System and method for rearranging containers in automated storage and retrieval system

Abstract

A method and system for rearranging containers in an automated storage and retrieval system comprising a frame structure (100) forming a three-dimensional storage grid structure (104) for storing storage containers (106) for storing items, where the grid structure (104) forms vertical storage columns (105), where the vertical storage columns (105) are arranged in parallel. Each vertical storage column (105) has a horizontal area defined by the size of an access opening (112) of the vertical storage column (105), and wherein the frame structure comprises a track system (108) arranged above the storage columns (105), the track system comprising a plurality of tracks extending in an X-direction and a Y-direction to form a grid, and a track system (108) defining a perimeter of each access opening (112) on top of each storage column (105), the track system (108) providing an available route in an X-direction or Y-direction for a container handling vehicle (201, 301) to carry and transfer storage containers (106) from and to a storage column (105), the method comprises the steps of checking whether free space exists along at least one edge of a grid of the storage and retrieval system, checking whether sufficient free space exists in non-edge cells of the grid of the storage and retrieval system to perform normal operation, when free space exists along at least one edge of the grid of the storage and retrieval system and sufficient free space does not exist in non-edge cells of the grid of the storage and retrieval system to perform normal operation, a rearrangement job is created in the central computer system, the container handling vehicle is notified to perform the rearrangement job, and the container handling vehicle is notified to perform the rearrangement job. Normal operation is continued on the grid of the storage and retrieval system after the container handling vehicle has performed the rearrangement work.

Description

Technical Field

[0001] The present invention relates to an automatic storage and retrieval system for storing and retrieving containers, and in particular to a system and method for evenly distributing containers around a grid to prevent many empty spaces from appearing at the edges of a container stack. Background Art

[0002] Figure 1 A prior art automatic storage and retrieval system 1 having a frame structure 100 is disclosed. Figure 2 , Figure 3 and Figure 4 Three different prior art container handling vehicles 201 , 301 , 401 suitable for operating on such a system 1 are disclosed.

[0003] The frame structure 100 comprises upright members 102 and a storage volume comprising storage columns 105 arranged in rows between the upright members 102. In these storage columns 105, storage containers 106 (also referred to as containers) are stacked one after another to form stacks 107. The members 102 may typically be made of metal, for example extruded aluminum profiles.

[0004] The frame structure 100 of the automatic storage and retrieval system 1 includes a rail system 108 arranged along the top of the frame structure 100, on which a plurality of container handling vehicles 201, 301, 401 can be operated to lift storage containers 106 from the storage row 105 and lower the storage containers 106 into the storage row 105, and also transport the storage containers 106 above the storage row 105. The rail system 108 includes a first set of parallel rails 110 and a second set of parallel rails 111, the first set of parallel rails being arranged to guide the movement of the container handling vehicles 201, 301, 401 in a first direction X along the top of the frame structure 100, and the second set of parallel rails being arranged perpendicular to the first set of rails 110 to guide the movement of the container handling vehicles 201, 301, 401 in a second direction Y perpendicular to the first direction X. The containers 106 stored in the row 105 are accessed by the container handling vehicles 201, 301, 401 through access openings 112 in the rail system 108. The container handling vehicles 201 , 301 , 401 can move laterally above the storage row 105 , ie in a plane parallel to the horizontal XY plane.

[0005] Upright members 102 of frame structure 100 may be used to guide storage containers during lifting and lowering of containers from row 105. Stack 107 of containers 106 is generally self-supporting.

[0006] Each prior art container handling vehicle 201, 301, 401 includes a body 201a, 301a, 401a and a first set of wheels and a second set of wheels 201b, 201c, 301b, 301c, 401b, 401c, which enable the container handling vehicle 201, 301, 401 to move laterally in the X direction and the Y direction, respectively. Figure 2 , Figure 3 and Figure 4 , the two wheels in each set are fully visible. The first set of wheels 201b, 301b, 401b is arranged to engage with two adjacent tracks in the first set of tracks 110, and the second set of wheels 201c, 301c, 401c is arranged to engage with two adjacent tracks in the second set of tracks 111. At least one set of wheels 201b, 201c, 301b, 301c, 401b, 401c can be raised and lowered so that the first set of wheels 201b, 301b, 401b and / or the second set of wheels 201c, 301c, 401c can engage with the corresponding set of tracks 110, 111 at any one time.

