Storage and Retrieval Systems

Abstract

A storage and retrieval system comprising a first zone (100) including a storage structure (1), the storage structure comprising a plurality of horizontal members arranged to form a grid pattern defining a plurality of grid cells, and a plurality of upright members (3) configured to support the horizontal members (5, 7) from below to define a storage area below the grid cells for storing stacks of storage containers (9), a second zone (200) separated from the first zone (100) by a divider (150), wherein the divider is The storage structure includes an opening (152) for fluidly connecting the first zone (100) to the second zone (200), a passageway (160) extending from an associated grid cell (14a) of the storage structure into the second zone (200) through the opening (152) in the partition (150) so that the storage container may be moved between the first zone (100) and the second zone (200) via the passageway (160), and a dehumidification system (300) configured to draw and dehumidify air from the second zone (200) and release the dehumidified air into the first zone (100).

Description

[Technical Field]

[0001] The present invention relates to a storage and retrieval system that includes a robotic load handling device that operates on a storage structure to handle storage containers stacked within the storage structure. [Background technology]

[0002] Some commercial and industrial activities require a system that allows for the storage and retrieval of a large number of different products. WO2015019055A1 describes a storage and retrieval system in which items are stored in storage containers, which are arranged in stacks within a storage structure. The system further includes remotely operated load handling devices configured to travel on tracks located above the storage structure. To pick up or drop off storage containers stored within the storage structure, each load handling device is equipped with a gripper device for releasably holding the storage container and a lifting assembly for raising and lowering the gripper device. To fulfill customer orders, storage containers containing ordered products are picked up from the storage structure and dropped off at a picking station, and the ordered products are removed from the storage containers and placed in a shipping container. The storage containers are then picked up from the picking station and returned to their storage locations within the storage structure. The picking station is typically located below or directly adjacent to a portion of the storage structure so that the storage containers can be efficiently moved between the storage structure and the picking station.

[0003] In the context of a grocery business, it is desirable to automate the storage and retrieval of a wide range of food products. While the above-mentioned storage and retrieval systems are commonly deployed for the storage and retrieval of ambient and refrigerated foods, there are challenges associated with automating the storage and retrieval of frozen foods, which require lower temperatures (typically -18°C or lower) than ambient and refrigerated goods for safe storage. For example, while the environment within an isolated freezer is relatively easy to control, a freezer section within a larger storage and retrieval system may be open to other sections of the system operating in different environments, and therefore the freezer section may be more difficult to control. There may also be issues regarding the comfort, health, and safety of human workers when working in freezing temperatures. Summary of the Invention

[0004] The present invention provides a storage and retrieval system comprising: a first zone comprising a storage structure; the storage structure comprising a plurality of horizontal members arranged to form a grid pattern defining a plurality of grid cells; and a plurality of upright members configured to support the horizontal members from below to define a storage area below the grid cells for storing a stack of storage containers; a second zone separated from the first zone by a partition, the partition having an opening such that the first zone is in fluid communication with the second zone, a passageway extending from an associated grid cell of the storage structure into the second zone through the opening in the partition such that storage containers may be moved between the first zone and the second zone via the passageway; and a dehumidification system configured to draw and dehumidify air from the second zone and release the dehumidified air into the first zone.

[0005] The storage and retrieval system further includes a temperature control system configured to maintain a first air temperature in the first zone and a second air temperature in the second zone. The second temperature may be higher than the first air temperature. This is particularly advantageous because it allows human workers to work at a comfortable temperature in the second zone, separate from the first zone. Dry air output from the dehumidification system may be pumped to the second zone.

[0006] The first air temperature may be from -30°C to 0°C. The first air temperature may be from -30°C to -18°C.

[0007] The second air temperature may be between -10°C and +8°C. The second air temperature may be between -10°C and 0°C, for example about -5°C.

[0008] The temperature control system may include a cooling system for maintaining a first air temperature in the first zone.

[0009] The temperature control system may include a heating system configured to maintain a second air temperature in the second zone.

[0010] Optionally, the dehumidification system may comprise a dehumidifier unit in a first zone and a dehumidifier unit in a second zone.

[0011] The dehumidification system may be configured to dehumidify the air drawn from the second zone such that the dew point of the discharged air is lower than the first air temperature.

[0012] The dehumidification system may be configured to release dehumidified air into the first zone at a rate such that a positive air pressure is created in the first zone relative to the second zone.

[0013] The dehumidification system may be further configured to draw air from the passageway, dehumidify the air drawn from the passageway, and discharge the dehumidified air into the first zone.

[0014] The dehumidification system may be configured to draw and mix air from the passageway with air from the second zone in a predetermined ratio. For example, 10% to 30% (e.g., about 20%) of the air drawn by the dehumidification system may be from the passageway. Thus, 90% to 70% (e.g., about 80%) of the air drawn by the dehumidification system may be from the second zone.

[0015] The second zone may be below at least a portion of the first zone. The second zone may be below at least a portion of a storage structure within the first zone. The aisle may extend vertically from its associated grid cell into the second zone. The divider may be a horizontal divider (e.g., a floor).

[0016] The second zone may be horizontally adjacent to the first zone. The aisle may extend vertically from its associated grid cell and then horizontally (or in a direction between vertical and horizontal) into the second zone. For example, the aisle may comprise an L-shaped aisle so that containers can be moved vertically in the vertical portion of the aisle and horizontally in the horizontal portion of the aisle. The horizontal portion of the aisle may extend from the vertical portion of the aisle by the length of at least one storage container. The divider may be a vertical divider.

[0017] The second zone may include a container station for receiving storage containers so that items can be moved into or out of the individual storage containers. A corridor may extend from its associated grid cell to the container station, whereby the storage containers can be moved between the storage structure and the container station via the corridor.

[0018] The aisle may be at least partially defined by a chute. The chute may be formed from a vertical portion of the aisle. The chute is positioned within the second zone. The chute may extend from the divider into the second zone, for example, to a container station. The aisle may include a horizontal portion communicating with the vertical portion of the aisle. The horizontal portion includes a conveyor extending from the vertical portion to an inventory handling processing station. The horizontal portion may extend a distance equal to the length of at least one storage container, for example, two, three, four, or five storage containers. In this context, "length" is defined as the longest side of a storage container. Thus, multiple storage containers can be accommodated within the aisle.

