number of pieces of any stacks of machined pieces 65, 66 (step 8); positioning and releasing the machined piece 60, 61, 62 on the second supporting plane 26 according to a predefined arrangement (step 9).

[0072] The method provides for repeating steps 3 to 9 for all the workpieces 50, 51, 52 arranged on the first supporting plane 261, in particular automatically by the suitably programmed robot 100.

[0073] The workpiece 50, 51, 52 comprises one of metal sheet 50, metal plate, semi-finished element 51, 52, sheet metal or metal plate scrap, and the machined piece 60, 61, 62 comprises one of machined piece 60, 62 and semi-finished piece 61.

[0074] According to the method, it is also provided to identify the workpiece(s) 50, 51, 52 to be picked up from the first supporting plane 261 among a set of preselected workpieces, in particular by an operator, for example only the metal sheets 50 to perform a specific and particular processing thereon to which the semi-finished elements 51 must not be subjected. It is also provided according to the method to pick up a non-compliant workpiece 52’ by the gripping means 110 of the robot 100 and transfer and release it onto a reject supporting plane 263 (step 4a), as illustrated in Figure 2.

[0075] The respective reference geometry with which to compare a geometry of each workpiece 50, 51, 52 to be picked up from the first supporting plane 261 comprises a CAD drawing of the workpiece 50, 51, 52.

[0076] The method further comprises, before positioning and releasing the machined piece 60, 61, 62 on the second supporting plane 262, verifying that the second supporting plane 262 is at least partially free (step 8a).

[0077] It is also provided by the method of the invention, before releasing the workpiece 50, 51, 52 on the worktable 260 of the operating machine 250, to acquire by means of the camera 2 and in cooperation with the laser emitter 3 at least a third three-dimensional image of the aforesaid worktable 260 and then process this third three-dimensional image to verify the presence on the worktable 261 of workpieces 50, 51, 52 and / or machined pieces 60, 61, 62 (step 4b).

[0078] If the worktable 261 supports at least one workpiece 50, 51, 52 and / or one machined piece 60, 61, 62, i.e. if it is not free and clear, the method comprising stopping the robot 100 and reporting the presence of pieces on said worktable 261 (step 4c).

[0079] According to the method, arranging the operating end 101 of the robot 100 at the predefined detection distance h comprises arranging the operating end 101 such that an intersection point P between an optical axis K of the camera 2 and the laser beam L emitted by the laser emitter 3 on the emission plane E is almost adjacent to the supporting plane 261, 262 and the worktable 260.

[0080] It is envisaged that the camera 2 and the laser emitter 3 are fixed to the operating end 101 of the robot 100, which are positioned relative to each other in such a way that an optical axis K of the camera 2 forms with the laser beam L a detection angle a between 20° and 40°, in particular between 25° and 35°.

[0081] The method comprises detecting and determining the respective positions and orientations of the first and second supporting planes 261, 262, the workpieces 50, 51, 52 and the machined pieces 60, 61, 62 and the stacks of workpieces 55 and stacks of machined pieces 65 with reference to the reference system X, Y, Z of the robot 100.

[0082] The system and method of the invention therefore make it possible to move pieces within a robotized work island for working sheet metals by means of an industrial robot programmable in a completely automatic way and at the same time precise and accurate. Thanks to the artificial vision apparatus 1 installed on the operating end 101 of the robot 100, the latter is in fact able to automatically identify and move the workpieces and machined or semi-finished pieces. In particular, the artificial vision apparatus 1 makes it possible to precisely, accurately and automatically detect the position, orientation, shape and dimensions of workpieces and machined and / or semi-finished pieces. It is also possible to detect the position and orientation of the supporting planes and the worktable of the pieces.

Claims

CLAIMS1. Method for moving workpieces (50, 51 , 52) to be machined and / or machined pieces (60, 61, 62) in a robotized work island (300) comprising at least one operating machine (250) for working sheet metal and provided with a worktable (260), a first supporting plane (261) for supporting at least one workpiece (50, 51, 52), a second supporting plane (262) for supporting at least one machined piece (60, 61, 62) and a programmable industrial robot (100) capable of picking up and moving said workpieces (50, 51, 52) and machined pieces (60, 61, 62) and having an operating end (101) provided with gripping means (110) and with an artificial vision apparatus (1) comprising a three-dimensional camera (2) and a laser emitter (3) arranged to generate a laser beam (L), said method comprising the steps of:- moving and arranging said operating end (101) with said vision apparatus (1) above said first supporting plane (261) at a predefined detection distance (h) to acquire by means of said camera (2) and in cooperation with said laser emitter (3) at least one first three-dimensional image of said first supporting plane (261) and of at least one workpiece (50, 51, 52) and / or of at least one stack of workpieces (55) positioned thereon (step 1);- processing said first three-dimensional image so as to detect and determine at least position and orientation of said first supporting plane (261), number, geometry, position and orientation of each workpiece (50, 51, 52) and / or number, position, orientation, height and number of workpieces of each stack of workpieces (55, 56) (step 2);- identifying at least one workpiece (50, 51, 52) to be picked up and compare its geometry with a respective reference geometry in order to ascertain whether said workpiece (50, 51, 52) is compliant and suitable to be machined (step 3);- picking up said at least one workpiece (50, 51, 52) if compliant by means of said gripping means (110) of the robot (100) and moving it towards and on said worktable (260) (step 4);- releasing said at least one workpiece (50, 51, 52) on said work plane (260) so as to be machined by the operating machine (250) and obtain a corresponding machined piece (60, 61, 62) (step 5);- picking up by means of said gripping means (110) at least one machined piece (60, 61, 62) from the worktable (260) of the operating machine (250) (step 6);- moving and arranging said operating end (101) and said vision apparatus (1) abovesaid second supporting plane (262) at the predefined detection distance (h) to acquire by means of said camera (2) and in cooperation with said laser emitter (3) at least one second three-dimensional image of said second supporting plane (262) and of any machined pieces (60, 61, 62) and / or stacks of machined pieces (65, 66) positioned thereon (step 7);- processing said at least one second three-dimensional image so as to detect and determine at least position and orientation of said second supporting plane (262), number, position and orientation of said any machined piece (60, 61, 62) and / or number, position, orientation, height and number of pieces of any stack of machined pieces (65, 66) (step 8);- positioning and releasing on said second supporting plane (262) said at least one machined piece (60, 61, 62) (step 9).