[0007] Each prior art container handling vehicle 201, 301, 401 also includes a lifting device for vertically transporting storage containers 106, such as lifting storage containers 106 from storage rows 105 and lowering storage containers 106 into storage rows 105. The lifting device includes one or more gripping / engaging devices, which are suitable for engaging storage containers 106 and can be lowered from the vehicle 201, 301, 401 so that the position of the gripping / engaging device relative to the vehicle 201, 301, 401 can be adjusted along a third direction Z orthogonal to the first direction X and the second direction Y. The portion of the gripping device of the container handling vehicle 301, 401 is Figure 3 and Figure 4 304, 404. The gripping device of the container handling device 201 is located at Figure 2 The interior of the vehicle body 201a and is therefore not shown.

[0008] Conventionally, and also for the purposes of this application, Z=1 identifies the uppermost level below the rails 110, 111 that can be used to store containers, i.e., the level immediately below the rail system 108, Z=2 identifies the second level below the rail system 108, Z=3 identifies the third level, etc. Figure 1 In the exemplary prior art disclosed in , Z=8 identifies the lowest bottom layer of the storage container. Similarly, X=1...n and Y=1...n identify the position of each storage column 105 in the horizontal plane. Thus, as an example, using Figure 1 The Cartesian coordinate system X, Y, Z shown, Figure 1The storage container denoted as 106' in FIG. 1 can be said to occupy storage location X=17, Y=1, Z=6. The container handling vehicles 201, 301, 401 can be said to be traveling in level Z=0, and each storage column 105 can be identified by its X and Y coordinates. Figure 1 The storage container shown in FIG. 1 , which extends above the rail system 108 , is arranged in level Z=0.

[0009] The storage volume of the frame structure 100 is often referred to as a grid 104, and the possible storage positions within the grid are referred to as storage cells. Each storage column can be identified by a position in the X and Y directions, and each storage cell can be identified by a container number in the X, Y and Z directions.

[0010] Each prior art container handling vehicle 201, 301, 401 includes a storage compartment or space for receiving and loading storage containers 106 while transporting the storage containers 106 across the track system 108. The storage space may include a cavity disposed within the vehicle body 201a, 401a, such as Figure 2 and Figure 4 As shown and described in WO2015 / 193278A1 and WO2019 / 206487A1, the contents of which are incorporated herein by reference.

[0011] Figure 3 An alternative configuration of a container handling vehicle 301 having a cantilever configuration is shown. Such a vehicle is described in detail in, for example, NO 317366, the contents of which are also incorporated herein by reference.

[0012] Figure 2 The footprint of the cavity container handling vehicle 201 shown may cover an area having dimensions in the X and Y directions generally equal to the lateral extent of the storage row 105, for example as described in WO 2015 / 193278 A1, the contents of which are incorporated herein by reference. The term "lateral" as used herein may refer to "horizontal".

[0013] Alternatively, if Figure 1 and Figure 4 As shown in , the footprint of the cavity container handling vehicle 401 can be larger than the lateral area defined by the storage row 105, for example, as described in WO 2014 / 090684 A1 or WO 2019 / 206487 A1.

[0014] The track system 108 typically includes a plurality of tracks having a plurality of grooves in which the wheels of the vehicle run. Alternatively, the tracks may include upwardly protruding elements, and the wheels of the vehicle include flanges to prevent derailment. These grooves and upwardly protruding elements are collectively referred to as tracks. Each track may include one guide rail, or each track 110, 111 may include two parallel guide rails. In other track systems 108, each track in one direction (e.g., the X direction) may include one guide rail, and each track in another perpendicular direction (e.g., the Y direction) may include two guide rails. Each track 110, 111 may also include two guide rail members fastened together, each guide rail member providing one of a pair of guide rails provided by each track.