[0019] The passageway may comprise a barrier for selectively opening and closing the passageway. The barrier may open and close horizontally. In particular, the barrier may open and close horizontally within a vertical portion of the passageway. The barrier may open and close vertically. In particular, the barrier may open and close vertically within a horizontal portion of the passageway.

[0020] The barrier may include at least one door movable between a closed configuration for preventing ingress of warm air from the second zone into the first zone and an open configuration for allowing one or more storage containers to move through the passageway between the first zone and the second zone. The at least one door may be a roller door, a segmented door, or a tilt door.

[0021] Alternatively or additionally, the barrier may comprise an air curtain unit for providing an air curtain across the passage opening.

[0022] At least a portion of the passageway may be surrounded by insulation. The insulation may extend from the partition to the barrier. The barrier may be bonded to the insulation on one side. The insulation may comprise silica aerogel. The first zone may be an enclosed area.

[0023] The first zone may comprise a floor, a plurality of walls, and a ceiling to define an enclosed area. The second zone may be an enclosed area. The second zone may comprise a floor, a plurality of walls, and a ceiling to define an enclosed area.

[0024] The storage and retrieval system may include a plurality of aisles. The divider may include a plurality of openings. Each aisle may extend from an associated grid cell through a respective opening into the second zone.

[0025] The storage structure may further include a track structure located on top of the horizontal members. The track structure may further include a plurality of tracks arranged to form a grid pattern corresponding to the grid pattern formed by the horizontal members.

[0026] The storage and retrieval system may further comprise one or more cargo handling devices.

[0027] Each load handling device is a drive assembly configured to move the load handling device on the track structure; a container retention assembly configured to releasably retain a storage container from above; and a lifting assembly configured to raise and lower the container holding assembly and enable the load handling device to raise and lower storage containers through the grid cells and into and out of the storage structure and aisles. [Brief explanation of the drawings]

[0028] The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a schematic side view of a storage and retrieval system comprising a first zone and a second zone. [Figure 2] FIG. 2 is a schematic perspective view of a storage structure located in a first zone, with containers disposed within the storage structure and a load handling device located on top of the storage structure. [Figure 3] FIG. 3 is a schematic plan view of the track structure above the storage structure. [Figure 4] FIG. 4 is a schematic perspective view of a load handling device with a container retention assembly in a position below the bottom of the load handling device. [Figure 5] FIG. 5 is a schematic perspective view of the load handling device of FIG. 4, with the side portions of the outer body omitted from the view to show the container receiving space. [Figure 6] FIG. 6 is a schematic perspective view of the load handling device of FIG. 5, with a container occupying the container receiving space. [Figure 7] FIG. 7 is a schematic diagram of a storage and retrieval system showing a first zone, a second zone, and a dehumidification system. [Figure 8] FIG. 8 is a schematic side view of a storage and retrieval system with a first zone and a second zone in an alternative arrangement to that shown in FIG. [Figure 9] FIG. 9 is a schematic side view of a storage and retrieval system with a first zone and a second zone in an alternative arrangement to that shown in FIG. [Figure 10] 10(a, b, c) are schematic side views of double doors in a passageway between a first zone and a second zone in (a) a closed configuration, (b) a partially open configuration, and (c) an open configuration. [Figure 11] 11(a, b, c) are schematic side views of a tilting door in the horizontal portion of the passageway between the first and second zones in (a) a closed configuration, (b) a partially open configuration, and (c) an open configuration. [Figure 12] 12(a, b, c) are schematic side views of a horizontally segmented door in a horizontal portion of a passageway between a first zone and a second zone in (a) a closed configuration, (b) a partially open configuration, and (c) an open configuration. DETAILED DESCRIPTION OF THE INVENTION

[0029] 1 shows a schematic side view of a storage and retrieval system for storing and retrieving frozen goods (e.g., frozen groceries) held in storage containers 9. The storage and retrieval system comprises a first zone 100 for storing storage containers within a storage structure 1 and a second zone 200 for accessing individual storage containers that have been removed from the first zone 100 and / or that are to be moved into the first zone 100.

[0030] FIG. 2 illustrates an exemplary storage structure 1 for storing storage containers 9 within a first zone 100. FIG. 1 includes a framework comprising upright members 3 and horizontal members 5, 7 supported by upright members 3. Horizontal members 5 extend parallel to each other and to the illustrated x-axis. Horizontal members 7 extend parallel to each other and to the illustrated y-axis and transverse to horizontal members 5. 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.

[0031] The storage structure 1 defines a storage space beneath the horizontal members 5, 7 comprising a plurality of storage columns, each located beneath a respective grid cell 14. Each storage column can accommodate a vertical stack 11 of storage containers. Beneath one or more other grid cells 14a (shown in FIG. 1), hereinafter referred to as "port cells" 14a, the storage structure 1 further defines port columns, each located beneath a respective port cell 14a. Each port column at least partially defines a passageway 160 for allowing storage containers 9 to be transported between the storage structure 1 in the first zone 100 and a container station 202 in the second zone 200, as shown in FIG. 1.

[0032] The second zone 200 includes one or more container stations 202. Each container station 202 is configured to receive storage containers 9 and individually present them so that items can be moved into or out of the storage containers 9. One exemplary type of container station 202 is a picking station, where storage containers 9 are received from the storage structure 1 and customer orders are prepared by picking items from the storage containers 9 and placing them into shipping containers, such as containers or bags. Another exemplary type of container station 202 is a stock station, where items are placed into empty storage containers 9 for storage in the storage structure 1. Other examples of container stations 202 at which storage containers 9 are received from and / or moved into the storage structure are also possible. The second zone 200 may include a single type of container station 202 or multiple types of container stations 202.

[0033] In the illustrated example shown in FIG. 1 , the second zone 200 is located directly below the overhead portion of the storage structure 1 and is separated from the first zone 100 by a partition 150. More specifically, the storage and retrieval system comprises a horizontal base floor 148 that defines the floor of the first zone 100 and the floor of the second zone 200, with the partition 150 being in the form of a horizontal mezzanine located above the base floor 150. The main portion of the storage structure 1 is supported on the base floor 148, and the overhead portion is supported on the mezzanine floor 150. The second zone 200 may be further separated from the first zone 100 by one or more vertical walls to define an enclosed area. The first zone 100 may also comprise walls and a ceiling to define an enclosed area around the storage structure 1.

