Robotic object handling systems, devices, and methods

Abstract

To provide a robotic object handling system 14 for operation, and a robotic load handling device 30.SOLUTION: The object handling system comprises a number of robotic load handling devices operable on a grid-like structure 20, the structure comprising a set of parallel tracks 22a, 22b being located above the ridge of stacked bins 10. The receptacles contain inventory items to be picked by the system. Load handling devices capable of carrying multiple receptacles of a single grid space size, or single receptacles of multiple grid spaces, are operable on the grid to retrieve and transport the receptacles under the control of a computerized order-picking utility.SELECTED DRAWING: Figure 4

Description

FIELD OF THE INVENTION

[0001] The present invention relates to robotic object handling systems, devices and methods, and more particularly, but not exclusively, to a range of robotic devices for use in robotic object handling systems and methods across a variety of items that can be handled in such systems.

[0002] This application claims priority from UK Patent Application No. GB1506364.7, filed April 15, 2015, and UK Patent Application No. GB1411254.4, filed June 25, 2014, the contents of both of which patent applications are incorporated herein by reference. Summary of the Invention

[0003] Some commercial and industrial activities require systems that allow for the storage and retrieval of a vast number of different products. One known type of system for the storage and retrieval of items in multiple product lines involves stacking storage bins or containers in a stack arranged in rows. The storage bins or containers are accessed from above, eliminating the need for aisles between the rows and allowing more containers to be stored in a given space.

[0004] Methods for handling containers stacked in rows are well known. Some such systems, such as those described in U.S. Pat. No. 2,701,065 to Bertel, provide freestanding stacks of containers arranged in rows to reduce the amount of storage associated with storing such containers while still providing access to a particular container when needed. Access to a given container is made possible by providing a relatively complex hoisting mechanism that can be used to stack and remove a given container from the stack. However, in many situations, the cost of such systems is impractical, and they are primarily commercialized for storing and handling large shipping containers.

[0005] The concept of using a stack of freestanding containers to provide a mechanism for retrieving and storing a particular container has been further developed, as described, for example, in EP 0767113B, Cimcorp. This document discloses a mechanism for removing multiple stacked containers using a robotic load handler in the form of a rectangular tube that is lowered around the stack of containers and configured to grab a container at any level in the stack. In this way, several containers can be lifted from the stack at once. The movable tube can be used to move several stacks from the top of one stack to the top of another stack, or to move containers from the stack to an external location and vice versa. Such a system can be particularly useful when all of the containers in a single stack contain the same product (known as a single product stack).

[0006] In the system described in '113, the height of the tube must be at least as high as the height of the largest stack of containers so that the tallest stack of containers can be extracted in a single motion. Thus, when used in a confined space such as a warehouse, the maximum height of the stack is limited by the need to accommodate the tube of the load handler.

[0007] EP1037828B1 (Autostore), the contents of which are incorporated herein by reference, describes a system in which a stack of containers is arranged within a frame structure. A system of this type is illustrated diagrammatically in Figures 1 to 4 of the accompanying drawings. A robotic load handling device can be controllably moved about the stack on a system of tracks on the top surface of the stack.

[0008] One form of robotic load handling device is further described in Norwegian Patent No. 317366, the contents of which are incorporated herein by reference. Figures 3(a) and 3(b) are schematic perspective views of a load handling device from the rear and front, respectively, and Figure 3(c) is a schematic front perspective view of a load handling device lifting a container.

[0009] A further development of the load handling device is described in UK Patent Application No. GB1413155.1 filed July 24, 2014, which is incorporated herein by reference, in which each robotic load handler covers only one grid space, thus allowing a higher density of load handlers and therefore higher throughput for a given size system.

[0010] One significant disadvantage of prior art systems is that they can only be used with containers of one specific footprint. Furthermore, the height of a container is often constrained by the design of the robotic load handler. This typically limits the use of such systems to items that fit inside the container. In typical applications, this means that 1-10% of a business's total volume requires a different, typically manual, handling method. This represents added complexity in the system, reduced productivity, and inefficient use of space. The present invention addresses these issues by providing a way to integrate a solution for smaller quantities of larger products within a system originally designed for larger quantities of smaller items.

[0011] In a typical retail or parcel handling situation, the systems described above can handle most, if not all, products or parcels. For most products, it is ideal to use standard containers measuring approximately 600 x 400 x 350 mm (l x w x h). This size container typically accommodates 90-99% of all products and is small enough to handle manually when the need arises. This size container is also small enough to provide a very large number of containers in a given size building, thus facilitating the handling of a very large number of different products. In some instances of prior art systems, it is also possible to use a mix of standard-height containers and shorter containers. The purpose of this is to increase the number of containers in a given size system, which can be advantageous under certain conditions.