[0015] WO 2018 / 146304 A1 (the contents of which are incorporated herein by reference) shows a typical configuration of a track system 108 comprising tracks and parallel guides in the X and Y directions.

[0016] In the frame structure 100, most of the rows 105 are storage rows 105, i.e. rows 105 in which storage containers 106 are stored in the form of stacks 107. However, some of the rows 105 may have other purposes. Figure 1 In the embodiment of the present invention, the columns 119 and 120 are such special columns that are used by the container handling vehicles 201, 301, 401 to unload and / or pick up the storage containers 106 so that they can be transported to the access station (not shown), where the storage containers 106 can be accessed from the outside of the frame structure 100 or transferred to the outside of the frame structure 100 or transferred to the frame structure. In the art, such positions are generally referred to as 'ports', and the columns where the ports are located can be referred to as 'port columns' 119, 120. The transportation to the access station can be in any direction, horizontal, inclined and / or vertical. For example, the storage container 106 can be placed in a random or special column 105 in the frame structure 100, and then picked up by any container handling vehicle and transported to the port columns 119, 120 for further transportation to the access station. The transportation from the port to the access station may need to move in various directions by means such as delivery vehicles, carts or other transportation routes. It is noted that the term "inclined" refers to the transport of storage containers 106 with a general direction of transport that is somewhere between horizontal and vertical.

[0017] exist Figure 1In the embodiment, the first port column 119 can be, for example, a dedicated unloading port column, at which container handling vehicles 201, 301, 401 can unload storage containers 106 to be transported to an access station or a transfer station, and the second port column 120 can be a dedicated picking port column, at which container handling vehicles 201, 301, 401 can pick up storage containers 106 that have been transported from an access station or a transfer station.

[0018] The access station may typically be a picking station or an inventory station, where product items are removed from or placed into storage containers 106. In a picking station or an inventory station, storage containers 106 are typically not removed from the automated storage and retrieval system 1, but once accessed are returned again to the frame structure 100. The port may also be used to transfer the storage container to another storage facility (e.g., to another frame structure or to another automated storage and retrieval system), to a transport vehicle (e.g., a train or truck), or to a production facility.

[0019] Storage containers are typically transported between the port rows 119, 120 and the access station using a conveying system including a conveyor.

[0020] If the port rows 119, 120 and the access station are located at different heights, the conveying system may include a lifting device with a vertical component for vertically transporting the storage container 106 between the port rows 119, 120 and the access station.

[0021] The conveying system may be arranged to transfer storage containers 106 between different frame structures, for example as described in WO 2014 / 075937 A1, the contents of which are incorporated herein by reference.

[0022] When stored in Figure 1When a storage container 106 in one of the rows 105 disclosed in the embodiment of the present invention is to be accessed, one of the container handling vehicles 201, 301, 401 may be instructed to retrieve the target storage container 106 from its position and transport it to the unloading port row 119. This operation involves moving the container handling vehicle 201, 301, 401 to a position above the storage row 105 where the target storage container 106 is located, retrieving the storage container 106 from the storage row 105 using a lifting device (not shown) of the container handling vehicle 201, 301, 401, and transporting the storage container 106 to the unloading port row 119. If the target storage container 106 is located deep within the stack 107, that is, one or more other storage containers 106 are located above the target storage container 106, the operation also involves temporarily moving these storage containers located above before lifting the target storage container 106 from the storage row 105. This step (sometimes referred to in the art as "digging") can be performed with the same container handling vehicle that is subsequently used to transport the target storage container to the unloading port column 119, or with one or more other cooperating container handling vehicles. Alternatively or additionally, the automated storage and retrieval system 1 can have a container handling vehicle 201, 301, 401 that is specifically dedicated to the task of temporarily removing a storage container 106 from a storage column 105. Once the target storage container 106 has been removed from the storage column 105, the temporarily removed storage container 106 can be repositioned into the original storage column 105. However, the removed storage container 106 can alternatively be repositioned to other storage columns 105.

