Robot Picking Station

Abstract

A robotic picking station (100) for use in a grid-based storage system (1), comprising: a robotic manipulator (106) having a suction device (112) configured to releasably engage an item; and a low-pressure circuit (145) having a vacuum source (146) mounted on the robotic manipulator (106) for supplying vacuum pressure at the suction device (112).

Description

[Technical Field]

[0001] The present invention relates generally to the field of picking stations for use in warehouses and / or fulfillment centers. [Background technology]

[0002] Online retail businesses that sell multiple product lines, such as online grocery stores and supermarkets, need systems capable of storing tens or even hundreds of thousands of different product lines. The use of a single product stack in such cases may be impractical because a significant amount of floor space would be required to accommodate all of the required stacks. Furthermore, it may be desirable to store only small quantities of some items, such as perishable foods or infrequently ordered goods, making a single product stack an inefficient solution.

[0003] PCT Publication No. WO2015 / 185628A (Ocado) describes a known storage and fulfillment system in which a stack of receptacles or containers is arranged within a framework structure. The receptacles or containers are accessed by load handling devices operating on tracks located at the top of the frame structure. The load handling devices are configured to lift the receptacles or containers from the stack, and multiple load handling devices may cooperate to access the receptacles or containers located at the lowest position in the stack. A system of this type is illustrated schematically in Figures 1 to 5 of the accompanying drawings.

[0004] 1 illustrates an automated storage and retrieval structure 1 comprising upright members 3 and horizontal members 5, 7 supported by upright member 3. Horizontal members 7 extend parallel to each other and to the illustrated x-axis. Horizontal members 5 extend parallel to each other and to the illustrated y-axis and transverse to horizontal members 7. Upright members 3 extend parallel to each other and to the illustrated z-axis and transverse to horizontal members 5, 7. Horizontal members 5, 7 form a grid pattern defining a plurality of grid cells. In the illustrated example, storage containers 9 are arranged in stacks 11, with each stack 11 located directly below a respective grid cell.

[0005] FIG. 2 shows an enlarged plan view of a section of a track structure 13 forming part of the storage structure 1 illustrated in FIG. 1. The track structure 13 is located on top of the horizontal members 5, 7 of the storage structure 1 illustrated in FIG. 1. The track structure 13 may be provided by the horizontal members 5, 7 themselves (e.g., formed in or on the surfaces of the horizontal members 5, 7) or by one or more additional components attached to the top of the horizontal members 5, 7. The illustrated track structure 13 includes x-direction tracks 17 and y-direction tracks 19, i.e., a first set of tracks 17 extending in the x-direction and a second set of tracks 19 extending in the y-direction that are transverse to the tracks 17 in the first set of tracks 17. The tracks 17, 19 define openings 15 in the centers of the grid cells. The openings 15 are sized to allow storage containers 9 located directly below the grid cells to be lifted and lowered therethrough. The x-direction tracks 17 are provided in pairs separated by channels 21, and the y-direction tracks 19 are provided in pairs separated by channels 23. Other arrangements of the track structures are also envisioned.

[0006] Figure 3 shows multiple load handling devices 31 moving on top of the storage structure 1 illustrated in Figure 1. The load handling devices 31, which may also be referred to as robots 31 or bots 31, are provided with sets of wheels for engaging with corresponding x-direction tracks 17 or y-direction tracks 19 to enable the bots 31 to travel across the track structure 13 and reach particular grid cells. The illustrated pair of tracks 17, 19, separated by channels 21, 23, allows the bots 31 to occupy (or pass each other on) adjacent grid cells without colliding with each other.

[0007] 4, the bot 31 comprises a body 33 to which one or more components are attached that enable the bot 31 to perform its intended functions. These functions may include moving across the storage structure 1 on the track structure 13 and raising or lowering storage containers 9 (e.g., from or to stacks 11) so that the bot 31 can retrieve or place storage containers 9 at specific locations defined by a grid pattern.

