Conveyor system with robotic induction

Abstract

A conveyor system that uses one or more robots to pick items, such as parcels, from one or more supplies of the items in bulk and place the items directly or indirectly on a registration conveyor, such as a ball belt with flights, in a single file. The items are spaced efficiently for high throughput and delivery to downstream processing, such as sorting.

Description

[0001] CONVEYOR SYSTEM WITH ROBOTIC INDUCTION

[0002] TECHNICAL FIELD

[0003] The invention relates generally to power-driven conveyors and, more particularly, to robots picking up items one by one from a collection of items in bulk and depositing those items directly or indirectly on a registration conveyor.

[0004] BACKGROUND

[0005] In parcel-sorting operations, parcels are individually removed from a collection of parcels in bulk and sent to a sorting conveyor that sorts the parcels to their intended destinations. Removing the parcels from the bulk supply and placing them on a sorting conveyor or on conveyors leading to the sorting conveyor is often performed by human operators, which is labor intensive, or by robots. In many cases it's important that the parcels be positioned on the sorting conveyor at equal intervals to avoid missorting.

[0006] BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is an isometric view of one version of a conveyor system using a robot to induct parcels onto a spur conveyor feeding a registration conveyor belt with spherical rollers and flights.

[0008] FIG. 2 is an isometric view of another version of a conveyor system as in FIG. 1, but with a robot having a pair of robotic arms.

[0009] FIG. 3 is an enlarged isometric view of the junction of the spur conveyor and the registration conveyor belt of FIGS. 1 and 2.

[0010] FIG. 4 is an isometric view of an expanded portion of the spur conveyor and the registration conveyor belt of FIG. 3.

[0011] FIG. 5 A is a cross section of the registration conveyor of FIG. 4 viewed along lines VA-VA with the roller balls free to rotate.

[0012] FIG. 5B is a cross section of the registration conveyor of FIG. 4 viewed along lines VB-VB with the roller balls activated.

[0013] FIG. 6 is an isometric view of a robot depositing parcels directly onto a conveyor belt and of a LIM-driven gapper with flights.

[0014] FIG. 7 is an isometric view of a robot depositing parcels onto a diverting roller belt running side by side with and transferring parcels to a roller-ball belt. FIG. 8 is an isometric view of a conveyor system as in FIG. 1 with an inspection camera and a reject chute.

[0015] FIG. 9 is an enlarged cross section of the conveyor system of FIG. 8 viewed along lines IX-IX.

[0016] FIG. 10 is a top plan view of a conveyor system showing two robots placing items one by one onto a gapping conveyor that leads to a merge conveyor and onto a registration conveyor.

[0017] FIG. 11 is a top plan view of a conveyor system using multiple robots to place parcels from collections of parcels in bulk onto a registration conveyor.

[0018] FIG. 12 is a block diagram of the conveyor system of FIG. 11.

[0019] FIG. 13 is a schematic of the sequence of loading items onto the registration conveyor of FIGS. 11 and 12.

[0020] DETAILED DESCRIPTION

[0021] FIG. 1 shows one version of a conveyor system used in a sorting operation. The conveyor system comprises a supply conveyor 20 providing a supply of items, such as parcels, in bulk. A robot 22 having a single arm 24 terminated in an end effector 26 picks items individually from the supply of items in bulk and deposits them on a spur conveyor 28. The robot 22 has pivots at which the various joints pivot as indicated by the curved arrows. The spur conveyor 28 feeds the items one at a time onto a registration conveyor belt 30. Thus, the robot 22 feeds the items indirectly onto the registration conveyor belt 30. The registration conveyor belt 30 is characterized by a plurality of roller balls 32 that protrude past top and bottom sides of the belt. Flights 34 spaced apart along the length of the belt 30 divide the top side of the belt into regions 36 sequentially disposed along the length of the top side. Each region 36 receives an individual item.

[0022] FIG. 2 shows another version of a conveyor system using robotic induction as in FIG. 1, but with a robot 38 having a pair of arms 40, 41 to increase throughput.