[0034] As mentioned above, the storage and retrieval system includes one or more aisles 160 to enable transport of storage containers 9 between the storage structure and the container station 202. Each aisle 160 extends vertically downward from its associated port cell 14a through an opening 152 in the mezzanine floor 150 to the container station 202.

[0035] Each container station 202 may have one or more aisles 160 leading to it. In FIG. 1 , the illustrated container station 202 has two aisles 160 leading to it: a drop-off aisle 160a, through which storage containers 9 are moved from the storage structure 1 to the container station 202, and a pickup aisle 160b, through which the storage containers 9 are moved from the container station 202 to the storage structure 1. In the context of a picking station, the drop-off aisle 160a may be used to drop off storage containers 9 containing products ordered by customers, and the pickup aisle 160b may be used to pick up the storage containers 9 after the products have been removed from the storage containers 9 for returning the storage containers 9 to the storage structure 1. The container station 202 may include one or more conveyors for moving the storage containers 9 between the drop-off aisle 160a and the pickup aisle 160b. Other container stations 202 may have only one aisle 160 leading to it. For example, a stock station may have only a pickup aisle 160b leading to it to allow a storage container 9 that has just been filled with new stock to be moved into the storage structure 1. Other configurations of aisles 160 for each container station 202 are possible. Each container station 202 may have one or more aisles 160 associated with it, each of which may be a different type of aisle 160, for example, a drop-off aisle, a pickup aisle, or an aisle that functions as a combination drop-off aisle and pickup aisle. To increase throughput, a container station 202 may have multiple aisles 160 of a particular type associated with it.

[0036] Each aisle 160 may be defined at least in part by a chute 162, i.e., a tubular structure that surrounds the aisle 160. Each chute 162 is preferably located within the second zone 200, e.g., between the mezzanine floor 150 and the container station 202, as shown in FIG. 1, but may also extend entirely between the port cell 14a and the container station 202.

[0037] 2, storage containers 9 are moved between the storage structure 1 and the container station 202 using a load handling device 25, hereafter referred to as a "bot," that operates on top of the storage structure 1. In particular, the bot 25 travels on a track on top of the storage structure 1 and is configured to raise and lower storage containers through the grid cells 14, as will be described in further detail herein.

[0038] FIG. 3 shows an enlarged plan view of a section of a track structure 13 that forms part of the storage structure 1 illustrated in FIG. 1 and is located on top of the horizontal members 5, 7 of the storage structure 1 illustrated in FIG. 2. 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 comprises 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 apertures 15 in the centers of the grid cells 14. The apertures 15 are sized to allow storage containers 9 located below the grid cells to be lifted and lowered through the apertures 15. 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 structure are possible. To enable the bot 25 to move across the track structure 13 and reach a particular grid cell 14, the bot 25 is provided with a set of wheels for engaging with the corresponding x-direction track 17 or y-direction track 19. The illustrated pairs of tracks 17, 19 separated by channels 21, 23 allow the bots 25 to occupy (or pass each other through) neighboring grid cells 14 without colliding with each other.

[0039] 4, the bot 25 comprises an outer body 27 having one or more components therein or attached thereto that enable the bot 25 to perform its intended functions. These functions may include moving throughout the storage structure 1 on the track structure 13 and raising or lowering containers 9 through the grid cells 14 so that the bot 25 can retrieve or place storage containers 9 at specific locations defined by the grid pattern.

[0040] The illustrated bot 25 includes a first set of wheels 29 and a second set of wheels 31 attached to the outer body 27 of the bot 25, allowing the bot 25 to move in the x and y directions along tracks 17 and 19, respectively. In particular, two wheels 29 are provided on the short side of the bot 25 visible in FIG. 4, and two additional wheels 29 are provided on the opposite short side of the bot 25. The wheels 29 engage with the tracks 17 and are rotatably attached to the outer body 27 of the bot 25, allowing the bot 25 to move along the tracks 17. Similarly, two wheels 31 are provided on the long side of the bot 25 visible in FIG. 4, and two additional wheels 31 are provided on the opposite long side of the bot 25. The wheels 31 engage with the tracks 19 and are rotatably attached to the outer body 27 of the bot 25, allowing the bot 25 to move along the tracks 19.

[0041] To enable the bot 25 to move in first and second directions on different wheels 29, 31, the drive assembly further includes a wheel positioning mechanism (not shown) for selectively engaging the first set of wheels 29 with the first set of tracks 17 or the second set of wheels 31 with the second set of tracks 19. The wheel positioning mechanism is configured to raise and lower the first set of wheels 29 and / or the second set of wheels 31 relative to the outer body 27, thereby enabling the load handling device 25 to selectively move in either the first direction or the second direction across the tracks 17, 19 of the storage structure 1.

[0042] 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 29, 31 relative to the outer body 27 of the bot 25 to move at least one set of wheels 29, 31 out of and into contact with the tracks 17, 19. In some examples, only one set of wheels is configured to raise and lower, such that the act of lowering one set of wheels can effectively lift the other set of wheels away from 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 examples, both sets of wheels may be raised and lowered, which advantageously means that the outer body 27 of the bot 25 remains at substantially the same height, and therefore the weight of the outer body 27 and components mounted thereon does not need to be raised and lowered by the wheel positioning mechanism.

[0043] The bot 25 also includes a lifting assembly 33 and a container retention assembly 37 configured to raise and lower the storage container 9. The illustrated lifting assembly 33 includes four tethers, which are connected at their lower ends to the container retention assembly 37. The tethers 35 may be in the form of cables, ropes, tapes, or any other form of tether that has the necessary physical properties to lift the storage container 9. The container retention assembly 37 includes a gripping mechanism 39 configured to engage features of the storage container 9 to releasably hold the container 9 from above. In the example shown, the gripping mechanism 39 includes legs that can be received in corresponding apertures 10 in the rim of the storage container 9 and then moved outward to engage the underside of the rim of the storage container 9. The tether 35 can be reeled in or unreeled as needed to raise or lower the container retention assembly 37. One or more motors and winches or other means can be provided to effect or control the reeling in or unreeling of the tether 35.