[0008] The illustrated bot 31 includes a first set of wheels 35 and a second set of wheels 37 mounted on the body 33 of the bot 31, enabling the bot 31 to move in the x and y directions, respectively, along tracks 17 and 19. In particular, two wheels 35 are provided on the short side of the bot 31 visible in FIG. 4, and two more wheels 35 are provided on the opposite short side of the bot 31 (the sides and two more wheels 35 are not visible in FIG. 4). The wheels 35 engage with the tracks 17 and are rotatably mounted on the body 33 of the bot 31, enabling the bot 31 to move along the tracks 17. Similarly, two wheels 37 are provided on the long side of the bot 31 visible in FIG. 4, and two more wheels 37 are provided on the opposite long side of the bot 31 (the sides and two more wheels 37 are not visible in FIG. 4). Wheels 37 engage the track 19 and are rotatably mounted on the body 33 of the bot 31 to enable the bot 31 to move along the track 19.

[0009] The bot 31 also includes container lifting means 39 configured to raise and lower the container 9. The illustrated container lifting means 39 includes four tapes or reels 41 connected at their lower ends to a container engaging assembly 43. The container engaging assembly 43 includes engagement means (which may be provided, for example, at the corners of the assembly 43, near the tapes 41) configured to engage features of the container 9. For example, the containers 9 may be provided with one or more openings on their upper sides through which the engagement means may engage. Alternatively or additionally, the engagement means may be configured to hook under a rim or lip of the container 9 and / or to clamp or grasp the container 9. The tapes 41 may be wound up or unwound to raise or lower the container engaging assembly, as required. One or more motors or other means may be provided to effect or control the winding or unwinding of the tapes 41.

[0010] As seen in FIG. 5 , the body 33 of the illustrated bot 31 has an upper portion 45 and a lower portion 47. The upper portion 45 is configured to house one or more operating components (not shown), and the lower portion 47 is located directly below the upper portion 45. The lower portion 47 comprises a container-receiving space or cavity for accommodating at least a portion of a container 9 raised by the container lifting means 39. The container-receiving space is sized so that the container 9 can fit sufficiently within the cavity to allow the bot 31 to move across the track structure 13 at the top of the storage structure 1 without the underside of the container 9 getting caught on the track structure 13 or another portion of the storage structure 1. When the bot 31 reaches its intended destination, the container lifting means 39 controls the tape 41 to lower the container gripping assembly 43 and corresponding container 9 out of the cavity in the lower portion 47 and to its intended position. This intended location may be a stack 11 of containers 9 or an exit point of the storage structure 1 (or an entrance point of the storage structure 1 if the bot 31 moves to collect a container 9 for storage within the storage structure 1). In the illustrated example, the upper portion 45 and the lower portion 47 are separated by a physical partition, but in other embodiments, the upper portion 45 and the lower portion 47 may not be physically separated by a particular component or part of the body 33 of the bot 31.

[0011] In some embodiments, the container-receiving space of the bot 31 may not be within the body 33 of the bot 31. For example, in some embodiments, the container-receiving space may be adjacent to the body 33 of the bot 31, e.g., in a cantilever arrangement in which the weight of the body 33 of the bot 31 balances the weight of the container to be lifted. In such embodiments, the frame or arms of the container lifting means 39 may protrude horizontally from the body 33 of the bot 31, and the tape / reel 41 may be disposed at respective locations on the protruding frame / arms and configured to be raised and lowered from those locations to raise and lower the container into the container-receiving space adjacent the body 33. The height at which the frame / arms are attached to and protrude from the body 33 of the bot 31 may be selected to provide a desired effect. For example, it may be preferable for the frame / arms to protrude at a high level above the body 33 of the bot 31 to allow a larger container (or multiple containers) to be lifted into the container-receiving space directly below the frame / arms. Alternatively, the frame / arms may be positioned to protrude lower on the body 33 (but still high enough to accommodate at least one container between the frame / arms and the track structure 13) to keep the center of gravity of the bot 31 lower when the bot 31 is loaded with containers.

[0012] To enable the bot 31 to move on different wheels 35, 37 in the first and second directions, the bot 31 includes a wheel positioning mechanism for selectively engaging either the first set of wheels 35 with the first set of tracks 17 or the second set of wheels 37 with the second set of tracks 19. The wheel positioning mechanism is configured to raise and lower the first set of wheels 35 and / or the second set of wheels 37 relative to the body 33, thereby enabling the load handling device 31 to selectively move in either the first direction or the second direction across the tracks 17, 19 of the storage structure 1.