[0023] The junction of the spur conveyor 28 feeding an item onto an individual region 36 of the registration conveyor belt 30 at a transfer position is shown in FIG. 3. The registration conveyor belt 30 is shown advancing in a conveying direction 42 along a carryway 44. The belt 30 is supported on parallel wearstrips 46 that underlie the belt in longitudinal columns between columns of the roller balls 32, as also shown in FIG. 5A. The roller balls 32 are freely rotatable so that items fed onto the registration conveyor belt 30 over a lateral side 48 slide easily atop the roller balls 32 and into the regions 36 with little friction.

[0024] After an item is transferred into a region 36, the roller balls 32 are activated by an activation system 49 at an activation position downstream of the transfer position along the carryway, as shown in FIGS. 4 and 5B. The activation system 49 can be stationary or can be raised and lowered as indicated by the arrow 50. When in a first raised position in contact with the roller balls 32 protruding below the bottom side of the registration conveyor belt 30, the activation system 49 causes the roller balls 32 to rotate in the conveying direction 42. The items atop the activated rollers 32 are pushed forward into registration against the rears of the flights 34, which define the leading ends of the regions 36. In that way, the leading ends of the items are equi-spaced, and the items are separated. If the activation system is not stationary, it can be lowered out of contact with the belt-roller balls 32 to prevent the roller balls from rotating in the conveying direction 42 while the item is already registered. In that way, the bottoms of the items aren't abraded by the roller balls 32.

[0025] A ball belt 52 in FIG. 6 is made a registration conveyor belt by flights 54 that extend laterally over the top side of the belt from a gapping mechanism 56 that drives the flights along the carry way in the conveying direction 42. The flights 54 divide the carry way into regions 58 into each of which an item can be loaded. The gapping mechanism 56 shown is a linear-motor driven mechanism including stator elements in the racetrack frame 60 that drive movers 62 around the racetrack. The flights 54 extend from the movers 62. In this version of a robotic induction system, a robot 64 loads the items from a bulk supply directly into the divided regions 58 on the top side of the belt 52. The gapping mechanism 56 can position the flights 54 in registration against the trailing ends of the items.

[0026] FIG. 7 shows a robot 64 placing a parcel on a transfer conveyor that includes a transfer belt 66 advancing in the conveying direction 42 of a ball belt 52 as in FIG. 6. The transfer conveyor belt 66 has a series of upper transfer rollers that protrudes beyond the belt's top side. Lower rollers protrude below the belt's bottom side and ride along a transferroller activation system below (not shown). The upper and lower rollers rotate on axles defining axes of rotation oblique to the conveying direction 42. Rotation of the lower rollers in contact with the upper rollers causes the upper rollers to rotate obliquely and toward the ball belt 52 and rearward relative to the top side of the transfer belt 66. In that way items are transferred perpendicularly onto the ball belt 52 from the transfer belt 66. The speed of the transfer conveyor belt 66 can be changed relative to the speed of the ball belt 52 so that the items can be transferred onto the ball belt in tightly spaced individual regions. In that way the ball belt 52 is effectively a registration conveyor belt indirectly fed items by the robot. An example of a suitable transfer belt conveyer is shown in U.S. Pat. No. 7,360,641, which is incorporated into this description by reference.

[0027] The conveyor system of FIG. 1 is supplemented by a reject system as shown in FIGS. 8 and 9. A reject collector, such as a chute 68, abuts a lateral side of the registration conveyor belt 30 downstream of an inspection station 70 including a camera viewing the items passing by on the belt. The camera senses items to be rejected because of illegible or missing indicia, unrecognized shapes, or other defects. A rejection activation system 72 includes a flat belt 74 whose upper run 76 is selectively movable into and out of contact with the registration conveyor belt's roller balls 32 by actuators 78 that can raise and lower the flat belt 74 as indicated by arrows 80. The upper run 76 of the flat belt 74 is raised and driven in the direction away from the reject collector 68 so that the tops of the roller balls 32 rotate in the opposite direction to transfer items to be rejected off the lateral side of the belt and onto the reject collector. The same rejection system can be used with the flightless ball belts of FIGS. 6 and 7.