[0044] 5 and 6, the sides of the external body 27 of the bot 25 are omitted from the illustration so that the interior of the bot 25 can be seen. The external body 27 of the illustrated bot 25 has an upper portion 41 and a lower portion 43. The upper portion 41 is configured to house or support one or more operating components (not shown), such as components of the lifting assembly 33 (e.g., motors), wireless communication components, and a bot control system including one or more processors for controlling the operation of the bot 25. The lower portion 43 is disposed below the upper portion 41. The lower portion 43 opens to the outside at the bottom and defines a container receiving space 45 for housing at least a portion of a storage container 9 lifted into the container receiving space 45 by the lifting assembly 33. FIG. 5 shows the container receiving space 45 before it is occupied by the storage container 9, and FIG. 6 shows the container receiving space 45 after it is occupied by the storage container 9. The container receiving space 45 is sized so that the storage container 9 can fit sufficiently within the cavity 45 to allow the bot 25 to move across the track structure 13 on top of the storage structure 1 without the underside of the storage container 9 getting caught on the track structure 13 or another portion of the storage structure 1. When the bot 25 reaches its intended destination, the lifting assembly 33 controls the tether 35 to lower the container retention assembly 37 and corresponding storage container 9 out of the container receiving space 45 and to its intended location. In the illustrated example, the upper and lower portions 41 and 43 are separated by a physical partition, but in other examples, the upper and lower portions 41 and 43 may not be physically separated by a particular component or part of the outer body 27 of the bot 25. The upper and lower configuration of the bot 25 allows the bot 25 to occupy only a single grid cell 14 on the track structure 13 of the storage system 1.

[0045] In an alternative example, the container receiving space 45 of the bot 25 may not be within the outer body 27 of the bot 25. For example, the container receiving space 45 may instead be adjacent to the outer body 27 of the bot 25, e.g., in a cantilever arrangement with the weight of the outer body 27 of the bot 25 balancing the weight of the container 9 being lifted. In such an embodiment, the frame or arms of the lifting assembly 33 may protrude horizontally from the outer body 27 of the bot 25, and the tethers 35 may be disposed at respective positions on the protruding frames / arms and configured to be raised and lowered from those positions to raise and lower the storage container 9 into the container receiving space 45 adjacent the outer body 27.

[0046] To transport a storage container 9 from a stack 11 in the storage structure 11 to a container station 202, the bot 25 uses its container holding assembly 37 and lifting assembly 33 to pick up the storage container 9 from the top of the stack 11, move along the track structure 13 to the port cell 14a, lower the storage container 9 through the port cell 14a and into the aisle 160, and then release the storage container 9 at the container station 202. To transport a storage container 9 from the container station 202 to a stack 11 in the storage structure 11, the operations are reversed; i.e., the bot 25 lowers its container holding assembly 37 through the port cell 14a and into the aisle 160, picks up the storage container 9 at the container station 202, lifts the storage container 9 through the aisle 160 and the port cell 14a, and then moves along the track structure 13 to place the storage container 9 on top of the stack 11.

[0047] Instead of bots 25 moving storage containers 9 along the entire length of aisles 160, one or more aisles 160 may contain container lifts for vertically transporting storage containers 9 within at least a portion of aisles 160. For example, to transport a storage container 9 from storage structure 1 to container station 202, bots 25 may lower the storage container 9 partway down aisle 160 and release it onto the container lift. The lift may then travel downward within aisle 160 to transport the storage container 9 the remaining way to container station 202. Similarly, to transport a storage container 9 from container station 202 to storage structure 1, the lift may receive the storage container 9 at container station 202 and travel upward within aisle 160 to a predetermined position along aisle 160, from which a bot 25 can pick up the storage container 9 and lift it the remaining way out of aisle 160.

[0048] FIG. 7 shows a schematic diagram of a storage and retrieval system including a first zone 100, a second zone 200, and a dehumidification system 300. As previously described, the storage and retrieval system can be used to store and retrieve frozen goods. The storage and retrieval system includes a temperature control system for regulating the air temperature in the first zone 100 and the second zone 200. The temperature control system includes a cooling system 320 having one or more cooling units 322 with appropriate control systems and a temperature sensor for maintaining the air temperature in the first zone 100 at a control temperature (set point) suitable for freezing food products, e.g., below 0°C. For food safety reasons, the control temperature in the first zone 100 is preferably below about -18°C, e.g., -30°C to -18°C.

[0049] The passageway 160 allows the storage containers 9 to be efficiently transported between the first zone 100 and the second zone 200 and, for efficiency, is preferably always open, at least during operating hours. However, this means that air can flow between the first zone 100 and the second zone 200 through the opening 152 in the partition 150, i.e., the first zone 100 and the second zone 200 are in fluid communication through the opening 152. Thus, the air temperature in the second zone 200 may reach a temperature similar to that in the first zone 100 in the absence of heating. Considering that human workers may be present in the second zone 200 to work, for example, at the container station 202, it is preferable that the air temperature in the second zone 200 be higher than that in the first zone 100 to provide a more comfortable working environment for the human workers.

[0050] Some heating of the second zone 200 may occur during operation (i.e., when the container station 202 is in operation) due to heat emitted from equipment (e.g., lights, motors, etc.) within the second zone 200. Heat may also enter the second zone 200 whenever any door between the second zone 200 and a warmer area of ​​the storage and retrieval system is opened. If this heat is not sufficient or reliable to heat the second zone 200 to a more comfortable working temperature, the temperature control system may further comprise a heating system 330 comprising at least one heating unit 332 and an appropriate control system with appropriate temperature sensors for maintaining the air temperature within the second zone 200 at a specified control temperature (set point) higher than the control temperature within the first zone 100. To balance energy efficiency and comfort, the control temperature of the second zone 200 is preferably −10° C. to +8° C., preferably −10° C. to +5° C., preferably −10° C. to 0° C., preferably about −5° C. To improve the energy efficiency of the heating system 330, the heat source is preferably derived from waste heat generated by the cooling system 320, or a heat pump can be used.

