Patent Publication Number: US-2023145325-A1

Title: Automated storage tower with multiple rows

Description:
FIELD OF THE INVENTION 
     The present invention relates to a storage tower and an automated storage and retrieval system for storage and retrieval of containers from/to such a storage tower. The present invention also relates to a method for storing and retrieving containers in such a storage tower to access deeper laying containers in a more time efficient manner. 
     BACKGROUND AND PRIOR ART 
       FIG.  1    discloses a typical prior art automated storage and retrieval system  1  with a framework structure  100  and  FIGS.  2  and  3    disclose two different prior art container handling vehicles  201 , 301  suitable for operating on such a system  1 . 
     The framework structure  100  comprises upright members  102 , horizontal members  103  and a storage volume comprising storage columns  105  arranged in rows between the upright members  102  and the horizontal members  103 . 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 ,  103  may typically be made of metal, e.g. extruded aluminium profiles. 
     The framework structure  100  of the automated storage and retrieval system  1  comprises a rail system  108  arranged across the top of framework structure  100 , on which rail system  108  a plurality of container handling vehicles  201 , 301  are 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  110  arranged to guide movement of the container handling vehicles  201 , 301  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 rails  110  to guide movement of the container handling vehicles  201 , 301  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 through access openings  112  in the rail system  108 . The container handling vehicles  201 , 301  can move laterally above the storage columns  105 , i.e. in a plane which is parallel to the horizontal X-Y plane. 
     The upright members  102  of the framework 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-supportive. 
     Each prior art container handling vehicle  201 , 301  comprises a vehicle body  201   a , 301   a , and first and second sets of wheels  201   b , 301   b , 201   c , 301   c  which enable the lateral movement of the container handling vehicles  201 , 301  in the X direction and in the Y direction, respectively. In  FIGS.  2  and  3    two wheels in each set are fully visible. The first set of wheels  201   b , 301   b  is arranged to engage with two adjacent rails of the first set  110  of rails, and the second set of wheels  201   c , 301   c  is arranged to engage with two adjacent rails of the second set  111  of rails. At least one of the sets of wheels  201   b , 301   b , 201   c , 301   c  can be lifted and lowered, so that the first set of wheels  201   b , 301   b  and/or the second set of wheels  201   c , 301   c  can be engaged with the respective set of rails  110 ,  111  at any one time. 
     Each prior art container handling vehicle  201 , 301  also comprises a lifting device (not shown) 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  so that the position of the gripping/engaging devices with respect to the vehicle  201 , 301  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 vehicle  301  are shown in  FIG.  3    indicated with reference number  304 . The gripping device of the container handling device  201  is located within the vehicle body  301   a  in  FIG.  2   . 
     Conventionally, and also for the purpose of this application, Z=1 identifies the uppermost layer of storage containers, i.e. the layer immediately below the rail system  108 , Z=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=1 . . . n and Y=1 . . . 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 X=10, Y=2, Z=3. The container handling 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. 
     The storage volume of the framework 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 Y−direction, while each storage cell may be identified by a container number in the X−, Y and Z−direction. 
     Each prior art container handling vehicle  201 , 301  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 centrally within the vehicle body  201   a  as shown in  FIG.  2    and as described in e.g. WO2015/193278A1, the contents of which are incorporated herein by reference. 
       FIG.  3    shows an alternative configuration of a container handling vehicle  301  with a cantilever construction. Such a vehicle is described in detail in e.g. NO317366, the contents of which are also incorporated herein by reference. 
     The central cavity container handling vehicles  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 WO2015/193278A1, the contents of which are incorporated herein by reference. The term ‘lateral’ used herein may mean ‘horizontal’. 
     Alternatively, the central cavity container handling vehicles  101  may have a footprint which is larger than the lateral area defined by a storage column  105 , e.g. as is disclosed in WO2014/090684A1. 
     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 may comprise two parallel tracks. 
     WO2018146304, 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. 
     In the framework 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  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 framework structure  100  or transferred out of or into the framework structure  100 . Within the art, such a location is normally referred to as a ‘port’ and the column in which the port is located may be referred to as a ‘port column’  119 , 120 . The transportation to the access station may be in any direction, that is horizontal, tilted and/or vertical. For example, the storage containers  106  may be placed in a random or dedicated column  105  within the framework 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. Note that the term ‘tilted’ means transportation of storage containers  106  having a general transportation orientation somewhere between horizontal and vertical. 
     In  FIG.  1   , the first port column  119  may for example be a dedicated drop-off port column where the container handling vehicles  201 , 301  can drop off storage containers  106  to be transported to an access or a transfer station, and the second port column  120  may be a dedicated pick-up port column where the container handling vehicles  201 , 301  can pick up storage containers  106  that have been transported from an access or a transfer station. 
     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 framework structure  100  again once accessed. A port can also be used for transferring storage containers to another storage facility (e.g. to another framework 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. 
     A conveyor system comprising conveyors is normally employed to transport the storage containers between the port columns  119 , 120  and the access station. 
     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. 
     The conveyor system may be arranged to transfer storage containers  106  between different framework structures, e.g. as is described in WO2014/075937A1, the contents of which are incorporated herein by reference. 
     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  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  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&#39;s  201 , 301  lifting device (not shown), 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 specifically dedicated to the task of temporarily removing storage containers from a storage column  105 . Once the target storage container  106  has been removed from the storage column  105 , the temporarily removed storage containers can be repositioned into the original storage column  105 . However, the removed storage containers may alternatively be relocated to other storage columns. 
     When a storage container  106  is to be stored in one of the columns  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 location above the storage column  105  where it is to be stored. After any storage containers positioned at or above the target position within the storage column stack  107  have been removed, the container handling vehicle  201 , 301  positions the storage container  106  at the desired position. The removed storage containers may then be lowered back into the storage column  105 , or relocated to other storage columns. 
     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 framework structure  100 , the content of each storage container  106 ; and the movement of the container handling vehicles  201 , 301  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  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 . 
       FIG.  4    shows examples of product items  80  stored in a storage container  106 . The storage container  106  illustrated in  FIG.  4    has a height Hƒ, a width Wƒ and a length Lƒ. The storage container  106  has a horizontal cross section Aƒ. 
     For systems containing a large number of bins in each stack, the above mentioned ‘digging’ may prove both time and space consuming when the target bin is located deep within the grid. For example, if the target bin has location Z=5, the vehicle(s) must lift four non-target bins and place them in other positions, often on top of the grid (Z=0), before the target bin can be reached. Before being replaced back into the grid, the non-target bins may force other robots to choose non-optimized paths to execute their respective operations. 
     An objective of the present invention is therefore to provide a storage grid and a storage and retrieval system using such a storage grid which may provide a more time efficient storage and retrieval method compared to prior art systems. 
     SUMMARY OF THE INVENTION 
     The present invention is set forth in the independent claims and the dependent claims describe certain optional features of the invention. 
     In particular, the invention concerns a storage tower for storing storage containers. The storage tower comprises a plurality of horizontal container supporting frameworks distributed vertically with vertical offsets. 
     The plurality of horizontal container supporting frameworks comprises a first horizontal container supporting framework and at least one second container supporting framework arranged beneath and parallel to the first container supporting framework. 
     The first and the at least one second container supporting frameworks comprises a horizontally extending container support with principal directions in a first direction and an orthogonal second direction, each container support being configured as a matrix of container spaces with a plurality of columns of container spaces arranged in the first direction and a plurality of rows of container spaces arranged in the second direction, 
     Further, each row of container spaces of at least the first container supporting framework is configured to receive a plurality of storage containers and displays at least one opening extending along the second direction, the at least one opening having an opening size being at least a maximum horizontal cross section of the storage containers to be stored. 
     The at least one opening, e.g., the total area of the at least one opening in each row, of the first container supporting framework and the at least one opening of the at least one second container supporting framework can be aligned vertically with respect to each other. 
     At least one container support is displaceable along the second direction. 
     At least one container supporting framework further comprises a support displacement device configured to displace the displaceable container support. 
     It is thus achieved a storage tower where remotely operated vehicles can pick storage containers without having to dig. 
     It is thus achieved a storage tower that can provide a more time efficient delivery of product items to a customer or other recipient of an item stored in a storage container. 
     It is thus achieved a storage tower that can provide a high throughput of product items, such as product items on sale or other products with a high demand. 
     The horizontal container supporting frameworks may have repeating geometry, particularly the second container supports. 
     The horizontal container supporting frameworks may be seen to provide a set of displaceable storage shelves for storage containers, the contents of which can be accessed easily through aligning openings in the container supporting frameworks above with a target storage container below. 
     The container supports may be a plate, e.g. one continuous plate or several plates connected to form the container support. In other words, the container support may provide a continuous surface on which to place the storage containers. 
     Alternatively, the container support may have a frame structure, i.e. without inner structure or material between frame members of the frame structure. Furthermore, the container support may be a combination of the two. The container supports in the storage tower may also be a mixture of the two. 
     The matrix of container spaces could be an imaginary division primarily set by the size of the storage containers. The size of the matrix of container spaces is linked to the number of rows and columns of the matrix. A matrix comprising l rows and m columns may extend a distance along the first direction X substantially equal to l*L ƒ  and extend a distance along the second direction Y substantially equal to m*W ƒ . Alternatively, a matrix comprising l rows and m columns may extend a distance along the first direction X substantially equal to l*W ƒ  and extend a distance along the second direction Y substantially equal to m*L ƒ . The extend of the matrix thus substantially corresponds to the size and number of the storage containers. If a rail system is used, adjacent storage containers will be spaced apart at least corresponding to the width of each rail. The total width of the spacing will depend on the number of rows and columns of the matrix, i.e. the number of storage containers and thus the number of spacings. The total width of the rails may be calculated as (l−1)*W r  or (m−1)*W r . W r  being the width of each rail. The spacing of the storage containers will add to the size of the matrix of container spaces in both the first direction X and the second direction Y. If a transport system (typically comprising a crane) is used, the storage containers may be stored closer together as compared to the system with rails. Any spacing of the storage containers should be added to the size of the matrix also when a transport system is used. 
     The opening or openings of one row of container spaces or some of the rows may be staggered (i.e., not all openings being aligned along the first direction X). The arrangement of openings may shift from one container support to another. 
     If the storage tower only comprises two container supports, the uppermost container support may be movable to align its opening with the lowermost container support without the lower most container support being movable. 
     The at least one second container supporting framework may comprise a plurality of container supports. 
     One example is a storage tower where each of the second container supporting frameworks comprise two container supports each being configured as a matrix of container spaces with four rows and three columns (i.e. a 4×3 matrix). The two container supports could be independently displaceable along the second direction Y such that an opening can be provided between the rows of the two container supports. Alternatively, by displacing one container support at the time, an opening may be provided at either end in the second direction Y of the container supporting framework. The first container supporting framework may comprise one container support being configured as a matrix of container spaces with four rows and five columns (i.e. a 4×5 matrix). A target container positioned in a third container supporting framework, having the same configuration as the second, could then be accessed through the openings provided at either end in the second direction Y of the container supporting framework. Both container supports of the second container supporting frameworks should then be displaceable by two spaces. 
     Each row of container spaces of the first container supporting framework and preferably also the at least one second container supporting frameworks may be configured to receive a plurality of storage containers and displays at least one opening extending along the second direction, the at least one opening having an opening size being at least a maximum horizontal cross section of the storage containers to be stored. 
     The vertical offset of each container supporting framework may vary within the same storage tower. Different container supporting frameworks of the same storage tower may be configured for storing of storage containers of different heights. In order to utilize the available space in the storage tower in an optimal way, container supporting frameworks configured for storing of storage containers of different heights may preferably have different vertical offsets. 
     The support displacement device may comprise a linear actuator, a gearwheel drive (e.g. rack and pinion), chain drive, a belt drive or any combination thereof. This includes ball-screws and cam type rotary devices that cause linear movement. It should also be understood as including electric, hydraulic and pneumatic actuators. 
     The support displacement device may be driven wheels arranged on the container support or on the container supporting framework. 
     The support displacement device may comprise a motor for driving the linear actuator, gearwheel drive, chain drive, belt drive or any combination thereof, the motor being arranged outside a horizontal extent of the respective container supporting framework containing at least one displaceable container support to be displaced. 
     The displacement device may comprise a centrally aligned actuator that is positioned to push and pull the container support. Alternatively, the displacement device may be arranged at an edge of the container supporting framework, preferably opposite edges. 
     The displacement devices of adjacent container supporting frameworks may be arranged at opposite edges. 
     The displacement device may be a direct drive mechanism arranged on the container support. The direct drive may e.g. be connected to rollers arranged on the container support. 
     Each container support may further comprise a plurality of horizontal movement shelf rollers rotationally arranged on at least one side of the container support extending along the second direction, the horizontal movement shelf rollers having a horizontal axis of rotation along the first direction. 
     Furthermore, each of the plurality of container supporting frameworks may further comprise a set of guiding tracks arranged on each side of the container supporting frameworks along the second direction, the set of guiding tracks being oriented with their longitudinal direction parallel to the second direction. 
     Furthermore, each guiding track may comprise a horizontal part for supporting and guiding the plurality of horizontal movement shelf rollers. 
     The horizontal movement shelf rollers may e.g. be a number of wheels or linear guide rails. 
     Each container support may further comprise a plurality of shelf guides, the plurality of shelf guides being arranged on at least the side of the container support comprising the plurality of horizontal movement shelf rollers. 
     Furthermore, each guiding track may comprise a vertical part for guiding of the plurality of shelf guides. 
     The shelf guide may e.g. be a number of wheels, linear guide rails or sliding surfaces (i.e. surfaces with low friction against contacting surfaces typically of the guiding track). 
     Each row may comprise vertical guide plates arranged at least partly around the perimeter of each of the at least one opening. 
     The vertical guide plates may be configured so that a storage container being lifted or lowered into the respective opening is aligned in the horizontal plane. 
     The at least one opening displayed by each row of container spaces may be a separate opening. 
     The at least one opening of each parallel arranged row of container spaces within the at least one container support may be horizontally aligned along the first direction. 
     The at least one opening displayed by each row of container spaces of at least one of the container supports may be merged together to form a continuous opening extending along the first direction to define an area substantially equal to one column of container spaces. 
     The container supports may also comprise a mixture of separate openings and merged openings. 
     At least one of the plurality of horizontal container supporting frameworks may comprise at least one container support having a horizontal extent smaller than the horizontal extent of the container supporting framework. 
     The extent of the container supporting frameworks in the second direction may exceed the extent of the container supports with a length substantially equal to W ƒ *i, where i is an integer, preferably i=1 or i=2. 
     The at least one displaceable container support may be displaceable a distance along the second direction substantially equal to Wƒ*i, where i is an integer, preferably i=1 or i=2. 
     Each row of container spaces may be configured to receive an equal number of storage containers on either side of the at least one opening. Such a row would not have an opening positioned at the end. 
     Each row of container spaces may display one opening and be configured to receive two or more storage containers on each side of the opening. 
     Each row may display a plurality of openings distributed with an offset corresponding to d+1 grid cells in the second direction, where d is an integer of 1 or more. 
     The matrix of container spaces of each container support may have an equal number of rows and columns. 
     The horizontal area of the at least one second container support may be the same as the horizontal area of any further second container supports. 
     The rows of container spaces of the first and the at least one second container support may have equal distributions of the at least one opening. 
     The lowermost container support may have at least one row of container spaces without an opening. 
     At least one of the container supports may comprise a plurality of sensor devices for sensing the presence of a storage container. The sensor devices may be distributed across the matrix of container spaces. 
     The sensors arranged on the storage container support or the container supporting framework may communicate with the control system. 
     The sensor device may be selected from a group comprising piezoelectric sensors, weight sensors, magnetic sensors (would require the storage container to be made of a magnetic material or to be provided with a magnet device), vision sensors, light sensors, motion sensors. 
     At least one of the container supports may comprise a sensor device for sensing the displacement of the container support relative to the container supporting framework. 
     The storage containers may be supported by at least one support plate and/or a plurality of support beams oriented in the first direction and/or the second direction. 
     The storage tower may further comprise a transport mechanism arranged above the uppermost container supporting framework at a first vertical offset. The offset providing a vertical gap between a lowermost point of the transport mechanism and an uppermost surface of the container space of the first container support being at least a maximum height of the storage containers to be stored. 
     Instead of a vehicle with wheels moving on a rail system, the transport system may comprise a crane moveable in X and Y−directions over the storage tower. For example, the crane may be moveable in the first direction on a sliding bar extending across the width of the storage tower. Movement in the second direction may be achieved by sliding the sliding bar along two fixed bars extending in the second direction on both sides of the storage tower. The crane may be a container handling vehicle with a cantilever construction supported on two parallel sliding bars. 
     It is thus achieved a storage tower that may operate despite not being level. The transport mechanism is less prone to derailing than the vehicle moving on wheels. The storage tower may thus be suitable for operations at sea, e.g. onboard a vessel. 
     The storage tower may further comprise a rail system arranged above the first container supporting framework at a first vertical offset. The offset providing a vertical gap between a lowermost point of the rail system and a uppermost surface of the container space of the first container support being at least a maximum height of the storage containers to be stored. 
     At least one of the container supporting frameworks may be arranged at a distance below a lower edge of the above adjacent rail system and/or a lower edge of an above adjacent container supporting framework, corresponding to a height that is equal or higher than a maximum height of a stack of several storage containers. 
     The rail system may provide access to the target openings of the storage tower and to adjacent storage towers and/or storage grids without having to cover the entire horizontal extent of the storage tower. 
     The invention also concerns an automated storage and retrieval system configured to store a plurality of storage containers. 
     The rail aligning the storage tower with the rail system such that each of the container spaces of the first container support can be vertically aligned below a grid opening of the cantilever part 
     The automated storage and retrieval system may comprise an above-described storage tower. 
     Furthermore, the automated storage and retrieval system may comprise a plurality of storage containers supported on the plurality of horizontally arranged container supporting frameworks. 
     Furthermore, the automated storage and retrieval system may comprise a remotely operated vehicle configured to move laterally above the plurality of container supporting frameworks, wherein the remotely operated vehicle comprises a lifting device configured to grab and vertically lift a storage container. 
     Furthermore, the automated storage and retrieval system may comprise a control system configured to monitor and control wirelessly movements of the remotely operated vehicle. 
     It is thus achieved an automated storage and retrieval system where remotely operated vehicles can pick storage containers without having to dig. 
     It is thus achieved an automated storage and retrieval system that can provide a more time efficient delivery of product items to a customer or other recipient of an item stored in a storage container. 
     It is thus achieved an automated storage and retrieval system that can provide a high throughput of product items, such as product items on sale or other products with a high demand. 
     The automated storage and retrieval system may further comprise a storage grid comprising:
         a plurality of vertical storage columns for stacking storage containers one on top of one another, and   a rail system on which a plurality of container handling vehicles may be operated, the rail system being arranged above the plurality of storage columns,   wherein storage containers stored in the storage columns are accessible by the container handling vehicles through grid openings in the rail system,   the rail system may comprise a cantilever part with a horizontal extent being equal the difference between the horizontal extent of the rail system and the horizontal extent of the plurality of storage columns.       