[0023] When a storage container 106 is to be stored in one of the rows 105, one of the container handling vehicles 201, 301, 401 is instructed to pick up a storage container 106 from the pick-up port row 120 and transport it to the location where the storage container is to be stored above the storage row 105. After any storage container 106 located at or above the target location within the stack 107 has been removed, the container handling vehicle 201, 301, 401 positions the storage container 106 at the desired location. The removed storage container 106 can then be lowered back into the storage row 105 or repositioned to another storage row 105.

[0024] In order to monitor and control the automatic storage and retrieval system 1, for example, to monitor and control the position of the corresponding storage container 106 within the frame structure 100, the content of each storage container 106 and the movement of the container handling vehicles 201, 301, 401, so as to deliver the required storage container 106 to the required location at the required time without collision of the handling vehicles 201, 301, 401, the automatic storage and retrieval system 1 includes a control system 500, which is typically computerized and typically includes a database for keeping track of the storage containers 106.

[0025] Conventional storage and retrieval systems sometimes have the problem of holes in the grid being concentrated at the edges of the storage and retrieval grid. A "hole" here refers to a cell that has at least one free space where an additional container can be placed. A "deep hole" usually refers to a cell with multiple free spaces. One of the tasks of the router software is to keep the holes evenly distributed throughout the grid, because these free spaces are used to temporarily store other containers during the excavation and preparation process before the container is sent to the port. The main way to balance the grid (spread out the holes) is to strategically place containers when they come out of the port. However, if all the ports are on one side of the grid (the south side or the north side), using this strategy, no containers will be placed on the opposite side of the grid. This usually results in relatively deep holes on the opposite side of the grid. Summary of the invention

[0026] The invention is set forth and characterized in the independent claim, while the dependent claims describe further characteristics of the invention.

[0027] In one aspect, the present invention relates to a method for rearranging containers in an automated storage and retrieval system, the automated storage and retrieval system comprising a frame structure (100) forming a three-dimensional storage grid structure (104) for storing storage containers (106), wherein the frame structure (100) forms vertical storage rows (105), each vertical storage row having a horizontal area defined by the size of an access opening (112) of the vertical storage row (105), and wherein the frame structure comprises a rail system (108) arranged above the storage rows (105), the rail system comprising a plurality of rails extending in an X direction and a plurality of rails extending in a Y direction to form a grid, the rails defining the perimeter of each access opening (112) on the top of each storage row (105), the rail system (108) providing an available route in the X direction or the Y direction for a container handling vehicle (201, 301) Carrying and transferring storage containers (106) from a storage column (105) and carrying and transferring storage containers to a storage column, wherein the method includes: using a central computer system to monitor the amount of free space along at least one edge of a grid of a storage and retrieval system to determine whether there is sufficient free space in the remaining cells of the grid of the storage and retrieval system to perform normal operations, if there is more than a predetermined density of free space along at least one edge of the grid of the storage and retrieval system and it is determined that the density of free cells in the remaining cells of the grid of the storage and retrieval system is insufficient to maintain normal operations, creating one or more rearrangement operations in the central computer system, instructing at least one container handling vehicle to perform at least one rearrangement operation, wherein the at least one container handling vehicle transports containers from cells in the remaining part of the grid of the storage and retrieval system to at least one edge of the grid.

[0028] Furthermore, after at least one container handling vehicle has performed at least one rearrangement operation, normal operation can continue on the grid of the storage and retrieval system, wherein normal operation includes performing deep excavation for containers or normal operation requires that the grid has sufficient free space to place containers returned from the port.

[0029] Furthermore, the central computer system may search for a target cell along at least one edge of the grid, and the central computer system may search for a source cell from the rest of the grid for each rearrangement job, and may search for a source container from the source cell. The central computer system may select the target cell and the source cell based on the free space and / or the number of available containers in the target cell and the source cell, or the central computer system may select a cell with the largest number of free spaces along at least one edge of the grid of the storage and retrieval system as the target cell.

[0030] The central computer system may select a cell having the least free space from the remaining cells as the source cell.

[0031] The amount of free space in neighboring cells may be considered when picking target cells and source cells and when picking source containers.

[0032] Alternatively, the central computer system may select a cell as a target cell if the target cell and its neighboring cells have the greatest number of free spaces in a given area of ​​the grid.