2. Method according to claim 1, comprising repeating steps 3 to 9 for all the workpieces (50, 51, 52) arranged on said first supporting plane (261).

3. Method according to claim 1 or 2, comprising identifying said at least one workpiece (50, 51, 52) to be picked up from said first supporting plane (261) among a set of preselected workpieces, in particular selected by an operator.

4. Method according to any preceding claim, comprising picking up said at least one workpiece (52) if it is non-compliant by means of said gripping means (110) of robot (100) and transferring and releasing it on a third reject supporting plane (263) (step 4a).

5. Method according to any preceding claim, wherein said respective reference geometry with which to compare a geometry of said workpiece (50, 51, 52) to be picked up comprises a CAD drawing of the workpiece (50, 51, 52).

6. Method according to any preceding claim, comprising, before said positioning and releasing said at least one machined piece (60, 61, 62) on said second supporting plane (262), verifying that said second supporting plane (262) is at least partially free (step 8a).

7. Method according to any preceding claim, comprising, before said releasing said at least one workpiece (50, 51, 52) on said work plane (260), acquiring by means of said camera (2) and in cooperation with said laser emitter (3) at least one third three-dimensional image of said worktable (260) and processing said third three-dimensional image to detect position and orientation of said worktable (260) and / or verify the presence on said worktable (261) of workpieces (50, 51, 52) and / or machined pieces (60, 61, 62) (step 4b).

8. Method according to claim 7, comprising stopping said robot (100) and signalling the presence of pieces on the worktable (260) if said worktable (260) supports at least one workpiece (50, 51, 52) and / or a machined piece (60, 61, 62) (step 4c).

9. Method according to any preceding claim, wherein arranging said operating end (101) of said robot (100) at said predefined detection distance (h) comprises arranging said operating end (101) in such a way that an intersection point (P) of an optical axis (K) of said camera (2) and the laser beam (L) emitted by said laser emitter (3) is almost adjacent to said supporting plane (261, 262) and / or to said worktable (260).

10. Method according to any preceding claim, comprising fixing said camera (2) and said laser emitter (3) to said operating end (101) of said robot (100) which are positioned relative to each other in such a way that an optical axis (K) of said camera (2) forms with said laser beam (L) a detection angle (a) between 20° and 40°, in particular between 25° and 35°.

11. Method according to any preceding claim, wherein said workpiece (50, 51, 52) comprises one of metal sheet (50), metal plate, semi-finished element (51, 52), sheet metal or metal plate scrap and wherein said machined piece (60, 61, 62) comprises one of machined piece (60) and semi-finished piece (61).

12. Method according to any preceding claim, comprising detecting and determining said position and orientation of said first and second supporting planes (261, 262) and of said workpieces (50, 51, 52) and machined pieces (60, 61, 62) and of said stacks of workpieces (55) and stacks of machined pieces (65) with respect to a reference system (X, Y, Z) of said robot (100).

13. Moving system (200) for moving workpieces (50, 51, 52) and / or machined pieces (60, 61, 62) in a robotic work island (300) that comprises at least one operating machine (250) for working metal sheets and provided with a worktable (260), a first supporting plane (261) for supporting at least one workpiece (50, 51, 52) and a second supporting plane (262) for supporting at least one machined piece (60, 61, 62) manufactured by said at least one operating machine (250), said moving system (200) comprising:- a programmable industrial robot (100) provided with an operating end (101) supporting gripping means (110) and configured to pick up and move workpieces (50, 51, 52) from said first supporting plane (261) and machined pieces (60, 61, 62) from said worktable (260); and- an artificial vision apparatus (1) fixed to said operating end (101) and comprising a three-dimensional camera (2) and a laser emitter (3) arranged to generate a laser beam(L).

14. Moving system (200) according to claim 13, comprising a processing unit (210) connected to said artificial vision apparatus (1) and configured to process respective three-dimensional images of said first supporting plane (261) and said second supporting plane (262) acquired by said camera (2) in cooperation with said laser emitter (3) in order to detect and determine at least: position and orientation of said first supporting plane (261), number, geometry, position and orientation of each workpiece (50, 51, 52) arranged on said first supporting plane (261) and / or number, position, orientation, height and number of pieces of each stack of workpieces (55, 56) arranged on said first supporting plane (261); position and orientation of said second supporting plane (262), number, position and orientation of said possible machined pieces (60, 61, 62) positioned on said second supporting plane (262) and / or number, position, orientation, height and number of pieces of any stacks of machined pieces (65, 66) positioned on said second supporting plane (262).

15. Moving system (200) according to claim 14, wherein said processing unit (210) is configured to further process at least one respective three-dimensional image of said worktable (260) acquired by said camera (2) in cooperation with said laser emitter (3) in order to detect the presence on said worktable (260) of any workpieces (50, 51, 52) and / or machined pieces (60, 61, 62).

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