     One or more of the storage towers may be at least party arranged below the cantilever part of the rail system and positioned such that each of the container spaces of the first container support can be vertically aligned below a grid opening of the cantilever part. 
     Alternatively, the automated storage and retrieval system may further comprise a storage grid comprising:
         a plurality of vertical storage columns for stacking storing containers one on top of another, and   a transport mechanism wherein the remotely operated vehicle is a crane being moveable along a sliding bar arranged in parallel to the first direction,   the sliding bar having two opposite ends being movable along two fixed bars arranged in parallel to the second direction,   the transport mechanism being arranged above the plurality of storage columns,   the transport mechanism comprises a cantilever part with a horizontal extent being equal the difference between the horizontal extent of the transport mechanism and the horizontal extent of the plurality of storage columns,       

     One or more of the storage towers may be at least partly arranged below the cantilever part of the traveling crane system. 
     It is thus achieved a storage and retrieval system combining the prior art grid and the inventive grid, i.e. a combination of a high runner grid and a low runner grid in which product items can be arranged according to their turnover. 
     It is thus achieved a storage and retrieval system combining storage capacity with time efficient delivery of product items to a customer or other recipient of an item stored in a storage container, e.g. where orders can be picked from the low runner grid, with high storage capacity, before intermediately stored (buffered) in the high runner grid, with time efficient delivery of product items to the customer, and subsequently efficiently delivered to the customers on their arrival. 
     A high runner storage tower is configured for high frequency of storage containers entering and leaving the storage tower. The storage containers will typically be stored for a shorter period in the high runner storage tower when compared to a low runner storage grid. The high runner storage tower is particularly suited for high demand products. The high runner storage tower provides quick access and is therefore suited for time critical storages. The high runner storage tower is less space efficient than a low runner storage grid. 
     A low runner storage grid is more space efficient when compared to the high runner storage tower. The storage containers will typically be stored for a longer period in the lower runner grid when compared to a high runner storage tower. The low runner storage grid has slower access compared to the high runner storage tower and is therefore better suited for a less time critical storage. 
     Hence, the high runner storage tower and the low runner storage grid complement each other. 
     The automated storage and retrieval system may further comprise a rail system arranged above the uppermost container supporting framework at a first vertical offset. The offset providing a vertical gap between a lowermost point of the rail system and a uppermost surface of the container space of the first container support being at least a maximum height of the storage containers to be stored. 
     At least one of the container supporting frameworks may be arranged at a distance below a lower edge of the above adjacent rail system and/or a lower edge of an above adjacent container supporting framework, corresponding to a height that is equal or higher than a maximum height of a stack of several storage containers. 
     The invention also concerns a method for storing and retrieving storage containers from an automated storage and retrieval system. The automated storage and retrieval system may be one as described above. 
     The plurality of horizontal container supporting frameworks preferably comprises a number of j parallel container supporting frameworks, where j is an integer of 2 or more. 
     The at least one container support of the at least one second container supporting framework are preferably displaceable along a second direction orthogonal to the first direction. 
     The method may comprise the following steps: 
     A. moving the remotely operated vehicle to a position where its lifting device is positioned in vertical alignment above either 
     a) a target storage container situated on the first container supporting framework, or 
     b) if the target storage container is situated on one of the j-1 parallel container supporting frameworks beneath the first container supporting framework, a target opening of the first container supporting framework being vertically alignable with the target storage container, 
     B. if the target storage container is not positioned in vertical alignment below the target opening, 
     a) displacing the displaceable container support of the container supporting framework, on which the target storage container is supported in the second direction to position the target storage container in vertical alignment below the target opening of the first container supporting framework or 
     b) if the at least one container support of the first container supporting framework is displaceable along the second direction, displacing the at least one displaceable container support of the one or more container supporting frameworks situated above, and having the same position in the first direction as the row of the displaceable container support, on which the target storage container is supported, an equal distance in the second direction opposite of the direction in a) to position the target storage container in vertical alignment below the target opening of the first container supporting framework or 
     c) if the at least one container support of the first container supporting framework is displaceable along the second direction, displacing both the target storage container supporting displaceable container support as described in step a) and the above arranged one or more displaceable container supports as described in step b) to position the target storage container in vertical alignment below the target opening, 
     C. grabbing and lifting the target storage container by use of the lifting device and 
     D. moving the remotely operated vehicle with the target storage container to a horizontally different location. 
     In the method for storing and retrieving storage containers from an automated storage and retrieval system, step B may be performed prior to or simultaneously with step A. If step B.c) is performed after step A, it may be required to reposition the remotely operated vehicle to a position where its lifting device is positioned in vertical alignment above a target opening of the first container supporting framework being vertically alignable with the target storage container. 
     It is thus achieved a method for picking storage container with remotely operated vehicles without having to dig. 
     It is thus achieved a method providing a more time efficient delivery of product items to a customer or other recipient of an item stored in a storage container. 
     It is thus achieved a method providing a high throughput of product items, such as product items on sale or other products with a high demand. 
     If the remotely operated vehicle or the crane is carrying a storage container to be stored in the automated storage and retrieval system, either before or after retrieval of the target storage container, the method may comprise the steps of: 
     E. moving the remotely operated vehicle to a position where its lifting device is positioned in vertical alignment above either 
     a) a vacant container space of the first container supporting framework, or 
     b) if the vacant container space is situated on one of the j-1 parallel container supporting frameworks beneath the first container supporting framework, a target opening of the first container supporting framework being vertically alignable with the vacant container space, 
     F. if the vacant container space is not positioned in vertical alignment below the target opening, 
     a) displacing the displaceable container support of the container supporting framework, on which the vacant container space is situated in the second direction to position the vacant container space in vertical alignment below the target opening of the first container supporting framework or 
     b) if the at least one container support of the first container supporting framework is displaceable along the second direction, displacing the at least one displaceable container support of the one or more container supporting frameworks situated above, and having the same position in the first direction as the row of the displaceable container support, on which the vacant container space is situated, an equal distance in the second direction opposite of the direction in a) to position the vacant container space in vertical alignment below the target opening of the first container supporting framework or 
     c) if the at least one container support of the first supporting framework is displaceable along the second direction, displacing both the displaceable container support of the vacant container space as described in step a) and the above arranged one or more displaceable container supports as described in step b) to position the vacant container space in vertical alignment below the target opening, 
     G. lowering the carried storage container into position on the vacant container space by use of the lifting device. 
     In the method for storing and retrieving storage containers from an automated storage and retrieval system, step F may be performed prior to step E. If step F.c) is performed after step E, it may be required to reposition the remotely operated vehicle to a position where its lifting device is positioned in vertical alignment above a target opening of the first container supporting framework being vertically alignable with the target storage container. 
     If the automated storage and retrieval system comprises a storage grid containing a target storage container, the method may comprise the steps of:
         Picking the target storage container from the storage grid, e.g. as described in the background section.   Storing the target storage container in the storage tower according to the above-described method.   Retrieving the storage container from the storage tower according to the above-described method.       

