SYSTEM AND METHOD FOR SEPARATING AND SINGULATING POSTAL ARTICLES

Abstract

The present disclosure concerns a method and a system for separating and singulating articles, such as postal parcels or small packages, said system comprising a feeding conveyor having a receiving end and a delivery end, and a divider for separating the bulk of postal articles arriving on the feeding conveyor into a plurality of parallel article streams on the feeding conveyor and forwarding said article streams in a first conveying direction from said receiving end to said delivery end; a takeaway conveyor having a second conveying direction, which is substantially different from said first conveying direction, and where said takeaway conveyor at its upstream end is abutted by the delivery end of said feeding conveyor; a plurality of gantry robots are provided across the delivery end of the feeding conveyor in such a way that each robot is handling each their article stream on the feeding conveyor and that the robots are adapted to picking an article from each their article stream on the feeding conveyor and placing said picked article on the takeaway conveyor; a vision system adapted to capturing image data of the articles on the feeding conveyor, and a robotic controller comprising a data processing unit for using said image data to identify an article to be singulated by one of the robots and for providing control inputs to the robots.

Claims

1. A system for separating and singulating articles, such as postal parcels or small packages, said system comprising a feeding conveyor having a receiving end and a delivery end separating the bulk of postal articles arriving on the feeding conveyor into a plurality of parallel article streams on the feeding conveyor and forwarding said article streams in a first conveying direction from said receiving end to said delivery end; a takeaway conveyor having a second conveying direction, which is substantially different from said first conveying direction, and where said takeaway conveyor at its upstream end is abutted by the delivery end of said feeding conveyor; a plurality of robots provided in parallel across the delivery end of the feeding conveyor in such a way that each robot is handling each their article stream on the feeding conveyor and that the robots are adapted to picking an article from each their article stream on the feeding conveyor and placing said picked article on the takeaway conveyor; a vision system adapted to capturing image data of the articles on the feeding conveyor, and a robotic controller comprising a data processing unit for using said image data to identify an article to be singulated by one of the robots and for providing control inputs to the robots.

2. A system according to claim 1, wherein the feeding conveyor comprises a divider for separating the bulk of postal articles arriving on the feeding conveyor.

3. A system according to claim 2, wherein the divider comprises a cascading diverter chute is provided upstream the feeding conveyor and preferably with a divider element for the formation of two parallel article streams, preferably a centrally positioned divider element.

4. A system according to claim 1, wherein the second conveying direction is substantially perpendicular to said first conveying direction.

5. A system according to claim 1, wherein the conveying velocity of the feeding conveyor and/or the takeaway conveyor is variable.

6. A system according to claim 1, wherein the feeding conveyor is intermittently driven (start-stop).

7. A system according to claim 1, wherein the robots are placing the picked article on the takeaway conveyor in a placement area at the upstream end of said takeaway conveyor.

8. A system according to claim 1, wherein the robots are gantry robots.

9. A system according to claim 8, wherein the gantry robots are 3-axis Cartesian robots and/or 6-axis Cartesian robots.

10. A system according to claim 1, wherein the robots may be any one of SCARA robot, a delta robot or 6-axis robot type.

11. A system according to claim 1, wherein the robots are each provided with a gripper for picking an article from each their article stream.

12. A system according to claim 11, wherein the robot grippers are adapted to pneumatically picking an article from each their article stream.

13. A system according to claim 11, wherein the robot grippers comprise pneumatic suction cups, mechanical gripping fingers, or hybrid design grippers that utilize a suction cup primarily assisted with a mechanical finger gripper.

14. A system according to claim 11, wherein soft robot gripper that has a controlled movement by adjusting pressure through combinations of pneumatic networks.

15. A system according to claim 1, wherein the vision system is adapted to record image data of the articles on all of the article streams on the feeding conveyor.

16. A system according to claim 1, wherein the takeaway conveyor after the delivery end of feeding conveyor is provided with an operator station and an auto reject station.

17. A system according to claim 16, wherein the auto reject station comprises an air guided reject actuator on one side of the takeaway conveyor and a collection bin on the opposite side thereof.

18. A system according to claim 1, wherein a tool exchange magazine for each of the gantry robots is provided on the side of the delivery end of the feeding conveyor.

