WO2025040269A1

WO2025040269A1 - A transporter for an automated storage and retrieval system

Info

Publication number: WO2025040269A1
Application number: PCT/EP2024/051339
Authority: WO
Inventors: Trond Austrheim; Ingvar FAGERLAND
Original assignee: Autostore Technology AS
Current assignee: Autostore Technology AS
Priority date: 2023-08-10
Filing date: 2024-01-22
Publication date: 2025-02-27
Anticipated expiration: 2026-02-10

Abstract

It is described a transporter (501) configured to operate on a rail system (108), wherein the transporter (501) comprises: - a first wheeled base (502') and a second wheeled base (502"), each of the first wheeled base (502') and the second wheeled base (502") comprising a first set of wheels (501b) for moving in a first direction (X) and a second set of wheels (501c) for moving in a second direction (Y), wherein the second direction (Y) is perpendicular to the first direction (X); - a transporter framework structure (503) extending between the first and second wheeled bases (502', 502"), wherein the transporter framework structure (503) defines an internal storage system comprising a plurality of transporter storage columns (504) for storing stacks (505) of storage containers (106) on top of each other. It is further described associated automated storage and retrieval system, methods and use of the transporter.

Description

A TRANSPORTER FOR AN AUTOMATED STORAGE AND RETRIEVAL SYSTEM

TECHNICAL FIELD

[001] The invention relates to a transporter configured to operate on a rail system of a storage grid of an automated storage and retrieval system. The invention also relates to an automated storage and retrieval system, related methods as well as uses of the transporter.

BACKGROUND AND PRIOR ART

[002] Fig. 1 discloses a prior art automated storage and retrieval system 1 with a frame structure 100 and Figs. 2, 3 and 4 disclose three different prior art container handling vehicles 201,301,401 suitable for operating on such a system 1.

[003] 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 known as bins, are stacked one on top of one another to form stacks 107. The members 102 may typically be made of metal, e.g. extruded aluminum profiles.

[004] The frame structure 100 of the automated storage and retrieval system 1 comprises a rail system 108 arranged across the top of frame structure 100, on which rail system 108 a plurality of container handling vehicles 201,301,401 may be operated to raise storage containers 106 from, and lower storage containers 106 into, the storage columns 105, and also to transport the storage containers 106 above the storage columns 105. The rail system 108 comprises a first set of parallel rails no arranged to guide movement of the container handling vehicles 201,301,401 in a first direction X across the top of the frame structure 100, and a second set of parallel rails 111 arranged perpendicular to the first set of parallel rails no to guide movement of the container handling vehicles 201,301,401 in a second direction Y which is perpendicular to the first direction X. Containers 106 stored in the columns 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 columns 105, i.e. in a plane which is parallel to the horizontal X-Y plane. [005] The upright members 102 of the frame structure 100 may be used to guide the storage containers during raising of the containers out from and lowering of the containers into the columns 105. The stacks 107 of containers 106 are typically self-supporting.

[006] Each prior art container handling vehicle 201,301,401 comprises a vehicle body 201a, 301a, 401a and first and second sets of wheels 201b, 201c, 301b, 301c, 401b, 401c which enable the lateral movement of the container handling vehicles 201,301,401 in the X direction and in the Y direction, respectively. In Figs. 2, 3 and 4 two wheels in each set are fully visible. The first set of wheels 201b, 301b, 401b is arranged to engage with two adjacent rails of the first set of parallel rails no, and the second set of wheels 201c, 301c, 401c is arranged to engage with two adjacent rails of the second set of parallel rails 111. At least one of the sets of wheels 201b, 201c, 301b, 301c, 401b, 401c can be lifted and lowered, so that the first set of wheels 201b, 301b, 401b and/or the second set of wheels 201c, 301c, 401c can be engaged with the respective set of parallel rails no, 111 at any one time.

[007] Each prior art container handling vehicle 201,301,401 also comprises a lifting device for vertical transportation of storage containers 106, e.g. raising a storage container 106 from, and lowering a storage container 106 into, a storage column 105. The lifting device comprises one or more gripping / engaging devices which are adapted to engage a storage container 106, and which gripping / engaging devices can be lowered from the vehicle 201,301,401 so that the position of the gripping / engaging devices with respect to the vehicle 201,301,401 can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y. Parts of the gripping device of the container handling vehicles 301,401 are shown in Figs. 3 and 4 indicated with reference number 304,404. The gripping device of the container handling device 201 is located within the vehicle body 201a in Fig. 2 and is thus not shown. The lifting device may comprise a lifting frame 4O4d suspended from lifting bands 404a. The lifting bands 404a may provide power and communication between the container handling vehicle and the lifting frame 4O4d. The lifting frame 404b may comprise gripping engaging devices/grippers 404b for connection to gripping recesses of a storage container 106. Guide pins 404c assist in aligning the grippers 404b relative the gripping recesses of the storage container 106.

[008] Conventionally, and also for the purpose of this application, Z=i identifies the uppermost layer available for storage containers below the rails iio,m, i.e. the layer immediately below the rail system 108, =2 the second layer below the rail system 108, Z=3 the third layer etc. In the exemplary prior art disclosed in Fig. 1, Z=8 identifies the lowermost, bottom layer of storage containers. Similarly, X=i...n and Y=i...n identifies the position of each storage column 105 in the horizontal plane. Consequently, as an example, and using the Cartesian coordinate system X, Y, Z indicated in Fig. 1, the storage container identified as 106’ in Fig. 1 can be said to occupy storage position =iy, Y=i, Z=6. The container handling vehicles 201,301,401 can be said to travel in layer Z=o, and each storage column 105 can be identified by its X and Y coordinates. Thus, the storage containers shown in Fig. 1 extending above the rail system 108 are also said to be arranged in layer Z=o.

[009] The storage volume of the frame structure 100 has often been referred to as a grid 104, where the possible storage positions within this grid are referred to as storage cells. Each storage column may be identified by a position in an X- and T-direction, while each storage cell may be identified by a container number in the X-, Y- and Z-direction.

[0010] Each prior art container handling vehicle 201,301,401 comprises a storage compartment or space for receiving and stowing a storage container 106 when transporting the storage container 106 across the rail system 108. The storage space may comprise a cavity arranged internally within the vehicle body 201a, 401a as shown in Figs. 2 and 4 (showing a cavity-type container handling vehicles) and as described in e.g. WO2O15/193278A1 and W02019/206488A1, the contents of which are incorporated herein by reference.

