Container handling vehicle with extendable wheelbase

Abstract

A container handling vehicle operating on an automated storage and retrieval system comprising a framework structure forming a three-dimensional storage grid structure for storage of storage containers storing items, wherein a rail system is arranged on the framework structure and provides available routes for the container handling vehicles to handle and transfer the storage containers. Each rail has a first rail and a second rail allowing two container handling vehicles to pass each other using the same rail. At least one container handling vehicle has front wheels (302), rear wheels and side wheels (301), wherein the front wheels (302) have extenders allowing the container handling vehicle to be steered using the second rail.

Description

Technical Field

[0001] This invention relates to an automated storage and retrieval system for containers, and more particularly to a system and method for improving the stability of container handling vehicles with cantilever arms. Background Technology

[0002] Figure 1 discloses a typical prior art automated storage and retrieval system 1 with a frame structure 100, and Figure 2 and Figure 3 Two different prior art technologies suitable for container handling vehicles 201 and 301 operating on such system 1 are disclosed.

[0003] The frame structure 100 includes upright members 102, horizontal members 103, and storage space comprising storage rows 105 arranged between the upright members 102 and the horizontal members 103. In these storage rows 105, storage containers 106, also referred to as boxes, are stacked one on top of another to form a stack 107. Members 102 and 103 can typically be made of metal, such as extruded aluminum profiles.

[0004] The frame structure 100 of the automated storage and retrieval system 1 includes a track system 108 arranged across the top of the frame structure 100. Multiple container handling vehicles 201, 301 operate on this track system 108 to lift and lower storage containers 106 from storage columns 105 into the storage columns, and also to transport storage containers 106 above the storage columns 105. The track system 108 includes: a first set of parallel tracks 110 arranged to guide the container handling vehicles 201, 301 along a first direction X across the top of the frame structure 100; and a second set of parallel tracks 111 arranged perpendicular to the first set of tracks 110 to guide the container handling vehicles 201, 301 along a second direction Y perpendicular to the first direction X. Containers 106 stored in the columns 105 are accessed by the container handling vehicles through access ports 112 in the track system 108. Container handling vehicles 201 and 301 can move laterally above storage column 105, that is, move in a plane parallel to the horizontal XY plane.

[0005] The upright members 102 of the frame structure 100 can be used to guide the storage containers during the process of lifting containers from column 105 and lowering containers into the column. The stack 107 of containers 106 is typically self-supporting.

[0006] Each prior art container handling vehicle 201, 301 includes a body 201a, 301a, and a first set of wheels and a second set of wheels 201b, 301b, 201c, 301c, which respectively enable the container handling vehicle 201, 301 to move laterally in the X and Y directions. (See Figure 2 and...) Figure 3In this configuration, two wheels in each group are fully visible. The first group of wheels 201b and 301b are arranged to engage with two adjacent tracks in the first group of tracks 110, and the second group of wheels 201c and 301c are arranged to engage with two adjacent tracks in the second group of tracks 111. At least one of these groups of wheels 201b, 301b, 201c, and 301c can be raised and lowered such that the first group of wheels 201b and 301b and / or the second group of wheels 201c and 301c can engage with the corresponding group of tracks 110 and 111 at any given time.

[0007] Each prior art container handling vehicle 201, 301 also includes a lifting device (not shown) for vertically transporting storage containers 106, such as lifting storage containers 106 from storage rows 105 and lowering storage containers 106 into the storage rows. The lifting device includes one or more clamping / engaging devices adapted to engage storage containers 106, and these clamping / engaging devices are lowerable from vehicles 201, 301 such that the position of the clamping / engaging devices relative to vehicles 201, 301 is adjustable along a third direction Z orthogonal to the first direction X and the second direction Y. A portion of the clamping device of container handling vehicle 301 is... Figure 3 The container handling vehicle 201 is indicated by reference numeral 304 in the accompanying drawings. The clamping device is located inside the vehicle body 301a in Figure 2.

