Robot picking station

Abstract

A robotic picking station (100) for use in a grid-based storage system (1) includes a robotic manipulator (106) including a sorption device (112) configured to releasably engage items, and a low pressure circuit (145) including a vacuum source (146) mounted on the robotic manipulator (106), the vacuum source (146) for providing a vacuum pressure at the sorption device (112).

Description

Field of the Invention

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

[0002] Online retail enterprises that sell multiple product lines, such as online grocers and supermarkets, etc., need systems that can store tens of thousands or even hundreds of thousands of different product lines. In such cases, stacking of a single product may be impractical because it requires a very large floor area to accommodate all the required stacks. Additionally, only small quantities of certain items (e.g., perishable or infrequently ordered goods) may need to be stored, making stacking of a single product an inefficient solution.

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

[0004] Figure 1 shows an automated storage and retrieval structure 1 including upright members 3 and horizontal members 5, 7 supported by the upright members 3. The horizontal members 7 extend parallel to each other and parallel to the shown x-axis. The horizontal members 5 extend parallel to each other and parallel to the shown y-axis, and extend transversely to the horizontal members 7. The upright members 3 extend parallel to each other and parallel to the shown z-axis, and extend transversely to the horizontal members 5, 7. The horizontal members 5, 7 form a grid pattern defining a plurality of grid cells. In the shown embodiment, storage containers 9 are arranged in stacks 11, with each stack 11 located below a respective grid cell.

[0005] Figure 2 shows a large-scale plan view of a section of the track structure 13 that forms part of the storage structure 1 shown in Figure 1. The track structure 13 is located on top of the horizontal members 5, 7 of the storage structure 1 shown in Figure 1. The track structure 13 can be provided by the horizontal members 5, 7 themselves (e.g., formed in or on the surface of the horizontal members 5, 7) or by one or more additional components mounted on 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 and transverse to the tracks 17 of the first set. The tracks 17, 19 define holes 15 at the centers of the grid cells. The size of the holes 15 is designed to allow the storage containers 9 located below the grid cells to be lifted and lowered through the holes 15. The x-direction tracks 17 are separated by channels 21 and are provided in pairs, and the y-direction tracks 19 are separated by channels 23 and are provided in pairs. Other arrangements of the track structure are also conceivable.

[0006] Figure 3 shows a plurality of load handling devices 31 moving on top of the storage structure 1 shown in Figure 1. The load handling devices 31 (which may also be referred to as automated handling devices 31 or robots 31) are provided with sets of wheels to engage with the corresponding x- or y-direction tracks 17, 19, enabling the robot 31 to travel on the track structure 13 and reach specific grid cells. The illustrated pairs of tracks 17, 19 separated by the channels 21, 23 allow the robot 31 to occupy (or pass by each other) adjacent grid cells without colliding with each other.

[0007] As shown in detail in Figure 4, the robot 31 includes a body 33, and one or more components enabling the robot 31 to perform its intended functions are mounted on the body 33. These functions can include moving across the storage structure 1 on the track structure 13 and raising or lowering the storage containers 9 (e.g., raising or lowering from / to the stack 11), such that the robot 31 can retrieve or deposit the storage containers 9 at specific positions defined by the grid pattern.

[0008] The robot 31 shown includes a first set and a second set of wheels 35, 37. The first set and the second set of wheels 35, 37 are mounted on the body 33 of the robot 31 and enable the robot 31 to move along the track 17 in the x direction and along the track 19 in the y direction respectively. Specifically, two wheels 35 are visibly provided on the shorter side of the robot 31 in FIG. 4, while the other two wheels 35 are provided on the opposite shorter side of the robot 31 (this side and the other two wheels 35 are not visible in FIG. 4). The wheels 35 engage with the track 17 and are rotatably mounted on the body 33 of the robot 31 to allow the robot 31 to move along the track 17. Similarly, two wheels 37 are visibly provided on the longer side of the robot 31 in FIG. 4, while the other two wheels 37 are provided on the opposite longer side of the robot 31 (this side and the other two wheels 37 are not visible in FIG. 4). The wheels 37 engage with the track 19 and are rotatably mounted on the body 33 of the robot 31 to allow the robot 31 to move along the track 19.