[0011] Fig. 3 shows an alternative configuration of a container handling vehicle 301 with a cantilever construction (referred to as a cantilever-type container handling vehicle). Such a vehicle is described in detail in e.g. NO317366, the contents of which are also incorporated herein by reference.

[0012] The cavity-type container handling vehicle 201 shown in Fig. 2 may have a footprint that covers an area with dimensions in the X and Y directions which is generally equal to the lateral extent of a storage column 105, e.g. as is described in WO2O15/193278A1, the contents of which are incorporated herein by reference. The term ‘lateral’ used herein may mean ‘horizontal’.

[0013] Alternatively, the cavity-type container handling vehicles 401 shown in Figs. 4 and 5 may have a footprint which is larger than the lateral area defined by a storage column 105 as shown in Fig. 1 and 4, e.g. as is disclosed in W02014/090684A1 or W02019/206488A1.

[0014] The rail system 108 typically comprises rails with grooves in which the wheels of the vehicles run. Alternatively, the rails may comprise upwardly protruding elements, where the wheels of the vehicles comprise flanges to prevent derailing. These grooves and upwardly protruding elements are collectively known as tracks. Each rail may comprise one track, or each rail 110,111 may comprise two parallel tracks. In other rail systems 108, each rail in one direction (e.g. an X direction) may comprise one track and each rail in the other, perpendicular direction (e.g. a Y direction) may comprise two tracks. Each rail 110,111 may also comprise two track members that are fastened together, each track member providing one of a pair of tracks provided by each rail.

[0015] W02018/146304A1, the contents of which are incorporated herein by reference, illustrates a typical configuration of rail system 108 comprising rails and parallel tracks in both X and Y directions.

[0016] In the frame structure 100, a majority of the columns 105 are storage columns 105, i.e. columns 105 where storage containers 106 are stored in stacks 107. However, some columns 105 may have other purposes. In Fig. 1, columns 119 and 120 are such special-purpose columns used by the container handling vehicles 201,301,401 to drop off and/or pick up storage containers 106 so that they can be transported to an access station (not shown) where the storage containers 106 can be accessed from outside of the frame structure 100 or transferred out of or into the frame structure 100. Within the art, such a location is normally referred to as a ‘port’ and the column in which the port is located maybe referred to as a ‘port column’ 119,120. The transportation to the access station maybe in any direction, that is horizontal, tilted and/or vertical. For example, the storage containers 106 maybe placed in a random or dedicated column 105 within the frame structure 100, then picked up by any container handling vehicle and transported to a port column 119,120 for further transportation to an access station. The transportation from the port to the access station may require movement along various different directions, by means such as delivery vehicles, trolleys or other transportation lines. Note that the term ‘tilted’ means transportation of storage containers 106 having a general transportation orientation somewhere between horizontal and vertical.

[0017] In Fig. 1, the first port column 119 may for example be a drop-off port column where the container handling vehicles 201,301,401 can drop off storage containers 106 to be transported to an access or a transfer station, and the second port column 120 maybe a pick-up port column where the container handling vehicles 201,301,401 can pick up storage containers 106 that have been transported from an access or a transfer station.

[0018] The access station may typically be a picking or a stocking station where product items are removed from or positioned into the storage containers 106. In a picking or a stocking station, the storage containers 106 are normally not removed from the automated storage and retrieval system 1, but are returned into the frame structure 100 again once accessed. A port can also be used for transferring storage containers 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 a lorry), or to a production facility.

[0019] A conveyor system comprising conveyors is normally employed to transport the storage containers between the port columns 119,120 and the access station.

[0020] If the port columns 119,120 and the access station are located at different levels, the conveyor system may comprise a lift device with a vertical component for transporting the storage containers 106 vertically between the port column 119,120 and the access station.

[0021] The conveyor system may be arranged to transfer storage containers 106 between different frame structures, e.g. as is described in W02014/075938A1, the contents of which are incorporated herein by reference.

[0022] A storage system may also use port columns 119,120 to transfer a storage container between the rail system 108 on top of the frame structure 100 and a container transfer vehicle arranged below a lower end of the port column. Such storage systems and suitable container transfer vehicles are disclosed in WO 2019/238694 Al and WO 2019/238697 Al, the contents of which are incorporated herein by reference.

[0023] When a storage container 106 stored in one of the columns 105 disclosed in Fig. 1 is to be accessed, one of the container handling vehicles 201,301,401 is instructed to retrieve the target storage container 106 from its position and transport it to the drop-off port column 119. This operation involves moving the container handling vehicle 201,301,401 to a location above the storage column 105 in which the target storage container 106 is positioned, retrieving the storage container 106 from the storage column 105 using the container handling vehicle’s 201,301,401 lifting device 116, and transporting the storage container 106 to the drop-off port column 119. If the target storage container 106 is located deep within a stack 107, i.e. with one or a plurality of other storage containers 106 positioned above the target storage container 106, the operation also involves temporarily moving the above-positioned storage containers prior to lifting the target storage container 106 from the storage column 105. This step, which is sometimes referred to as “digging” within the art, may be performed with the same container handling vehicle that is subsequently used for transporting the target storage container to the drop-off port column 119, or with one or a plurality of other cooperating container handling vehicles. Alternatively, or in addition, the automated storage and retrieval system 1 may have container handling vehicles 201,301,401 specifically dedicated to the task of temporarily removing storage containers 106 from a storage column 105. Once the target storage container 106 has been removed from the storage column 105, the temporarily removed storage containers 106 can be repositioned into the original storage column 105. However, the removed storage containers 106 may alternatively be relocated to other storage columns 105.

[0024] When a storage container 106 is to be stored in one of the columns 105, one of the container handling vehicles 201,301,401 is instructed to pick up the storage container 106 from the pick-up port column 120 and transport it to a location above the storage column 105 where it is to be stored. After any storage containers 106 positioned at or above the target position within the stack 107 have been removed, the container handling vehicle 201,301,401 positions the storage container 106 at the desired position. The removed storage containers 106 may then be lowered back into the storage column 105, or relocated to other storage columns 105.

[0025] For monitoring and controlling the automated storage and retrieval system 1, e.g. monitoring and controlling the location of respective storage containers 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 that a desired storage container 106 can be delivered to the desired location at the desired time without the container handling vehicles 201,301,401 colliding with each other, the automated storage and retrieval system 1 comprises a control system 500 which typically is computerized and which typically comprises a database for keeping track of the storage containers 106. [0026] An aim of the invention is to provide a vehicle which can operate on a rail system and which has the possibility of transporting a large number of storage containers.

SUMMARY OF THE INVENTION

[0027] This summary is provided to introduce in simplified form a selection of concepts that are further described herein. The summary is not intended to identify key or essential features of the invention.