[0008] Typically, and for the purposes of this application, Z=1 represents the uppermost layer of the storage container, i.e., the layer directly below the track system 108; Z=2 represents the second layer below the track system 108; Z=3 represents the third layer, and so on. In the exemplary prior art disclosed in FIG1, Z=8 represents the lowest 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, and using the Cartesian coordinate system X, Y, Z indicated in FIG1, the storage container labeled 106' in FIG1 can be said to occupy storage position X=10, Y=2, Z=3. The container transport vehicles 201, 301 can be said to travel in layer Z=0, and each storage column 105 can be identified by its X and Y coordinates.

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

[0010] Each prior art container handling vehicle 201, 301 includes a storage compartment or space for receiving and storing the storage container 106 when transporting it on the track system 108. The storage space may include a cavity centrally arranged within the vehicle body 201a, as shown in FIG2, and is described, for example, in WO2015 / 193278A1, the contents of which are incorporated herein by reference.

[0011] Figure 3 An alternative construction of a container handling vehicle 301 with a cantilever structure is shown. Such a vehicle is described in detail, for example, in NO317366, the contents of which are also incorporated herein by reference.

[0012] The central cavity container transport vehicle 201 shown in Figure 2 may have a coverage area that is approximately equal in size to the lateral extent of the storage column 105 in the X and Y directions, as described, for example, in WO2015 / 193278A1, the contents of which are incorporated herein by reference. The term “lateral” as used herein may mean “horizontal”.

[0013] Alternatively, the central cavity container transport vehicle 101 may have a coverage area larger than the lateral area defined by the storage column 105, such as that disclosed in WO2014 / 090684A1.

[0014] The track system 108 typically includes a track with grooves in which the vehicle's wheels run. Alternatively, the track may include upwardly projecting elements, where the vehicle's wheels include flanges to prevent derailment. These grooves and upwardly projecting elements are collectively referred to as guide rails. Each track may include one guide rail, or each track may include two parallel guide rails.

[0015] WO2018146304 (the contents of which are incorporated herein by reference) shows a typical construction of a track system 108 including a track and parallel guide rails in the X and Y directions.

[0016] In frame structure 100, most columns 105 are storage columns 105, i.e., columns 105 where storage containers 106 are stored in stacks 107. However, some columns 105 may serve other purposes. In Figure 1, columns 119 and 120 are such dedicated columns, used by container handling vehicles 201, 301 to drop 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 frame structure 100, or where the storage containers can be transferred out of or into frame structure 100. In the art, such locations are commonly referred to as “ports,” and the columns where ports are located may be referred to as “port columns” 119, 120. Transport to the access station can be in any direction, i.e., horizontal, inclined, and / or vertical. For example, storage container 106 can be placed in a random or dedicated column 105 within the frame structure 100, and then picked up by any container handling vehicle and transported to port columns 119, 120 for further transport to the retrieval station. It should be noted that the term "inclined" means that the transport of storage container 106 has a general transport direction somewhere between horizontal and vertical.

[0017] In Figure 1, the first port column 119 may be a dedicated unloading port column, where container handling vehicles 201 and 301 can unload the storage container 106 to be transported to the storage station or transfer station, and the second port column 120 may be a dedicated picking port column, where container handling vehicles 201 and 301 can pick up the storage container 106 that has been transported from the storage station or transfer station.

[0018] The storage and retrieval station can typically be a pick-up station or a storage station, where product items are removed from or placed into storage container 106. At the pick-up station or storage station, storage container 106 is not typically removed from the automated storage and retrieval system 1, but is instead returned to the frame structure 100 after being retrieved. The port can also be used to transfer 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 truck), or to a production facility.

[0019] Storage containers are typically transported between port columns 119, 120 and the access station using a transmitter system that includes a transmitter.

[0020] If port columns 119, 120 and access stations are located at different horizontal levels, the conveyor system may include a lifting device with vertical components for vertically transporting storage container 106 between port columns 119, 120 and access stations.

[0021] The transport system can be arranged to transfer storage container 106 between different frame structures, for example, as described in WO2014 / 075937A1, the contents of which are incorporated herein by reference.