     If two target storage containers are situated on one of the j-1 parallel container supporting frameworks and horizontally aligned in the first direction, and 
     the system further comprises a second remotely operated vehicle, and 
     the control system may be configured to monitor and control wirelessly movements of the second remotely operated vehicle, 
     the method may further comprise the steps of: 
     A2. moving the second remotely operated vehicle to a position where its lifting device is positioned in vertical alignment above a target opening of the first container supporting framework being vertically alignable with the second target storage container, 
     C 2 . grabbing and lifting the second target storage container by use of the lifting device of the second remotely operated vehicle and 
     D 2 . moving the second remotely operated vehicle with the second target storage container to a horizontally different location. 
     When a storage container is being positioned in a vacant container space or a target storage container is being retrieved from the storage tower, the other container spaces of the same row of container spaces are not available for other remotely operated vehicles to pick from. The same applies for the other rows of the same matrix of container spaces. To avoid a queuing, the above-described storage and retrieval system could therefore preferably have specific remotely operated vehicles covering the container spaces of the storage towers. 
     The control system may be configured to coordinate simultaneous picking by multiple remotely operated vehicles covering the same container spaces of one or several storage towers, as described in the method above, further efficiencies may be achieved. 
     The control system may be configured to coordinate that two remotely operated vehicles simultaneously pick target storage containers from the same container support. Alternatively, two remotely operated vehicles simultaneously store two storage containers in the same container support. As a further alternative, one remotely operated vehicle retrieving a target storage container from the same container support as another remotely operated vehicle simultaneously is storing a storage container. 
     The invention also concerns a method for installing a storage tower in an automated storage and retrieval system. The storage tower and the automated storage and retrieval system may be one in accordance with the above description. 
     The automated storage and retrieval system may comprise:
         a storage grid, and   a vehicle movements system having a larger horizontal extent than the storage grid.       

     The method may comprise the steps of:
         assembling at least a part of the storage tower according to the above description underneath the cantilever part of the vehicle movement system.       

     It is thus achieved a storage tower that can be retrofitted to existing storage and retrieval systems. 
     The vehicle movement system may comprise a rail system, and the method may then further comprise the step of:
         aligning the storage tower with the rail system such that each of the container spaces of the first container support can be vertically aligned below a grid opening of the cantilever part.       