[0028] The present invention is set forth and characterized in the independent claims, while the dependent claims define other optional features.

[0029] At least preferred embodiments of the invention relate to a transporter which can transport a large number of storage containers at the same time.

[0030] It is described a transporter configured to operate on a rail system, wherein the transporter comprises:

- a first wheeled base and a second wheeled base, each of the first wheeled base and the second wheeled base comprising a first set of wheels for moving in a first direction and a second set of wheels for moving in a second direction, wherein the second direction is perpendicular to the first direction;

- a transporter framework structure extending between the first and second wheeled bases, wherein the transporter framework structure defines an internal storage system comprising a plurality of transporter storage columns for storing stacks of storage containers on top of each other.

[0031] Having a first and a second wheeled base makes a more modular system as the transporter can be made larger or smaller dependent on the requirements.

[0032] The transporter can be a rail-bound vehicle where the first and second sets of heels of the wheeled bases drive in tracks of the rail system.

[0033] The transporter can be used for transporting storage containers from grid to port area, and or it can function as a buffer for storage containers to be picked at an access station.

[0034] Additionally, the transporter can be used for transporting storage containers between separate grids that are connected with a rail system. [0035] The least first wheeled base and the second wheeled base may be spaced apart from each other.

[0036] If operating on grid storage system, the first and second wheeled bases may be spaced apart from each other at a distance equal to an integer number of grid cells.

[0037] Alternatively or additionally, the first and second wheeled bases may be spaced apart from each other at a distance equal to an integer number of wheeled bases. In this regard, it will be advantageous if the wheeled bases are identical to each other.

[0038] This provides for the opportunity of a larger transporter framework structure.

[0039] The first wheeled base and the second wheeled base may be structurally identical.

[0040] Making the wheeled bases identical, eases manufacturing and thus lowers the cost.

[0041] The transporter storage columns each have an open upper end such that the storage containers can be inserted into, and retrieved out from, the transporter storage columns through said open upper ends.

[0042] The first set of wheels and the second set of wheels of each of the first wheeled base and second wheeled base may comprise four wheels, and wherein two wheels may be arranged on each four sides of the wheeled base.

[0043] The transporter framework structure may comprise a platform supported by the first wheeled base and the second wheeled base and wherein the transporter framework structure may comprise transporter upright members may extend from the platform and defining the transporter storage columns for storing the stacks of storage containers.

[0044] The platform thus supports the upright members of the framework structure. The platform may be a continuous base extending between the first and second wheeled bases. The platform may also function as a floor for supporting the stacks of storage containers within the framework structure.

[0045] The transporter may comprise a transporter transfer column may extend from an open upper end in the same plane as open upper ends of the transporter storage columns to an open lower end, and wherein the transporter transfer column may be arranged between the first and second wheeled bases and may be configured for allowing transfer of a storage container to a position below the transporter.

[0046] The position below the transporter can typically be in a storage grid below the underlying rail system that the transporter is running on.

[0047] The platform may have an opening in order to allow for a storage container to pass through.

[0048] The transporter may comprise a third wheeled base and a fourth wheeled base, each of the third wheeled base and the fourth wheeled base may comprise a first set of wheels for moving in the first direction and a second set of wheels for moving in the second direction, and wherein the transporter framework structure may extend between the first wheeled base, the second wheeled base, the third wheeled base and the fourth wheeled base.

[0049] Four wheeled bases provide a more stable transporter.

[0050] Additional wheel bases are also possible. For example, one or more wheel bases may be in the middle of larger transporters.

[0051] First wheeled base may be arranged in a first corner of the transporter, the second wheeled base may be arranged in a second corner of the transporter, the third wheeled base may be arranged in a third corner of the transporter, and the fourth wheeled base may be arranged in a fourth corner of the transporter, wherein the first corner, the second corner, the third corner and the fourth corner together form a rectangular shape.

[0052] Four wheeled bases arranged in corners of a rectangle provide an even more stable transporter.

[0053] The present invention also relates to a a rectangular shape with length and width dimensions corresponding to an integer number of grid cells.

[0054] The four wheeled bases may be in the same plane.

[0055] Each of the wheeled bases may comprise a rechargeable battery and wherein the rechargeable battery of the different wheeled bases may be connected to each other such that all batteries can be charged via a common charging connector on one of the wheeled bases. [0056] Such a setup will simplify charging.

[0057] The transporter may comprise a central battery common for all of the wheel bases and for powering all of the wheeled bases.

[0058] Such a setup will simplify charging.

[0059] The transporter framework structure may comprise cross-bracing members on one or more sides of the framework structure.

[0060] The cross-bracing members may provide a cage-like structure for providing the necessary rigidity to the structure in order to support the rail structure and container handling vehicle on top of it. In addition, the crossbracing members secure the storage containers which are stored within the storage columns of the framework structure from falling out. The cross-bracing members may be panels, covers, rods, struts or plates on one or more of the sides, i.e. outer surfaces) of the transporter.

[0061] The transporter may comprise a gantry container handling device at a level above the transporter storage columns.

[0062] The gantry container handling device can be arranged on the framework structure and move in a plane above the storage columns.

[0063] The gantry container handling device may be movable in the first direction and in the second direction.

[0064] The gantry container handling device may comprise a movable trolley and a lifting frame suspended from the movable trolley, and wherein the lifting frame may be connectable to a storage container from above.

[0065] The transporter may comprise a picking device for picking items from a storage container stored in the transporter storage columns.

[0066] The picking device spans across the transporter storage columns and may be configured to pick items from storage containers stored in any of the transporter storage columns.

[0067] This fact, i.e. that the picking device 700 may be able to access multiple locations within the transporter storage columns 504 completely removes, or at least minimizes, the need for another picking device 700 on the same transporter 501. However, if it is more convenient to have an additional picking device 700 on the transporter 501, this is also possible.

[oo68] The transporter may comprise a controller for controlling the gantry container handling device and/ or the picking device.

[0069] The picking device may consolidate orders in one or more storage containers. Alternatively, or additionally, the picking device may sort items between one or more storage containers.

[0070] The transporter may comprise a protective structure for protecting the gantry container handling device and/ or the picking device.

[0071] The protective structure ensures that storage containers handled by the container handling device are prevented from falling down.

[0072] The present invention also relates to an automated storage and retrieval system comprising:

- a storage grid with a rail system, the rail system comprising a first set of parallel rails arranged to guide movement of vehicles in the first direction, and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the vehicles in a second direction which is perpendicular to the first direction, the first and second sets of parallel rails forming a grid which divides the rail system into a plurality of grid cells;

- a plurality of container handling vehicles operating on the rail system of the storage grid; and

- a transporter as defined above arranged to operate on the rail system of the storage grid.

