Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G59/00—De-stacking of articles
  • B65G59/02—De-stacking from the top of the stack
  • B65G59/026—De-stacking from the top of the stack with a stepwise upward movement of the stack
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G57/00—Stacking of articles
  • B65G57/02—Stacking of articles by adding to the top of the stack
  • B65G57/03—Stacking of articles by adding to the top of the stack from above
  • B65G57/035—Stacking of articles by adding to the top of the stack from above with a stepwise downward movement of the stack
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G61/00—Use of pick-up or transfer devices or of manipulators for stacking or de-stacking articles not otherwise provided for
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G2203/00—Indexing code relating to control or detection of the articles or the load carriers during conveying
  • B65G2203/04—Detection means
  • B65G2203/041—Camera
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G57/00—Stacking of articles
  • B65G57/02—Stacking of articles by adding to the top of the stack
  • B65G57/03—Stacking of articles by adding to the top of the stack from above
  • B65G57/04—Stacking of articles by adding to the top of the stack from above by suction or magnetic devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G59/00—De-stacking of articles
  • B65G59/02—De-stacking from the top of the stack
  • B65G59/04—De-stacking from the top of the stack by suction or magnetic devices
  • B65G59/045—De-stacking from the top of the stack by suction or magnetic devices with a stepwise upward movement of the stack

Definitions

• the invention relates to an automated system and method for loading and / or unloading packages, also called a palletizing / depalletizing system.
• a palletizing / depalletizing system also called a palletizing / depalletizing system.
• Such a system is for example applicable to the field of logistics.
• the known systems use a robot to deposit or remove, in a certain order, a set of packages.
• a package can be any type of object of regular shape capable of being transported in a container, for example in the form of a cubic or cuboid box or in the form of a packaging unit, such as a set of bags or bottles sealed to each other by plastic film.
• a container can be, for example, a pallet, a roll or a crate.
• Figure 1 shows a known example of a depalletization system 1 in which the container 2, here a pallet, comprises a set 3 of packages 31 arranged in superimposed layers.
• a robot 4 provided with a gripper 5 is arranged to come into contact with a packet 31.
• the gripper 5 grips the packet 31, for example by suction, then moves it to a reception area 6, such as a conveyor, and sets it down.
• FIG. 2 represents, by way of example, the trajectory 7 of the gripper 5 and of the package 31 described above. This trajectory includes three stages:
• Step 1 the gripper 5 of the robot 4 grasps the package 31, then raises it up to a secure clearance level to ensure that when the package 31 is released, it does not hit another object that would be on its path;
• Step 2 the package 31 is moved to the top of the conveyor 6; then
• Step 3 the gripper 5 of robot 4 goes down with the package 31 to the level of the conveyor and deposits the package 31.
• the object of the present invention is therefore to provide a palletization and / or depalletization system making it possible to solve at least part of the problems mentioned above. Summary of the invention
• the invention relates to a package unloading system, comprising:
• a lifting table movable relative to the ground along a vertical axis and arranged to receive a container comprising a set of packages, each having an upper end, a lower end and a height corresponding to the difference between said ends,
• a first detection means for example 3D, the detection field of which covers at least the top packets of said set of packets
• a robot for example multiaxial, equipped with a gripper configured to grab a package from the container, lift it a determined distance and move it to a reception area to deposit it in said reception area,
• a computer control means connected (connected by computer) to the first detection means on the one hand and to the lifting table on the other hand, said first detection means being configured to determine the vertical positions with respect to the ground of the upper ends of the packets from above (that is to say the height from the ground of the upper face of each packet visible from above) and transmitting them to the control means, said control means being configured to: calculate a deviation along said vertical axis of the table between an initial position of the upper end of a determined package and a vertical reference position, predetermined as a function of a depth detection range of the first detection means and / or of the positions depending on the vertical axis at which the gripper is able to grip a package, - cause the lifting table to move vertically by a distance equal to the gap, and determine a minimum vertical distance with which the gripper should lift the package to allow safe movement to the receiving area while keeping the table at a fixed height.
• vertical position is meant a height from the ground, according to a projection on the vertical axis ZZ ".
• the vertical reference position can, for example, correspond to the position for picking up packages by the gripper.
• upper end and lower end of a packet we denote respectively the upper face and the lower face of a packet.
