END EFFECTOR WITH ITEM GRABERS AND LOAD CARRIER GRABERS

Description

[0001] The invention relates to an end effector for a picking robot according to the preamble of claim 1.

[0002] It is known from various contexts to use order picking robots with suction grippers for handling products or articles. A wide variety of suction grippers are available on the market, optimized for different applications, such as gripping packages, pharmacy items, bags or sacks, individual items, sheet materials, and paper or cardboard sheets.

[0003] Furthermore, suction grippers or other load carrier grippers are known for gripping source or destination containers in a picking process, especially shipping cartons. These are not suitable for gripping typical items with dimensions of a few decimeters, particularly 2–50 cm, especially advantageously 3–20 cm, and a weight on the order of a few grams up to a maximum of 5 kg, particularly a few grams up to 1 kg, as are typically required in robot-assisted logistics systems for automated small parts picking. Likewise, typical item grippers are not suitable for gripping and moving load carriers or containers.

[0004] From EP3738719A1, a mobile picking robot is known that can be retrofitted or used as an interchangeable replacement for a human picker at a picking workstation designed for human use. At such picking workstations, shipping cartons are typically provided as target containers on shelves or via conveyor tracks located above the storage location where the target container is placed during the actual picking process. The human picker takes one of the shipping cartons provided in this way from the elevated storage location and places it in front of them on the storage location or worktable.

[0005] This process of providing target containers cannot be handled by existing picking robots. Retrofitting the picking station with conveyor technology to transport the target containers on the same level is complex, often impractical due to space constraints, and would also eliminate the frequently desired dual use of the same space by robots and humans.

[0006] From EP 2 708 335 A1 a high-speed gripper exchange system is known in which a suction gripper can be attached by magnetic force to a front end effector main body of an articulated arm of a gripper system.

[0007] From WO 2012163666 A1, a picking system for the automated picking of articles is known, using an articulated gripper to pick up the article from a container. The articulated gripper has a substantially vertical longitudinal arm and a hinged arm that can be bent at an angle, on which a suction gripper is provided for gripping the article. The longitudinal arm of the articulated gripper is at least twice as long, and in particular at least five times as long, as the hinged arm of the articulated gripper. This is intended to enable better gripping of articles, especially those lying at an angle within the storage container. However, converting the picking system to a different type of suction gripper is associated with the aforementioned difficulties.

[0008] From DE 10 2010 002 317 B4 a system for singulating and picking pharmacy articles is known, which comprises a handling device for separately removing articles from a first transport device and transferring them to a second transport device, wherein the handling device has several gripping and / or suction devices that can be selected depending on the article to be handled and which are attached in a tool turret arrangement to the front end effector main body of the gripper arm.

[0009] DE 10 2018 114 341 B3 discloses a gripper with several fingers arranged on a base body. DD 246 723 A1 discloses a gripper with two gripping elements arranged at an angle of 90° to each other.

[0010] From EP 3738719A1 a picking robot with a movable base and a gripper arm arranged on the base for picking goods at a goods-to-person picking workstation is known.

[0011] From DE 10 2019 110 516 B3, an end effector for order picking robots according to the preamble of claim 1 is known. The end effector comprises an end effector main body and a gripper carrier with two opposing article grippers which can be activated or deactivated by rotating the gripper carrier.

[0012] Other end effectors of this type are known from documents DE 10 2018 108 195 A1, JP 3 362656 B2, DE 10 2007 052 ​​012 A1, DE 199 59 285 A1, EP 3 854 735 A1, WO 2016 / 029 299 A and WO 2005 / 019 072 A1.

[0013] The invention is based in particular on the objective of providing a generic end effector, a picking robot with such an end effector and a method for picking with a picking robot that can be used not only for picking articles but also for providing source or destination containers without time-consuming tool changes.

[0014] The problem is solved by an end effector with the features of claim 1, by a picking robot with the features of claim 8, and by a method with the features of claim 9. Advantageous embodiments of the invention are set forth in the dependent claims.

[0015] The invention relates to an end effector for a picking robot with an elongated end effector main body and an article gripper or a gripper carrier with several article grippers, wherein the end effector main body has a proximal end for connection to a gripper arm of the picking robot and a distal end, wherein the gripper or gripper carrier is arranged at the distal end of the end effector main body.