[0013] The wheel positioning mechanism may include one or more linear actuators, rotary components, or other means for raising and lowering at least one set of wheels 35, 37 relative to the body 33 of the bot 31 to move the at least one set of wheels 35, 37 into and out of contact with the tracks 17, 19. In some examples, only one set of wheels is configured to be raised and lowered, such that the act of lowering one set of wheels may effectively lift the other set of wheels away from the corresponding tracks, while the act of raising one set of wheels may effectively lower the other set of wheels into contact with the corresponding tracks. In other examples, both sets of wheels may be raised and lowered, advantageously allowing the body 33 of the bot 31 to remain at substantially the same height, thus meaning that the weight of the body 33 and components mounted thereon does not need to be lifted and lowered by the wheel positioning mechanism.

[0014] As shown in Figure 3, multiple identical load handling apparatuses 31 may be provided, whereby each load handling apparatus 31 may operate simultaneously to increase system throughput. The system illustrated in Figure 3 may include specific locations known as ports, where containers may be transferred into or out of the system. Additional conveyor systems (not shown) may be associated with each port, whereby containers 9 delivered to the port by the load handling apparatus 31 may be transported by the conveyor system to another location, e.g., a picking station (not shown). Similarly, containers 9 may be moved by the conveyor system from an external location to the port, e.g., a container filling station (not shown), and then transported by the load handling apparatus 30 to the stacks 12 to replenish stock within the system.

[0015] Each load handling device 31 can lift and move one container 9 at a time. If a container 9 that is not located at the top of a stack (a "target container 9") needs to be removed, the containers 9 above ("non-target containers 9") must first be moved to allow access to the target container. This is accomplished in an operation hereafter referred to as "digging." During a digging operation, one of the load handling devices 31 sequentially lifts each non-target container from the stack 11 containing the target container and places it in a vacant position in another stack 11. The target container can then be accessed by the load handling device 31 and moved to a port for further transport.

[0016] Each of the load handling devices 31 is under the control of a central computer. Each individual container 9 in the system is tracked so that it can be removed, transported, and replaced as needed. For example, during an excavation operation, the location of each non-target container is logged so that the non-target containers can be tracked.

[0017] The system described with reference to Figures 1-5 has many advantages and is suitable for a wide range of storage and retrieval operations. In particular, the described system allows for very high density storage of products and provides a very economical way of storing a wide range of different items in containers while allowing reasonably economical access to all containers when required for picking.

[0018] Referring to FIG. 6 , the system may further include a robotic picking station, generally designated 50, mounted on top of the storage and retrieval structure 1 along with load handling equipment 31 (not shown). The robotic picking station 50 includes a robotic manipulator 52, including a robotic arm 54 and an end effector 56 for releasably engaging a product to be manipulated, along with several designated grid cells 60, 62. The robotic manipulator 52 is mounted on a pedestal 58 above a single grid cell 60 and, depending on its location on the structure 1, may be surrounded by up to eight other grid cells 62, as shown in FIG. 6 . Generally, the robotic manipulator 52 is configured to pick an item or product from any one of the containers 9 located in one of the designated grid cells 62 and place it in a container 9 located in another of the designated grid cells 62, with the load handling equipment 31 collecting the containers 9 from the designated grid cells 62 and transporting them to the designated grid cells 62 as needed. In this manner, the robotic picking station 50 and the load handling device 31 work in conjunction to fulfill customer orders or redistribute products throughout the storage and retrieval structure 1. The end effector 56 includes a suction device 64 connected to a vacuum source in the form of a rotary vane pump (not shown). The vane pump forms part of a low-pressure circuit configured to provide vacuum pressure at the suction device 64, allowing the suction device 64 to be attached to the product being handled. The vane pump is located away from the top of the storage and retrieval structure 1 due to its size and weight and so as not to occupy any grid cells. Instead, the vane pump is typically located at ground level where it can be easily accessed, making installation and maintenance easier. However, this arrangement presents a number of problems. First, locating the vane pump at ground level can pose a risk of burns from the heat generated by the vane pump during use.Second, because the distance between the vane pump and the adsorber 64 can be on the order of several meters, a large-diameter vacuum line 66 must be used to minimize the pressure drop between the vane pump and the adsorber 64. However, to prevent collapse due to vacuum pressure, the vacuum line 66 must be reinforced to provide adequate rigidity. This can reduce the dexterity of the robotic manipulator 52, as routing the vacuum line 66 to the adsorber 64 requires mounting the vacuum line 66 on the robotic arm 54. Finally, vane pumps are typically not rated to operate below 5°C, making their use unsuitable for some environments (e.g., refrigerated areas).