     The above-described automated storage and retrieval system may be used for delivering items arranged within the storage containers stored in the storage grid directly to end users. 
     The cantilever part of a rail system does not need to extend the entire horizontal extent of the storage tower. The cantilever part of the rail system may e.g. only extend enough to reach the target openings of the storage tower. 
     Due to the configuration of the container supports, i.e. the matrix of container spaces, vertical pillars cannot be positioned between the rows of container spaces or between the columns of container spaces of the same container support. This means that there will be a larger span between the vertical pillars of the storage tower, and thus higher loads on each vertical pillar as compared to the upright members of the prior art storage grid. 
     The rail system, when it is present, must extend over and support the weight of the remotely operated vehicles over a larger area than with a conventional storage grid where each grid space is being supported at the corners by upright members. 
     To withstand the increasing loads, the vertical pillars and/or the rail system may need to be reinforced as compared to the prior art upright members and rail system. 
     A remotely operated vehicle approaching the storage tower to pick a target storage container typically brings another storage container that is to be stored in the storage and retrieval system. Before the remotely operated vehicle can pick the target storage container, the vehicle held storage container is advantageously placed in a vacant container space within the same storage tower. This is a process typically referred to as an exchange process. Such an exchange process can take place in the storage tower and the automated storage and retrieval system as described above. 
     By having fewer storage containers than there are available container spaces within the storage system, there will always be at least one vacant container space. Vacant container spaces will also be dynamically generated as remotely operated vehicles pick storage containers from within the storage tower. If there are no vacant container spaces in the storage system, the remotely operated vehicle must either refrain from bringing another storage container from for example the port column or place the held storage container on top of the storage tower. Both alternatives suffer disadvantages in respect of time efficiency. 
     The vacant container space (into which the storage container is to be placed) and the target storage container are preferably horizontally closest to the same target opening. In this way the remotely operated vehicle does not need to move between the two operations during the same exchange process. Even more preferred, in addition to being available through the same target opening, the vacant container space and the target storage container can be located on the same container support. In this way the remotely operated vehicle can have a minimum movement of its lifting device between the two operations of the exchange process. Thus, the exchange process time will not be prolonged due to conflicting displacements of the lifting device and the container support of the target storage container. 
     When the openings are merged the guide structure and the rail system or transport system, if used, may be configured to allowing sideways movement of the lifting device while the lifting device is still lowered into the storage tower. This will save time in an exchange process where a carried storage container is positioned in a row next to the target storage container. The remotely operated vehicle may then move sideways without having to raise and lower the lifting device. 
     After positioning the previously held storage container in the vacant container space, the lifting device is retracted to allow displacement of the container supports, i.e. return of the container support of the previously vacant container and deployment of the container support of the target storage container such that the target storage container is situated beneath the target opening. If the lifting device is retracted higher than just above the container supporting framework of the target storage container, the exchange process would become less time efficient. 
     If the target storage container is positioned deeper than the vacant container space, the container support of the target storage container can be deployed prior to the retraction of the lifting device and the displacement back to the initial position of the container support of the previously vacant container space. 
     After the target storage container has been lifted above the container supporting framework, the container support can be displaced back to its initial position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings depict alternatives of the present invention and 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: 
         FIG.  1    is a perspective view of a framework structure of a prior art automated storage and retrieval system; 
         FIG.  2    is a perspective view of a prior art container handling vehicle having a centrally arranged cavity for carrying storage containers therein; 
         FIG.  3    is a perspective view of a prior art container handling vehicle having a cantilever for carrying storage containers underneath; 
         FIG.  4    is a perspective view of a storage container and product items stored in the storage container; 
         FIG.  5    is a top view of a storage system where all container supports of a storage tower are vertically aligned; 
         FIG.  6    is a side view of the storage system of  FIG.  5   ; 
         FIG.  7    is a perspective view of a container support configured as a matrix of container spaces (when the storage containers are not present) with a plurality of columns of container spaces arranged in the first horizontal direction and a plurality of rows of container spaces arranged in the second horizontal direction; 
         FIG.  8    is a perspective view of a container support configured as a matrix of container spaces with a plurality of columns of container spaces arranged in the first horizontal direction and a plurality of rows of container spaces arranged in the second horizontal direction, where storage containers are positioned in the container spaces; 
         FIG.  9    is a perspective view of details of a container support and a container supporting framework, in particular of a support displacement device; 
         FIG.  10    is a perspective view of details of the container support, in particular of shelf rollers; 
         FIG.  11    is a perspective view of further details of the container support and the container supporting framework, in particular of a support displacement device, where a lowermost container support is displaced relative to the above container supports; 
         FIG.  12    is a side view of a storage system in accordance with an embodiment of the invention, where a storage grid and a storage tower are positioned side by side and below a rail system; 
         FIG.  13    is a perspective view of the storage system of  FIG.  12   , where a storage grid and a storage tower are positioned side by side; 
         FIG.  14    is a perspective view of the storage system of  FIG.  12   , where a storage grid and a storage tower are positioned side by side, where one container support is displaced; 
         FIG.  15 A  is a perspective view of the storage system of  FIG.  12   , where a storage grid and a storage tower are positioned side by side, where a plurality of container supports are displaced in opposite directions; 
         FIG.  15 B  is a cross-section of the storage system in accordance with  FIG.  15 A . 
         FIG.  16 A  and  FIG.  16 B  are different perspective views of another embodiment of the storage system according to the invention, where a storage tower is positioned below a transport system; 
         FIG.  17    is a side view of the storage system of  FIG.  16 A ; 
         FIG.  18 A  and  FIG.  18 B  are different perspective views showing details of the storage system of  FIGS.  16 A-B  and  17 A-B, in particular of the transport mechanism; and 
         FIG.  19   a - c    are perspective views of three storage towers, each with a different configuration of the container supporting frameworks and the container supports. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following, different alternatives 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 scope of the invention to the subject-matter depicted in the drawings. Furthermore, even if some of the features are described in relation to the system only, it is apparent that they are valid for the methods as well, and vice versa. 
     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. 
     With particular reference to  FIG.  5 - 6    and  FIG.  12 - 15   , the inventive storage and retrieval system  1  comprises remotely operated vehicles  301  operating on a rail system  408  comprising a first set of parallel rails  410  arranged to guide movements of the remotely operated vehicles  301  in a first direction X across a storage tower  400  and a second set of parallel rails  411  arranged perpendicular to the first set of rails  410  to guide movement of the remotely operated vehicles  301  in a second direction Y which is perpendicular to the first direction X. The storage containers  106  stored within the storage tower  400  are accessed by the remotely operated vehicles  301  through grid openings  415  in the rail system  408 . Each grid opening  415  of the rail system  408  is enclosed by a grid cell  422 . The rail system  408  extends in a horizontal plane P rs . 
     As best seen in  FIG.  6   , the storage containers  106  are stored on a plurality of container supporting frameworks  401  distributed in a Z direction below the rail system  408  with a vertical offset indicated by V rl  (i.e. the offset between the lower edge of the rail system  408  and the lower edge for the first container supporting framework  401   a  directly beneath the rail system  408 ) and a vertical offset indicated by ΔdVb-n (i.e. the offset between the lower edges of two adjacent container supporting frameworks  401   a - n ). 
     The vertical offsets V rl  and ΔdVb-n may be selected to provide a height that is equal to or higher than a maximum height of one storage container  106  or a stack  107  of several storage containers  106  or equal to or higher than a maximum height of different storage containers  106  stored in respective container supporting frameworks  401 . As an example, the first container supporting framework  401   a  may be adapted to store stacks  107  of storage containers  106  while the below situated container supporting frameworks  401   b - n  may be adapted to store single (unstacked) storage containers  106 . As a further example, several or all container supporting frameworks  401  of the tower  400  may be adapted to store stacks  107  of several storage containers  106 . The different container supporting frameworks  401  of the same tower  400  may be configured to store stacks  107  of unequal numbers of storage containers  106 . The vertical space (i.e. the available height) required for one or several container supporting frameworks  401  of the tower  400  to be adapted to store a stack  107  of several storage containers  106  may be obtained by reducing the total number of container supporting frameworks  401  as compared to a configuration of the tower  400  where all container supporting frameworks  401  are adapted to store single (unstacked) storage containers  106 . 
       FIG.  6    shows a storage tower  400  where each container supporting framework  401   a - n  comprises one horizontally extending container support  402 . 
       FIG.  7    and  FIG.  8    show an example of such a container support design.  FIG.  7    shows a container support  402  without storage containers  106  and  FIG.  8    shows the same container support  402  where storage containers  106  are positioned in the container spaces. 
     The container support  402  has principal directions in a first direction X and an orthogonal second direction Y. The container support  402  is configured as a horizontal matrix of container spaces with a plurality of columns of container spaces arranged in the first horizontal direction X and a plurality of rows of container spaces arranged in the second horizontal direction Y. Each row of container spaces is configured to receive a plurality of storage containers  106  and typically further displays at least one opening  403  extending along the second direction Y. The opening  403  may have a horizontal extent along the first direction X substantially equal to the horizontal extent of the row along the first direction X. The container support  402  of the lowermost container supporting framework  401   n  typically does not display an opening  403 . The at least one opening  403  of each row of container spaces typically has an opening size being at least a maximum horizontal cross section A ƒ  (W ƒ *L ƒ ) of the storage containers  106  to be stored. 
     The container support  402  of  FIG.  7    and  FIG.  8    comprises a plurality of guide structures  409  for the openings  403 . The guide structure  409  is fixed along the peripherals of each opening  403   a - d  in order to aid the storage container  106  to be guiding correctly through the opening  403   a - d  during lifting/lowering by the respective remotely operated vehicles  201 ; 301 ; 601 . 
     The container support  402  may be a plate or a frame without inner structure. The container spaces typically have a horizontal extent being at least a maximum horizontal cross section A ƒ  (W ƒ *L ƒ ) of the storage containers  106  to be stored. The matrix of container spaces could be an imaginary division primarily set by the size of the storage containers  106 . The size of the matrix of container spaces is linked to the number of rows and columns of the matrix. A matrix comprising l rows and m columns may extend a distance along the first direction X substantially equal to l*L ƒ  and extend a distance along the second direction Y substantially equal to m*W ƒ . 
     Alternatively, a matrix comprising l rows and m columns may extend a distance along the first direction X substantially equal to 1*W ƒ  and extend a distance along the second direction Y substantially equal to m*L ƒ . If a rail system  108  is used, the storage containers  106  will be spaced apart at least corresponding to the width of the rail W r . The spacing of the storage containers  106  will add to the size of the matrix of container spaces. The total contribution from this spacing depends on the number of containers  106  and thus the number of spacings. The total spacing width may be calculated as (l−1)*W r  or (m−1)*W r . If a transport system  601  (typically comprising a crane  602 ) is used, the storage containers  106  may be stored closer together as compared to the system with rails  108 . Any spacing of the storage containers  106  should be added to the size of the matrix also when a transport system  601  is used. 
     In the example of  FIG.  7   , the container support  402  has a matrix of container spaces comprising four rows and five columns. The horizontal extent of this matrix is a distance substantially equal to 4*L ƒ  along the first direction X and a distance substantially equal to 5*W ƒ  along the second direction Y. Any spacing of the storage containers  106  should be added to the size of the matrix of container spaces, as described above. The container support may have a central line of openings  403 , e.g. four openings  403  along a column. Alternatively, one single opening  403  extending through all four rows. Alternatively, a combination of openings  403  extend through one, two or three rows. On both sides of the central opening  403  or line of openings  403 , container spaces are provided in a 4×2 configuration. This may be construed as two columns each of four container spaces on either side of the opening(s)  403 . Alternatively, this may be construed as four rows each of five container spaces wherein the central container space being the opening  403 . Alternatively, this may be construed as four rows each of four container spaces with two container spaces on either side of the opening  403 . 
     The opening  403 , i.e. the perimeter of the at least one opening  403   a - d  in each row, of the first container supporting framework  401   a  and the at least one opening  403  of the at least one second container supporting framework  40   b - n  can be aligned vertically with respect to each other. This can be achieved by the at least one container support  402  of the at least one second container supporting framework  401   b - n  being displaceable along the second direction Y. The displacement may be achieved by the at least one second container supporting framework  401   b - n  comprising a support displacement device  700  configured to displace the displaceable container support  402  of the at least one second container supporting framework  401   b - n . An example of such a support displacement device  700  is illustrated in  FIG.  9    and further described below. Since all container spaces of the first container support  402   a , i.e. the uppermost container support  402 , are accessible through grid openings  415 . The first container supporting framework  401   a , i.e. the uppermost container supporting framework  401 , does not need to be provided with a support displacing device  700 , though efficiencies can be improved where it is provided with one. 
     The container support  402  of  FIG.  7    and  FIG.  8    comprise support plates  404  providing container spaces. In  FIG.  8   , storage containers  106  are placed on top of the support plates  404 . One support plate  404  may provide four container spaces distributed along the first horizontal direction X forming a complete column. Alternatively, each column may comprise a plurality of support plates  404 , e.g. one support plate  404  per container space. As a further alternative, one support plate  404  may provide two or more container spaces distributed along the second horizontal direction Y forming at least a part of a row. One support plate  404  may also provide a plurality of container spaces distributed along both the first direction X and the second direction Y. 
     Each container support  402  comprises a first container support beam  406  extending in the first horizontal direction X and a second container support beam  407  extending in the second horizontal direction Y. The first and second support beams  406 , 407  may be used to provide stiffness and stabilize the container support  402  in the horizontal plane P rs . The first support beams  406  may extend the full length of a column. The second support beams  407  may extend the full length of a row. 