[0016] It is proposed that a load carrier gripper for grasping source or target containers be provided between the proximal and distal ends on a longitudinal side surface of the end effector main body. This allows a picking robot equipped with the end effector to perform tasks such as picking items from or into source or target containers, as well as providing and / or removing these containers, without requiring a gripper change. In this way, monotonous tasks can be automated.

[0017] Depending on the application, the load carriers used as source or destination containers can be shipping cartons, plastic containers or metal containers.

[0018] According to the invention, it is proposed that the load carrier gripper be a suction gripper whose suction direction is essentially perpendicular to the longitudinal direction of the end effector main body. However, embodiments are also conceivable that are not part of the invention, in which the load carrier gripper is a claw gripper or a combination of claw and suction gripper, or even a gripping hook that can engage in corresponding grip structures on the container. Magnetic grippers are also conceivable for magnetizable load carriers or those equipped with magnets.

[0019] In one embodiment of the invention, it is proposed that the load carrier gripper comprises at least two suction grippers. This ensures a stable hold.

[0020] In one embodiment of the invention, it is proposed that the load carrier gripper comprises a gripping hook designed to engage a handle or undercut of the source or target load carrier. This allows load carriers with such handle structures to be held and transported securely.

[0021] According to the invention, the end effector is designed to suction and grip the base of the source or target load carrier with the article gripper when gripping source or target load carriers. The at least two gripping points ensure a stable hold.

[0022] In an advantageous embodiment of the invention, it is proposed that a valve for switching between a compressed or suction air supply for actuating the article gripper and the further load carrier gripper be arranged within the end effector main body. This eliminates the need for a separate compressed air supply or a separate compressed air connection at the interface between the end effector and the gripper arm of the picking robot. However, it is also conceivable to provide separate compressed air connections for the two grippers.

[0023] The article gripper and the load carrier gripper can be controlled by the control unit via separate compressed or suction air supplies, thus enabling particularly flexible control, especially for simultaneously gripping a side wall of the load carrier with the load carrier gripper and a base with the article gripper. In an alternative embodiment of the invention, it is proposed that the gripper carrier be rotatably or pivotably mounted on the end effector main body via a rotary or pivot bearing about a rotational or pivot axis extending transversely to a longitudinal direction of the end effector main body. The end effector is designed, in particular, for mounting at the end of a robot arm that can rotate the end effector about its longitudinal axis. Alternatively, the end effector itself can have a rotational degree of freedom that allows at least its end region to rotate about the longitudinal axis.In particular, a gripper carrier with at least two article grippers can be arranged at the distal end of the end effector main body. These grippers can be activated or deactivated, in particular by rotating the gripper carrier or by a switchable valve. This further improves the flexibility of the end effector.

[0024] In a particularly advantageous embodiment of the invention, the end effector comprises exactly two article grippers arranged on the gripper carrier in positions opposite each other with respect to the horizontal axis of rotation or pivoting. This allows the inactive article gripper to be pivoted as far as possible out of the working area of ​​the active article gripper, thus preventing collisions with container walls.

[0025] The end effector can be easily adapted to different types of load carriers in terms of its design, since in an advantageous embodiment an interface for connecting different types of load carrier grippers is provided on the end effector main body.

[0026] Another aspect of the invention relates to a picking robot with an end effector of the type described above and a control unit, wherein the control unit is designed to receive a picking order, to place a target container from a conveyor track to a picking station with the load carrier gripper, and then to remove items from one or more source containers in accordance with the picking order and place them in the target container(s) with the item gripper.

[0027] Another aspect of the invention relates to a picking method that uses the picking robot of the type described above. The method comprises receiving a picking order, gripping a target container positioned on a conveyor track with the load carrier gripper and placing the target container on a picking station, removing items according to the picking order from one or more source containers with the item gripper and placing the items into the target container(s).

[0028] Furthermore, it is proposed that a suction or compressed air line for supplying the suction air or compressed air for the article grippers is guided through the rotary or swivel bearing, whereby a connection exists or remains between the respective active article gripper and the suction or compressed air line during rotary movements of the gripper carrier within the specified angular interval.