[0009] The robot 31 further includes a container lifting tool 39 configured to raise and lower the container 9. The container lifting tool 39 shown includes four straps or spools 41 connected to a container engaging assembly 43 at its lower end. The container engaging assembly 43 includes an engaging tool configured to engage with features of the container 9 (for example, the engaging tool may be provided at the corners of the assembly 43, near the straps 41). For example, the container 9 may be provided with one or more holes on its upper side, and the engaging tool may engage with the holes. Alternatively or additionally, the engaging tool may be configured to hook under the edge or lip of the container 9, and / or clamp or grip the container 9. The straps 41 can be wound up or down as needed to raise or lower the container engaging assembly. One or more motors or other tools may be provided to effect or control the up or down winding of the straps 41.

[0010] As seen in FIG. 5, the body 33 of the illustrated robot 31 has an upper portion 45 and a lower portion 47. The upper portion 45 is configured to receive one or more operating components (not shown), and the lower portion 47 is disposed below the upper portion 45. The lower portion 47 includes a container receiving space or cavity for receiving at least a portion of the container 9 that has been elevated by the container lifting tool 39. The size of the container receiving space is designed such that the container 9 can be fully received within the cavity so that the robot 31 can move across the track structure 13 at the top of the storage structure 1 without the lower side of the container 9 catching on the track structure 13 or another part of the storage structure 1. When the robot 31 reaches its intended destination, the container lifting tool 39 controls the belt 41 to lower the container clamping assembly 43 and the corresponding container 9 from the cavity of the lower portion 47 to the intended position. The intended position can be the stack 11 of the containers 9 or the exit point of the storage structure 1 (or, if the robot 31 has moved and collected the containers 9 for storage in the storage structure 1, the entry point of the storage structure 1). Although in the illustrated embodiment, the upper and lower portions 45, 47 are separated by a physical separator, in other embodiments, the upper and lower portions 45, 47 may not be physically separated by a specific component or portion of the body 33 of the robot 31.

[0011] In some embodiments, the container receiving space of the robot 31 may not be within the body 33 of the robot 31. For example, in some embodiments, the container receiving space may be adjacent to the body 33 of the robot 31, such as in a cantilever arrangement, with the weight of the body 33 of the robot 31 balancing the weight of the container to be lifted. In such an embodiment, the frame or arm of the container lifting tool 39 may project horizontally from the body 33 of the robot 31, and the belt / spool 41 may be disposed at various positions on the projecting frame / arm and configured to be elevated and lowered from these positions to elevate and lower the container into the container receiving space adjacent to the body 33. The height at which the frame / arm is mounted on the body 33 of the robot 31 and the height at which it projects from the body 33 of the robot 31 can be selected to achieve the desired effect. For example, for the frame / arm, it is preferred to project at a high level of the body 33 of the robot 31 to allow a larger container (or plural containers) to be elevated into the container receiving space below the frame / arm. Alternatively, the frame / arm may be arranged to project at a lower level below the body 33 (but still at a height sufficient to accommodate at least one container between the frame / arm and the track structure 13) to maintain the center of gravity of the robot 31 when the robot 31 is loaded with a container.

[0012] To enable the robot 31 to move on different wheels 35, 37 in the first and second directions, the robot 31 includes a wheel positioning mechanism for selectively engaging the first set of wheels 35 with the first set of tracks 17 or engaging 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 along the first direction or the second direction on the tracks 17, 19 of the storage structure 1.

[0013] The wheel positioning mechanism may include one or more linear actuators, rotating components, or other tools for raising and lowering at least one set of wheels 35, 37 relative to the body 33 of the robot 31 to bring at least one set of wheels 35, 37 into contact with and out of contact with the tracks 17, 19. In some embodiments, only one set of wheels is configured to be raised and lowered, and the act of lowering one set of wheels can effectively lift the other set of wheels off the corresponding tracks, while the act of raising one set of wheels can effectively lower the other set of wheels into contact with the corresponding tracks. In other embodiments, both sets of wheels can be raised and lowered, which advantageously means that the body 33 of the robot 31 remains substantially at the same height. Therefore, the weight of the body 33 and the weight of the components mounted on the body 33 do not need to be lifted and lowered by the wheel positioning mechanism.