[0051] During operation of the storage and retrieval system, water vapor within the second zone 200 may increase. This may be due, for example, to the presence of human workers working in the second zone 200. Additionally, the second zone 200 may include one or more access doors to allow access between the second zone 200 and other areas of the storage and retrieval system. Whenever an access door is opened, moist air may enter the second zone 200 from these other areas. For example, the second zone 200 may be adjacent to a third zone that may be operated at a higher temperature than the controlled temperature of the second zone 200. For example, the third zone may be operated at a temperature suitable for storing and / or handling refrigerated goods (i.e., goods that must be stored at refrigerated room temperatures), e.g., 0°C to 8°C, preferably 0°C to 5°C. In another example, the temperature of the third zone may be operated at a temperature suitable for storing ambient goods (i.e., goods that can be safely stored at room temperature), e.g., approximately 15°C to 25°C. The third zone may have a cooling, heating or air conditioning system as appropriate to maintain the third zone at a controlled temperature according to its use.

[0052] Given that there is fluid communication between the first zone 100 and the second zone 200 via the opening 152, warmer, humid air from the second zone 200 will tend to flow into the cooler first zone 100 via the opening 152. If the relative humidity of the air in the second zone 200 is high enough, there is a risk of condensation occurring within the first zone 100 due to the air temperature in the first zone 100 being lower than the dew point of the air entering the first zone 100 from the second zone 200. Due to the freezing air temperature in the first zone 100, any condensation that occurs within the first zone 100 may result in the undesirable formation of frost or ice on the walls and equipment within the first zone 100.

[0053] To mitigate condensation, the storage and retrieval system further includes a dehumidification system 300. The dehumidification system 300 includes a dehumidifier unit 302 configured to draw air from the second zone 200, dehumidify (i.e., remove moisture from) the air drawn from the second zone 200, and release the dehumidified air into the first zone 100. The dehumidification system 300 may include ducts configured to direct air from one or more inlets of the second zone 200 to the dehumidifier unit 302 and ducts configured to direct air from the dehumidifier unit 302 to one or more outlets of the first zone 100. Air may be drawn in and released using one or more fans. The inlets of the second zone 200 and the outlets of the first zone 100 may be located near the walls or ceilings of the second zone 200 and the first zone 100, respectively, for example.

[0054] The dehumidifier unit 302 may be any suitable type of dehumidifier for operation at low temperatures (e.g., below 0°C), such as a dry dehumidifier. Dry dehumidifiers typically operate by passing a moist process air stream through a desiccant (e.g., silica gel), which absorbs moisture from the passing process air stream. To regenerate the desiccant (i.e., remove the absorbed moisture), the regeneration air stream is heated and passed through the desiccant, and the absorbed moisture is drawn into the regeneration air stream, which is then released, for example, to the exterior of a building. To operate a dry dehumidifier continuously, the desiccant is typically housed in a rotating wheel, with one portion of the wheel passing through the process air stream and another portion of the wheel passing through the regeneration air stream. If the dehumidifier unit 302 is a dry dehumidifier, the regeneration air stream may originate from a warmer area of ​​the storage and retrieval system, e.g., a room-temperature area, to improve energy efficiency. The dehumidification system 300 or the dehumidifier unit 302 itself may optionally include a cooling unit for cooling the process air (before or after the drying process). This is because the drying process within the dry dehumidifier typically results in heat being transferred to the process air stream, which may be undesirable given that the dehumidified air will be discharged into the first zone 100, which is operating at a lower temperature.

[0055] The dehumidifier unit 302 is configured to dehumidify the air drawn from the second zone 200 so that the dew point of the air discharged into the first zone 100 is lower than the control temperature of the first zone 100. As a safety margin, the dew point of the discharged air is preferably at least 2 to 3°C lower than the control temperature of the first zone 100. Considering that the cooling unit 322 of the cooling system 320 may be outputting air slightly cooler than the control temperature in the first zone 100 to maintain the air temperature at the setpoint, the dew point of the discharged air is preferably lower than the temperature of the air output by the cooling unit 322 to minimize the risk of ice forming on and near the cooling unit 322. Therefore, as an additional safety margin, the dew point of the discharged air is preferably at least 2 to 3°C lower than the temperature of the air output from the cooling unit 320. The temperature of the air output from the cooling unit 322 may be measured with a temperature sensor or a static expected value may be assumed.

[0056] To dehumidify the air drawn from the second zone 200 to a specific dew point, the dehumidification system 300 includes a control system that includes a humidity sensor (e.g., a capacitive or resistive humidity sensor) for measuring relative humidity and a temperature sensor for measuring air temperature. The control system further includes a controller for calculating the dew point based on these measurements using a known equation relating dew point, relative humidity, and temperature, such as the Magnus equation or the Ardenbach equation. The controller can then control the operation of the dehumidifier unit 302 (i.e., control parameters of the dehumidifier unit 302 to increase or decrease moisture absorption) to maintain the dew point of the discharged air at a specific set point. Alternatively, the control system may be configured to control the operation of the dehumidifier unit 302 to maintain the relative humidity of the discharged air at a specific set point that results in a dew point lower than the control temperature of the first zone 100 (based on previously performed calculations).

[0057] The airflow rate of the dehumidifier unit 302 (i.e., the rate at which air is drawn through and expelled from the dehumidifier unit 302) is preferably high enough to overcome the air vapor pressure of the air in the second zone 200, thereby minimizing the ingress of air from the second zone 200 into the first zone 100 through the opening 152. In other words, the dehumidifier airflow rate is preferably high enough to create a positive pressure in the first zone 100 relative to the second zone 200, substantially preventing air from flowing from the second zone 200 into the first zone 100 through the opening 152. The required airflow rate can be determined by calculating the theoretical flow rate at which air would flow from the second zone 200 into the first zone 100 through the opening 152 due to the temperature difference between the first and second zones 100 and 200. This velocity can be calculated or approximated based on the total area of ​​the openings 152 between the first zone 100 and the second zone 200 (i.e., the total number of openings 152 multiplied by the area of ​​each opening 152) and the air velocity value as a function of the temperature difference between the two areas.