[0033] The central computer system may select a cell as a source cell if the source cell and its neighboring cells have the least number of free spaces in a given area of ​​the grid.

[0034] Furthermore, the central computer system may select a container as a source container based on the number of times the source container has been transported to the port for picking within a predefined time period.

[0035] Furthermore, the central computer system may select as the source container a container which has been transported to the port for picking the least number of times within a predefined time period.

[0036] In a second aspect, the present invention relates to a system for rearranging containers in an automatic storage and retrieval system, the automatic storage and retrieval system comprising a frame structure (100) forming a three-dimensional storage grid structure (104) for storing storage containers (106), wherein the frame structure (100) forms vertical storage columns (105), each vertical storage column having a horizontal area defined by the size of an access opening (112) of the vertical storage column (105), and wherein the frame structure comprises a rail system (108) arranged above the storage columns (105), the rail system comprising a plurality of rails extending in an X direction and a plurality of rails extending in a Y direction to form a grid, the rails defining each access opening (112) on the top of each storage column (105) 112), the track system (108) providing an available route in the X direction or the Y direction for container handling vehicles (201, 301) to carry and transfer storage containers (106) from the storage column (105) and to carry and transfer the storage containers to the storage column, the system comprising: a central computer system for evaluating the distribution of containers in the grid of the storage and retrieval system, the central computer system for creating a rearrangement operation when there is free space along at least one edge of the grid of the storage and retrieval system and there is not enough free space in the non-edge cells of the grid of the storage and retrieval system to maintain normal operation; at least one container handling vehicle for executing the rearrangement operation created by the central computer system.

[0037] The rearrangement operations may be given a higher priority in the central computer system than ordinary transport operations between the grid of the storage and retrieval system and the ports of the storage and retrieval system.

[0038] A third aspect of the invention may relate to a computer program product stored on a non-transitory computer readable medium, the computer program product comprising instructions which, when executed by a processor, cause the processor to perform a method for rearranging containers in an automated storage and retrieval system as claimed in the method claim.

[0039] By using the solution presented here, the containers will be regularly distributed around the grid, ensuring that the grid is optimally prepared for deep excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The following drawings are attached to facilitate understanding of the present invention. The drawings illustrate embodiments of the present invention which will now be described by way of example only, wherein:

[0041] Figure 1 It is a perspective view of the framework structure of the prior art automatic storage and retrieval system.

[0042] Figure 2is a perspective view of a prior art container handling vehicle having a cavity disposed internally for carrying a storage container therein.

[0043] Figure 3 is a perspective view of a prior art container handling vehicle having a cantilever for carrying a storage container underneath.

[0044] Figure 4 is a perspective view from below of a prior art container handling vehicle having a cavity disposed internally for carrying a storage container therein.

[0045] Figure 5 is a flow chart of the process used to evenly distribute containers around a grid.

[0046] Figure 6 This is a side view cutaway of the mesh before cleaning.

[0047] Figure 7 yes Figure 6 A side cutaway view of the mesh after cleaning. DETAILED DESCRIPTION

[0048] In the following, embodiments of the present invention will be discussed in more detail with reference to the accompanying drawings. It should be understood, however, that the drawings are not intended to limit the present invention to the subject matter depicted in the drawings.

[0049] The frame structure 100 of the automatic storage and retrieval system 1 is combined with the above Figures 1 to 3 The prior art frame structure 100 described is constructed in a similar manner. That is, the frame structure 100 includes a plurality of upright members 102 and includes a first upper rail system 108 extending in the X-direction and the Y-direction.

[0050] The frame structure 100 further comprises storage compartments in the form of storage rows 105 arranged between the components 102 , wherein storage containers 106 can be stacked in the storage rows 105 to form stacks 107 .

[0051] The frame structure 100 may have any size. In particular, it will be appreciated that the frame structure may be larger than Figure 1 The disclosed structures are much wider and / or much longer and / or much deeper. For example, the frame structure 100 can have a horizontal extent of greater than 700x700 columns and a storage depth of greater than 12 containers.