19. A system according to claim 1, wherein the gantry robots are provided with overlap and the data processing unit is adapted for ensuring a sequential placing of articles by the robots.

20. A method of separating and singulating articles, such as postal parcels or small packages, comprising the steps of: providing a bulk of postal articles, and dividing said bulk of articles into a plurality of parallel article streams on a feeding conveyor and forwarding said article streams in a first conveying direction from a receiving end to a delivery end of said feeding conveyor; providing a takeaway conveyor having a second conveying direction, which is substantially different from said first conveying direction, and where said takeaway conveyor at its upstream end is abutted by the delivery end of said feeding conveyor; providing a plurality of robots in parallel across the delivery end of the feeding conveyor in such a way that each robot is handling each their article stream on the feeding conveyor and that the robots are adapted to picking an article from each their article stream on the feeding conveyor and placing said picked article on the takeaway conveyor; capturing image data of the articles in the article streams on the feeding conveyor by a vision system adapted to, and processing said image data in a data processing unit of a robotic controller to identify an article to be singulated and moved onto the takeaway conveyor by one of the gantry robots and for providing control inputs to the robots.

21. A method according to claim 20, whereby the step of dividing the bulk of articles in a cascading diverter chute is provided upstream the feeding conveyor for the formation of two parallel article streams, preferably by a centrally positioned divider.

22. A method according to claim 20, whereby the robots are placing the picked article on the takeaway conveyor in a placement area at the upstream end of said takeaway conveyor.

23. A method according to any of claims 20, whereby the conveying velocity of the feeding conveyor and/or the takeaway conveyor is variable and either continuously or driven (start-stop).

24. A method according to any of claims 20, wherein the robots are each provided with a gripper for picking an article from each their article stream and wherein the robot grippers are adapted to pneumatically picking an article from each their article stream.

25. A method according to any of claims 20, whereby the vision system is adapted to record image data of the articles on all of the article streams on the feeding conveyor.

26. A method according to any of claims 20, whereby the takeaway conveyor after the delivery end of feeding conveyor is provided with an operator station and an auto reject station.

27. A method according to any of claims 20, whereby the auto reject station comprises an air guided reject actuator on one side of the takeaway conveyor and a collection bin on the opposite side thereof.

28. A method according to any of claims 20, whereby the second conveying direction is substantially perpendicular to said first conveying direction.

29. A method according to any of claims 20, whereby the gantry robots are provided with overlap and the robotic controller and the data processing unit is adapted for ensuring a sequential placing of articles by the robots.

Description

[0024] In the following, the invention is described in more detail with reference to the accompanying drawings, in which:

[0025] FIG. 1 is a schematic view of a system for separating and singulating articles according to the invention; and

[0026] FIG. 2 is a perspective detailed view of the robotic singulation of this system.

[0027] In FIG. 1 there is shown a system for separating and singulating postal parcels or small packages according to an embodiment of the invention. A feeding conveyor 2 having a receiving end 2A and a delivery end 2B receives a bulk of articles which are delivered onto the feeding conveyor 2 from a cascading chute 10. The chute 10 is provided with a divider 14 for separating the bulk of postal articles B arriving in the chute into two parallel article streams A1, A2 on the feeding conveyor 2 and forwarding said article streams A1, A2 with a virtual separation zone 12 in a first conveying direction D1 from the receiving end 2A to the delivery end 2B.

[0028] The feeding conveyor 2 abuts at its delivery end 2B the upstream end of a takeaway conveyor 4 which has a second conveying direction D2, which is substantially different from said first conveying direction D1, preferably the two directions are perpendicular as shown in the figure.

[0029] Across the delivery end 2B of the feeding conveyor 2, there are provided a gantry robot 6, 8 for each article stream A1, A2. Each robot 6, 8 is handling each their article stream A1, A2 on the feeding conveyor 2. The gantry robots 6, 8 are 3-axis Cartesian robots and/or 6-axis Cartesian robots.