[0022] When access is required for a storage container 106 stored in one of the columns 105 disclosed in Figure 1, one of the container handling vehicles 201, 301 is instructed to remove the target storage container 106 from its location and transport it to the unloading port column 119. This operation includes moving the container handling vehicles 201, 301 to a position above the storage column 105 where the target storage container 106 is located, removing the storage container 106 from the storage column 105 using the lifting device (not shown) of the container handling vehicles 201, 301, and transporting the storage container 106 to the unloading port column 119. If the target storage container 106 is located deep within the stack 107, i.e., one or more other storage containers 106 are located above the target storage container 106, the operation also includes temporarily moving the storage container located above the target storage container before lifting the target storage container 106 from the storage column 105. This step, sometimes referred to in the art as “digging,” can be performed using the same container handling vehicle subsequently used to transport the target storage container to the unloading port column 119, or using one or more other cooperating container handling vehicles. Alternatively, or additionally, the automated storage and retrieval system 1 may have container handling vehicles 201, 301 specifically designed for the task of temporarily removing storage containers 106 from storage columns 105. After the target storage container 106 has been removed from the storage column 105, the temporarily removed storage container 106 can be repositioned back into the original storage column 105. However, the removed storage container 106 may alternatively be repositioned to another storage column 105.

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

[0024] In order to monitor and control the automated storage and retrieval system 1, such as monitoring and controlling the position of the corresponding storage containers 106 within the frame structure 100, the contents of each storage container 106, and the movement of the container transport vehicles 201, 301, so that the desired storage containers 106 can be delivered to the desired location at the desired time without the container transport vehicles 201, 301 colliding with each other, the automated storage and retrieval system 1 includes a control system 500, which is typically computerized and typically includes a database for tracking the storage containers 106.

[0025] Robots using cantilever solutions present problems. The issue is instability within the robot, particularly when a container handling vehicle is carrying a container. This instability stems from the positioning of the cantilever section of the robot, as well as the container and its weight relative to the wheels. The center of gravity of the cantilever and container lies outside the base of several sets of wheels. This makes the solution unstable, especially if the container is heavy. Summary of the Invention

[0026] The invention is set forth and its features are shown in the independent claims, while other features of the invention are described in the dependent claims.

[0027] In one aspect, the present invention relates to a container handling vehicle with a cantilever solution operating in an automated storage and retrieval system, the automated storage and retrieval system comprising a frame structure forming a three-dimensional storage grid structure for storing storage containers for storing articles, wherein the grid structure forms vertical storage columns, each vertical storage column having a horizontal area defined by the size of an access port of the vertical storage column, and wherein a track system is arranged on the frame structure, the tracks of the track system extending in the X and Y directions to define a grid at the top of each storage column and to define the perimeter of each access port, the track system providing for the container handling vehicle to handle storage containers and to transfer storage containers to and from storage columns. The available routes for the container handling vehicles are provided, each track having a first guide rail and a parallel second guide rail, thereby allowing two container handling vehicles to pass each other using the same track. Each vehicle communicates with a central computer system controlling the operation, and at least one container handling vehicle has a container handling platform with a set of grippers for handling storage containers. The cantilevered wheels of the container handling vehicles for manipulating the container handling vehicles in the Y direction are positioned relative to the container handling vehicles or can be positioned relative to the container handling vehicles such that: when the wheels on the other side of the container handling vehicles use the first guide rail of the track in the Y direction, the wheels on the cantilevered side of the container handling vehicles are allowed to manipulate the container handling vehicles in the Y direction using the second guide rail of the adjacent track.

[0028] The wheels on the cantilever side of the container handling vehicle are positioned relative to the container handling vehicle such that the wheelbase of the container handling vehicle is extended in the X direction.

[0029] The wheelbase extension is a permanent extension by positioning the wheels used to maneuver the container handling vehicle in the Y direction on the cantilever side of the container handling vehicle.