[0014] As shown in FIG. 3, a plurality of identical load handling devices 31 are provided so that each load handling device 31 can operate simultaneously to increase the throughput of the system. The system shown in FIG. 3 may include specific locations called ports where containers can be transported into or out of the system. An additional conveyor system (not shown) is associated with each port such that the container 9 transported to the port by the load handling device 31 can be transported by the conveyor system to another location, such as a picking station (not shown). Similarly, containers can be moved from an external location through the conveyor system to the port, such as to a container filling station (not shown), and transported by the load handling device 30 to the stack 12 to replenish the inventory in the system.

[0015] Each load handling device 31 can lift and move one container 9 at a time. If it is necessary to retrieve a container 9 that is not at the top of the stack ("target container" 9), the containers 9 stacked on top ("non-target containers" 9) must first be moved to access the target container. This is achieved in an operation hereinafter referred to as "digging". During the 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 an empty position within another stack 11. Then, the target container can be accessed by the load handling device 31 and moved to the port for further transportation.

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

[0017] The system described with reference to FIGS. 1 to 5 has many advantages and is suitable for a wide range of storage and retrieval operations. Specifically, it allows for very dense storage of products and provides a very economical way to store a large number of different items in containers while allowing reasonable and economical access to all containers when picking is required.

[0018] Referring to FIG. 6, the system may further include a robotic picking station, generally designated 50, which is mounted on top of the storage and retrieval structure 1 along with the load handling device 31 (not shown). The robotic picking station 50 includes a robotic manipulator 52 and a number of designated grid cells 60, 62. The robotic manipulator 52 includes a robotic arm 54 and an end effector 56 for releasably engaging a product to be manipulated. The robotic manipulator 52 is mounted on a base 58 above a single grid cell 60 and, depending on its position on the structure 1, the robotic manipulator 52 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 grid cell in the designated grid cells 62. The load handling device 31 then picks up the container 9 from the designated grid cells 62 and delivers the container 9 to the designated grid cells 62 as needed. In this way, the robotic picking station 50 and the load handling device 31 work together 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 (not shown), the vacuum source being in the form of a rotary vane pump. The vane pump forms part of a low pressure circuit configured to provide a vacuum pressure at the suction device 64 to enable it to attach to the product to be manipulated. Due to the size and weight of the vane pump, it is positioned away from the top of the storage and retrieval structure 1 so as not to occupy any grid cells. It is typically positioned at ground level where it can be easily accessed to make installation and maintenance easier. However, this arrangement also presents several problems. First, there is a risk of burns due to the heat generated during use when the vane pump is positioned at ground level. Second, since the distance between the vane pump and the suction device 64 can be on the order of several meters, large diameter vacuum lines 66 must be used to minimize the pressure drop between the vane pump and the suction device 64. However, to prevent the vacuum line 66 from collapsing due to the vacuum pressure, the vacuum line 66 must be reinforced to make it relatively rigid. Since the vacuum line 66 must be mounted on the robotic arm 54 to route it to the suction device 64, this reduces the dexterity of the robotic manipulator 52. Finally, since the vane pump is generally not suitable for operation below 5 degrees Celsius, it is not suitable for use in some environments, such as refrigerated areas.

[0019] It is in this context that the present invention has been devised. Summary of the Invention

[0020] Accordingly, in one aspect, there is provided a robotic picking station for use in a grid-based storage system. The robotic picking station includes a robotic manipulator and a low-pressure circuit. The robotic manipulator includes an adsorption device configured to releasably engage an item or product. The low-pressure circuit includes a vacuum source for providing a vacuum pressure at the adsorption device, wherein the vacuum source is mounted on the robotic manipulator. In the field of robotic manipulators, there is a generally accepted view that appliances, especially heavy and / or bulky items, should be avoided as much as possible on the robotic manipulator itself, as doing so can degrade the performance and dexterity of the manipulator. This is particularly discouraged when alternative options exist. Therefore, mounting the vacuum source on the robotic manipulator is counterintuitive and defies conventional knowledge and expectations.