• the package may for example be a package having a regular shape, for example cubic or cylindrical. It may also have an irregular shape, but must have at least one surface allowing gripping by the gripper, for example a generally flat upper face which may have an inclination, with respect to the two horizontal planes, of 20 °.
• a depth detection range designates a range along the vertical axis ZZ ’in which the first detection means is able to provide with an acceptable resolution a relief showing the differences in the heights of the packets.
• said range can be defined by a distance along the axis ZZ 'from the focal plane of the camera, for example the range can be +/- 35 cm from the focal plane, i.e. a range of 70 cm.
• the system calculates the difference between the position of this upper end and the vertical reference position and then moves vertically the lifting table by a distance equal to this distance. Consequently, the upper end of said packet is found displaced at the level of the vertical reference position.
• the packet can for example be determined as the next packet to be unloaded by the unloading system. In this case, as the container is unloaded, the robot equipped with a gripper grasps the package at a fixed height relative to the ground.
• the system can be configured so that the packet to be picked up by the gripper and to be unloaded is systematically the highest packet.
• the advantage of this configuration is that the stroke of the vertical movement of the gripper is reduced.
• the vertical reference position can correspond to the position for picking up packages by the gripper.
• the vertical reference position can be a focal length of the first 3D detection means.
• the first detection means can for example comprise one or more 3D cameras.
• the information transmitted to the control means concerning the shape and / or orientation of the packet is more precise. This results in a more precise capture of the package by the gripper.
• the first detection means can comprise a 3D camera, for example stereoscopic, configured to take one or more photos when the lifting table is moved by the deviation calculated as described above. In this case, the upper end of the targeted packet is positioned at the vertical reference position.
• the optimum working area (around the focal length) of said camera coincides with the vertical reference position.
• the camera takes high-resolution photos which allows a more precise value of the position, orientation and area of the top side of the package to be obtained.
• the optimal working area may be +/- 10 cm from the focal length.
• the stereoscopic camera can be replaced by other types of 3D cameras with similar benefits to those described above.
• the first detection means can be arranged above the lifting table and at the height thereof to allow good coverage of the packages and of the lifting table by its field of vision.
• the first detection means is laterally offset by a distance "d" with respect to the vertical axis of the lifting table, said distance "d" is determined to prevent the camera from being hidden by the gripper and therefore making it shade when approaching the container to pick up a package. This therefore further improves the precision when picking up a package.
• control means are configured to determine a minimum vertical distance with which the gripper must lift a package seized from the container before it is moved towards the reception area to ensure movement without collision with a neighboring package.
• This configuration is particularly advantageous, because it does not require lowering the table to allow movement. secure the packet to the receiving area. As a result, the unloading cycle time is optimized.
• Said vertical distance can for example be determined by comparing the vertical position of the upper end of said grasped package, its height and the vertical position of the upper end of the highest neighboring package (determined by the first detection means). between the seized packet and the reception area.
• the system can comprise a second detection means, said second detection means being configured to discriminate adjacent packets.
• the second detection means can be a 2D or 3D camera, for example positioned adjacent to the first detection means.
• Discriminating packets from each other improves accuracy. For example, this is advantageous when adjacent packets can be confused by the first detection means, for example, when two packs have the same height and / or are not sufficiently spaced from each other.
• control means comprises a database fed by a learning process with data making it possible to distinguish a packet or a set of packets having an unusual characteristic (example: a position and / or an orientation).
• unusual position or orientation is meant packages having, for example, an inclination, or an unusual orientation of the packages glued to each other, packages having a shadow phenomenon due to too great a difference in height.
• control means may include an artificial neural network processor configured to enable the learning process.
• the gripper can include a set of input elements, for example by suction, the latter can be controlled independently of one another. Good precision is required, because the activation of an element (for example a suction cup) without it being entirely in contact with the pack can result in a loss of pressure which risks leading to a fall of the pack.
• an element for example a suction cup
• the system can further comprise a third lateral detection means, arranged so that its detection field covers the package seized in its initial position and in its raised position (i.e. just before its displacement towards the zone. reception).
• the third detection means can be a 2D or 3D detection means, for example a 2D camera or a 3D camera.
• the third detection means can be arranged along an axis perpendicular to the axis of the lifting table, for example its axis can coincide with the vertical reference position.