[0030] The wheels on the cantilever side of the container handling vehicle, which are used to maneuver the container handling vehicle in the X direction, can be displaced in the X direction so that the track width of the wheels arranged perpendicular to the cantilever side is extended in the X direction.

[0031] The wheels on the cantilever side of the container handling vehicle, which are used to maneuver the container handling vehicle in the X direction, are permanently displaced in the X direction, so that the track width of the wheels arranged perpendicular to the cantilever side is extended in the X direction. The extension of the track width is controlled by an electric actuator.

[0032] The wheels on the cantilever side of the container handling vehicle, which are used to maneuver the container handling vehicle in the Y direction, are positioned in the extended wheelbase position when the container handling vehicle is set to be maneuvered in the X direction.

[0033] The cantilever side of the container handling vehicle has two sets of wheels on each axle for maneuvering the vehicle in the Y direction.

[0034] Each double set of wheels has one wheel in each of the first and second guide rails of the track.

[0035] The wheelbase extension is controlled based on the weight of the container attached to the lifting platform of the container handling vehicle.

[0036] The wheelbase extension is controlled by a central computer system.

[0037] In a second aspect, the invention relates to a method for operating a cantilevered container transport vehicle on an automated storage and retrieval system, the automated storage and retrieval system comprising a frame structure forming a three-dimensional storage grid structure for storing storage containers for storing articles, wherein the grid structure forms vertical storage columns, each vertical storage column having a horizontal area identical to a horizontal area defined by the size of an access port of the vertical storage column, and wherein a track system is provided on the frame structure, the tracks of the track system extending in the X and Y directions to define a grid at the top of each storage column and to define the perimeter of each access port, the track system providing for the container transport vehicle to transport storage containers and transfer storage containers to storage columns and Available routes for transferring storage containers from storage columns, each track having a first guide rail and a parallel second guide rail, thereby allowing two container handling vehicles to pass each other using the same track, each vehicle including a vehicle controller communicating with a central computer system controlling operations, and at least one container handling vehicle having a container handling platform having a set of grippers for handling storage containers, wherein the wheels on the cantilever side of the container handling vehicle for manipulating the container handling vehicle in the Y direction are positioned relative to the container handling vehicle such that when the wheels on the other side of the container handling vehicle use the first guide rail of the track in the Y direction, the wheels on the cantilever side of the container handling vehicle are allowed to manipulate the container handling vehicle in the Y direction using the second guide rail of the adjacent track.

[0038] The method includes the following steps: lowering the wheels of the container transport vehicle for manipulating the container transport vehicle in the X direction, raising the container transport vehicle such that the wheels of the container transport vehicle for manipulating the container transport vehicle in the Y direction are raised from a first guide rail of the track, repositioning the wheels of the container transport vehicle for manipulating the container transport vehicle in the Y direction on the cantilever side of the container transport vehicle, and raising the wheels of the container transport vehicle for manipulating the container transport vehicle in the X direction adjacent to the cantilever side of the container transport vehicle. Attached Figure Description

[0039] The following figures are provided to facilitate understanding of the invention. The figures illustrate embodiments of the invention, which will now be described by way of example only, in which:

[0040] Figure 1 is a perspective view of the framework structure of an existing automated storage and retrieval system.

[0041] Figure 2 is a perspective view of a prior art container handling vehicle having a cantilever for supporting storage containers below.

[0042] Figure 3 It is a 3D view of a container handling vehicle with a cantilever.

[0043] Figure 4This is a perspective view of an embodiment of the present invention, showing a container transport vehicle located on a storage and retrieval system, wherein the X and Y directions are indicated.

[0044] Figure 5 This is a perspective view of an embodiment of the present invention, showing a wheel implemented by the present invention.

[0045] Figure 6 It is a perspective view of the wheels of the container handling vehicle, which are used to manipulate the vehicle in the Y direction, extending in the X direction, on the cantilever side of the container handling vehicle.

[0046] Figure 7 It is a perspective view of the wheels of the container handling vehicle, which are used to manipulate the vehicle in the Y direction, extending in the X direction, on the cantilever side of the container handling vehicle.