     In  FIG.  7 - 8   , a first support beam  406  is arranged between each column of container spaces, in total four first beams  406 . The first support beams  406  may be used for attachment of the guide structures  409 . The first support beams  406  may also be used for attachment of the support plates  404 . The first support beams  406  may protrude upwards relative to the support plates  404 , thereby preventing storage containers  106  from moving along the second horizontal direction Y relative to the container support  402 . The first support beams  406  may also be used to support storage containers  106  and thus provide container spaces, i.e. a container space without a support plate  404 . 
     In  FIG.  7 - 8   , two second support beams  407  are arranged in parallel with the rows. In this example the second support beams  407  are arranged not to divide the rows, i.e. on the edges of the container support  402 . Second support beams  407  may additionally be arranged to divide the rows. The second support beams  407  may be used for attachment of the guide structures  409 . The second support beams  407  may also be used for attachment of the support plates  404 . The second support beams  407  may protrude upwards relative to the support plates  404 , thereby preventing storage containers  106  from moving in the first direction X relative to the container support  402 . The second support beams  407  may also be used to support storage containers  106  and thus provide container spaces, i.e. a container space without a support plate  404 . Alternatively, the first and second support beams  406 , 407  may together provide container spaces. The second support beams  407  may also be used for attachment of shelf guides  709 . The second support beams  407  may also be used for attachment of horizontal movement shelf rollers  709 ′. The shelf rollers  709 , 709 ′ are further described below with reference to  FIG.  10   . The second support beams  407  may also be used for attachment of vertical pillars  431 . These are inter alia illustrated in  FIG.  11   . 
     Each container support  402  may comprise a stabilization rib  405  arranged in the first direction X. In  FIG.  7 - 8   , two stabilization ribs  405  are arranged not to divide the columns, i.e. on the edges of the container support  402 . The stabilization ribs  405  may additionally be arranged to divide the columns. The stabilization ribs  405  may be used for attachment of the guide structures  409 . The stabilization ribs  405  may also be used for attachment of the support plates  404 . The stabilization ribs  405  may have a vertical extent higher than the support plate  404 . The stabilization ribs  405  may be used for stabilizing storage containers  106 . The stabilization ribs  405  may also stabilize the container support by stiffening the structure to prevent twisting, e.g., under uneven loading. Stabilization ribs  405  may also be arranged in the second direction Y. The stabilization rib  405  may replace one or more first support beams  406 , and vice versa. The stabilization rib  405  may replace one or more second support beams  407 , and vice versa. 
     The first support beam  406 , the second support beam  407  the stabilization rib  405 , the support plate  404 , the guide structure  409  and any other components associated with the container support  402  may be connected to each other by means of fasteners, welding, snap lock systems, tongue and groove system or other known methods know to those skilled in the art. 
       FIG.  9    and  FIG.  10    shows that a container support  402  of one or more container supporting frameworks  401  may be made displaceable along the second horizontal direction Y relative to the container supporting framework  401 . To displace the displaceable container support  402  along the second horizontal direction Y, the container supporting framework  401  of  FIG.  9    comprises a support displacement device  700 . Alternatively, the container support  402  may comprise the support displacement device  700 . The support displacement device  700  is configured to displace the displaceable container support  402  relative to the container supporting framework  401 . 
     To be displaceable along the second horizontal direction Y, the container support  402  and the corresponding container supporting framework  401  comprises a guide track  710  and a plurality of shelf rollers  709 , 709 ′. The shelf rollers  709 , 709 ′ are configured to travel along the guide track  710 . The guide track  710  may be provided on the container supporting framework  401  and the shelf rollers  709 , 709 ′ may be provided on the container support  402  as illustrated in  FIG.  9    and  FIG.  10   , or vice versa. 
     The guide track  710  of  FIG.  9    is an extruded profile. This guide track  710  comprises a horizontal part  710 ″ and a vertical part  710 ′. When the guide track  710  is arranged with a longitudinal direction extending along the second horizontal direction Y, the horizontal part  710 ″ is horizontally extending and the vertical part  710 ′ is vertically extending. 
     The rollers  709 , 709 ′ of  FIG.  10    are provided in pairs comprising a shelf guide  709  and a horizontal movement shelf roller  709 ′. The shelf guide  709  has a vertically oriented axis of rotation. The horizontal movement shelf roller  709 ′ has an axis of rotation oriented along the first horizontal direction X. As illustrated in  FIG.  7   , three pairs of rollers  709 , 709 ′ can be arranged along the side of the container support  402  to cooperate with the corresponding guide track  710 . The pairs of rollers  709 , 709 ′ are distributed with one pair in the centre and one pair at each distal end of the edge of the container support  402 . One container support  402  will typically have rollers  709 , 709 ′ arranged at two opposing edges. 
       FIG.  9    shows how the horizontal movement shelf rollers  709 ′ cooperate with the guide track horizontal part  710 ″, in that the horizontal movement shelf rollers  709 ′ can roll along the guide track horizontal part  710 ″. The cooperation of the guiding track horizontal part  710 ″ and the horizontal movement shelf rollers  709 ′ allow the relative displacement between the container support  402  and the container supporting framework  401 . 
       FIG.  9    shows how the shelf guides  709  cooperate with the guide track horizontal part  710 , in that the vertical movement shelf rollers  709 ′ can roll along the guide track vertical part  710 ″. The cooperation of the guiding track vertical part  710 ′ and the shelf guides  709  control the direction of the relative movement between the container support  402  and the container supporting framework  401 . 
       FIG.  9    shows an example of a support displacement device  700 . This support displacement device  700  comprises an electric motor  701 . The electric motor  701  is arranged on the container supporting framework  401  by means of a bracket  713 . The bracket can e.g. be connected to a vertical pillar  431 . For maintenance purposes, the components of the support displacement device  700  are preferably arranged in positions easily accessible for technicians. In particular the electric motors  701  or alternative drive devices should preferably be arranged on the edge of the container supporting framework  401  and extending on the outside of the container supporting framework  401 . Preferably also close to a corner of the container supporting framework  401 . By arranging the electric motors  701  of adjoining container supporting frameworks  401  on opposite sides of the container supporting frameworks  401 , more space is made available for the technicians to install or perform maintenance on the electric motor  701  and/or the support displacement device  700 . 
     The support displacement device  700  comprises a drive shaft  702  configured to be driven by the electric motor  701 . The drive shaft  702  is also configured to drive, i.e. displace, the displaceable container support  402 . 
       FIG.  9    and  FIG.  11    show how the drive shaft  702  can be arranged on the container supporting framework  401 . The drive shaft  702  is arranged on the container supporting framework  401  by means of brackets  712 . These brackets  712  can be arranged on the vertical pillars  431 . These brackets  712  are typically arranged at the distal ends of the drive shaft  702 . The brackets  712  must allow rotation of the drive shaft  702 . The drive shaft  712  is arranged substantially level and extends along the first direction X. 
     In  FIG.  9    and  FIG.  11   , rotation of the electric motor  701  causes rotation of the drive shaft  702  by means of a belt wheel  708  arranged on the electric motor  701 , a belt wheel  708  arranged on the drive shaft  702 , and a first belt  706  connecting these belt wheels  708 . The belt wheel  708  arranged on the drive shaft  702  is arranged on the distal end of the drive shaft  702  to align with the belt wheel  708  arranged on the electric motor  701 . In  FIG.  9    and  FIG.  11   , each drive shaft  702  is driven by one electric motor  701 . This is advantageous since it requires fewer parts and the movements along each side are synchronised by the drive shaft  702  which is common to both sides. Alternatively, two electric motors  701  can be provided for each drive shaft  702 , connected to opposite ends of the drive shaft  702  or drive shaft portions. 
     In  FIG.  9    and  FIG.  11   , rotation of the drive shaft  702  causes displacement of the displaceable container support  402  by means of two belt wheels  708  arranged on the drive shaft  702 , two belt wheels  708  arranged on the container supporting framework  401 , two brackets  711  arranged on the container support  402 , and two second belt  707 . 
     The two belt wheels  708  arranged on the drive shaft  702  and configured to drive the container support  402  are concentric with each other and concentric with the belt wheel  708  arranged on the drive shaft and configured to cooperate with the electric motor  701 . 
     The two belt wheels  708  arranged on the container supporting framework  401  are provided on opposite sides of the container supporting framework  401  and connected e.g. to the guiding tracks  710  or the vertical pillars  431 . The belt wheels  708  arranged on the container supporting framework  401  are aligned with the belt wheels  708  arranged on the drive shaft  702 . 
     The two second belts  707  each connect one belt wheel  708  arranged on the drive shaft  702  with one belt wheel  708  arranged on the container supporting framework  401 . When connected, the second belts  707  extend along the second horizontal direction Y. The second belts  707  then extend in the same direction as the intended displacement of the container support  402 . The extension of the second belts  707  along the second horizontal direction Y should substantially corresponding to or exceed the predetermined distance of displacement of the container support  402 . 
     The two second belts  707  are arranged with a distance between them in the first direction X exceeding the horizontal extension of the container support  402  along the first direction X. 
     The two brackets  711  are arranged on opposite sides of the container support  402  and facing respective second belts  707 . Each bracket  711  is aligned with and connected to respective second belts  707 . The bracket  711  and the second belt  707  can be clamped by means of a plate bolted to the bracket  711  and the second belt being arranged between them. In this way the bracket can be connected to any given part of the second belt  707 . 
     The direction of displacement of the container support  402  depends on the direction of rotation of the drive shaft  702  and thus the direction of rotation of the electric motor  701 . By providing a clockwise rotation from the electric motor  701 , the container support  402  will be displaced in an opposite direction as compared to when a counter-clockwise rotation is provided from the electric motor  701 . The displacement-rotation ration between the container support  402  and the drive shaft  702  or the electric motor  701  can be configured by selecting the size of the belt wheels  708 . 
       FIG.  11    is a perspective view of a lowermost part of the storage tower  400 . The lowermost container support  402   n , i.e. one of the second container supports  402   b - n , are displaced relative to the above container supports  402 . The displaced container support  402  is displaced a distance in the second direction Y corresponding to one grid cell  422 . 
     In  FIG.  11    it is shown that the storage tower  400  comprises a plurality of vertical pillars  431 . These vertical pillars  431  are typically supported by a floor  440 , and possibly also connected to the floor  440  by means of pillar brackets  435 . The plurality of vertical pillars  431  are configured to support a plurality of guide tracks  710 . If the storage tower  400  comprises a rail system  408 , the plurality of vertical pillars  431  can be configured to support the rail system  408 . The vertical pillars  431  are distributed with distances along the first direction X and/or the second direction Y that are larger than the distances between the upright members  102  of the prior art framework structure  100 . This is because the container supports  402  have a larger span than the storage columns  105  of the prior art framework structure  100 . Therefore, each vertical pillar  431  should be configured to withstand greater loads than the upright members  102  since there are fewer of them. If the storage tower  400  comprises a transport system  601 , the plurality of vertical pillars  431  can be configured to support the transport system  601 . This is illustrated in  FIGS.  18 A and  18 B . 
       FIG.  12    shows a side view of a storage and retrieval system  1  with one inventive storage tower  400  and one prior art storage grid  100 . The above-mentioned support displacement devices  700  are shown arranged at the end of each container support  402 . This particular configuration comprises fourteen container supporting frameworks  401   a - n  arranged beneath a rail system  408 , each with one container support  402  displaceable in the Y direction. Other numbers of container supporting frameworks could be present as appropriate. Preferably there are more than five container supporting frameworks, more preferably more than ten. In order to enable movement between the storage grid  100  and the storage tower  400 , a coupling rail system  408 ′ is seen interconnecting the rail system  108  of the prior art storage grid  100  and the rail system  408  of the inventive storage tower  400 . The rail system  408  of the inventive storage tower  400  and the rail system  108  of the prior art storage grid  100  have a mutual orientation and design such that the same type of vehicles  301  may operate on both rail systems  108 , 408 . Due to the different construction of the container supporting frameworks  401  for the inventive storage tower  400  and the stacks  107  of storage containers  106  for the prior art storage grid  100 , the rails  410 , 411  above the container supporting frameworks  401  can with advantage be made wider compared to the rails  110 , 111  above the stacks  107 , at least in one of the X-Y directions. 
       FIG.  13    shows a perspective view of the same storage and retrieval system  1  as  FIG.  12   . 
     Both the inventive storage tower  400  and the prior art storage grid  100  can be of any size. In particular it is understood that the storage tower  400  and/or the storage grid  100  can be considerably wider and/or longer and/or deeper than disclosed in the accompanied figures. For example, storage tower  400  and/or the storage grid  100  may have a horizontal extent having space for more than 700×700 storage containers  106  and a storage depth of more than fourteen storage containers  106 . 
     One way of installing the storage tower  400  as described above can be to remove all stacks  107  of storage containers  106  beneath a rail system  108  part of a prior art storage and retrieval system  1  as shown in  FIG.  1   , leaving a cantilever part CP of the rail system  108 . Then inserting one or more inventive storage towers  400  within the empty volume below the cantilever part CP of the rail system  108 . 
       FIGS.  14  and  15 A  are perspective views of a storage system  1  comprising the storage tower  400  during operation.  FIG.  15 B  shows a vertical cross-section of the storage system  1  of  FIG.  15 A . 
     In order to store and retrieve a target storage container  106 ′ using the storage tower  400 , the following operations are performed (with reference to  FIG.  14   ):
         The control system  500  gives instructions to the vehicle  301  to pick up a target storage container  106 ′ with coordinates X,Y,Z. This position corresponds to a storage container  106  positioned in a container space of a container support  402  forming part of a horizontal container supporting framework  401   g  at a depth of 5×ΔdV+Vrl below the rail system  408 . Since all the openings  403  in the storage tower  400  are initially aligned (with same X-Y coordinates), the X-Y position of the target opening  403 ′ of the container supporting framework  401   a  adjacent the rail system  408  is equal to the X-Y positions of the target openings  403 ′ of the underlying container supporting frameworks  401   b - n.      The vehicle  301  moves by aid of its drive means  301   b,c  in the X and Y directions until its lifting device  304  is located directly above the target opening  403 ′ situated in the row of storage containers in which the target storage container  106 ′ is positioned.   During and/or after movement of the vehicle  301  to the position above the target opening  403 ′, the control system  500  sends an instruction to the support displacement device  700  to displace the container support  402  of the container supporting framework  401   g  a sufficient distance in the second direction Y so that the target storage container  106 ′ is vertically aligned with the target openings  403 ′ of the above situated container supporting frameworks  401   a - f.      During and/or after the displacement of the container support  402 , the lifting device  304  of the vehicle  301  is activated and lowered down through the grip opening  415  and the aligned target openings  403 ′ until the gripping part of the lifting device  304  is in position to grip the target storage container  106 ′.   After the target storage container  106 ′ has been gripped by the lifting device  304  and lifted above the above situated container supporting framework  401   f , the support displacement device  700  is again activated in order to move the container support  402  back to its initial Y position.   When the target storage container  106 ′ has been lifted above the rail system  408 , the vehicle  301  is moved to another location on the rail system  408 , for example to a dedicated port column/chute  436  for delivery to an access station  437 .       