[0019] It is against this background that the present invention was conceived. Summary of the Invention

[0020] Thus, in one aspect, a robotic picking station for use in a grid-based storage system is provided. The robotic picking station includes a robotic manipulator including a suction device configured to releasably engage an item or product, and a low-pressure circuit including a vacuum source for providing vacuum pressure at the suction device, the vacuum source mounted on the robotic manipulator. In the field of robotic manipulators, there is a generally accepted concept that mounting equipment, particularly heavy and / or bulky items, on the robotic manipulator itself should be avoided whenever possible, as it can impair the manipulator's performance and dexterity. This is particularly inadvisable when alternative options exist. Thus, mounting a vacuum source on the robotic manipulator is counterintuitive and violates expectations and norms.

[0021] Optionally, the vacuum source is movable relative to the base of the robotic manipulator.

[0022] Optionally, the vacuum source is movable about a substantially vertical axis of the robotic manipulator.

[0023] Optionally, the substantially vertical axis defines an axis of rotation for a movable joint of the robotic manipulator, and the vacuum source is mounted on the robotic manipulator above the movable joint.

[0024] Optionally, a vacuum source is mounted on the base of the robotic manipulator.

[0025] Optionally, the robotic picking station further comprises a support attached to the base, the support configured to carry a vacuum source.

[0026] Optionally, the vacuum source is movable about a generally horizontal axis of the robotic manipulator.

[0027] Optionally, a vacuum source is positioned on the robotic manipulator so that, in use, it is counterbalanced by the load carried by the suction device.

[0028] Optionally, the robotic manipulator further comprises means for adjusting the distance between the vacuum source and the generally horizontal axis.

[0029] Optionally, the low pressure circuit further comprises a vacuum filter positioned between the adsorption device and the vacuum source.

[0030] Optionally, the vacuum filter is mounted on a robotic manipulator.

[0031] Optionally, the vacuum filter is mounted on a link of the robotic manipulator.

[0032] Optionally, the vacuum source comprises a venturi vacuum generator connectable to a pressure source for providing a pressurized air supply to the vacuum source.

[0033] Optionally, the vacuum source comprises a plurality of venturi vacuum generators, an air supply manifold connectable to a pressure source, and a vacuum manifold fluidly connecting the plurality of venturi vacuum generators to the adsorber.

[0034] Optionally, the low pressure circuit further comprises a plurality of push-to-connect fittings.

[0035] Optionally, the low pressure circuit further comprises food grade tubing.

[0036] Optionally, the robotic picking station further comprises a pedestal for mounting the robotic manipulator to one or more framework members of the grid-based storage system such that the robotic manipulator is received within a single grid cell of the storage system.

[0037] Optionally, the pressure source is connectable to a venturi vacuum generator by a tube, the base comprising a moveable bracket defining a conduit through which the tube is fed.

[0038] According to a second aspect, there is provided a grid-based storage and retrieval system comprising a first set of tracks extending in a first direction and a second set of tracks extending in a second direction transverse to the first direction so as to form a grid comprising a plurality of grid cells, the grid-based storage system further comprising a framework structure on which the first and second sets of tracks are received such that a stack of containers may be stored beneath each of the plurality of grid cells, and a robotic picking station according to the first aspect.