[0073] Each of the first and second wheeled bases of the transporter may be identical in size to a grid cell.

[0074] The distance between the wheeled bases may be equal to one grid cell. Alternatively, the distance between the wheeled bases may be equal to two grid cells, three, grid cells, four grid cells etc. In either case, the distance may be equal to an integer number of grid cells of the underlying rail system such that the wheeled base footprint matches an underlying grid cell of the rail system which e.g. makes it easier to determine and decide where to position the one or more transporter storage columns. [0075] The present invention also relates to a method of transferring a storage container in an automated storage and retrieval system as defined above between a transporter storage column of the internal storage system of the transporter operating on the rail system and a storage column of the underlying storage grid, the method comprising the steps of:

- using a gantry container handling device of the transporter to pick up the storage container from the transporter storage column of the internal storage system;

- delivering the storage container to the storage column of the underlying storage grid.

[0076] The method may comprise delivering the storage container to the storage column of the underlying rail system through a transporter transfer column.

[0077] The present invention also relates to a method of moving an item from a first storage container to a second storage container, wherein the first and second storage containers are stored in a transporter as defined above, wherein the method comprises: using a picking device of the transporter to pick the item.

[0078] The present invention also relates to a method of temporary storing a non-target storage container while digging for a target storage container in a storage grid by using the system as defined above, wherein the method comprises the steps of: a) using the gantry container handling device to pick up a non-target storage container which is positioned above the target storage container in the storage column of the storage grid; b) positioning the non-target storage container in the transporter storage columns of the internal storage system; c) repeating steps a) and b) until the target storage container is retrievable; d) using the gantry container handling device or a container handling vehicle operating on the rail system to pick up the target storage container.

[0079] The present invention also relates to use of a transporter as defined above for transporting a plurality of storage containers on a delivery rail system arranged at a level below a first rail system of a first storage grid and a second rail system of a second storage grid, wherein the delivery rail system extends between the first storage grid and the second storage grid. [0080] The present invention also relates to use of a transporter as defined above for transporting a plurality of storage containers to a port area of a storage grid.

[0081] The automated storage and retrieval system may comprise a plurality of upright members and each storage column is defined by four of the upright members.

[0082] The rail system may be arranged on top of the upright members, the rail system comprising a first set of parallel rails and a second set of parallel rails arranged perpendicular to the first set of rails. The first and second set of rails providing a horizontal grid-based rail system defining a plurality of grid cells. The first and second set of rails of the rail system may comprise one or two tracks. Preferably both directions of rail comprise two tracks (double tracks), e.g., either as two parallel channels formed in a rail, or as a channel provided in each of a pair of rail members that have been fastened to the other to form a rail. In such arrangements the access opening (also named grid opening) and a trackwidth on each side defines the “grid cell”. In arrangements where one direction of rails has only a single track, the grid cell may extend a full rail-width on those sides.

[0083] In the present specification the term “storage container” is intended to mean any goods holder unit having a bottom plate and side portions suitable for releasable connection to the container lift device, e.g. a bin, a tote, a tray or similar. The side portions may preferably comprise gripping recesses. The side portions are preferably sidewalls. The height of the sidewalls may vary depending on the intended use of the automated storage and retrieval system and the goods to be stored. The gripping recesses may be arranged at an upper rim of the sidewalls. The outer horizontal periphery of the storage container is preferably rectangular.

[0084] For monitoring and controlling the transporter, e.g. monitoring and controlling the location of the transporter, the respective storage containers within the transporter framework structure and the storage positions within the storage grid, the content of each storage container, and the movement of the transporter and any container handling vehicles such that a desired storage container can be delivered to the desired location at the desired time without the transporter and the container handling vehicles colliding with each other, the automated storage and retrieval system comprises a control system which typically is computerized and which typically comprises a database for keeping track of the storage containers.

[0085] The relative terms “upper”, “lower”, “below”, “above”, “higher” etc. shall be understood in their normal sense and as seen in a cartesian coordinate system.

[0086] The invention may be used in connection with storage containers and systems as described above. However, other areas where the disclosed automated storage and retrieval system and methods may be used is within vertical farming, micro-fulfilment or grocery/e-grocery.

BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Following drawings are appended to facilitate the understanding of the invention. The drawings show embodiments of the invention, which will now be described by way of example only, where:

[0088] Fig. 1 is a perspective view of a frame structure of a prior art automated storage and retrieval system;

[0089] Fig. 2 is a perspective view of a prior art container handling vehicle having an internally arranged cavity for carrying storage containers therein;

[0090] Fig. 3 is a perspective view of a prior art container handling vehicle having a cantilever for carrying storage containers underneath;

[0091] Fig. 4 is a perspective view, seen from below, of a prior art container handling vehicle having an internally arranged cavity for carrying storage containers therein;

[0092] Fig. 5A is a side perspective view of a transporter operating on a rail system, the transporter comprises wheeled bases and a transporter framework structure which extends between the wheeled bases;

[0093] Fig. 5B and 5C show an exemplary wheeled base for the transporter;

[0094] Fig. 6A is a side perspective view of a transporter operating on a rail system, the transporter comprises wheeled bases and a transporter framework structure which extends between the wheeled bases, and wherein an upper level of the transporter framework structure is provided with a transporter rail system for supporting a container handling vehicle; [0095] Fig- 6B is a side perspective view of a transporter operating on a rail system, the transporter comprises wheeled bases and a transporter framework structure which extends between the wheeled bases, and wherein an upper level of the transporter framework structure is provided with a transporter rail system and wherein a container handling vehicle operates on the transporter rail system;

[0096] Fig. 6C is a top perspective view of Fig. 6B;

[0097] Fig. 6D is a side perspective view of the transporter of Figs. 6A-6C on a rail system;

[0098] Fig. 7 is a side perspective view of a transporter for operation on a rail system, the transporter comprises wheeled bases and a transporter framework structure which extends between the wheeled bases, and wherein the transporter comprises a gantry container handling device;

[0099] Fig. 8A is a side perspective view of a transporter for operation on a rail system, the transporter comprises wheeled bases and a transporter framework structure which extends between the wheeled bases, and wherein the transporter comprises a gantry container handling device and a picking device;

[00100] Fig. 8B shows the transporter of Fig. 8A from another side;

[00101] Fig. 8C shows the transporter of Figs. 8A and 8B on a rail system;

[00102] Fig. 9 is a side perspective view of two automated storage and retrieval systems which are connected via a delivery rail system, transporters operating on the delivery rail system, and wherein the storage and retrieval systems comprises a tunnel for the transporters to enter in order to receive storage containers from container handling vehicles operating above.