[0028] Another version of a conveyor system with robotic induction is shown in FIG. 10. A pair of robots 82, 83 pick items from a supply 84 of items in bulk and place them in individual lanes of a gapping conveyor 86 that ensures a fixed interval between consecutive items. The two lanes of items are merged into a single file on a merge conveyor 88, which transfers the items one by one onto a conveyor 90, such as a flighted registration conveyor belt 30 as in FIG. 1 or a ball belt 52 as in FIG. 7 advancing in the conveying direction 42 toward a downstream sorting station.

[0029] FIGS. 11 and 12 depict another version of a conveyor system with robotic induction of items. Five robots R1-R5 are shown picking up items from supplies 91 of items in bulk and depositing them directly on a conveyor 92. A system computer 94 or other programmable device executes program steps that instruct the robots R1-R5 through corresponding station processors 96-1-96-N to place items on the conveyor 92 advancing in the conveying direction 42. Each robot is assigned a region on the conveyor into which to deposit its recently picked item. By default, regions 1-5 are sequential regions on the conveyor 92 corresponding to the robots R1-R5 in order. FIG. 13 shows the sequential arrangement of the regions 1-5 in line a. The size of each item picked from the bulk supply is determined by a camera 97 associated with each robot R1-R5. The camera 97 produces a digital image of each item picked up by its associated robot R1-R5. Either the associated station processor 96-1-96-5 or the system computer 94 determines the length of each item in a preferred orientation on the conveyor 92 so that the length of the region required for each robot's item can be set. In that way each robot R1-R5 places an item on the conveyor 92 in a region dynamically assigned to it so that no two items occupy the same region. Because the sizes of the items are measured, the lengths of the regions depend on the lengths of the items destined for their assigned regions. Thus, the conveyor 92 is effectively a registration conveyor directly fed items by the robots R1-R5.

[0030] In FIG. 13 the cross-hatched items represent unoccupied regions on the conveyor 92 reserved for items to be placed downstream by the robots R1-R5. Items filled with dots represent items actually placed on the conveyor 92. Below each line of FIG. 13, the numbers 1 through 5 represent the regions reserved or occupied by an item assigned to that region. In this example, the sequence of assigned regions 1-5 matches the positions of the robots R1-R5 along the length of the conveyor 92 in the conveying direction 42. Fines (a) through (e) represent the conveyor 92 at sequential times. As an unoccupied region passes its designated robot, the robot places the item in that region. For example, in line (c), the lead robot R1 has already placed two items (shown dotted) in their assigned regions. The second and third robots R2, R3 have each placed one item in its assigned region. And the first three robots R1-R3 have avoided placing products in the unoccupied regions reserved for other items from other robots. The leading unoccupied region 4 is not filled by the robot R4 until line (d), and the leading unoccupied region 5 is not filled by the robot R5 until line (e). It can also be seen that, by line (e), the lead robot R1 has placed four items on the conveyor 92, the second robot R2 has placed three items on the conveyor, the third robot R3 has placed two items on the conveyor, and the fourth robot R4 and the fifth robot R5 have each placed one item on the conveyor.

[0031] Further details of the robot control are described with reference to FIG. 12. The system computer 94 communicates with the robot station processors 96-1-96-N, where in this example N = 5. But N could be a greater or lesser number. The system computer 94 receives conveyor speed data from a speed sensor 95. For a belt conveyor, the speed sensor can be a rotary encoder mounted on the conveyor's drive shaft, for example. The cameras 97 produce digital images of each of the items picked by the robots R1-R5. The digital images are sent to the system computer 94 via the station processors 96-1-96-N. The system computer 94 determines from the length of each item the lengths of the regions on the belt to be assigned to each robot. From the images the system computer 94 can also instruct each robot R1-R5 through the robot station processors 96-1-96-5 to place each item in its assigned region oriented with its length parallel to the conveying direction 42.