• the third detection means can be arranged at a fixed height.
• control means can be configured to cooperate with said third detection means to determine the minimum vertical distance with which the gripper must lift a package before it is moved towards the reception area.
• the third detection means can be arranged on the side of the reception zone, for example on a conveyor.
• This third detection means has the advantage of being able to detect the vertical clearance (play between the lower end of the packet taken by the gripper and the upper end of the second highest packet), i.e. detecting that the packet taken by the gripper is detached from the set of packages.
• This allows on the one hand to measure the height of the bundle with precision, and on the other hand to check that there is no adjacent bundle higher than the lower limit of the bundle seized that might hinder him when moving to the reception area.
• the bundle can be released in complete safety without having to rise to a pre-established maximum level as is the case with known systems.
• measuring the height of the packet makes it possible to accurately estimate the height at which the packet positions itself above the reception area before it is deposited (for example, the distance between the underside of the packet 31 and the conveyor belt or rollers). As a result, the delivery of packets to the reception area is more controlled and precise, thus protecting the integrity of the packet.
• the reception zone is arranged at a vertical position relative to the ground, determined so that the trajectory of the robot is optimized by reducing the vertical movements of the gripper.
• it can be at the same height as the vertical reference position.
• the vertical position of the reception zone can be variable so as to keep an optimized trajectory of the packet.
• the receiving area can be lowered to receive a package with a high height, or conversely raised to receive a package with a low height.
• the invention relates to a package loading system comprising:
• a lifting table movable relative to the ground along a vertical axis and arranged to receive a container to be loaded with a set of packages, each having an upper end, a lower end and a height corresponding to the difference between said ends,
• a first detection means whose detection field covers the container and when packages are placed on the container, at least the top packages of said set of packages, - a robot equipped with a gripper configured to pick up a package from a reception area, move it to the container and deposit it,
• a computer control means connected to the first detection means on the one hand and to the lifting table on the other hand, said first detection means being configured to determine the vertical positions with respect to the ground of the upper ends of the packages covered by the detection field and transmit them to the control means, the control means being configured to: on the one hand, calculate a deviation along said vertical axis of the table between an initial position of the upper end of a determined packet and a predetermined reference vertical position as a function of a depth detection range of the first detection means and / or of the positions along the vertical axis at which the gripper is able to deposit a packet, and on the other hand, to cause the vertical displacement of the lifting table a distance equal to the gap.
• the loading system according to the invention is similar to the unloading system described above, with an adaptation so that the purpose is loading instead of unloading of packages, the characteristics described above in relation to the system of unloading also apply in whole or in part to this loading system.
• the vertical movement of the table can be up or down.
• the table will be lowered as the container is loaded and conversely, during unloading, the table is raised as the container is unloaded.
• the system can automatically adjust the position of the table downward even in the case unloading, and conversely mount the table during loading, for example to facilitate the positioning of the gripper.
• the system according to the invention can also comprise, at least in the case of loading, a fourth detection means communicating with the control means and arranged so that its field of vision covers the reception area (at least partially).
• This fourth detection means is, for example, configured to detect the dimensions of packets arriving at this reception area in an unknown order and / or with unknown dimensions. This will allow the system to determine in real time their arrangement on or in the container.
• the invention also relates to a method for loading and / or unloading a container. Said method is characterized in that it implements the system according to any of the combinations of characteristics described above.
• Figure 1 shows a depalletization system known from the state of the art
• Figure 2 shows a typical path of a package unloaded by a known depalletizing system
• FIG. 3 represents an exemplary embodiment of a system according to the invention comprising a detection means
• FIG. 4 represents a second exemplary embodiment in which the system comprises a second detection means
• FIG. 5 represents a third exemplary embodiment in which the system comprises a third detection means
• Figure 6 illustrates an example of an optimized trajectory of a packet unloaded by a system according to the invention.
• FIG. 3 represents a package unloading system (also called a depalletization system) 10 according to a first embodiment of the invention.
• the depalletization system 10 comprises a lifting table 11 on which is placed a container 2 which is in this example a pallet.
• the container 2 may however be different from a pallet, for example a crate, a roll, a tray, ... etc.
• the container 2 comprises a set of packages 3 arranged as shown in FIG. 3.