[0047] Figure 8 It is a close-up 3D image of an extended wheel. Detailed Implementation

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

[0049] The frame structure 100 of the automatic storage and retrieval system 1 is constructed according to the prior art frame structure 100 described above in conjunction with FIG1, namely, a plurality of upright members 102 and a plurality of horizontal members 103 supported by the upright members 102, and the frame structure 100 further includes a first track system 108 in the upper part in the X and Y directions.

[0050] The frame structure 100 also includes storage compartments arranged in the form of storage columns 105 between the members 102 and 103, wherein storage containers 106 can be stacked in the storage columns 105 in the form of stacks 107.

[0051] The frame structure 100 can be of any size. In particular, it should be understood that the frame structure can be much wider and / or much longer and / or much deeper than disclosed in Figure 1. For example, the frame structure 100 can have a horizontal range of more than 700 × 700 columns and a storage depth of more than twelve containers.

[0052] Figure 2 is a perspective view of a prior art container handling vehicle having a cantilever for supporting storage containers below.

[0053] Each cantilevered container handling vehicle comprises a body and a cantilever. A portion of the cantilever is attached to the top of the body, and a portion extends from the body, including a lifting platform for handling containers. The container handling vehicle has four sets of wheels. All wheels are attached to the body of the container handling vehicle. There are two front wheels and two rear wheels in the X-direction, and two front wheels and two rear wheels in the Y-direction. The side of the container handling vehicle where the cantilever extends is considered the front of the vehicle.

[0054] Figure 3 This is a perspective view of a container handling vehicle with a cantilever. In this solution, the lifting platform 305 is raised all the way to the top. The attached figure shows a container handling vehicle with a cantilever, positioned above a column in a storage and retrieval system. As shown, the container handling vehicle occupies the space of more than one column. The main body is located above the column adjacent to the column where the lifting platform operates. Furthermore, it can be seen how the robot's wheels are positioned in the rails closest to the main body of the container handling vehicle. The first wheel on each side of the container handling vehicle in the X direction is an extendable wheel 301. These extendable wheels 301 extend toward the cantilever portion of the container handling vehicle. The extendable wheels extend along the same set of rails as they were initially positioned on. By extending these wheels, the center of mass is translated toward the cantilever. This ensures a more stable container handling vehicle during the transport of heavy containers.

[0055] Figure 4 and Figure 5 This is a perspective view of an embodiment of the invention, showing a container transport vehicle located on a storage and retrieval system, with the X and Y directions indicated. A first set of wheels 302 in the Y direction is positioned in an inner guide rail. In this figure, both the X and Y wheels are shown lowered and positioned in the inner guide rail. The Y-direction wheels can be raised and lowered to allow the container transport vehicle to switch between directions of movement. As the container transport vehicle changes direction of movement, the Y-direction wheels continuously lower, pushing the container transport vehicle upwards, so that both sets of wheels in the X direction are above the guide rails of the storage and retrieval system.

[0056] The two front wheels 301 in the X direction can extend forward to ensure better stability when the container handling vehicle is carrying containers. The drive medium for these wheels can be a splined shaft engaged with a belt or chain, which transfers torque from the splined shaft to the wheels.

[0057] Figure 6 , Figure 7 and Figure 8 It is a perspective view in which the first set of wheels for maneuvering the container transport vehicle in the Y direction 302 is extended such that the first set of wheels is located in the outer guide rail 304 furthest from the body of the container transport vehicle.

[0058] As shown in the diagram, the front wheels, used for maneuvering in the Y direction, engage with the outer guide rail, while the rear wheels, also used for maneuvering in the Y direction, engage with the inner guide rail. This ensures that two container handling vehicles can use the same track to pass each other, while still ensuring good stability when carrying containers.

[0059] In a preferred embodiment of the invention, the extension of wheel 302 may be permanent, wherein it will always engage with the outer guide rail.

[0060] In an alternative embodiment of the invention, wheel 302 may be extended or retracted using, for example, an electric motor that drives a rack and pinion system, to extend wheel 302 when needed. This allows wheel 302 to use both inner and outer guide rails when necessary.