DETAILED DESCRIPTION OF THE INVENTION

[00103] In overview, a transporter (501) is provided. The transporter (501) is configured to operate on a rail system (108). The transporter (501) comprises: a first wheeled base (502’), a second wheeled base (502”) and a transporter framework structure(5O3). Each of the first wheeled base (502’) and the second wheeled base (502”) comprises a first set of wheels (501b) for moving in a first direction (X) and a second set of wheels (501c) for moving in a second direction (Y), wherein the second direction (Y) is perpendicular to the first direction (X). The transporter framework structure (503) extends between the first and second wheeled bases (502’, 502”). The transporter framework structure (503) defines an internal storage system comprising a plurality of transporter storage columns (504) for storing stacks (505) of storage containers (106) on top of each other.

[00104] In the following, embodiments of the invention will be discussed in more detail with reference to the appended drawings. It should be understood, however, that the drawings are not intended to limit the invention to the subject-matter depicted in the drawings.

[00105] A framework structure 100 of the automated storage and retrieval system 1 may be constructed in a similar manner to the prior art framework structure 100 described above in connection with Figs. 1-3. That is, the framework structure 100 may comprise a number of upright members 102, and comprise a first, upper rail system 108 extending in the X direction and Y direction.

[00106] The prior art framework structure 100 may further comprise storage compartments in the form of storage columns 105 provided between the members 102 wherein storage containers 106 maybe stackable in stacks 107 within the storage columns 105.

[00107] The framework structure 100 can be of any size. In particular it is understood that the framework structure can be considerably wider and/or longer and/or deeper than disclosed in Fig. 1. For example, the framework structure 100 may have a horizontal extent of more than 700x700 columns and a storage depth of more than twelve containers.

[00108] Fig. 5A is a side perspective view of a transporter 501 operating on a rail system 108 of a storage grid. The rail system 108 comprising a first set of parallel rails no arranged to guide movement of vehicles in the first direction X, and a second set of parallel rails 111 arranged perpendicular to the first set of rails no to guide movement of the vehicles in a second direction Y which is perpendicular to the first direction X The first and second sets of parallel rails 110,111 forming a grid which divides the rail system 108 into a plurality of grid cells 122. The transporter 501 in Fig. 5 has four wheeled bases

502’, 502”, 502”’, 502”” (the fourth wheeled base 502”” not shown in the Figure). [00109] The transporter 501 further comprising a transporter framework structure 503 extending between the wheeled bases 502’, 502”, 502”’, 502””. The transporter framework structure 503 defines an internal storage system of the transporter 501 comprising a plurality of transporter storage columns 504 for storing stacks 505 of storage containers 106 on top of each other.

[00110] The transporter framework structure 503 comprises a platform 509 supported by the wheeled bases 502’, 502”, 502”’, 502””. The transporter framework structure 503 comprises transporter upright members 512 extending from the platform 509 and defining the transporter storage columns 504 for storing the stacks 505 of storage containers 106. The platform 509 thus supports the transporter upright members 512 of the transporter framework structure 503. The platform 509 maybe a continuous base extending between the wheeled bases 502’, 502”, 502”’, 502””. The platform 509 may also function as a floor for supporting the stacks 505 of storage containers 106 within the transporter framework structure 503.

[00111] The dimensions and configurations between the transporter framework structure 503 and the framework structure 100 of the grid are preferably similar and they are preferably able to align. The transporter storage columns 504 and the storage columns 105 are both preferably configured to receive the same storage containers 106 so they are of the same size and the same orientation. The height of the transporter 501 will be set to receive a suitable number of storage containers 106 stacked on top of each other. The transporter 501 in Fig. 5 has 34 x 3 footprint, however other footprints are possible. The transporter 501 of Fig. 5A has two transporter transfer columns 514 and ten transporter storage columns 504. The transporter stacks 505 of the transported storage containers 106 are shown as being three storage containers 106 high, but may be of other heights as well, such as two, four, five, six etc. storage containers 106 high. The transporter 501 in Fig. 5A can carry up to 30 storage containers 106.

[00112] The transporter framework structure 503 comprises cross-bracing members 513 on one or more sides of the transporter 501 for stabilizing the transporter framework structure 503. The cross-bracing members 513 is disclosed as providing a cage-like structure for providing the necessary rigidity to the transporter framework structure 503 in order to secure the storage containers 106 which are stored within the transporter storage columns 504 of the transporter framework structure 503 from falling out. The cross-bracing members may be panels, covers, rods, struts or plates on one or more of the sides, i.e. outer surfaces) of the transporter.

[00113] The cross-bracing members 513 may be mounted to the wheeled bases with fasteners (not shown).

[00114] An exemplary wheeled base 502’, 502”, 502”’, 502”” for a transporter 501 is shown in Figs. 5B and 5C. The wheeled base 502’, 502”, 502”’, 502”” features a wheel arrangement 501b, 501c having a first set of wheels 501b for movement in the first direction X upon a rail system and a second set of wheels 502b for movement in the second direction Y. Each set of wheels comprises two pairs of wheels arranged on opposite sides of the wheeled base

502’, 502”, 502”’, 502””. To change the direction in which the wheeled base 502’, 502”, 502”’, 502”” may travel upon the rail system 108, one of the sets of wheels 501b is connected to a wheel displacement assembly 7. The wheel displacement assembly 7 is able to lift and lower the connected set of wheels 501b relative to the other set of wheels 501a such that only the set of wheels travelling in a desired direction is in contact with the rail system 108. The wheel displacement assembly 7 is driven by an electric motor 8. Further, two electric motors 4,4’, powered by a rechargeable battery 6, are connected to the set of wheels 501b, 501c to move the wheeled base 502’, 502”, 502”’, 502”” in the desired direction. The rechargeable batteries 6 can be connected to each other such that all batteries can be charged via a common charging connector on one of the wheeled bases 502’, 502”, 502”’, 502””. Alternatively, the wheeled bases 502’, 502”, 502”’, 502”” may be powered by a central battery common for all of the wheeled bases 502’, 502”, 502”’, 502””. Such a setup will simplify charging.