[0029] Because the gripper extends beyond a free end of the end effector body, even items or products located deep within a container can be gripped effectively, and any interference from the end effector body is minimized. The rotating bearing simultaneously rotates the other gripper(s) towards the proximal end of the end effector body as one gripper is extended, thus protecting them from collisions and preventing process disruption.

[0030] In an advantageous embodiment of the invention, the multiple article grippers comprise at least two article grippers with different characteristics. Besides diameter, the different article grippers can also differ in other parameters, e.g., material, type and specifications of the bellows, load-bearing capacity, surface finish, etc., article grippers optimized for bags, cardboard boxes, or metal. The article grippers can be arranged interchangeably on the gripper carrier.

[0031] In one embodiment of the picking robot according to the invention, it is proposed that the image processing device or other sensor technology is designed to detect a load carrier type and a position or orientation of the load carrier to be gripped on a staging area, and that the control unit is designed to determine a suitable gripping point for the load carrier gripper depending on the load carrier type and its position.

[0032] The article grippers and load carrier grippers of an end effector according to the invention are not limited to suction grippers. The gripper carrier can include other types of article grippers in addition to or instead of suction heads, for example, claw grippers that can be actuated hydraulically or pneumatically via the suction or compressed air line, or magnetic grippers, wherein the magnetic gripper can be arranged, for example, at a position on the gripper carrier opposite the article gripper. The magnetic gripper can be passively activated via sliding contacts / contact strips that connect an electromagnet of the magnetic gripper to an electrical circuit at specific angular intervals of the gripper carrier. The magnetic gripper can be used for gripping metallic, and in particular magnetizable, articles.

[0033] Further features and advantages will become apparent from the following character description.

[0034] This shows: Fig. 1 a picking system with a picking robot according to a first embodiment of the invention; Fig. 2 an end effector according to the first embodiment of the invention comprising an end effector main body, a rotating gripper carrier with two article grippers and a load carrier gripper; Fig. 3 a schematic sectional view of the end effector according to Fig. 2 ; Fig. 4 a schematic representation of the order picking system according to Fig. 1 in a top view; Fig. 5a - 5f a schematic representation of various steps of a picking process according to the invention; Fig. 6a an alternative embodiment of an end effector according to the invention with a single article gripper; Fig. 6b a further alternative embodiment of an end effector according to the invention with a single article gripper designed as a suction gripper and two suction grippers as load carrier grippers; Fig. 7 a further alternative embodiment of an end effector according to the invention with a load carrier gripper comprising a suction gripper and a gripping hook; Fig. 8 a further alternative embodiment of an end effector according to the invention with a load carrier gripper which is designed as a gripping hook; Fig 9 a further alternative embodiment of an end effector according to the invention with a load carrier gripper comprising a gripping hook and two suction grippers in a side view; and Fig. 10 the end effector Fig. 9 in an oblique view.

[0035] Fig. 1 Figure 1 shows a picking system at a picking workstation with a mobile picking robot 50, a control unit 52, and a camera system comprising a first camera 54a and a second camera 54b according to a first embodiment of the invention. The control unit 52 uses the camera system to detect the position and / or orientation as well as the type of articles, products, or objects located in source containers 28 transported to and / or from a conveyor system and places the articles in target containers 30. For this purpose, the picking system utilizes the picking robot 50, which is equipped with an end effector 10 according to the invention. The end effector 10 is attached to the end or hand of an articulated arm of the picking robot 50 and can be rotated there about its longitudinal axis Z via a rotational degree of freedom Z of the picking robot 50.

[0036] The picking workstation, when the mobile picking robot 50, which can be moved on wheels, has been removed, can be used as a picking workstation for a person and is ergonomically adapted to the size of an adult person with regard to the height of the conveyor technology or the storage places for the source containers 28 and target containers 30.

[0037] The source tanks 28 are, as in Fig. 4 More easily recognizable, the goods are delivered and removed via a first conveyor system 40a at table height from an automated high-bay warehouse or similar. This first conveyor system 40a comprises two parallel roller conveyors connected at their ends by a transverse loading area.

[0038] The target containers 30, which in this example are shipping cartons, are placed on a second conveyor system 40b and transported away. The second conveyor system 40b comprises only a roller conveyor running alongside the picking robot 50 and forms a storage or picking station for the target containers 30.