     The process has the advantage that the need for digging performed for prior art storage and retrieval system is no longer necessary. 
     In the operational example of  FIG.  14    the target storage container  106 ′ is positioned next to the opening  403  of the same row of container spaces. Some rows of container spaces may comprise more than one container space on either side of the opening  403 . If a target storage container  106 ′ is not positioned next to the opening  403 , i.e. there is a container space between the target storage container  106 ′ and the opening  403 , the container support  402  must be displaced a distance along the second horizontal direction Y corresponding to two grid cells  422  to position the target storage container  106 ′ in vertically aligned with the target openings  403 ′ of the above situated container supporting frameworks  401   a - f . From the initial position of the container support  402 , there may not be sufficient space in the storage tower  400  for the container support  402  to be displaced a distance corresponding to two grid cells  422  both directions along the second direction Y. In that case the target storage container  106 ′ can be retrieved as illustrated in  FIG.  15 A  by displacing all of the container supports above a distance of one grid cell in the other direction. 
     The retrieval operation of  FIG.  15 A  is similar to the operation described with reference to  FIG.  14   . However, an additional step is performed.
         During movement of the vehicle  301  to the position above the target openings  403 ′, the control system  500  sends an instruction to the support displacement devices  700  to displace the container supports  402  of the container supporting frameworks  401   a - f  situated above the target storage container  106 ′ a sufficient distance in the second horizontal direction Y so that the target storage container  106 ′ is vertically aligned with the target openings  403 ′ of the above situated container supporting frameworks  401   a - f . The container supports  402  of the container supporting frameworks  401   a - f  situated above the target storage container  106 ′ are displaced along the second horizontal direction Y a distance corresponding to one grid cell  422  and opposite the displacement of the container support  402  of the target storage container  106 ′.       