• the packages 3 are, for example, packages. They can be heterogeneous as shown in Figure 3, but they can also be partially or totally homogeneous in other examples not shown.
• the system 10 comprises a depalletizing robot (not shown) similar to the robot 4 of FIG. 1 and which comprises a gripper similar to the gripper 5.
• the system also comprises a first detection means which is in this example three-dimensional (3D) 13, which can comprise one or more elements such as a 3D camera (for example time-of-flight, stereoscopic or laser triangulation), a scanner 3D, or any other similar means.
• a 3D camera for example time-of-flight, stereoscopic or laser triangulation
• a scanner 3D or any other similar means.
• the first detection means 13 comprises a 3D camera and a stereoscopic camera.
• This first detection means 13 has a field of view covering at least the packets placed above the container 2, that is to say the top packets of the set of packets 3 (one can speak of a layer higher in the case of packages of homogeneous shape).
• the first detection means 13 is arranged above the lifting table 11 and at a certain height thereof so as to allow the gripper of the robot to take the packages 31.
• the first detection means 13 comprises a 3D camera offset with respect to the vertical axis of the table so as to avoid having areas of shadow when the gripper of the robot is at- above the table and approaches a package 31 to be unloaded.
• the system 10 further comprises a computer control means, not shown in the drawings, to which the robot 4, the first detection means 13 and the lifting table 11 are connected.
• the first detection means 13 is configured to determine the vertical positions with respect to the ground of the upper ends 33 of the top packets 31, 32 and to transmit them to the control means.
• the control means being configured for: on the one hand, calculating a difference D1 between a position PO of the upper end 33 of a determined package 31, 32 and a vertical reference position P1 fixed with respect to the ground, and d 'on the other hand to cause the lifting table 11 to move vertically by a distance equal to the distance D1.
• FIG. 4 represents an exemplary embodiment in which the unloading system 100 is similar to the system of FIG. 3, but it further comprises a second detection means 14 also connected to the control means and the field of view of which covers at least the top packages 31, 32 of the set of packages 3.
• This second detection means 14 is for example positioned at the same location as the first detection means 13.
• Said second detection means 14, (for example a 2D camera) is configured to make it possible to discriminate the contours of neighboring packets 31, 32.
• the lifting table is moved by D1, a 2D camera takes one or more photos to determine the contours of the targeted packet following the detection carried out previously by the first means 13.
• This determination of the contours is all the more precise when the 2D camera has an optimal working area (around the focal length) which includes the vertical reference position P1 and when the upper face of the targeted package (to be unloaded) is positioned at this height from the ground following the displacement of the table of D1.
• the gripper 5 is of a type known per se, for example comprising a set of actuatable suction cups to suck the package to be unloaded.
• the suction cups of the gripper 5 can be actuated individually and can be controlled so as to activate only those which come into contact with the targeted package. This makes it possible to avoid disturbing the position of adjacent packages and consequently avoids pressure losses and consequently to control the seizure of packages.
• the second detection means 14 is connected to an artificial neural network (designated in FIG. 4 by “A1”) to allow the system, via a learning process, to further control the discrimination of the contours of the packets. .
• A1 an artificial neural network
• control means comprises a database fed by a learning process with data making it possible to distinguish a packet or a set of packets having an unusual position and / or orientation. For example, when a package is tilted the system may not recognize it. To allow its recognition, learning is carried out by presenting such a position to the first and / or to the second detection means and by associating it with an image of the package as known by the system. This type of learning can be carried out for unusual packet orientations, new packet types or peculiarities of certain packets (stains, presence of adhesive tapes, labels, slight deformations, ... etc) which can prevent the system from recognizing just the package. According to a variant, images taken by the first and the second detection means can be crossed or associated to allow this recognition.
• the system can recognize the situation by referring to its database. For example, the system is able to recognize that a package is tilted or misoriented and as a result the gripper will also be tilted or reoriented to grab it.
• FIG. 5 represents another exemplary embodiment in which the system 1000 is similar to the system 100 of FIG. 4 but further comprises a third detection means 15 also connected by computer to the control means.
• the third detection means 15 is for example a 3D camera. It can be positioned laterally so that its field of view covers, at least, the bundle 31 to be unloaded before it is moved vertically and at least immediately after it leaves the bundle of bundle 3.
• the horizontal viewing axis of the third detection means 15 can be positioned at the level of the vertical reference position P1.