[0039] Due to the ergonomic requirements for a human order picker, the first and second conveying systems 40a, 40b are arranged at a height that allows an order picker working standing or on a standing stool to comfortably reach into the source containers 28 and destination containers 30 placed on them, i.e. at about the height of an ordinary table or slightly below, approximately 60 - 90 cm, in particular 75 cm.

[0040] The target containers 30 are in the in Fig. 1 In the illustrated embodiment, cardboard shipping cartons are unfolded or set up centrally at a workstation and are provided to the order picker by a third conveyor system 40c at staging areas 40c1 and 40c2, so that the picker can easily reach them and, if necessary, place them as target containers 30 onto the second conveyor system 40b. For space reasons, the third conveyor system 40c and the staging areas 40c1 and 40c2 are arranged at a higher level than the first conveyor system 40a and the second conveyor system 40b. In the Fig. 4 In the top view shown, the first conveyor system 40a is therefore partially obscured by the third conveyor system 40c and the staging areas 40c1, 40c2.

[0041] The in Fig. 2 and 3The end effector 10, shown in more detail, comprises an elongated end effector main body 12 and a gripper carrier 14 arranged at a distal end of the end effector main body 12. The gripper carrier 14 is rotatable relative to the end effector main body 12 about a rotation axis X that is perpendicular to the longitudinal and rotation axis Z of the end effector main body 12. Various article grippers 18a, 18b are arranged on the gripper carrier 14 and can be selected or activated by rotating the gripper carrier 14. The grippers are connected via hoses 62 ( Fig. 1 ) at its proximal end, the end effector 10 is supplied with compressed or suction air to grip the article grippers 18a, 18b, which are designed as suction grippers ( Fig. 4 ) to be able to actuate. Via an interface at the end of the robot arm, the end effector receives 10 signals to rotate the gripper carrier 14 around the axis of rotation X.

[0042] For further details of the order picking system, reference is made to EP 3738719 A1, the contents of which are incorporated into this description by reference.

[0043] The control unit 52 is designed by software to set a rotation angle of the end effector main body 12 about the Z-axis and of the gripper carrier 14 about the X-axis depending on the detected position and orientation of the article and of load carrier walls of the load carrier 30.

[0044] The end effector 10 includes at its proximal end an interface 56 for connection to the robot arm, a connection 58 for suction air or compressed air and a signal line as well as a housing 60 for a drive motor.

[0045] Between the proximal end and the distal end on a longitudinal side surface 12a of the end effector main body 12, a load carrier gripper 24 for gripping source or target containers 28, 30 is provided according to the invention. Fig. 1 In the illustrated embodiment, the load carrier gripper 24 is designed for gripping target containers 30 used as shipping cartons. The load carrier gripper 24 is a suction gripper whose suction direction is essentially perpendicular to the longitudinal direction Z of the end effector main body 12 and to the suction direction of the two article grippers 18a, 18b.

[0046] As in Fig. 3 The end effector 10 also includes a rotary bearing 16, via which the gripper carrier 14 is rotatably connected to an end effector main body 12. The gripper carrier 14 comprises two article grippers 18a, 18b that can be actuated with suction or compressed air, and a suction or compressed air line 20 for supplying the suction air to the article grippers 18a, 18b.

[0047] The rotary bearing 16 comprises two bearing bodies 16a, 16b rotatable relative to each other, which simultaneously form a rotary feedthrough for the suction air or compressed air and a valve mechanism 22 for establishing and disconnecting a connection between the suction or compressed air line 20 and each of the article grippers 18a, 18b selectable by changing the rotational position of the bearing bodies 16a, 16b.

[0048] For further design details of the gripper carrier, e.g. regarding the drive and the air passage, reference is made to DE 10 2019 110 516 B3, the relevant content of which is part of the disclosure of the present invention.

[0049] Inside the end effector main body 12 is a valve 26 which can be actuated by the control unit 52 via the signal line ( Fig. 3 The valve 26 is arranged for switching a compressed or suction air supply between actuation of the currently active article gripper 18a, 18b and actuation of the load carrier gripper 24. The valve 26 can be designed as a solenoid valve or rotary slide valve, or it can be activated by a touch sensor that reacts as soon as the load carrier gripper 24 touches a target container. Alternatively, two compressed air supplies can be provided for the two grippers, which can be switched on and off by the control unit 52.