[0012] According to the invention, there is provided an object handling system comprising two sets of substantially vertical rails forming a grid above a plurality of stacked containers, a portion of the stack comprising containers of larger cross-sectional area than the containers in the remainder of the stack, the handling system further comprising a plurality of robotic load handling devices operating on the grid above the stacked containers, the load handling devices having bodies mounted on wheels such that at any one time only one set of wheels moving is engaged with the grid, thereby enabling movement of the load handling device along the rails to any point on the grid by driving only the set of wheels engaged with the rails, the wheels of a first set being configured to engage at least two of the rails of the first set and the wheels of a second set being configured to engage at least two of the rails of the second set, the wheels of the first set being independently movable and drivable with respect to the wheels of the second set, and at least one robotic handling device operable on the grid is sized to lift and move containers from within the portion of the stack comprising the large containers.

[0013] According to the invention, there is also provided a robotic load handling device comprising a body having a cavity, the body further comprising two sets of wheels mounted on vertical sides of the body, each set of wheels being independently retractable and drivable with respect to the other set of wheels, the cavity in the body being sized to receive a container from an object handling system, the object handling system comprising a grid disposed over a plurality of stacks of containers, the cavity in the body being sized to receive a container of a cross-sectional area defined by an integral number of grid spaces in the object handling system.

[0014] In this way, the height of the container is no longer constrained by the dimensions of the robotic load handler: using taller containers, for example 600 x 400 x 800 mm, it will be possible to handle many of the items that would not fit in a normal container. [Brief explanation of the drawings]

[0015] The invention will now be described with reference to the accompanying diagrammatic drawings. [Figure 1] FIG. 1 is a schematic perspective view of a frame structure for housing a stack of containers in a known storage system. [Figure 2] FIG. 2 is a schematic plan view of a portion of the frame structure of FIG. [Figure 3a] FIG. 3(a) is a schematic rear and front perspective view, respectively, of one form of robotic load handling device for use in the frame structure of FIGS. 1 and 2. [Figure 3b] FIG. 3(b) is a schematic rear and front perspective view, respectively, of one form of robotic load handling device for use in the frame structure of FIGS. 1 and 2. [Figure 3c] Figure 3(c) is a schematic perspective view of a known load handler device in use to lift a container. [Figure 4] Figure 4 is a schematic perspective view of a known storage system comprising a plurality of load handler devices of the type shown in Figures 3(a), 3(b) and 3(c) mounted on the frame structure of Figures 1 and 2. [Figure 5] Figure 5 is a schematic perspective view of a known storage system comprising a plurality of load handling devices of the type shown in Figures 3(a), 3(b) and 3(c) mounted on a frame structure of Figures 1 and 2 containing containers of varying dimensions. [Figure 6]Figure 6a is a schematic perspective representation of a conventional container, and Figure 6b is a schematic perspective representation of a taller container of different dimensions capable of carrying cargo of larger size for movement by a load handler in one form of the invention. [Figure 7] Figure 7 is a schematic representation of a load handling device according to one aspect of the invention capable of transporting a container such as that shown in Figure 6b. [Figure 8] FIG. 8 is a schematic representation of a mixture of load handling devices such as those shown in FIG. 7 operable on a grid and regular size load handling devices, the stack containing regular dimension and tall dimension containers. [Figure 9] Figure 9 is a schematic representation of a load handling device of a second form of the invention in operation on a grid as shown in Figures 1 and 2, the second form of load handling device being larger in all dimensions than a conventional load handling device (also shown for comparison). [Figure 10] FIG. 10 is a schematic representation of a selection of large containers of different dimensions relative to regular receptacles that may be stored in a stack for removal by a load handling device according to a further aspect of the invention. [Figure 11] FIG. 11 is a schematic representation of a large load handling device for lifting large containers according to a third embodiment of the invention. [Figure 12] FIG. 12 is a schematic representation of a large load handling device in accordance with one aspect of the invention for lifting a large container from a stack of large containers of different heights. [Figure 13] FIG. 13 is a schematic representation of a grid system having an area for large containers and several stations for large containers, along with areas and stations containing only regular size containers and load handling devices. Detailed Description

[0016] As shown in Figures 1 and 2, stackable containers known as bins 10 are stacked one on top of the other to form a stack 12. The stacks 12 are arranged in a lattice frame structure 14 in a warehouse or manufacturing environment. Figure 1 is a schematic perspective view of the frame structure 14, and Figure 2 is a top-down view showing a single stack 12 of bins 10 arranged within the frame structure 14. Each bin 10 typically holds multiple product items (not shown), which may be identical or may be of different product types depending on the application.