[0061] In another solution, there can be two sets of wheels 302, which engage simultaneously with both the inner guide rail 303 and the outer guide rail 304. This provides greater stability and better load distribution, but it also results in greater friction during maneuvering.

[0062] In the foregoing description, various aspects of the transport vehicle and automated storage and retrieval system according to the present invention have been described with reference to illustrative embodiments. Specific figures, systems, and configurations have been set forth for illustrative purposes to provide a full understanding of the system and its operation. However, this specification is not intended to be interpreted in a limiting sense. It will be apparent to those skilled in the art to which the disclosed subject matter pertains that various modifications and variations to the illustrative embodiments, as well as other embodiments of the system, are considered to fall within the scope of the invention.

[0063] List of reference numerals in the attached figures

[0064] Existing technology (Figure 1 to Figure 4 ):

[0065] 1. Existing automated storage and retrieval systems

[0066] 100 Frame Structure

[0067] 102. Upright members of a frame structure

[0068] 103 Horizontal members of frame structures

[0069] 104 Storage Grid

[0070] 105 Storage Columns

[0071] 106 Storage Containers

[0072] 106' Storage container in a specific location

[0073] 107 Stacking

[0074] 108 orbital system

[0075] 110 Parallel orbits in the first direction (X)

[0076] 110a First track in the first direction (X)

[0077] 110b Second orbit in the first direction (X)

[0078] 111 Parallel track in the second direction (Y)

[0079] 111a First track in the second direction (Y)

[0080] 111b Second track in the second direction (Y)

[0081] 112 Access Port

[0082] 119 First Port Column

[0083] 120 Second Port Column

[0084] 201 Existing cantilevered storage container vehicles

[0085] 201a The body of storage container vehicle 301

[0086] 201b Drive device in the first direction (X)

[0087] 201c Drive device in the second direction (Y)

[0088] 202 Cantilever

[0089] 301 Extendable wheel for operation in the X direction

[0090] 302 Front wheel for Y-direction steering

[0091] 303 inner guide rail

[0092] 304 outer guide rail

[0093] 500 Control System

[0094] X First Direction

[0095] Y Second Direction

[0096] Z Third Direction

Claims

1. A container handling vehicle with a cantilever (202) solution, the container handling vehicle operating on an automated storage and retrieval system comprising a framework structure (100) forming a three-dimensional storage grid structure (104) for storage of storage containers (106) storing articles, the footprint of the container handling vehicle being larger than the footprint of one cell on the grid structure, wherein the grid structure (104) forms vertical storage columns (105), each vertical storage column having a horizontal area defined by the dimensions of an access opening (112) of the vertical storage column (105), and wherein a rail system (108) is provided on the framework structure (100), the rails of the rail system extending in an X-direction and a Y-direction to define a grid on top of each storage column (105) and to define the perimeter of each access opening (112), the rail system (108) providing available routes for the container handling vehicles (201) to handle storage containers (106) and to transfer storage containers to and from the storage columns (105), each rail having a first rail and a parallel second rail allowing two container handling vehicles to pass each other using the same rail, each container handling vehicle (201) being in communication with a central computer system controlling the operation, and at least one of the container handling vehicles (201) having a container handling platform (500) with a set of grippers for handling storage containers (106), characterized in that, The side of the container handling vehicle (201) where the cantilever (202) is located is a cantilever side, and the wheels on the cantilever side are used for manoeuvring the container handling vehicle in the Y direction and are positioned or positionable relative to the container handling vehicle such that when the wheels on the other side of the container handling vehicle use the inner guide rails of the first and second guide rails of a track in the Y direction, the wheels on the cantilever side of the container handling vehicle are allowed to use the outer guide rails of the first and second guide rails of an adjacent track to manoeuvre the container handling vehicle (201) in the Y direction, and wherein the wheels on the cantilever side of the container handling vehicle (201) are positioned relative to the container handling vehicle such that the wheel base of the container handling vehicle is elongated in the X direction.