[0050] According to the invention, the control unit 52 of the picking robot is designed to receive a picking order, to place a target container from the third conveyor track 40c or the staging area 40c1, 40c2 onto a picking station or the second conveyor track 40b using the load carrier gripper 24, and then to remove items from source containers 28 according to the picking order using the article gripper 18a, 18b and place them in the target container 30.

[0051] The picking procedure implemented in control unit 52, which uses the picking robot of the type described above, is in the Figuren 5a - 5f A more detailed presentation.

[0052] After receiving a picking order, the picking robot 50 is controlled so that it uses the load carrier gripper 24 ( Fig. 2 ) grabs one or more target containers 30 that are ready on the staging areas 40c1, 40c2 of the third conveyor track ( Fig. 5a ) and places the picked target container 30 on a picking station on the second conveyor track 40b ( Fig. 5b In the case of multi-order picking orders, the following can be considered: Fig. 5a und Fig. 5b The steps shown are repeated 30 times for each target container.

[0053] To enable short distances during the subsequent, actual order picking process, the target containers 30 are placed as close as possible to the base of the picking robot 50 on the second conveyor system 40b. For this purpose, the picking robot 50 grasps larger load carriers 30, in particular, by their inner wall, as shown in Fig. 5c This is shown because otherwise, when the load carrier gripper 24 docks to an outer wall of the load carrier 30 facing the base of the picking robot 50, a gap would have to remain between the load carrier 30 and the base due to the width of the end effector 10. The article gripper 18a can be used in the Fig. 5c The gripper 24 can also grasp the base of the load carrier 30 from the inside, thus ensuring a particularly stable hold. Especially with smaller load carriers 30, the picking robot 50 can also grip the load carrier by docking the load carrier gripper 24 to the outer wall of the load carrier 30 facing away from the base of the picking robot 50, as shown in Fig. 5d is shown.

[0054] After the target containers 30 have been set up, the actual order picking process begins with the removal of items A according to the picking order from the source containers 28 ( Fig. 5e ) with the article gripper 18a, 18b and placing the articles A into the corresponding target container 30, also with the article gripper 18a, 18b ( Fig. 5f ), wherein the required source containers 28 are automatically supplied by the first conveying technology 40a.

[0055] The image processing device, consisting of a control unit 52 and a camera system, is designed to determine the position and orientation of the article and, for example, its article number. The article number is generally known for the respective source container 28, and additional verification can be performed by the image processing system. Depending on the detected article type, the control unit 52 is designed to select a suitable article gripper 18a, 18b and rotate it into an active position. For this purpose, the control unit 52 accesses, in particular, the article's master data in a database, which contains information such as weight, surface structure, article shape, other article properties, and, if applicable, a specific article gripper 18a, 18b to be used.

[0056] Simultaneously, the third conveyor system 40c provides new target containers 30 to the staging areas 40c1 and 40c2. After completion of the picking order, the target containers 30 are transported away for further processing or shipping by the second conveyor system 40b.

[0057] Fig. 6a shows an alternative embodiment of an end effector 10 according to the invention with a single article gripper 18a dh without a rotatable gripper carrier.

[0058] Fig. 6b Figure 1 shows a further alternative embodiment of an end effector 10 according to the invention, with two suction grippers 24a, 24b arranged horizontally one above the other as load carrier grippers. The arrangement of two suction grippers one above the other allows a horizontal tilting moment, which inevitably occurs when gripping the side wall of a load carrier, to be supported.

[0059] Fig. 7 Figure 1 shows a further alternative embodiment of an end effector 10 according to the invention with a load carrier gripper 24 comprising a suction gripper 24a and a gripping hook 24b. The end effector made of Fig. 7 is designed and suitable for handling load carriers 30 which have a handle 30a or an undercut into which the gripping hook 24b can engage, with the suction gripper 24a further stabilizing the hold.

[0060] Fig. 8 Figure 1 shows a further alternative embodiment of an end effector 10 according to the invention with a load carrier gripper 24, which is configured as a gripping hook 24b. The end effector 10 is made of Fig. 8 is designed and suitable for handling load carriers 30 which have a handle 30a or an undercut into which the gripping hook 24b can engage.