[0017] The frame structure 14 includes a plurality of upright members 16 supporting horizontal members 18, 20. A first set of parallel horizontal members 18 are arranged perpendicular to a second set of parallel horizontal members 20 to form a plurality of horizontal lattice structures supported by the upright members 16. The members 16, 18, 20 are typically fabricated from metal. The containers 10 are stacked between the members 16, 18, 20 of the frame structure 14, so that the frame structure 14 guards against horizontal movement of the stack 12 of containers 10 and guides vertical movement of the containers 10.

[0018] The top level of the frame structure 14 includes rails 22 arranged in a grid pattern 22 across the top of the stacks 12. Further referring to FIGS. 3 and 4 , the rails 22 support a plurality of robotic load handling devices 30. A first set 22a of parallel rails 22 guides movement of the load handling devices 30 in a first direction (X) across the top of the frame structure 14, and a second set 22b of parallel rails 22 is disposed perpendicular to the first set 22a and guides movement of the load handling devices 30 in a second direction (Y) perpendicular to the first direction. In this manner, the rails 22 enable movement of the load handling devices 30 in two dimensions, in the XY plane, so that the load handling devices 30 can be moved to a position above any of the stacks 12.

[0019] Each load handling device 30 includes a vehicle 32 that is positioned to move in the X and Y directions on the rails 22 of the frame structure 14 above the stack 12. A first set of wheels 34, consisting of a pair of wheels 34 at the front of the vehicle 32 and a pair of wheels 34 at the rear of the vehicle 32, are positioned to engage two adjacent rails of the first set 22a of rails 22. Similarly, a second set of wheels 36, consisting of a pair of wheels 36 on each side of the vehicle 32, are positioned to engage two adjacent rails of the second set 22b of rails 22. Each set of wheels 34, 36 can be raised and lowered so that either the first set of wheels 34 or the second set of wheels 36 is engaged with the respective set of rails 22a, 22b at any one time.

[0020] When the first set of wheels 34 is engaged with the first set of rails 22a and the second set of wheels 36 is fully lifted off the rails 22a, the wheels 34 can be driven to move the load handling device 30 in the X direction via a drive mechanism (not shown) housed within the vehicle 32. To move the load handling device 30 in the Y direction, the first set of wheels 34 is fully lifted off the rails 22a and the second set of wheels 36 is lowered into engagement with the second set of rails 22a. The drive mechanism can then be used to drive the second set of wheels 36 to achieve movement in the Y direction.

[0021] In this manner, one or more robotic load handling devices 30 can move around the top surface of the stack 12 on the frame structure 14 under the control of a central picking system (not shown). Each robotic load handling device 30 is provided with means for lifting one or more receptacles or containers from the stack to access the required products.

[0022] In this way, multiple products can be accessed from multiple locations in the grid and stack at any one time.

[0023] From the above description and with reference to the drawings, it will be noted that the portion of the load handling device 30 carried by the wheels covers one grid space of the grid system above the stack.

[0024] FIG. 4 shows a typical storage system as described above, with multiple load handling devices 30 active on stack 12 .

[0025] In a first embodiment of the invention, a tall robotic load handler is used. The tall robotic load handler device 50 will now be described with reference to Figures 6 to 8. All items common to the load handling device described with reference to Figures 1 to 5 will carry the same reference numbers.

[0026] These taller load handling devices are sized to carry containers similar to those shown in FIG. 6. FIG. 7 shows a taller load handling device lifting a taller container. When lifting a container to the top of a stack, the container is positioned within the body of the load handling device. The load handling device 50 maintains the same dimensions as a regular load handling device in that the wheel portion of the device occupies one grid space of the track system above the stacked containers. In this way, the stack can contain containers of different heights. The taller load handling device is moved into the grid space to remove the taller container as and when needed. The regular height device can continue to remove regular height containers as needed.

[0027] Figure 8 shows multiple tall load handling devices operable on a grid above a stack along with multiple regular-sized load handling devices. Note that the stack contains containers of different heights; however, all containers occupy positions in the stack that have a footprint of a single grid space.

[0028] It will be appreciated that these taller load handlers may have less mechanical stability compared to conventional robotic load handlers, but this is acceptable if accelerations and speeds are sufficiently reduced.

[0029] For larger items, another embodiment of the present invention provides a solution with a robotic load handler that spans more than one grid space. This could be, for example, two, four, six, eight, or nine grid spaces, representing 2x1, 1x2, 2x2, 2x3, or 4x2, 2x4, or 3x3 grid spaces. In the following example, we will describe just the case of a load handling device with a footprint of a 2x2 space. However, it will be appreciated that the larger load handling devices described may occupy any number of grid spaces. To maximize use of the integrated system for both conventional and larger robotic load handlers, these larger load handling devices 50a would be designed to move on the same grid structure as conventional load handlers, as shown in FIG. 9.