[0058] To provide a sufficiently high air flow rate and / or to provide redundancy in the event of a dehumidifier unit failure, the dehumidification system 300 may include multiple dehumidifier units 302 configured to draw air from the second zone 200, dehumidify the air drawn from the second zone 200, and release the dehumidified air into the first zone 100.

[0059] In addition to drawing air from the second zone 200, the dehumidifier unit 302 may be further configured to draw air from the passages 160, for example, near the openings 152. Drawing air from the passages 160 helps increase the effect of positive pressure in the first zone 100, thereby further minimizing the risk of air from the second zone 200 infiltrating into the first zone 100 through the openings 152. The passages 160 are also the closest point at which air from the second zone 200 can enter the first zone 100; therefore, drawing air from the passages 160 further reduces the risk of air intrusion. The dehumidification system 300 may include ducts configured to direct air from each passage 160 to the dehumidifier unit 302. For example, each chute defining a passage 160 may include a notch, and the duct may connect to the chute 162 at the notch. The dehumidification system 300 is preferably configured to mix air from the second zone 200 with air from the passageway 160 and draw the mixed air through the dehumidifier unit 302. The dehumidification system 300 may draw air from the passageway 160 and air from the second zone 200 in a predetermined ratio. The proportion of mixed air drawn from the passageways 160 is preferably 10% to 30%, for example about 20%. The dehumidification system 300 may include an air damper 304 (e.g., a volume control damper) for controlling the proportion of air drawn from the passageways 160 and the second zone 200, so that the air is mixed according to a predetermined proportion. If the dehumidification system 300 includes multiple dehumidifier units 302, each dehumidifier unit 302 may be configured to draw and dehumidify air from a subset of the passageways 160.

[0060] Each aisle 160 may also include a barrier 164 for selectively blocking and opening the aisle 160, such that when the barrier 164 is closed, airflow through the aisle 160 is reduced or substantially blocked. The barrier 164 may include any suitable mechanism that allows it to be selectively opened and closed, such as a hinge or sliding mechanism, and may be manually operated or automated using an actuator and controller. The example barrier 164 shown in FIGS. 10(a-c) includes at least one door that is rotatable between a closed configuration (see FIG. 10a) to prevent cool air from the first zone 100 from entering the second zone 200 and an open configuration (see FIG. 10b) to allow one or more storage containers to move through the aisle as they move between the first zone 100 and the second zone 200. Actuators known in the art, such as a linear solenoid, may be used to rotate the at least one door between the open and closed configurations. In certain embodiments of the present invention, at least one door comprises two doors or double doors or two leaves 166, where one of the leaves rotates clockwise and the other rotates counterclockwise to move the double doors between open and closed configurations. The at least one door comprises suitable insulation to prevent or at least limit heat transfer from the second zone to the first zone when the at least one door is in the closed configuration. For example, the door may comprise an insulating jacket. In the particular example shown in Figures 10(a-c), each of the two leaves comprises an upper side and a lower side. The upper side of each leaf comprises insulation 168. The lower side of each leaf comprises tote guides 170 such that the lower side of the door functions to guide the storage container 9 through the passageway 160 when the at least one door is in the open configuration, as shown in Figure 10c, i.e., in a substantially vertical orientation. In the particular embodiment shown in Figure 10c, the double doors 164 function to allow the storage container to move up and down the aisle between the first zone 100 and the second zone 200. To guide the storage container when the double doors are in the open configuration, the underside of the doors includes 90° guide plates for cooperating with the corners of the storage container.The barrier 164 may be a completely separate object that can be manually inserted and removed from the aisle 160 to substantially block or open the aisle 160. The barrier 164 may comprise a thermal insulating material, such as polymer foam. The barrier 164 may be located within the second zone 200, for example, at or near the end of the aisle 160 where it enters the container station 202. The purpose of the barrier 164 is to help prevent cold air from the first zone 100 from entering the second zone 200 via the aisle 160 when the second zone 200 is not operating, i.e., when the container station 202 is not operating, for example, during system downtime. This is particularly important when the container station 202 in the second zone 200 is not operating, for example, at night. Thus, heat loss from the second zone 200 during non-operating periods can be minimized, which helps minimize the energy cost of the heating system 330 to maintain the second zone 200 at its controlled temperature when the second zone 200 is not operating, or to raise the second zone 200 to a certain temperature if the heating system 330 is switched off during non-operating periods.

[0061] The barrier shown in Figures 10(a-c) opens and closes horizontally. However, it is also possible to open and close the barrier vertically, as shown in Figures 11(a-c) and 12(a-c). In Figures 11(a-c) and 12(a-c), the barrier 164 is positioned within the horizontal portion of the aisle 160. If one or more conveyors 182 are present within the horizontal portion of the aisle 160, as shown in Figures 11(a-c) and 12(a-c), the barrier 164 is positioned between adjacent conveyors when the barrier 164 is in the closed configuration. Alternatively, the base of the barrier 164 may rest on the conveyors 182 when the barrier 164 is in the closed configuration.

[0062] Each barrier in Figures 11(a-c) and 12(a-c) comprises a single vertically opening door or door assembly 180, 190 movable between a closed configuration (see Figures 11(a) and 12(a)) to prevent cool air from the first zone 100 from entering the second zone 200, and an open configuration (see Figures 11(c) and 12(c)) to allow one or more storage containers to move (horizontally) through the aisle 160 when moving between the first zone 100 and the second zone 200. In the open configuration, the door 180, 190 is positioned to extend in a direction perpendicular to the direction the door extends when in the closed position. In other words, the doors 180, 190 are positioned horizontally above the aisle 160 when the doors are in the open configuration, allowing one or more storage containers to move directly underneath the open doors and through the aisle 160 when moving between the first zone 100 and the second zone 200.