[0061] Fig 9 Figure 1 shows a further alternative embodiment of an end effector 18 according to the invention with a load carrier gripper 24 comprising a gripping hook 24b and two suction grippers 24a1, 24a2 in a side view and Fig. 10 shows the end effector Fig. 9 in an oblique view. The gripping hook 24b and two suction grippers 24a1, 24a2 form three gripping points arranged in a triangle, so that the load carrier 30 is held stably and also in a horizontal direction without tilting or pivoting.

[0062] The article gripper 18a, 18b (in Fig. 9 und 10 (not mounted on the gripper carrier 14) and the load carrier gripper 24 can be controlled by the control unit 52 via separate compressed or suction air supplies 58a, 58b and are thus particularly flexible in their controllability.

[0063] The end effector 10 includes a universal interface 32 on the end effector main body 12 for connecting various types of load carrier grippers 24. The interface 32 includes a compressed air or suction air connection and a mounting base plate for gripping hooks 24b. Bezugszeichenliste

[0064] End effector 10 End effector main body 12 Side surface 12a Gripper carrier 14 Rotary bearing 16 Bearing body 16a, 16b Article gripper 18a, 18b Compressed air line 20 Valve mechanism 22 Load carrier gripper 24 Valve 26 Source container 28 Destination container 30 Interface 32 First conveyor system 40a Second conveyor system 40b Third conveyor system 40c Staging area 40c1, 40c2 Picking robot 50 Control unit 52

Claims

1. An end effector for a commissioning robot with an elongated end effector main body (12) and an article gripper (18a) or a gripper carrier (14) with several article grippers (18a, 18b), wherein the end effector main body (12) has a proximal end for connection to a gripping arm of the commissioning robot and a distal end, wherein the article gripper (18a) or gripper carrier (14) is arranged at the distal end of the end effector main body (12), wherein between the proximal end and the distal end, a load carrier gripper (24) for gripping source load carriers (28) or target load carriers (30) is provided on a side surface (12a) extending in the longitudinal direction (Z) of the end effector main body (12), wherein the load carrier gripper (24) comprises at least one suction gripper (24a), characterized in that the suction direction of the suction gripper (24a) extends substantially perpendicular to the longitudinal direction (Z) of the end effector main body (12) and toward the side surface (12a), so that simultaneously the load carrier gripper (24) can grip an inner wall and the article gripper (18a) can additionally grip a bottom of source load carriers (28) or target load carriers (30).

2. An end effector according to claim 1, characterized in that the load carrier gripper (24) comprises at least two suction grippers (24a1, 24a2).

3. An end effector according to one of the preceding claims, characterized in that the load carrier gripper (24) comprises a gripping hook (24b) that is designed to engage in a handle (30a) or an undercut of the source load carrier (28) or target load carrier (30).

4. An end effector according to one of the preceding claims, characterized in that at the distal end of the end effector main body (12), a gripper carrier (14) with at least two article grippers (18a, 18b) is arranged, which can be activated or deactivated by a rotation of the gripper carrier (14).

5. An end effector according to claim 4, characterized in that exactly two article grippers (18a, 18b) are arranged in positions opposite to each other on the gripper carrier (14) with respect to the horizontal rotational or pivoting axis (X).

6. An end effector according to one of the preceding claims, characterized in that an interface (32) for connecting different types of load carrier grippers is provided on the end effector main body (12).

7. An end effector according to one of the preceding claims, characterized in that a valve (26) for switching a pressure or suction air supply between an actuation of the article gripper (18a, 18b) and an actuation of the load carrier gripper (24) is arranged within the end effector main body (12).

8. A commissioning robot with an end effector according to one of the preceding claims and a control unit, wherein the control unit is designed to receive a commissioning order, to place a target load carrier (30) from a conveyor track (40c) onto a commissioning place or another conveyor track (40b) with the load carrier gripper (24), and subsequently to remove articles according to the commissioning order from source load carriers (28) with the article gripper (18a, 18b) and to place them in the target load carrier (30).

9. A method for commissioning with a commissioning robot according to claim 8, wherein the method comprises: receiving a commissioning order, gripping a target load carrier (30) standing ready on a conveyor track (40c) with the load carrier gripper (24) and placing the target load carrier (30) on a commissioning place or on another conveyor track (40b), and removing articles according to the commissioning order from source containers (28) with the article gripper (18a, 18b) and placing the articles in the target container (30).