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

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

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

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

[0025] Optionally, the robotic picking station further includes a support member mounted to the base, the support member being configured to carry the vacuum source.

[0026] Optionally, the vacuum source may be movable about a substantially horizontal axis of the robotic manipulator.

[0027] Optionally, the vacuum source is positioned on the robotic manipulator such that, in use, it can balance the load carried by the adsorption device.

[0028] Optionally, the robotic manipulator further includes a tool for adjusting the distance between the vacuum source and the substantially horizontal axis.

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

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

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

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

[0033] Optionally, the vacuum source includes a plurality of venturi vacuum generators, a supply manifold connectable to a pressure source, and a vacuum manifold fluidly connecting the plurality of venturi vacuum generators to the adsorption device.

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

[0035] Optionally, the low-pressure circuit further includes food-grade pipe fittings.

[0036] Optionally, the robotic picking station further includes a base for mounting the robotic manipulator to one or more frame members of a 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 the venturi vacuum generator via a tube, and wherein the base includes a movable bracket defining a conduit into which the tube is fed.

[0038] According to a second aspect, there is provided a grid-based storage and retrieval system including 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 to form a grid including a plurality of grid cells. The grid-based storage system further includes a frame structure and a robotic picking station according to the first aspect, the first set of tracks and the second set of tracks being received on the frame structure such that stacks of containers can be stored beneath each of the plurality of grid cells. Description of the Drawings

[0039] These and other aspects of the invention will now be described by way of example only with reference to the accompanying drawings, in which: FIG. 1 shows a schematic depiction of an automated storage and retrieval structure; FIG. 2 is a schematic depiction of a plan view of a section of the track structure forming part of the storage structure of FIG. 1; FIG. 3 shows a schematic depiction of a plurality of load handling devices moving on top of the storage structure of FIG. 1; FIGS. 4 and 5 show schematic depictions of load handling devices interacting with containers; FIG. 6 shows a schematic depiction of a known robotic picking station; Figure 7a and Figure 7b shows a schematic depiction of a robotic picking station according to an embodiment of the invention and a robotic manipulator used in the picking station; Figure 8 a and Figure 8 b are isometric depictions of a vacuum source used with the robotic picking station of FIG. 7; and Figure 9a and Figure 9b shows a schematic depiction of an alternative robot manipulator according to an embodiment of the present invention for use in the robotic picking station of FIG. 7.

[0040] In the drawings, like features are denoted by like reference numerals where appropriate. Detailed Description

[0041] The following description includes some specific details for a thorough understanding of the disclosed embodiments. However, those skilled in the art will understand that other embodiments may be practiced without one or more of these specific details, or with other components, materials, etc., and structural changes may be made without departing from the scope of the present invention as defined by the appended claims. Additionally, any terms with an orientation meaning mentioned in the following description are not intended to be limiting, but only refer to the orientation of the features shown in the drawings. In some cases, well-known features or systems (such as processors, sensors, storage devices, network interfaces, fasteners, electrical connectors, etc.) are not shown or described in detail to avoid unnecessary ambiguity in the description of the disclosed embodiments.

[0042] In this specification and the appended claims, unless the context otherwise requires, the word "comprising" and its related words, such as "comprises" and "comprising", are to be construed in an open, inclusive sense, meaning "including but not limited to".

[0043] In this specification, the use of "a", "an", or "another" for "embodiment" or "example" means that at least one embodiment, example, or instance includes the particular reference feature, structure, or characteristic described in relation to the embodiment, example, or instance. Thus, the appearances of "in one embodiment" or similar phrases in this specification do not necessarily all refer to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, examples, or instances.

[0044] It should be noted that in this specification and the appended claims, unless the context clearly dictates otherwise, the use of "a", "an", and "the" includes plural forms. It should also be noted that unless the context clearly provides otherwise, "or" generally is to be construed in its ordinary sense as "and / or".