[0063] FIGS. 11(a) through 11(c) show a barrier 164 with a tilt-up and down door 180. The door 180 is positioned within a door frame 181. The door frame may include thermal insulation, for example, one side of the door frame may include silica aerogel. The door frame 181 extends along the top of the door 180 and along the vertical sides of the door 180 when the door is in the closed configuration, as shown in FIG. 11(a). The door 180 moves along a pair of horizontal guides 183. Movement of the door may be facilitated by a resilient member. In FIGS. 11(a) through 11(c), the resilient members are two tension springs 184, which are extended to their maximum length when the door 180 is in the closed configuration, as shown in FIG. 11(a). The bottom of the tension springs 184 is held stationary, and the tops of the springs are each fixed to one of two lever arms 186. Each lever arm 186 is connected to the door 180 by a connecting piece 188, allowing the lever arm 186 to pivot about the connecting piece at or near the bottom of the door 180. When the door is actuated open, a motor (not shown) cycles a belt drive 189. One end of the arm 185 is attached to the top of the door 180 and the other end is attached to a drive belt 189. As the drive belt cycles, the arm 185 moves to pull the door 180 into the open configuration (as shown in FIG. 11(c)), and the tension spring 184 contracts to help lift the door's weight. Conversely, when the drive belt cycles in the opposite direction, the arm 185 is moved to push the door 180 into the closed configuration (as shown in FIG. 11(a)), and the tension spring 184 is driven to extend. As shown in FIG. 11(b), the door tilts upward and downward in a diagonal motion as it moves to the closed or open configuration. A tension spring is useful for lifting the weight of the door as the spring biases it towards the open configuration, but if the motor has enough power to overcome the weight of the door, it is not necessary to have a spring.

[0064] The barrier 164 in FIGS. 12(a)-(c) comprises a roller door. In particular, the roller door of FIGS. 12(a)-(c) is a horizontally split or sectioned door 190 that opens and closes vertically. The door 190 is positioned within a door frame 181. The door frame may comprise insulation, for example, one side of the door frame may comprise silica aerogel. The door frame 181 extends along the top of the door 190 and along the vertical sides of the door 190 when the door is in the closed configuration, as shown in FIG. 12(a). Although seven segments 192 are shown on the door 190 in FIGS. 12(a)-(c), there may be three to five, six to eight, nine to twelve, or more than thirteen segments. Linear bearings (not shown) are attached to the segments 192, allowing the bearings to move along one or more guides 183. In FIG. 12 , the one or more guides are a single guide with a vertical portion, a horizontal portion 194, and a curved portion 187, although it is also possible to have the portions of the guide as separate guides. The curved portion 187 is positioned between the vertical portion and the horizontal portion 194 to allow the segmented door 190 to move from a vertical orientation (as shown in FIG. 12( a)) to a horizontal orientation (as shown in FIG. 12( c)) and vice versa. FIG. 12( a) shows the door in a closed configuration, while FIG. 12( b) shows the door in a partially open configuration whereby a portion of the segment 192 has been moved into the horizontal portion 194 of the guide 183. The radius of curvature of the door 190 when undergoing a change in orientation or direction is determined by the segment size and configuration of the segments 192. A high radius of curvature requires smaller segment sizes, while a low radius of curvature can be achieved with a larger segment size. A motor (not shown) cycles a belt drive 189 to move the door 190 from a closed configuration (shown in Figure 12(a)) to an open configuration (shown in Figure 12(c)).One end of the arm 185 is attached to the top of the door 190, and the opposite end of the arm 185 is connected to a drive belt 189. When the drive belt 189 rotates in one direction, the arm 185 moves to pull the door 190 upward along the guide 183, and the door 190 gradually moves to the horizontal portion of the guide (shown in FIG. 12(b)) and then moves to the open configuration (shown in FIG. 12(c)). Conversely, when the drive belt 189 is circulated in the opposite direction, the arm 185 moves to push the door 190 to the closed configuration (as shown in FIG. 12(a)). Instead of moving the door 190 to the horizontal portion of the guide 183, the door 190 may be wound around a spool at the top of the passage.

[0065] The belt drive 189 in Figures 11 and 12 comprises a rubber belt, preferably a steel-reinforced rubber belt. Alternatively, a chain belt can be used. The doors 180, 190 in Figures 11 and 12 can be driven by a rotary motor, gear screw, stepper motor, linear motor, DC or AC motor. The motor may be mounted directly to the door or to the top or bottom of the walkway 160. The door can be locked in a closed or open configuration by a shot bolt, electromagnet, electric clutch, or any other known mechanism.

[0066] Instead of, or in addition to, at least one door, the barrier 164 can include an air curtain unit (not shown) that generates an air flow across the aisle 160 to create an air door. The air curtain unit can be positioned within the aisle 160 with an inlet extending into the aisle to draw cool air from either the first zone or the second zone and an outlet with a nozzle configured to direct the cool air across the aisle 160 to create a seal or air curtain across the aisle. The air curtain separates the different temperature environments of the first zone 100 and the second zone 200 while allowing for a smooth, uninterrupted flow of storage containers up and down the aisle 160. Similar to a physical door, the air curtain also prevents cool air from the first zone 100 from entering the second zone 200. One advantage of using an air curtain over a physical opening door is that fewer moving parts are required, reducing the risk of mechanical failure. Another advantage of using an air curtain is that it is more time-efficient because there is no need to wait for a physical door to open or close.

[0067] Each passage 160 may also be insulated along at least a portion of its length. For example, each passage 160 may be insulated along the portion that lies within the second zone 200. If the passage 160 is defined by a chute 162, the walls of the chute 162 may be covered with an insulating material, such as polymer foam, or the walls themselves may be made of an insulating material. If each passage 160 includes a barrier 164, the chute 162 may be insulated from the divider 150 to the location of the barrier 164 to further help prevent cool air from leaking from the first zone 100 to the second zone 200 during non-operating periods. The insulation may also help prevent moist air in the second zone 200 from condensing on the outside of the chute 162. Without the insulation, the temperature outside the chute 162 may be similar to the air temperature in the first zone 100 due to the chute 162's proximity to the first zone 100 and, therefore, may be lower than the dew point of the air in the second zone 200.

[0068] The divider 150 and / or any other walls separating the second zone 200 from the first zone 100 may also include insulation to further insulate the second zone 200 from the first zone 100 and reduce the energy costs of the heating system 330.