[0030] The gantry robots 6, 8 are adapted to pneumatically picking an article from each their article stream on the feeding conveyor 2 and placing the picked article on the takeaway conveyor 4. The robots are provided with a pneumatic pick-up head, which comprises a suction cup which is operated by vacuum for picking an article on the feeding conveyor 2. Beside each of the gantry robots 6, 8 there are arranged a tool exchange magazine 16 (only shown for one of the robots in FIG. 1). The tool exchange magazines 16 are provided on each side of the delivery end 2B of the feeding conveyor 2. In the tool exchange magazine 16, the robot can automatically disconnect the pick-up tool if there is detected a damage of the suction cup and connect a new pick-up head to the robot.

[0031] The system also comprises a vision system (not shown) adapted to capturing image data of the articles on the feeding conveyor 2. These image data are processed in a robotic controller comprising a data processing unit to identify an article to be singulated by one of the robots. The vision system is preferably adapted to record image data of the articles on both of the article streams on the feeding conveyor.

[0032] The articles have been picked up from the article streams A1, A2 on the feeding conveyor 2 and placed on the takeaway conveyor 4 in a singulated manner. Means for providing a placing confirmation 28 may be provided, such as a vision system to provide feedback to the robotic controller (not shown). Downstream where the feeding conveyor 2 abuts the takeaway conveyor 4, the takeaway conveyor 4 is provided with an operator station 18 and an auto reject station 20. The auto reject station 20 comprises an air guided reject actuator 22 on one side of the takeaway conveyor 4 and a collection bin 24 on the opposite side thereof.

[0033] As shown in FIG. 2, the feeding conveyor 2 has its delivery end 2B in the same level as the takeaway conveyor 4. This means that if any articles cannot be handled by the two gantry robots 6, 8, such unhandled articles will be delivered onto the takeaway conveyor 4. From here, such articles can be manually handled in the operator station 18 and/or rejected in the auto reject station 20. As an example, such articles can be odd-shaped articles or a cluster of articles with a too complex geometry for the robots to be able to handle them.

[0034] The invention is described above and illustrated in the drawings with reference to a gantry robot. By the term “a gantry robot” is meant a robot that comprises a manipulator mounted onto an overhead system that allows movement across a horizontal plane. Gantry robots may also be called Cartesian or linear robots and are found advantageous in large systems that perform pick and place applications.

[0035] By the invention, it is found advantageous that gantry robot systems provide the advantage of large work areas and good positioning accuracy. Position accuracy is the ability of the robot to place a part correctly. Furthermore, gantry robots are easy to program, with respect to motion, because they work with an X, Y, Z coordinate system. Another advantage is that the gantry robots are less limited by floor space constraints.

[0036] However, by the invention, it is realized that the robot types that could be used for the present singulator solution could also be a 6-axis robot type, a SCARA robot type (SCARA: Selective Compliance Assembly Robot Arm or Selective Compliance Articulated Robot Arm) or a Delta robot.

[0037] A SCARA robot may comprise an arm which is rigid in the Z-axis and pliable in the XY-axes, which allowed it to adapt to holes in the XY-axes. The SCARA is the jointed two-link arm layout similar to our human arms. This feature allows the arm to extend into confined areas and then retract or “fold up” out of the way. This is advantageous for transferring parts from one place to another.

[0038] The delta robot is a parallel robot, which comprises multiple kinematic chains connecting a base with the end-effector. The robot can also be seen as a spatial generalisation of a four-bar linkage.

[0039] The key concept of the delta robot is the use of parallelograms which restrict the movement of the end platform to pure translation, i.e. only movement in the X, Y or Z direction with no rotation.

[0040] The robot's base is mounted above the workspace and all its actuators are located on it. From the base, three middle jointed arms extend. The ends of these arms are connected to a small triangular platform. Actuation of the input links will move the triangular platform along the X, Y or Z direction. Actuation can be done with linear or rotational actuators, with or without reductions (direct drive). Since the actuators are all located in the base, the arms can be made of a light composite material. Because of this, the moving parts of the delta robot have a small inertia. This allows for very high speed and high accelerations. Having all the arms connected together to the end-effector increases the robot stiffness, but reduces its working volume.

[0041] Above the invention has been described with reference to some currently preferred specified embodiments. However, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms “comprising” or “comprises” do not exclude other possible elements or steps. Also, the mentioning of references such as “a” or “an” etc. should not be construed as excluding a plurality. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.