[0045] Figure 7aFIG. 0 shows a schematic depiction of a robotic picking station 100 according to an 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 aforementioned known system. The robotic picking station 100 includes a base 104 on which a robotic manipulator 106 is mounted. The size and shape of the base 104 are such that it can be received within a hole 108 of a grid cell formed by intersecting horizontal members 5, 7. The base 104 is connected to the frame of the system 102 such that the arm of the robotic manipulator 106 is mounted on the frame. For example, the base 104 can be connected to one or more upright members 3 of the system 102. Alternatively or additionally, the base 104 can be connected to one or more horizontal members 5, 7 of the system 102. The surface of the base 104 can extend substantially over the entire area of the hole 108 of the grid cell in which it is received. This will reduce the risk that a dropped product may fall into the system 102 and thereby potentially interfere with its operation. Alternatively, the surface of the base 104 can only partially extend over the area of the grid cell in which it is received.

[0046] The robotic manipulator 106 includes 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 Figure 7b , in this embodiment of the robotic manipulator 106, the robotic arm 110 includes a base 114 and seven linkages, all of the linkages being connected by six joints. The base 114 extends substantially vertically from the base 104 and includes a lower base linkage 116 and an upper base linkage 118 connected by a base joint 120. The base joint 120 is configured to enable the upper base linkage 118 to rotate relative to the lower base linkage 116 about a substantially vertical axis 122. The upper base linkage 118 is rotatably connected to an upper arm linkage 126 by a shoulder joint 124, and the upper arm linkage 126 is rotatably connected to a lower arm linkage 128 by an elbow joint 130. The robotic arm 110 further includes a wrist 132 configured to hold the suction device 112 and a tool flange 134. The wrist 132 includes two wrist linkages 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 in six degrees of freedom, enabling the robotic arm 110 to engage a product stored in one container and move it to another container. Other robotic arms including more or fewer linkages and joints will be known to those skilled in the art.

[0047] The robotic picking station 100 further includes a low-pressure circuit 145 that includes a vacuum source 146 configured to provide vacuum pressure at the suction device 112. In this embodiment, the vacuum source 146 includes an array of venturi vacuum generators 148 (hereinafter referred to as "array 148") connectable to a pressure source 149 that supplies a pressurized air supply thereto. In this implementation, the array 148 includes four venturi vacuum generators 148. The pressure source can be a separate pump or a pressurized air reservoir configured to supply pressurized air to the facility in which the robotic picking station 100 is installed. The low-pressure circuit 145 further includes a flexible tube 150 and a vacuum filter 152. The flexible tube 150 extends between the vacuum side 151 of the array 148 and the suction device 112 for supplying vacuum pressure at the suction device 112, and the vacuum filter 152 is connected to the tube 150 between the array 148 and the suction device 112. The function of the vacuum filter 152 is to isolate debris picked up by the array 148 and the suction device 112. In this embodiment, the vacuum filter 152 is mounted on one of the wrist links 136 of the robotic arm 110 as close as possible to the suction device 112, subject to the configuration of the robotic arm 110 allowing it.

[0048] The array 148 is mounted on the robotic manipulator 106 and is movable relative to the lower base link 116, which is rigidly fastened to the base 104. In this embodiment, the array 148 is mounted on the upper base link 118, directly above the base joint 120 and as close as reasonably practicable to the vertical axis 122 so as to rotate with the upper base link 118 about a substantially vertical axis 122. Mounting the array 148 radially close to the vertical axis 122 minimizes its moment of inertia as the array 148 moves about the axis 122. The array 148 is fastened to a support 154, which in this embodiment takes the form of a platform 156 mounted to the upper base link 118. The platform 156 provides additional surface area to carry the array 148 compared to the upper surface of the upper base link 118, thus improving the load distribution on the base joint 120.

[0049] Refer to Figure 8 a and Figure 8b. The vacuum side 151 of the vacuum source 146 includes a vacuum manifold 158 that fluidly connects the array 148 to the tube 150 for supplying the vacuum pressure at the adsorption device 112. Similarly, the pressure side 160 of the vacuum source 146 includes a gas supply manifold 162 that can be connected to the tube 164 for supplying a pressurized gas stream from a pressure source to the array 148. The use of the manifolds 158, 162 reduces the need for additional fittings or tubes that would connect the pressure source and the vacuum source to the array 148, thereby minimizing the pressure drop between the pressure source and the gas supply manifold 162 and the vacuum loss in the low-pressure circuit 145. In addition, both the manifolds 158, 162 are configured to ensure a uniform mass flow rate in the array 148, thereby further minimizing the pressure loss and the vacuum loss in the array. The vacuum source 146 further includes a tube fitting 164 that connects the vacuum manifold 158 to the tube 150 of the low-pressure circuit 145. The tube fitting 164 is rotatably mounted to the vacuum manifold 158 by a bearing block (not shown). This enables the tube fitting 164 to rotate about an axis defined by the bearing block, thereby preventing the tube 150 from being over-tightened when the robotic arm 110 moves relative to the vacuum source 146.