[0052] Now refer to Figures 5 to 7 One embodiment of the automated storage and retrieval system according to the present invention is discussed in more detail.

[0053] Figure 5 is a flow chart of an example of a process for evenly distributing containers around a grid.

[0054] In storage and retrieval systems, it is not uncommon that empty spaces tend to be located around the edges of the storage and retrieval system, especially if all ports are located on one side of the grid. If this is the case, the empty spaces will usually be located on the side of the storage and retrieval system opposite the port.

[0055] A free space is a situation in which the number of containers in a row is at least one less than the maximum number of containers allowed in a stack of this row. If a row has more than one free space, it is called a deep hole.

[0056] The most used containers will end up in the stack closest to the port. This is because the most used containers will automatically end up on the top of the stack close to the port, so the free space will end up in the least active area of ​​the grid.

[0057] One of the tasks of the central computer system software is to keep free space throughout the grid, because these free spaces are used to temporarily store other containers during the excavation and preparation operations before sending the container to the port. The main way to distribute the free space is by strategically placing the containers as they come out of the ports. However, if all or most of the ports are on one side of the grid, very few containers will be placed on the opposite side of the grid. This usually results in relatively deep holes on the side of the grid opposite to one or more ports.

[0058] Edge cleaning refers to a routine operation performed by the central computer system to fill relatively deep holes that may exist at the edge of the grid. This is only done when the central computer system finds it absolutely necessary to perform this routine operation to avoid unnecessary work. Rearrangement jobs are created to improve the performance of the storage and retrieval system. For example, if there is not enough free space in the non-edge cells of the grid to perform normal operations (such as digging from the bottom of the cell), a rearrangement job is created. A rearrangement job can be created when there is not enough free space for a container to come out of the port and return to the grid. If any of the above criteria are met, the central computer system searches for the best edge target cell and the best source container / cell for the job. The best target cell and source cell are found based on the number of container free spaces available in the cell and the score calculated based on the free space in nearby cells.

[0059] The embodiment of the present invention has the following method.

[0060] Is there a high concentration of free space on a given area of ​​the storage and retrieval system? If so, the central computer system evaluates whether there is enough free space on the rest of the grid to perform normal operations? If the distribution of containers is such that the free space is not concentrated in one area of ​​the grid, the operation of the storage and retrieval system will continue normally.

[0061] If not present, the central computer system creates a job to rearrange the container in the storage and retrieval system.

[0062] Furthermore, the central computer system commands the container handling vehicles to carry out the rearrangement of the containers on the grid.

[0063] In an alternative solution, in the storage and retrieval system, rearrangement of containers is initiated by the number of free cells in a given area in the storage and retrieval system, even if there are enough free cells on the rest of the grid to perform normal operations.

[0064] In yet another alternative solution of the present invention, rearrangement of containers in the storage and retrieval system is automatically initiated when activity on the storage and retrieval system falls below a certain level. An example of this is when the system is operating at, for example, 50%. This solution initiates rearrangement of containers in the storage and retrieval system at night, when activity is typically reduced, for example.

[0065] After at least one container handling vehicle has performed at least one rearrangement operation, normal operation continues on the grid of the storage and retrieval system.

[0066] Normal operation involves performing deep mining on containers and requiring the grid to have enough free space to place containers returning from the ports.

[0067] Figure 6 is a side view of a grid before re-arranging containers in a given area of ​​the storage and retrieval system. During normal operation of the storage and retrieval system, containers will automatically be stored closest to the ports. If the ports are located on one side of the storage and retrieval system, the containers will automatically be stored closest to the ports. This will then result in a number of free cells along the edge of the storage and retrieval system, on the side away from where the ports are located.

[0068] When there are not enough free cells in the busiest areas of the storage and retrieval system, normal operation will be delayed because the container handling vehicles must travel farther with the containers to find free space to place the containers. Normal operation is considered to be transporting containers to and from the port, as well as performing digging. Digging is when a container handling vehicle must lift one or more containers in a column to reach containers that are located below other containers in the column. Containers stored above the container of interest must be moved before the container of interest can be lifted and transported to the port. The longer the distance a container handling vehicle must travel in order to find free space for a container, the longer it takes to dig, and the efficiency of the storage and retrieval system is reduced.