2. The container handling vehicle according to claim 1, wherein, The wheels adjacent the cantilever side of the container handling vehicle (201) for manoeuvring the container handling vehicle (201) in the X direction are displaceable in the X direction to elongate the wheel base of the wheels arranged perpendicular to the cantilever side in the X direction.

3. The container handling vehicle according to claim 1 or 2, wherein, The wheels adjacent the cantilever side of the container handling vehicle (201) for manoeuvring the container handling vehicle in the X direction are permanently displaced in the X direction to elongate the wheel base of the wheels arranged perpendicular to the cantilever side in the X direction.

4. The container handling vehicle according to claim 1 or 2, wherein, The wheels of the container handling vehicle are configured with means for elongating the wheel base by control of an electric actuator.

5. The container handling vehicle according to claim 1 or 2, wherein, The wheels on the cantilever side of the container handling vehicle (201) for manoeuvring the container handling vehicle in the Y direction are positioned in an elongated wheel base position when the container handling vehicle is set for manoeuvring in the X direction.

6. The container handling vehicle according to claim 1, wherein, The wheels on the cantilever side of the container handling vehicle (201) for manoeuvring the container handling vehicle in the Y direction are provided with a double set of wheels on each axle.

7. The container handling vehicle according to claim 6, wherein, Each of the double sets of wheels has one wheel in each of the first and second guide rails (303, 304) of the track.

8. The container handling vehicle according to claim 4, wherein, The wheels of the container handling vehicle are configured with means for elongating the wheel base according to control by the weight of the containers attached to a lifting platform (305) of the container handling vehicle (201).

9. The container handling vehicle according to claim 8, wherein, The wheels of the container handling vehicle are configured with means for elongating the wheel base controlled by the central computer system. The wheels of the container handling vehicle are configured with means for elongating the wheel base controlled by the central computer system.

10. A method of operating a container handling vehicle having an overhang on an automated storage and retrieval system, the automated storage and retrieval system comprising a framework structure (100) forming a three-dimensional storage grid structure (104) for storage of storage containers (106) storing items, the footprint of the container handling vehicle being larger than the footprint of one cell on the grid structure, wherein the grid structure (104) forms vertical storage columns (105) each having the same horizontal area as defined by the dimensions of an access opening (112) of the vertical storage column (105), and wherein a rail system (108) is provided on the framework structure (100), the rails of the rail system extending in an X-direction and a Y-direction to define a grid on top of each of the storage columns (105) and to define the perimeter of each of the access openings (112), the rail system (108) providing available routes for the container handling vehicle (201) to handle storage containers (106) and to transfer storage containers to and from the storage columns (105), each of the rails having a first rail and a parallel second rail allowing two container handling vehicles to pass each other using the same rail, each container handling vehicle (201) comprising a vehicle controller (230) for performing the steps of: - communicating with a central computer system controlling the operation and at least one of the container handling vehicles (201) having a container handling platform (500) having a set of grippers for handling the storage containers (106), and characterized in that: - the side of the container handling vehicle (201) where the overhang is located is an overhang side, the wheels on the overhang side for maneuvering the container handling vehicle in the Y-direction are positioned relative to the container handling vehicle to allow the wheels on the overhang side of the container handling vehicle to maneuver the container handling vehicle (201) in the Y-direction using the second rail (304) of an adjacent rail when the wheels on the other side of the container handling vehicle are using the first rail of a rail in the Y-direction.

11. The method of claim 10, wherein, the method comprising the steps of: - lowering the wheels for maneuvering the container handling vehicle in the X-direction, - lifting the container handling vehicle (201) such that the wheels for maneuvering the container handling vehicle (201) in the Y-direction are lifted from the first rail (303) of the rail, - repositioning the wheels on the overhang side of the container handling vehicle (201) for maneuvering the container handling vehicle in the Y-direction, - lifting the wheels adjacent to the overhang side of the container handling vehicle (201) for maneuvering the container handling vehicle in the X-direction.

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