Claims

What is claimed is:

1. A conveyor system comprising: a supply of items in bulk; a registration conveyor belt arranged to advance in a conveying direction along a carryway and including: a top side and a bottom side; a plurality of roller balls protruding past the top and bottom sides; wherein the top side of the registration conveyor belt is divided into individual regions sequentially disposed in the conveying direction along the top side; a robot programmed to pick an item from the supply of items in bulk and supply the item to be fed directly or indirectly into an empty region atop the roller balls in the registration conveyor belt.

2. The conveyor system as claimed in claim 1 comprising a plurality of flights spaced apart in the conveying direction at the top side of the registration conveyor belt to divide the top side into the individual regions separated by the flights.

3. The conveyor system as claimed in claim 2 comprising an activation system in the carryway that is configured to contact the roller balls protruding past the bottom side to cause the roller balls to rotate in the conveying direction and move the item atop the roller balls in the region forward into registration against the flight that defines a leading end of the region.

4. The conveyor system as claimed in claim 3 wherein the activation system is selectively movable from a first position in contact with the roller balls in the region in which the item has been deposited to cause the roller balls to rotate in the conveying direction to move the item forward in the region into registration against the flight that defines a leading end of the region to a second position out of contact with the roller balls in the region in which the item has been deposited to make the roller balls freely rotatable to ease the item's entry into the region atop the belt rollers.

5. The conveyor system as claimed in claim 3 comprising a spur conveyor receiving the item from the robot and conveying the item to the registration conveyor belt at a transfer position and wherein the activation system is disposed in the carryway at an activation position downstream in the conveying direction.

6. The conveyor system as claimed in claim 2 comprising a spur conveyor advancing to an end at the registration conveyor belt and wherein the robot deposits the item on the spur conveyor, which conveys the item onto the roller balls in the empty region on the registration conveyor belt.

7. The conveyor system as claimed in claim 1 comprising a gapping mechanism that includes a plurality of driven flights that extend laterally over the registration conveyor belt to divide the top side of the registration conveyor belt into the individual regions.

8. The conveyor system as claimed in claim 1 comprising a transfer conveyor including a transfer conveyor belt advancing in the conveying direction parallel and adjacent to the registration conveyor belt, wherein the transfer conveyor belt includes a plurality of transfer rollers and wherein the robot deposits the item onto the transfer rollers of the transfer conveyor belt and wherein the transfer conveyor includes a transfer-roller activation system that selectively drives the transfer rollers supporting the item to rotate and transfer the item to the adjacent registration conveyor belt.

9. The conveyor system as claimed in claim 8 wherein the transfer rollers rotate on axes oblique to the conveying direction.

10. The conveyor system as claimed in claim 1 wherein the robot has multiple arms, each of which can pick items from the supply of items in bulk and deposit the items directly or indirectly into empty regions of the registration conveyor belt.

11. The conveyor system as claimed in claim 1 comprising an inspection station viewing the item on the registration conveyor belt to sense items to be rejected, a reject collector downstream in the conveying direction from the inspection station at a lateral side of the registration conveyor belt, and a rejection activation system configured to cause the roller balls to rotate laterally to transfer items to be rejected off the registration conveyor belt and to the reject collector.

12. The conveyor system as claimed in claim 1 comprising: a second robot; a gapping conveyor receiving items from the two robots in separate lanes and separating the items by a gap; a merge conveyor receiving the two lanes of items from the gapping conveyor and merging the two lanes of items into a single file;wherein the registration conveyor belt receives the items from the merge conveyor and conveys them in the conveying direction.

13. A conveyor system comprising: a plurality of supplies of items in bulk; a registration conveyor arranged to advance in a conveying direction along a carryway; a plurality of robots programmed to pick individual items from the plurality of supplies of items in bulk; a camera associated with each of the robots to produce a digital image of each item picked by the robot; a system computer programmed to execute program steps that assign sequential regions on the top side of the registration conveyor to each of the plurality of robots; wherein each of the robots deposits each of its items individually in the regions assigned to it; wherein the system computer is programmed to execute program steps to determine the length of each item in a preferred orientation on the conveyor from the digital images of the items and to assign a length of the region required for each robot's item.

14. The conveyor system as claimed in claim 13 wherein the regions are assigned in the order of the robots' positions along the conveyor in the conveying direction.

Images