[0069] Thus, the above-described storage and retrieval system helps overcome problems associated with storing and retrieving frozen goods where a freezer-temperature zone (first zone 100) is in fluid communication with a warmer, potentially humid area (second zone 200). In particular, by discharging dehumidified air into the first zone 100, the first zone 100 can be kept dry enough to minimize the risk of frost and ice formation. Furthermore, by drawing air from the second zone 200 and the aisle 160 and discharging the air into the first zone 100, a positive pressure can be created within the first zone 100, reducing the risk of moist air ingress from the second zone 200 into the first zone 100. Furthermore, the dehumidified air discharged into the first zone 100 also circulates back to the second zone 200 via the opening 152, thereby reducing the relative humidity in the second zone 200 and reducing the risk of condensation in the second zone 200. As a result of these effects, the second zone 200 may be maintained at a warmer temperature than the first zone 100, providing a more comfortable working environment for human workers.

[0070] The invention is not limited to the exact form described above, and various modifications and variations will be apparent to those skilled in the art that fall within the scope of the claims.

[0071] For example, instead of the second zone 200 being located below only a portion of the storage structure 1 through the use of the mezzanine 150, the second zone 200 may be located at a level below the entire storage structure 1, as illustrated in Figure 8. In other words, the divider 150 may be positioned between the entire storage structure 1 and the second zone 200.

[0072] Furthermore, the walkway 160 need not extend vertically to the container station 202. The walkway may extend downward to a location away from the container station 202 and then be transported to the container station 202 in a different direction (e.g., horizontally), for example, via a conveyor.

[0073] The second zone 200 also need not be below the first zone 100. Instead, the second zone 200 can be horizontally adjacent to the first zone 100. In this case, the partition 150 separating the first zone 100 and the second zone 200 can be a vertical wall rather than a floor, and the aisles can extend downward from the port cells 14a and then horizontally through openings 152 in the partition 150 into the second zone 200. Each aisle can be equipped with a conveyor for transporting storage containers 9 along the horizontal portion of the aisle 160. An example of such an arrangement is shown in FIG. 9.

Claims

1. 1. A storage and retrieval system comprising: a first zone comprising a storage structure; a plurality of horizontal members arranged to form a grid pattern defining a plurality of grid cells; a plurality of upright members configured to support the horizontal members from below to define a storage area below the grid cells for storing a stack of storage containers; a second zone separated from the first zone by a partition, wherein the partition comprises an opening such that the first zone is in fluid communication with the second zone; an aisle extending from an associated grid cell of the storage structure into the second zone through the opening in the divider such that storage containers may be moved between the first zone and the second zone via the aisle; a dehumidification system configured to draw and dehumidify air from the second zone and release the dehumidified air into the first zone.

2. 10. The storage and retrieval system of claim 1, further comprising a temperature control system configured to maintain a first air temperature in the first zone and a second air temperature in the second zone, wherein the second air temperature is higher than the first air temperature.

3. 3. The storage and retrieval system of claim 2, wherein the first air temperature is between -30°C and 0°C.

4. 4. The storage and retrieval system of claim 3, wherein the first air temperature is between -30°C and -18°C.

5. 5. A storage and retrieval system according to any one of claims 2 to 4, wherein the second air temperature is between -10°C and +8°C.

6. 6. The storage and retrieval system of claim 5, wherein the second air temperature is between -10°C and 0°C.

7. 7. The storage and retrieval system of claim 2, wherein the temperature control system comprises a refrigeration system for maintaining the first air temperature within the first zone.

8. 8. The storage and retrieval system of claim 2, wherein the temperature control system comprises a heating system configured to maintain the second air temperature within the second zone.

9. 9. The storage system of claim 2, wherein the dehumidification system is configured to dehumidify the air drawn from the second zone such that the dew point of the released air is lower than the first air temperature.

10. 10. The storage system of claim 2, wherein the dehumidification system is configured to release the dehumidified air into the first zone at a rate such that a positive air pressure is created in the first zone relative to the second zone.

11. 11. The storage system of claim 1, wherein the dehumidification system is further configured to draw air from the aisle, dehumidify the air drawn from the aisle, and release the dehumidified air into the first zone.

12. 12. The storage system of claim 11, wherein the dehumidification system is configured to draw and mix air from the aisle and air from the second zone in a predetermined ratio.

13. 13. The storage system of claim 12, wherein 10% to 30% of the air drawn by the dehumidification system is from the passageway.

14. 14. The storage and retrieval system of claim 1, wherein the second zone is below at least a portion of the first zone, and the aisle extends vertically from its associated grid cell into the second zone.

15. 15. The storage and retrieval system of any one of claims 1 to 14, wherein the second zone comprises a container station for receiving storage containers so that items may be moved into or out of individual storage containers, and wherein the aisles extend from their associated grid cells to the container stations so that storage containers may be moved between the storage structure and the container stations via the aisles.

16. 16. A storage and retrieval system according to any one of claims 1 to 15, wherein the passageway comprises a barrier for selectively opening and closing the passageway.

17. 17. The storage and retrieval system of claim 16, wherein the barrier comprises at least one door.

18. 20. The storage and retrieval system of claim 17, wherein the at least one door is a tilting door.

19. 20. The storage and retrieval system of claim 17, wherein the at least one door is a roller door.

20. 20. The storage and retrieval system of any one of claims 16 to 19, wherein the barrier comprises an air curtain unit configured to provide an air curtain across an opening in the passageway.

21. 21. A storage and retrieval system according to any one of claims 1 to 20, wherein at least a portion of the passageway is surrounded by insulating material.

22. 22. The storage and retrieval system of any one of claims 1 to 21, wherein the storage and retrieval system comprises a plurality of aisles and the divider comprises a plurality of openings, wherein each aisle extends from an associated grid cell through a respective opening into the second zone.

23. The storage structure further comprises a track structure located on top of the horizontal members, wherein the track structure comprises a plurality of tracks arranged to form a grid pattern corresponding to the grid pattern formed by the horizontal members, and the storage and retrieval system further comprises one or more load handling devices, each load handling device comprising: a drive assembly configured to move a load handling device on the track structure; a container retention assembly configured to releasably retain a storage container from above; 23. The storage and retrieval system of any one of claims 1 to 22, comprising a lifting assembly configured to raise and lower a container holding assembly to enable the load handling device to raise and lower storage containers through the grid cells and into and out of the storage structure and the aisles.

Images