[00115] Further referring to Figs. 5B and 5C, the horizontal periphery of the wheeled base 502’, 502”, 502”’, 502”” is dimensioned to fit within the horizontal area defined by a grid cell 122 of the rail system 108. In other words, the wheeled base 502’, 502”, 502”’, 502”” may have a footprint, i.e. an extent in the X and Y directions, which is generally equal to the horizontal area of a grid cell 122, i.e. the extent of a grid cell in the X and Y directions, e.g. as is described in WO2O15/193278A1.

[00116] Referring to Fig. 5C, the wheeled base 502’, 502”, 502”’, 502”” has a top panel/flange 9 (i.e. an upper surface) configured as a connecting interface for the transporter framework structure 503. The top panel 9 has a centre opening 20 and features multiple through-holes 10 (i.e. connecting elements) suitable for a bolt connection via corresponding through-holes in a lower section (e.g. a platform 509) of the transporter framework structure 503. In other embodiments, the connecting elements of the top panel 9 may for instance be threaded pins for interaction with the through-holes of the lower section. The presence of a centre opening 20 is advantageous as it provides access to internal components of the wheeled base 502’, 502”, 502”’, 502””, such as the rechargeable battery 6 and an electronic control system 21.

[00117] The wheeled bases 502’, 502”, 502”’, 502”” of the transporter 501 in Fig. 5A is spaced apart from each other at a distance equal to an integer number of grid cells 122. The wheeled bases 502’, 502”, 502”’, 502”” have a height which is taller than the height of the wheels, large enough to provide a box to put everything in but not taller than a storage container 106. The wheeled bases 502’, 502”, 502”’, 502”” maybe linkable to each other so that one master module can take control of slave modules in order to allow synchronous movement both on the rail system 108 and up and down in the z direction (when changing direction on the rail system 108). The modules may communicate through wired or wireless connection.

[00118] Figs. 6A-6D are different views of a transporter 501 with a transporter rail system 508 on top, where:

Fig. 6A is a side perspective view of a transporter 501 operating on a rail system 108,

Fig. 6B is a side perspective view of the transporter 501 of Fig. 6A with a container handling vehicle 301 operating on the transporter rail system 508, Fig. 6C is a top perspective view of Fig. 6B, and

Fig. 6D is a side perspective view of the transporter 501 of Figs. 6A-6C on a rail system 108. In all Figs. 6A-6D it is shown a transporter 501 comprising wheeled bases 502’, 502”, 502”’, 502”” and a transporter framework structure 503 which extends between the wheeled bases 502’, 502”, 502”’, 502””.

[00119] An upper level of the transporter framework structure 503 is provided with a transporter rail system 508 for supporting a container handling vehicle (see Figs. 6B-6D). Except for the transporter rail system 508 and the protective structure 510, the transporter 501 in the embodiment of Figs. 6A-6D has all features of the transporter 501 in Fig. 5. These common features will not be repeated herein. The protective structure 510 ensures that no container handling vehicles 301 operating on the transporter rail system 508 accidentally fall down. Similarly, storage containers 106 handled by the container handling vehicles 301 operating on the transporter rail system 508 are prevented from falling down. [00120] The transporter rail system 508 and the underlying rail system 108 of the storage grid are preferably the same - e.g., a double-double track rail system of the same track width. The rail system 108 and transporter rail system 508 typically comprise rails with grooves into which the wheels of the vehicles are inserted. Alternatively, the rails may comprise upwardly protruding elements, where the wheels of the vehicles comprise flanges to prevent derailing. These grooves and upwardly protruding elements are collectively known as tracks. Each rail may comprise one track, or each rail may comprise two parallel tracks (so-called ’’double tracks”). W02018146304, the contents of which are incorporated herein by reference, illustrates a typical configuration of rail system 108 comprising rails and parallel tracks in both X and Y directions.

[00121] The container handling vehicle 301 may comprise a lifting device 315 for vertical transportation of storage containers 106, i.e. raising a storage container 106 and lowering a storage container 106. The lifting device 315 comprises a lifting frame 316 which comprises one or more gripping / engaging devices (not shown) which are adapted to engage a storage container 106, and which gripping / engaging devices can be lowered from the vehicle 301 so that the position of the gripping / engaging devices with respect to the vehicle 301 can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y. The gripping device comprises grippers which can enter into gripper holes 130 on the storage 106 containers. The gripper holes 130 maybe on an upper rim of the storage container 106 such that the grippers can enter the gripper holes 130 from above and thus lift the storage container 106 from above. The storage containers 106 are shown with four gripper holes 130.

[00122] The lifting frame 316 can be suspended from the container handling vehicle 301 via flexible lifting members 317 such as lifting bands, lifting wires, lifting cables etc. The flexible lifting members 317 may provide a signal and communication between the container handling vehicle 301 and the lifting frame 316, e.g. for activation and/or deactivation of the gripping / engaging devices (not shown) on the lifting frame 316.

[00123] The container handling vehicle 301 on the transporter may require lengthened lifting bands 317 in order to reach a full height of a deep digging process in the storage grid below.

[00124] If using the cantilever-type container handling vehicles 301 as shown in Figs 6B-6D, in order to reach all of the transporter storage columns 504 and transporter transfer columns 514, there maybe at least two container handling vehicles 301 on the transporter rail system 508, where at least two of the vehicles 301 are oriented in opposite directions, e.g. North/South facing and South/North facing.

[00125] Although only a cantilever-type prior art container handling vehicle 301 has been shown in Figs. 6B-6D, it is clear that any of the prior art container handling vehicles 201,301,401 of Figs. 2-4 can be used.

[00126] Fig. 7 is a side perspective view of a transporter 501 for operation on a rail system 108, the transporter 501 comprises wheeled bases 5O2’,5O2”,5O2”’,5O2””and a transporter framework structure 503 which extends between the wheeled bases 502’, 502”, 502”’, 502””, and wherein the transporter 501 comprises a gantry container handling device 600. Except for the gantry container handling device 600 and the protective structure 510, the transporter 501 in the embodiment of Fig. 7 has all features of the transporter 501 in Fig. 5. These common features will not be repeated herein.

[00127] The gantry container handling device 600 is arranged at a level above the transporter storage columns 504. The gantry container handling device 600 is movable in the first direction X and in the second direction Y. The gantry container handling device 600 comprises a movable trolley 602 and a lifting frame 601 suspended from the movable trolley 602. The lifting frame 601 is connectable to a storage container 106 from above and is configured for vertical transportation of storage containers 106, i.e. raising a storage container 106 and lowering a storage container 106. The lifting frame 601 comprises one or more gripping / engaging devices 605 which are adapted to engage a storage container 106, and which gripping / engaging devices can be lowered from the trolley 602 so that the position of the gripping / engaging devices with respect to the transporter 501 can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y. The gripping device comprises grippers which can enter into gripper holes 130 on the storage 106 containers. The gripper holes 130 maybe on an upper rim of the storage container 106 such that the grippers can enter the gripper holes 130 from above and thus lift the storage container 106 from above. The storage containers 106 are shown with four gripper holes 130.