[0050] Figure 9a and Figure 9b Another embodiment of the robotic manipulator 206 used in a robotic picking station according to the present disclosure is shown. This embodiment is substantially the same as the previous embodiment, except that the configuration of the robot 210 is slightly different, which enables the vacuum source 246 to be positioned on the robotic manipulator 206 to balance the load carried by the adsorption device 212 during use. Specifically, in this configuration of the robotic arm 210, the upper arm link 226 extends longitudinally on both sides of a substantially horizontal axis 223 defined by the shoulder joint 224, thereby providing a space for mounting the vacuum source 246 at the end 225 of the upper arm link 226 that is remote from the lower arm link 228. In this way, the vacuum source 246 can be used as a counterweight to leverage and reduce the force required for the robotic arm 210 to lift the load. To adjust the leverage to be more or less beneficial, the robotic manipulator further includes a tool for adjusting the distance between the vacuum source 246 and the horizontal axis 223. For this purpose, the vacuum source 246 can be mounted on a platform system that is configured to move towards or away from the horizontal axis 223. Alternatively, the vacuum source 246 can be mounted to a guide rail that extends in the direction of the horizontal axis 223. The distance between the vacuum source 246 and the horizontal axis 223 can be changed according to the load carried by the adsorption device. For example, for a light load or zero load, the vacuum source 246 will be moved as close as possible to the horizontal axis 223 to minimize the leverage. For a gradually increasing load, the distance between the vacuum source 246 and the horizontal axis 223 will increase in order to benefit from the leverage.

Claims

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

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

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

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

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

6. The robotic picking station according to claim 5, further comprising a support member mounted to the base, the support member being configured to carry the vacuum source.

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

8. The robotic picking station according to claim 7, wherein, The vacuum source is positioned on the robot manipulator so as to balance a load carried by the adsorption device during use.

9. The robotic picking station according to claim 8, wherein, The robot manipulator further includes a tool for adjusting the distance between the vacuum source and the substantially horizontal axis.

10. The robotic picking station according to any of the preceding claims, wherein, The low-pressure circuit further includes a vacuum filter positioned between the adsorption device and the vacuum source.

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

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

13. The robotic picking station according to any of the preceding claims, wherein, The vacuum source includes a Venturi vacuum generator connectable to a pressure source for supplying pressurized air to the Venturi vacuum generator.

14. The robotic picking station according to claim 13, wherein, The vacuum source includes a plurality of Venturi vacuum generators, a gas supply manifold connectable to the pressure source, and a vacuum manifold fluidly connecting the plurality of Venturi vacuum generators to the adsorption device.

15. The robotic picking station according to claim 14, wherein, The low-pressure circuit further includes a plurality of push-in type fittings.

16. The robotic picking station according to any of the preceding claims, wherein, The low-pressure circuit further includes food-grade pipe fittings.

17. The robotic picking station according to any of the preceding claims, further comprising a base for mounting the robotic manipulator to one or more frame members of the grid-based storage system such that the robotic manipulator is received within a single grid cell of the storage system.

18. The robotic picking station according to claim 17, which depends from claim 13 or any of its dependent claims, wherein, The pressure source is connectable to the Venturi vacuum generator by a pipe, and wherein the base includes a movable bracket defining a duct into which the pipe is fed.

19. A grid-based storage and retrieval system, comprising: 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 including a plurality of grid cells; A frame structure, the first set of tracks and the second set of tracks being received on the frame structure such that a stack of containers can be stored beneath each of the plurality of grid cells; and A robot picking station according to any one of claims 1 to 18.

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