       FIG.  15 B  shows a cross-section of the storage system  1  in accordance with  FIG.  15 A . Here two vehicles  301  are simultaneously retrieving respective target containers  106 ′ positioned on the same container support  402 . If the control system  500  detects two target storage containers  106 ′ positioned on the same container support  402 , and in particular when positioned in the same column of container spaces, the control system  500  may give instructions to two vehicles  301  to pick up these target storage containers  106 ′ simultaneously. 
       FIGS.  16 A-B ,  FIG.  17    and  FIGS.  18 A-B  show storage and retrieval system  1  comprising one storage tower  400 . Instead of a vehicle  201 , 301  with wheels moving on a rail system  408 , the storage and retrieval system  1  comprises a transport system  601 . The transport system  601  comprises a crane  602  moveable in the first direction X on a sliding bar  603  extending across the width of the storage tower  400 . Movements in the second direction Y is achieved by sliding the sliding bar  603  along two fixed bars  604  extending in the second direction Y on both sides of the storage tower  400 . In  FIGS.  16 - 18   , the crane  602  is shown as a container handling vehicle with a cantilever construction supported on two parallel sliding bars  603 . 
     When the transport system  601  receives an instruction from the control system  500  to retrieve a target storage container  106 ′ stored in for example the sixth container supporting framework  401   f  counted from above (as shown in  FIG.  17   ), the support displacement device  700  displaces the container support  402  in the Y direction until the target storage container  106 ′ is vertically aligned with the target opening  403 ′ vertically aligned within the above situated five container supporting frameworks  401   a - e . Before, during or after the displacement of the container support  402 , the crane  602  of the transport system  601  is moved by use of the sliding bar  603  and the fixed bar  604  to a location in which the lifting device  304  is vertically aligned above the target opening  403 ′ of the first container supporting framework  401   a  (and due to the initial alignment, also the corresponding openings  403  of the container supporting frameworks  401   b - e  down to at least to the container supporting framework  401   f  with the target storage container  106 ′). 
     The storage tower  400  shown in  FIGS.  16 A- 18 B  also comprise a dedicated port column or chute  436  into which the target storage container  106 ′ can be lowered/raised by use of the lifting device  403  of the crane  602 . In  FIGS.  16 A-B  and  FIG.  17   , an access station  437  is shown arranged below the lower end of the chute  436  to receive and to provide storage containers  106  to be retrieved and stored, respectively. 
     The operations described with reference to  FIGS.  14  and  15 A -B applies mutatis mutandis to a storage tower  400  comprising a transport system  601 . 
       FIG.  18 A-B  show that the storage tower  400  can comprise horizontal beams  432  for connection to the top of the vertical pillars  431 . 
     In the preceding description, various aspects of the automated storage and retrieval system and associated method of picking product items using vehicles 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. 
       FIGS.  19   a - c    shows three different storage towers  400 . 
     The storage tower  400  in  FIG.  19   a    has container supports  402  with a matrix of container spaces comprising four rows and five columns, i.e. a 4×5 matrix. The four rows of container spaces are symmetric. Each row is configured to receiving four storage containers  106  and comprises one opening  403 . 
     The storage tower  400  in  FIG.  19   b    has container supports  402  with a matrix of container spaces comprising four rows and ten columns, i.e. a 4×10 matrix. The four rows of container spaces are symmetric. Each row is configured to receiving eight storage containers  106  and comprises two openings  403 . One container support  402  of the storage tower  400  of  FIG.  19   b    is equal to two container supports  402  of the storage tower  400  of  FIG.  19   a    placed side by side along the second direction Y. 
     The storage tower  400  in  FIG.  19   c    has container supports  402  with a matrix of container spaces comprising four rows and fifteen columns, i.e. a 4×15 matrix. The four rows of container spaces are symmetric. Each row is configured to receiving twelve storage containers  106  and comprises three openings  403 . One container support  402  of the storage tower  400  in  FIG.  19   c    is equal to three container supports  402  of the storage tower  400  of  FIG.  19   a    placed side by side along the second direction Y. 
     In  FIGS.  19   b  and  19   c    each row of container spaces displays a plurality of openings  403  distributed with an offset corresponding to d+1 grid cells  422  in the second direction Y, where d is an integer of 1 or more. In these particular examples d=4. 
     LIST OF REFERENCE NUMBERS 
       