[00128] The lifting frame 601 can be suspended from the trolley 602 via flexible lifting members (not shown) such as lifting bands, lifting wires, lifting cables etc. The flexible lifting members may provide a signal and communication between the trolley 602 and the lifting frame 601, e.g. for activation and/or deactivation of the gripping / engaging devices 605 on the lifting frame 601.

[00129] The trolley 602 may require lengthened lifting bands in order to reach a full height of a deep digging process in the storage grid below.

[00130] The trolley 602 is movable along a beam 603 in the Y direction and the beam 603 is moveable along the protective structure 610 in the X direction via e.g. rollers or wheels. As such, the lifting frame 601 of the gantry container handling device 600 can access all of the transporter storage columns 504 and the transporter transfer columns 514 such that the lifting frame 601 of the gantry container handling device 600 can pick up and deliver storage containers to all of the transporter storage columns 504 as well as picking up storage containers stored in a storage grid below the transporter 501.

[00131] Fig. 8A is a side perspective view of a transporter 501 operating on a rail system 108, the transporter 501 comprises wheeled bases

502’, 502”, 502”’, 502”” and a transporter framework structure 503 which extends between the wheeled bases 502’, 502”, 502”’, 502””.

[00132] The transporter 501 comprises a gantry container handling device 600 as disclosed in Fig. 7 and a picking device 700. The picking device 700 may span across the transporter storage columns 504 and is configured to pick items from storage containers 106 stored in any of the transporter storage columns 504. This fact, i.e. that the picking device 700 maybe able to access multiple locations within the transporter storage columns 504 completely removes, or at least minimizes, the need for another picking device 700 on the same transporter 501. However, if it is more convenient to have an additional picking device 700 on the transporter 501, this is also possible.

[00133] The picking device 700 maybe any suitable device for picking product items from a storage container 106. The picking device 700 may move all product item(s) from one container 106 into another, for example combining partially empty storage containers 106 to make a full container and a spare empty container. Conversely, the picking device 700 could distribute product items from a container 106 to ensure multiple storage containers have the needed product item, increasing access efficiency for that product item type.

[00134] The picking device 700 maybe configured to re-organize or re-arrange product item(s) within a storage container 106, and/or move product item(s) between storage containers. The picking device 700 maybe configured to transfer product items between storage containers 106 prior to at least one of the storage containers being presented for picking of product items therein. Therefore, the robotic operators may be configured to organize product items, and/or maybe used to cultivate the contents of storage containers. This maybe advantageous for example in the event that one storage container is almost empty and that the remaining item(s) is moved to another storage container with the same product item(s).

[00135] Furthermore, the picking device 70 may move product item(s) from one or more storage containers 106 into a storage container used for consolidation of product orders for finishing or partly finishing product orders before presenting at the handling or picking station or to an item consolidating area.

[00136] The picking device 700 maybe in the form of at least one robot arm supported on top of the transporter framework structure 503.

[00137] The transporter 501 may comprise a protective structure 510 for protecting the gantry container handling device 600 and/or the picking device 700 from falling down. Additionally, the protective structure 510 assist in preventing storage containers handled by the gantry container handling vehicle 600 as well as items handled by the picking device 700 from falling or dropping down.

[00138] Except for the gantry container handling device 600, the protective structure 510, and the picking device 700, the transporter 501 in the embodiment of Fig. 8A has all features of the transporter 501 in Fig. 5. These common features will not be repeated herein.

[00139] Fig. 8B shows the transporter 501 of Fig. 8A from another side.

[00140] Fig. 8C shows the transporter 501 of Figs. 8A and 8B on a rail system 108.

[00141] Fig. 9 is a side perspective view of two automated storage and retrieval systems 1 which are connected via a delivery rail system 800, i.e. a first rail system 108’ of a first storage grid 1 and a second rail system 108” of a second storage grid 1. Two transporters 501 are disclosed operating on the delivery rail system 800. The delivery rail system 800 is arranged at a level below the first rail system 108’ and the second rail system 108”. Each of the storage and retrieval systems comprises a tunnel 2 for the transporters 501 to enter in order to receive storage containers from container handling vehicles (not shown) operating on a rail system 108’, 108” above and thus being able to transport a plurality of storage containers between the first storage grid 1 and the second storage grid 1. The transporters 501 in Fig. 9 are similar to the transporter 501 described in relation to Fig. 5A and will not be described in greater detail herein.

[00142] Preferably, the transporter rail system 508, the rail system 108’, 108” of the storage grid 1 and the delivery rail system 800 are preferably the same - e.g., a double-double track rail system of the same track width. The rail system 108’, 108”, transporter rail system 508 and the delivery rail system 800 typically comprise rails with grooves into which the wheels of the vehicles are inserted.

[00143] In the preceding description, various aspects of the delivery vehicle and the automated storage and retrieval system according to the invention have been described with reference to the illustrative embodiment. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the system and its workings. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the illustrative embodiment, as well as other embodiments of the system, which are apparent to persons skilled in the art to which the disclosed subject matter pertains, are deemed to lie within the scope of the present invention.

List of reference numbers

Claims

1. A transporter (501) configured to operate on a rail system (108), wherein the transporter (501) comprises:

- a first wheeled base (502’) and a second wheeled base (502”), each of the first wheeled base (502’) and the second wheeled base (502”) comprising a first set of wheels (501b) for moving in a first direction (X) and a second set of wheels (501c) for moving in a second direction (Y), wherein the second direction (Y) is perpendicular to the first direction (X);

- a transporter framework structure (503) extending between the first and second wheeled bases (502’, 502”), wherein the transporter framework structure (503) defines an internal storage system comprising a plurality of transporter storage columns (504) for storing stacks (505) of storage containers (106) on top of each other.

2. The transporter according to claim 1, wherein the least first wheeled base (502’) and the second wheeled base (502”) are spaced apart from each other.

3. The transporter according to claim 2, wherein the first wheeled base (502’) and the second wheeled base (502”) are structurally identical.

4. The transporter (501) according to any of the preceding claims, wherein the transporter storage columns (504) each have an open upper end (511) such that the storage containers (106) can be inserted into, and retrieved out from, the transporter storage columns (504) through said open upper ends (511).