[0039] These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0040] [Figure 1]FIG. 1 shows a schematic diagram of the automated storage and retrieval structure. [Figure 2] FIG. 2 shows a schematic diagram of a plan view of a section of a track structure forming part of the storage structure of FIG. [Figure 3] FIG. 3 shows a schematic diagram of a number of load handling devices moving on top of the storage structure of FIG. [Figure 4] FIG. 4 shows a schematic diagram of a load handling device interacting with a container. [Figure 5] FIG. 5 shows a schematic diagram of a load handling device interacting with a container. [Figure 6] FIG. 6 shows a schematic diagram of a known robotic picking station. [Figure 7a] FIG. 7a shows a schematic diagram of a robotic picking station according to one embodiment of the present invention. [Figure 7b] FIG. 7b shows a schematic diagram of a robotic manipulator used in a picking station. [Figure 8] 8a and 8b are isometric views of a vacuum source for use with the robotic picking station of FIG. [Figure 9a] FIG. 9a shows a schematic diagram of an alternative robotic manipulator according to one embodiment of the present invention for use in the robotic picking station of FIG. [Figure 9b] FIG. 9b shows a schematic diagram of an alternative robotic manipulator according to one embodiment of the present invention for use in the robotic picking station of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0041] In the drawings, like features are indicated by like reference numerals where appropriate.

[0042] In the following description, some specific details are included to provide a thorough understanding of the disclosed examples. However, those skilled in the art will recognize that other examples may be practiced without one or more of these specific details, or with other components, materials, etc., and that structural changes may be made without departing from the scope of the present invention as defined in the appended claims. Furthermore, in the following description, references to any terms having an implied orientation are not intended to be limiting and refer only to the orientation of the features as shown in the accompanying drawings. In some instances, well-known features or systems, such as processors, sensors, storage devices, network interfaces, fasteners, electrical connectors, and the like, are not shown or described in detail to avoid unnecessarily obscuring the description of the disclosed embodiments.

[0043] Unless the context requires otherwise, throughout this specification and the appended claims, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be interpreted in their open and inclusive sense, such as "including, but not limited to."

[0044] Throughout this specification, references to "one," "an," or "another" applied to an "embodiment," "example," or "implementation" mean that the particular referent feature, structure, or characteristic described in connection with an embodiment, example, or implementation is included in at least one embodiment, example, or implementation. Thus, the appearances of "in one embodiment" or similar phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, examples, or implementations.

[0045] It should be noted that, as used in this specification and the appended claims, the user forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally used in its sense to include "and / or" unless the content clearly dictates otherwise.

[0046] FIG. 7a shows a schematic diagram of a robotic picking station 100 according to one embodiment of the present invention. The robotic picking station 100 is mounted on top of a grid-based storage and retrieval system 102 similar to the previously described known systems. The robotic picking station 100 comprises a pedestal 104 on which a robotic manipulator 106 is mounted. The pedestal 104 is sized and shaped so that it can be received within a grid cell opening 108 formed by the intersecting horizontal members 5 and 7. The pedestal 104 is connected to the framework of the system 102 such that the arm of the robotic manipulator 106 is mounted thereon. For example, the pedestal 104 may be connected to one or more of the upright members 3 of the system 102. Alternatively or additionally, the pedestal 104 may be connected to one or more of the horizontal members 5 and 7 of the system 102. The surface of the pedestal 104 may extend substantially across the grid cell opening 108 in which it is received. This reduces the risk of dropped product falling into the system 102 and potentially disrupting its operation. Alternatively, the surface of the pedestal 104 may extend only partially over the area of ​​the grid cell in which it is received.

[0047] The robotic manipulator 106 comprises a robotic arm 110 and an end effector in the form of a suction device 112 configured to releasably engage an item. The exact configuration of the robotic arm 110 is not central to the present invention and will not be described in detail. Referring to FIG. 7b, in this example of the robotic manipulator 106, the robotic arm 110 comprises a base 114 and seven links, all connected by six joints. The base 114 extends generally vertically from the pedestal 104 and comprises a lower base link 116 and an upper base link 118 connected by a base joint 120. The base joint 120 is configured to allow the upper base link 118 to rotate relative to the lower base link 116 about a generally vertical axis 122. The upper base link 118 is rotatably connected to an upper arm link 126 by a shoulder joint 124, which is in turn rotatably connected to a lower arm link 128 by an elbow joint 130. The robotic arm 110 further includes a wrist 132 and a tool flange 134 configured to hold the suction device 112. The wrist 132 includes two wrist links 136, 138 and three wrist joints 140, 142, 144 connecting the lower arm 128 and the tool flange 134. Each joint 120, 124, 130, 140, 142, 144 can be selectively actuated such that the suction device 112 can be moved within six degrees of freedom, enabling the robotic arm 110 to engage product stored in one container and transfer it to another container. Other robotic arms with greater or fewer links and joints will be known to those skilled in the art.