• the third detection means 15 makes it possible to detect the moment when the lower end 34 of this packet 31 exceeds the upper end 33 'of the second highest pack 32 (that is to say a play between these two ends 34, 33 'is detected by the third detection means 15).
• the information is transmitted to the computer control means which stops the vertical movement of the gripper 5.
• the robot then moves the packet towards the reception area 6. In this way the vertical displacement of the gripper 5 after taking a packet 31 is limited to the displacement necessary to ensure that the package 31 does not risk colliding with another package during its movement. Limiting this vertical displacement therefore makes it possible to further reduce the time required for the robot to move a package.
• the third detection means makes it possible to measure the height h of the package taken by the gripper as soon as its lower end 34 is detected.
• the information on the height h can be used by the checking facility to check the information it has in its database if it is available. It can also be used to better define the trajectory of the package during its movement by the robot to the reception area 6. This makes it possible, on the one hand, to reduce the time of movement by the robot, and on the other hand to reduce the risk of impact on the package upon removal. Indeed, knowing the height of the package makes it possible to accurately estimate the vertical position above the reception area 6 to which the robot must bring the package before depositing it.
• FIG. 6 illustrates an example of an optimized trajectory 17 of a package unloaded by the system described above, from the moment of its grasping by the gripper 5 until the moment of its deposit on a conveyor 6.
• the optimized trajectory 17 is compared to the typical trajectory 7 in Figure 1.
• the vertical position of the conveyor 6 can also be adjusted to further control the trajectory of the robot and to reduce the cycle time.
• the systems described above with reference to Figures 3 to 5 can be used for container loading with packages arriving at the reception area.
• the configuration of the first, second and / or third detection means, as well as the configuration of the control means are adapted.
• the overall implementation remains similar.
• the unloading system described above can be implemented to unload a container comprising a set of packages 3, for example, with some or all of the following steps:
• the first detection means 13 determines the vertical positions relative to the ground of the upper ends (faces) 33, 33 ’of the top packages 31, 32 and transmits them to the control means.
• the way to determine its positions is for example by returning an image of the relief observed by a 3D camera with colors indicating the altitude not from the ground of each packet seen by this camera,
• the control means from the data received from the first detection means 13, determines a target packet to be unloaded, according to pre-established criteria, for example the target packet can be determined as the packet 31 having the upper end 33 the highest of all 3. Then:
• the control means calculates a difference D1 between the initial position PO of the upper end 33 of the targeted package 31 and a vertical reference position P1 fixed with respect to the ground.
• the difference D1 is calculated between the end upper 33 'of the second highest package 32 and the vertical reference position P1, then
• control means instructs the lifting table 11 to move it vertically by a distance equal to the distance D1.
• the first detection means 13 and / or the second detection means 14 take one or more images at this new position of the table to determine the contours of the packet to be unloaded and to discriminate it from its neighbors.
• the gripper grasps the package 31 to be unloaded and lifts it a certain distance until its lower end 34 exceeds the upper end 33 'of the second highest package 32.
• This distance can be either calculated from data known by the system on the dimensions of the packages 31, 32, is determined following a detection of a clearance by the third detection means 15 (detection that the lower end 34 of the package 31 exceeds the end upper 33 'of the second package 32).
• the control means calculates the height h (distance between upper face 33 and lower face 34) of the package 31 taken by the gripper 5, and determines the minimum distance from the reception area 6 with which the package can reach the above this area for removal.
• the above steps can be used in part or in full, in reverse order and / or with adaptations so that the packages are seized in the reception area 6 by the gripper, moved up to the top of the container to be placed in an order, a location and / or a height, determined by the detection means or means or the control means.
• a step of pre-positioning the table in height relative to the ground can be envisaged, for example, to allow the first detection means, in the case of unloading, to accurately detect the vertical positions of the upper ends. packages or, in the case of a load, to detect the bottom of the container.

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• Mechanical Engineering (AREA)
• Manipulator (AREA)

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• 2019
  • 2019-10-29 FR FR1912151A patent/FR3102468B1/fr active Active
• 2020
  • 2020-10-29 EP EP20796823.1A patent/EP4051609A1/de active Pending
  • 2020-10-29 WO PCT/EP2020/080399 patent/WO2021084009A1/fr unknown

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