5. The transporter (501) according to any of the preceding claims, wherein the first set of wheels (501b) and the second set of wheels (501c) of each of the first wheeled base (502’) and second wheeled base (502”) comprises four wheels, and wherein two wheels are arranged on each four sides of the wheeled base (502’, 502”).

6. The transporter (501) according to any of the preceding claims, wherein the transporter framework structure (503) comprises a platform (509) supported by the first wheeled base (502’) and the second wheeled base (502”) and wherein the transporter framework structure (503) comprises transporter upright members (512) extending from the platform (509) and defining the transporter storage columns (504) for storing the stacks (505) of storage containers (106).

7. The transporter (501) according to any of the preceding claims, wherein the transporter comprises a transporter transfer column (514) extending from an open upper end in the same plane as open upper ends (11) of the transporter storage columns (504) to an open lower end, and wherein the transporter transfer column (514) is arranged between the first and second wheeled bases (502’, 502”) and is configured for allowing transfer of a storage container (106) to a position below the transporter (501).

8. The transporter (501) according to any of the preceding claims, wherein the transporter (501) comprises a third wheeled base (502”’) and a fourth wheeled base (502””), each of the third wheeled base (502”’) and the fourth wheeled base (502””) comprising a first set of wheels (501b) for moving in the first direction (X) and a second set of wheels (501c) for moving in the second direction (Y), and wherein the transporter framework structure (503) extends between the first wheeled base (502’), the second wheeled base (502”), the third wheeled base (502”’) and the fourth wheeled base (502””).

9. The transporter (501) according to claim 8, wherein first wheeled base (502’) is arranged in a first corner of the transporter, the second wheeled base (502”) is arranged in a second corner of the transporter, the third wheeled base (502”’) is arranged in a third corner of the transporter, and the fourth wheeled base (502””) is arranged in a fourth corner of the transporter, wherein the first corner, the second corner, the third corner and the fourth corner together form a rectangular shape.

10. The transporter (501) according to any of the preceding claims, wherein each of the wheeled bases (502’, 502”, 502”’, 502””) comprises a rechargeable battery (6) and wherein the rechargeable battery (6) of the different wheeled bases (502’, 502”, 502”’, 502””) are connected to each other such that all batteries can be charged via a common charging connector on one of the wheeled bases (502’, 502”, 502”’, 502””).

11. The transporter (501) according to any of the preceding claims 1-9, wherein the transporter (501) comprises a central battery common for all of the wheel bases (502’, 502”, 502”’, 502””) and for powering all of the wheeled bases (502’, 502”, 502”’, 502””).

12. The transporter (501) according to any of the preceding claims, wherein the transporter framework structure (503) comprises cross-bracing members (513) on one or more sides of the framework structure (503).

13. The transporter (501) according to any of the preceding claims, wherein the transporter (501) comprises a gantry container handling device (600) at a level above the transporter storage columns (504).

14. The transporter (501) according to claim 13, wherein the gantry container handling device (600) is movable in the first direction (X) and in the second direction (Y).

15. The transporter (501) according to claim 13 or 14, wherein the gantry container handling device (600) comprises a movable trolley (602) and a lifting frame (601) suspended from the movable trolley (602), and wherein the lifting frame (601) is connectable to a storage container (106) from above.

16. The transporter (501) according to any of the preceding claims, wherein the transporter (501) comprises a picking device (700) for picking items from a storage container (106) stored in the transporter storage columns (504).

17. The transporter (501) according to claim 16, wherein the picking device (700) spans across the transporter storage columns (504) and is configured to pick items from storage containers (106) stored in any of the transporter storage columns (504).

18. The transporter (501) according to cany of the preceding claims 13-17, wherein the transporter (501) comprises a controller for controlling the gantry container handling device (600) and/or the picking device (700).

19. The transporter (501) according to any of the preceding claims 13-18, wherein the transporter (501) comprises a protective structure (510) for protecting the gantry container handling device (600) and/or the picking device (700).

20. An automated storage and retrieval system (1) comprising:

- a storage grid with a rail system (108), the rail system (108) comprising a first set of parallel rails (110) arranged to guide movement of vehicles in the first direction (X), and a second set of parallel rails (111) arranged perpendicular to the first set of rails (no) to guide movement of the vehicles in a second direction (Y) which is perpendicular to the first direction (X), the first and second sets of parallel rails (110,111) forming a grid which divides the rail system (108) into a plurality of grid cells (122);

- a plurality of container handling vehicles (201,301,401) operating on the rail system (108) of the storage grid; and

- a transporter (501) according to any of the preceding claims arranged to operate on the rail system (108) of the storage grid.

21. The automated storage and retrieval system according to claim 20, wherein each of the first and second wheeled bases (502’, 502”) of the transporter (501) is identical in size to a grid cell (122).

22. A method of transferring a storage container in an automated storage and retrieval system according to claims 20-21, between a transporter storage column (504) of the internal storage system of the transporter (501) operating on the rail system and a storage column of the underlying storage grid, the method comprising the steps of:

- using a gantry container handling device (600) of the transporter (501) to pick up the storage container (106) from the transporter storage column (504) of the internal storage system;

- delivering the storage container (106) to the storage column of the underlying storage grid.

23. The method according to claim 22, wherein the method comprises delivering the storage container (106) to the storage column of the underlying rail system (108) through a transporter transfer column (514).

24.A method of moving an item from a first storage container (106) to a second storage container (106), wherein the first and second storage containers (106) are stored in a transporter (501) according to any of claims 1-19, wherein the method comprises:

- using a picking device (700) of the transporter (501) to pick the item.

25. A method of temporary storing a non-target storage container (106) while digging for a target storage container (106) in a storage grid by using the system according to claims 13-15, wherein the method comprises the steps of: a) using the gantry container handling device (600) to pick up a nontarget storage container (106) which is positioned above the target storage container in the storage column of the storage grid; b) positioning the non-target storage container(s) (106) in the transporter storage columns (504) of the internal storage system; c) repeating steps a) and b) until the target storage container (106) is retrievable; d) using the gantry container handling device (600) or a container handling vehicle (201,301,401) operating on the rail system (108) to pick up the target storage container (106).

26. Use of a transporter (501) according to any of the preceding claims 1-18 for transporting a plurality of storage containers (106) on a delivery rail system arranged at a level below a first rail system (108’) of a first storage grid and a second rail system (108”) of a second storage grid, wherein the delivery rail system extends between the first storage grid and the second storage grid.

27. Use of a transporter (501) according to any of the preceding claims 1-18 for transporting a plurality of storage containers (106) to a port area of a storage grid.