[0069] To overcome the problem of uneven distribution of free cells, a central computer system in the storage and retrieval system creates a job that includes finding a source cell with a container that is to be moved to a target cell with at least one free space.

[0070] The central computer system also evaluates the distribution of containers in the grid of the storage and retrieval system to estimate the distribution of free space in the grid and whether containers need to be rearranged.

[0071] The operations performed by the central computer system for rearranging containers in a given area of ​​the storage and retrieval system have a higher priority in the central computer system than ordinary transport operations between the grid of the storage and retrieval system and the ports of the storage and retrieval system.

[0072] Figure 7 yes Figure 6 A side view of the cleaned-up grid in Figure 1, where you can see that the free space is evenly distributed across all columns.

[0073] In the foregoing description, various aspects of the delivery vehicle and automated storage and retrieval system according to the present invention have been described with reference to illustrative embodiments. For purposes of explanation, specific numbers, systems, and configurations are set forth to provide a thorough understanding of the system and its operation. However, this description is not intended to be interpreted in a limiting sense. The scope of the present invention is intended to include various modifications and variations that are apparent to those skilled in the art within the field to which the disclosed subject matter belongs, as well as other embodiments of the system.

[0074] Reference numerals list

[0075] Prior art ( Figures 1 to 4 ), the present invention ( Figures 5 to 7 ):

[0076] 1 Prior Art Automatic Storage and Retrieval System

[0077] 100 frame structure

[0078] 102 Vertical members of the frame structure

[0079] 104 Storage Grid

[0080] 105 storage columns

[0081] 106 Storage Containers

[0082] Specific location of 106' storage container

[0083] 107 Stacking

[0084] 108 Track System

[0085] 110 parallel tracks in a first direction (X)

[0086] 112 access port

[0087] 119 First port column

[0088] 120 Second port column

[0089] 201 Prior Art Container Handling Vehicle

[0090] 201a Body of container transport vehicle 201

[0091] 201b driving device / wheel device / first set of wheels in first direction (X)

[0092] 201c Driving device / wheel device / second set of wheels in the second direction (Y)

[0093] 301 Prior Art Cantilever Container Handling Vehicle

[0094] 301a Body of container transport vehicle 301

[0095] 301b Driving device / first set of wheels in first direction (X)

[0096] 301c Drive device in the second direction (Y) / second set of wheels

[0097] 304 gripping device

[0098] 401 Prior Art Container Handling Vehicle

[0099] 401a Body of container transport vehicle 401

[0100] 401b Drive device / first set of wheels in first direction (X)

[0101] 401c Drive device in second direction (Y) / second set of wheels

[0102] 404 gripping device

[0103] 404a lifting belt

[0104] 404b gripper

[0105] 404c guide pin

[0106] 404d lifting frame

[0107] 500 control system

[0108] 601 free cells

[0109] Port 602

[0110] X first direction

[0111] Y second direction

[0112] Z: third direction.

Claims

1. A method for rearranging containers in an automated storage and retrieval system, the automated storage and retrieval system comprising a frame structure (100) forming a three-dimensional storage grid structure (104) for storing storage containers (106), wherein: The frame structure (100) forms vertical storage rows (105), each of the vertical storage rows having a horizontal area defined by the size of an access opening (112) of the vertical storage row (105), and wherein the frame structure comprises a track system (108) arranged above the storage rows (105), the track system comprising a plurality of tracks extending in an X direction and a plurality of tracks extending in a Y direction to form a grid, the tracks defining the perimeter of each access opening (112) on the top of each storage row (105), the track system (108) providing an available route in the X direction or the Y direction, the available route being used for a container handling vehicle (201, 301) to carry and transfer the storage container (106) from the storage row (105) and to carry and transfer the storage container to the storage row, wherein the method comprises: - using a central computer system to monitor the amount of free space along at least one edge of the grid of the storage and retrieval system to determine whether there is sufficient free space in the remaining cells of the grid of the storage and retrieval system to perform normal operations, - creating one or more rearrangement jobs in the central computer system if there is more free space than a predetermined density along at least one edge of the grid of the storage and retrieval system and it is determined that the density of free cells in the remaining cells of the grid of the storage and retrieval system is insufficient to maintain normal operation, - instructing at least one container handling vehicle to perform the at least one rearrangement operation, wherein the at least one container handling vehicle transports containers from cells in the remainder of the grid of the storage and retrieval system to at least one edge of the grid.