[0030] Large load handling devices may be provided with multiple sets of wheels 34,36.

[0031] As seen in Figure 9, a larger 2x2 grid space footprint load handling device can be operable on a grid along with other conventional single grid space footprint load handling devices. A 2x2 load handling device 50a is provided with a first set of wheels 34, consisting of multiple pairs on opposite parallel sides of the vehicle 50a. The wheels 34 are positioned to engage three adjacent rails of the first set 22a of rails 22.

[0032] Similarly, a second set of pairs of wheels 36 is provided, this set consisting of pairs of wheels 36 on opposite sides of the vehicle, the opposite sides being substantially perpendicular to the first set of opposite sides of the vehicle. The wheels 36 are positioned to engage two adjacent rails of the second set 22b of rails 22.

[0033] Each set of wheels 34, 36 can be raised and lowered so that either the first set of wheels 34 or the second set of wheels 36 is engaged with the respective set of rails 22a, 22b at any one time.

[0034] As shown in Figure 9, a large load handling device can operate on the same grid as a normal load handling device, however in Figure 9 the device will lift multiple containers the size of a single grid space.

[0035] In use, as shown in Figure 11, if a typical container positioned in a single grid space is 600 x 400 mm, with 100 mm spacing between stacks, the large load handling device can lift a container that is approximately 1300 x 900 mm. These 2 x 2 grid space containers can then be of different heights to accommodate different size products. For example, as shown in Figure 10, the heights of these large containers can be 300, 500, and 1000 mm.

[0036] The larger 2x2 grid-spaced containers shown in FIG. 10 cannot be stacked with the smaller 1x1 grid-spaced containers. Conversely, a conventional 1x1 grid-spaced load handling device cannot pass through the space above a stack of large containers. A typical system according to this embodiment of the invention would have a collection of equipment dedicated to conventional containers and conventional robotic load handlers. There would be a few workstations for picking / packing and in-shipment cargo designed for larger containers, and a relatively small section of storage space and associated grid dedicated to large containers. This arrangement is shown in FIGS. 12 and 13.

[0037] In use, a large robotic load handling device operates on the grid above the stack as normal, but only lifts large containers from the stack in locations where the stack contains exclusively larger footprint and multiple height containers.

[0038] To lift the container completely off the grid above the stack, the load handling device lifts the larger container from the stack into a cavity within the body of the load handling device.

[0039] It will be appreciated that the robotic load handling device described above is merely an embodiment of the invention. Load handling devices capable of carrying containers of any of a plurality of grid spaces in an area with multiple height possibilities may be contemplated.

[0040] The picking systems described above may relate to order picking systems such as those devised for online retail, or to systems such as parcel handling and sorting systems. It will be appreciated that the invention applies to any system in which items are stored in containers in a stacked configuration and may be accessed by a robotic handling device.

Claims

1. 1. An object handling system comprising two sets of substantially vertical rails forming a grid above a plurality of stacked containers, a portion of the stack comprising containers of larger cross-sectional area than the containers in the remainder of the stack, the handling system further comprising a plurality of robotic load handling devices operating on the grid above the stacked containers, the load handling devices comprising bodies mounted on wheels such that at any one time only one set of wheels moving is engaged with the grid, thereby enabling movement of the load handling devices along the rails to any point on the grid by driving only the wheels of the set engaged with the rails, wherein a first set of wheels is configured to engage at least two of the first set of rails and a second set of wheels is configured to engage at least two of the second set of rails, the wheels of the first set being independently movable and drivable with respect to the wheels of the second set, and at least one robotic handling device operable on the grid is sized to lift and move containers from within the portion of the stack comprising large containers.

2. The object handling system of claim 1 , wherein the load handling device comprises a body capable of lifting and transporting containers of multiple heights.

3. 3. The object handling system of claim 1 or 2, wherein the at least one load handling device comprises a body spanning approximately a 1x2, 2x2, 2x3, or 3x3 grid space, the grid space being defined by the spacing of a set of substantially vertical rails.

4. 10. An object handling system according to any preceding claim, wherein the container, when transported by the load handling device, is positioned within a cavity in the body of the load handling device.

5. A robotic load handling device for use in an object handling system as set forth in any one of claims 1 to 4.

6. 1. A robotic load handling device comprising a body having a cavity, the body further comprising two sets of wheels mounted on vertical sides of the body, each set of wheels being independently retractable and drivable with respect to the other set of wheels, the cavity in the body being sized to receive a container from an object handling system, the object handling system comprising a grid disposed over a plurality of stacks of containers, the cavity in the body being sized to receive a container of a cross-sectional area defined by an integral number of grid spaces in the object handling system.

7. A robotic load handling device or object picking system as hereinbefore described with reference to Figures 6 to 13 of the accompanying drawings.

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