[0048] The robotic picking station 100 further includes a low-pressure circuit 145 including a vacuum source 146 configured to provide vacuum pressure at the adsorber 112. In this example, the vacuum source 146 includes an array of venturi vacuum generators 148 (hereinafter "array 148") connectable to a pressure source 149 for providing a pressurized air supply to the vacuum source. In this embodiment, the array 148 includes four venturi vacuum generators 148. The pressure source may be a stand-alone pump or a reservoir of pressurized air configured to supply the facility in which the robotic picking station 100 is installed. The low-pressure circuit 145 further includes a flexible hose 150 extending between a vacuum side 151 of the array 148 and the adsorber 112 for providing vacuum pressure at the adsorber 112, along with a vacuum filter 152 connected to the hose 150 between the array 148 and the adsorber 112. The vacuum filter 152 functions to isolate the array 148 from debris picked up from the adsorber 112. In this example, the vacuum filter 152 is mounted on one of the wrist links 136 of the robot arm 110 as close as feasible to the adsorption device 112 as this configuration of the robot arm 110 allows.

[0049] The array 148 is mounted on the robotic manipulator 106 and is movable relative to the lower base link 116, which is rigidly fixed to the pedestal 104. In this example, the array 148 is mounted on the upper base link 118 as close to the vertical axis 122 as reasonably practicable, directly above the base joint 120, so as to rotate with the upper base link 118 about a generally vertical axis 122. Mounting the array 148 radially close to the vertical axis 122 minimizes its moment of inertia as it moves about axis 122. The array 148 is fixed to a support 154, in this example in the form of a platform 156 attached to the upper base link 118. The platform 156 provides additional surface area for supporting the array 148, compared to the top surface of the upper base link 118, improving load distribution across the base joint 120.

[0050] 8a and 8b, the vacuum side 151 of the vacuum source 146 includes a vacuum manifold 158 fluidly connecting the array 148 to the hoses 150 for supplying vacuum pressure at the adsorber 112. Similarly, the pressure side 160 of the vacuum source 146 includes an air supply manifold 162 connectable to hoses 164 for supplying pressurized air flow from the pressure source to the array 148. The use of manifolds 158, 162 reduces the need for additional fittings or hoses connecting the pressure and vacuum sources 146 to the array 148, minimizing the pressure drop between the pressure source and the air supply manifold 162 and vacuum loss through the low-pressure circuit 145. Additionally, both manifolds 158, 162 are configured to ensure uniform mass flow across the array 148, further minimizing pressure and vacuum loss therethrough. The vacuum source 146 further includes a hose fitting 164 connecting the vacuum manifold 158 to the hoses 150 of the low-pressure circuit 145. The hose fitting 164 is rotatably mounted to the vacuum manifold 158 by a bearing block (not shown), which allows the hose fitting 164 to rotate about an axis defined by the bearing block and prevents excessive tensioning of the hose 150 as the robot arm 110 moves relative to the vacuum source 146.