2. The method according to claim 1, wherein: After the at least one container handling vehicle has performed the at least one rearrangement operation, normal operations continue on the grid of the storage and retrieval system.

3. The method according to claim 2, wherein: The normal operation includes performing a deep excavation on the container.

4. A method according to any one of the preceding claims, wherein: The normal operation requires that the grid has enough free space to place containers returning from the ports.

5. A method according to any one of the preceding claims, wherein: The central computer system searches for a target cell along at least one edge of the grid, and.

6. A method according to any one of the preceding claims, wherein: The central computer system searches for source cells from the remainder of the grid, and optionally source containers from the source cells, for each rearrangement job.

7. The method according to claim 4, wherein: The central computer system selects the target cell and the source cell based on the amount of free space in the target cell and the source cell and / or the amount of available containers.

8. The method according to claim 5, wherein: The central computer system selects a cell along the at least one edge of the grid of the storage and retrieval system having the largest amount of free space as a target cell.

9. The method according to claim 5 or 6, wherein: The central computer system selects a cell with the least free space from the remaining cells as a source cell.

10. The method according to any one of claims 5 to 7, wherein: When picking the target cell and the source cell, the amount of free space in the neighboring cells is considered.

11. The method according to any one of claims 5 to 7, wherein: When picking a source container, the amount of free space in neighboring cells is taken into account.

12. The method according to claim 8, wherein: The central computer system selects a cell as the target cell if that target cell and its neighboring cells have the greatest amount of free space in a given area of ​​the grid.

13. The method according to claim 8 or 9, wherein: The central computer system selects a cell as a source cell.

14. The method according to claim 13, wherein: The central computer system selects a cell as the source cell if that source cell and its neighboring cells have the least amount of free space in a given area of ​​the grid.

15. The method according to any one of claims 4 to 10, wherein: The central computer system selects a container as the source container based on the number of times the source container has been transported to the port for picking within a predefined time period.

16. The method according to claim 11, wherein: The central computer system selects as the source container the container which has been transported to the port for picking the least number of times within a predefined time period.

17. A system for rearranging containers in an automated storage and retrieval system, the automated storage and retrieval system comprising a frame structure (100) forming a three-dimensional storage grid structure (104) for storing storage containers (106), wherein: The frame structure (100) forms vertical storage rows (105), each of the vertical storage rows having a horizontal area defined by the size of an access opening (112) of the vertical storage row (105), and wherein the frame structure comprises a track system (108) arranged above the storage rows (105), the track system comprising a plurality of tracks extending in an X direction and a plurality of tracks extending in a Y direction to form a grid, the tracks defining the perimeter of each access opening (112) on the top of each storage row (105), the track system (108) providing an available route in the X direction or the Y direction, the available route being used for a container handling vehicle (201, 301) to carry and transfer the storage container (106) from the storage row (105) and to carry and transfer the storage container to the storage row, wherein the system comprises: - a central computer system for evaluating the distribution of containers in said grid of said storage and retrieval system, - creating a rearrangement job if there is free space along at least one edge of the grid of the storage and retrieval system and there is not enough free space in non-edge cells of the grid of the storage and retrieval system to maintain normal operation, - at least one container handling vehicle for carrying out said rearrangement job created by said central computer system.

18. The system of claim 13, wherein: The rearrangement operation is given a higher priority in the central computer system than ordinary transport operations between the grid of the storage and retrieval system and the ports of the storage and retrieval system.

19. A computer program product stored on a non-transitory computer readable medium, the computer program product comprising instructions which, when executed by a processor, cause the processor to perform the method for rearranging containers in an automated storage and retrieval system as claimed in any one of claims 1 to 16.

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