[0051] 9a and 9b show another example of a robotic manipulator 206 for use in a robotic picking station according to the present disclosure. This example is substantially similar to the previous example, except that a slightly different configuration of the robotic arm 210 allows a vacuum source 246 to be positioned on the robotic manipulator 206 so that, in use, it counterbalances a load carried by the suction device 212. Specifically, in this configuration of the robotic arm 210, the upper arm link 226 extends longitudinally on either side of a generally horizontal axis 223 defined by the shoulder joint 224, providing space for attachment of the vacuum source 246 at the end 225 of the upper arm link 226, distal from the lower arm link 228. In this manner, the vacuum source 246 can be used as a counterweight, providing leverage to reduce the effort required by the robotic arm 210 to lift a load. To adjust the leverage effect to make it more or less beneficial, the robotic manipulator further comprises means for adjusting the distance between the vacuum source 246 and the horizontal axis 223. To that end, the vacuum source 246 may be mounted on a platform system configured to move toward and away from the horizontal axis 223. Alternatively, the vacuum source 246 may be mounted on a guide rail extending in the direction of the horizontal axis 223. The distance between the vacuum source 246 and the horizontal axis 223 may vary depending on the load carried by the suction device. For example, with a light load or no load, the vacuum source 246 would be moved as close as possible to the horizontal axis 223 to minimize the leverage effect. With increasingly heavier loads, the distance between the vacuum source 246 and the horizontal axis 223 would be increased to benefit from the leverage effect.

Claims

1. 1. A robotic picking station for use in a grid-based storage system, the robotic picking station comprising: a robotic manipulator comprising a suction device configured to releasably engage an item; a low pressure circuit including a vacuum source for supplying vacuum pressure at the suction device, wherein the vacuum source is mounted on the robot manipulator; A robotic picking station comprising:

2. The robotic picking station of claim 1 , wherein the vacuum source is movable relative to a base of the robotic manipulator.

3. The robotic picking station of claim 1 or 2, wherein the vacuum source is movable about a substantially vertical axis of the robotic manipulator.

4. The robotic picking station of claim 3 , wherein the generally vertical axis defines an axis of rotation of a movable joint of the robotic manipulator, and the vacuum source is mounted on the robotic manipulator above the movable joint.

5. The robotic picking station of any one of claims 2 to 4, wherein the vacuum source is mounted on the base of the robotic manipulator.

6. The robotic picking station of claim 5 , further comprising a support attached to the base, the support configured to carry the vacuum source.

7. The robotic picking station of claim 1 or 2, wherein the vacuum source is movable about a substantially horizontal axis of the robotic manipulator.

8. The robotic picking station of claim 7 , wherein the vacuum source is positioned on the robotic manipulator so as to be in balance with a load carried by the suction device.

9. The robotic picking station of claim 8 , wherein the robotic manipulator further comprises means for adjusting the distance between the vacuum source and the generally horizontal axis.

10. The robotic picking station of any one of claims 1 to 9, wherein the low pressure circuit further comprises a vacuum filter positioned between the suction device and the vacuum source.

11. The robotic picking station of claim 10 , wherein the vacuum filter is mounted on the robotic manipulator.

12. The robotic picking station of claim 11 , wherein the vacuum filter is mounted on a link of the robotic manipulator.

13. The robotic picking station of any preceding claim, wherein the vacuum source comprises a venturi vacuum generator connectable to a pressure source for providing a pressurized air supply to the vacuum source.

14. 14. The robotic picking station of claim 13, wherein the vacuum source comprises a plurality of venturi vacuum generators, an air supply manifold connectable to the pressure source, and a vacuum manifold fluidly connecting the plurality of venturi vacuum generators to the suction device.

15. The robotic picking station of claim 14 , wherein the low voltage circuit further comprises a plurality of push-to-connect fittings.

16. The robotic picking station of any one of claims 1 to 15, wherein the low pressure circuit further comprises food grade tubing.

17. 17. The robotic picking station of claim 1, further comprising a pedestal for mounting the robotic manipulator to one or more framework members of the grid-based storage system such that the robotic manipulator is received within a single grid cell of the storage system.

18. 18. The robotic picking station of claim 17 when dependent on claim 13 or any claim dependent on claim 13, wherein the pressure source is connectable to the Venturi vacuum generator by a tube, and the base comprises a moveable bracket defining a conduit through which the tube is fed.

19. a first set of tracks extending in a first direction; a second set of tracks extending in a second direction transverse to the first direction to form a grid comprising a plurality of grid cells; a framework structure upon which the first and second sets of tracks are received such that a stack of containers may be stored beneath each of the plurality of grid cells; A robotic picking station according to any one of claims 1 to 18; 1. A grid-based storage and retrieval system comprising:

Images