     
       
         
           
               
               
             
               
                   
               
             
            
               
                  1 
                 Storage and retrieval system 
               
               
                  80 
                 Product items 
               
               
                 100 
                 Framework structure/prior art storage grid 
               
               
                 102 
                 Upright members of framework structure 
               
               
                 103 
                 Horizontal members of framework structure 
               
               
                 105 
                 Storage column 
               
               
                 106 
                 Storage container 
               
               
                 106′ 
                 Particular position of a storage container/target storage 
               
               
                   
                 container 
               
               
                 106″ 
                 Vacant container space for a storage container 
               
               
                 107 
                 Stack 
               
               
                 108 
                 Prior art rail system 
               
               
                 110 
                 Parallel rails in first direction (X) 
               
               
                 110a 
                 First rail in first direction (X) 
               
               
                 110b 
                 Second rail in first direction (X) 
               
               
                 111 
                 Parallel rail in second direction (Y) 
               
               
                 111a 
                 First rail of second direction (Y) 
               
               
                 111b 
                 Second rail of second direction (Y) 
               
               
                 115 
                 Grid opening 
               
               
                 119 
                 First port column 
               
               
                 120 
                 Second port column 
               
               
                 201 
                 Prior art storage container vehicle 
               
               
                 201a 
                 Vehicle body of the storage container vehicle 101 
               
               
                 201b 
                 Drive means/wheel arrangement, first direction (X) 
               
               
                 201c 
                 Drive means/wheel arrangement, second direction (Y) 
               
               
                 301 
                 Prior art cantilever storage container vehicle/remotely 
               
               
                   
                 operated vehicle 
               
               
                 301a 
                 Vehicle body of the vehicle 301 
               
               
                 301b 
                 Drive means in first direction (X) 
               
               
                 301c 
                 Drive means in second direction (Y) 
               
               
                 304 
                 Lifting device 
               
               
                 400 
                 Storage tower 
               
               
                 401 
                 (Horizontally extending) container supporting framework 
               
               
                 401a 
                 First container supporting framework 
               
               
                 401b-n 
                 Second/underlying container supporting framework(s) 
               
               
                 402 
                 Container support 
               
               
                 403, 403a-d 
                 Opening (in container support 402) 
               
               
                 403′, 403a′-d′ 
                 Target opening 
               
               
                 404 
                 Support plate for storage container 
               
               
                 405 
                 Stabilization rib (for stabilizing storage containers) 
               
               
                 406 
                 First container support beam (oriented in the first 
               
               
                   
                 direction X) 
               
               
                 407 
                 Second container support beam (oriented in the second 
               
               
                   
                 direction Y) 
               
               
                 408 
                 Rail system 
               
               
                 408′ 
                 Coupling rail system 
               
               
                 409 
                 Guiding structure (for opening) 
               
               
                 410 
                 A first set of parallel rails 
               
               
                 411 
                 A second set of parallel rails 
               
               
                 415 
                 Grid opening 
               
               
                 422 
                 Grid cell 
               
               
                 431 
                 Vertical pillar 
               
               
                 432 
                 Horizontal beam (for connecting vertical pillars 431) 
               
               
                 435 
                 Pillar bracket (for vertical pillar 431) 
               
               
                 436 
                 Port column/chute 
               
               
                 437 
                 Access station 
               
               
                 440 
                 Floor 
               
               
                 500 
                 Control system 
               
               
                 601 
                 Transport system 
               
               
                 602 
                 Crane 
               
               
                 603 
                 Sliding bar 
               
               
                 604 
                 Fixed bar 
               
               
                 700 
                 Support displacement device 
               
               
                 701 
                 Electric motor 
               
               
                 702 
                 Drive shaft 
               
               
                 706 
                 First belt/chain 
               
               
                 707 
                 Second belt/chain 
               
               
                 708 
                 Belt wheel 
               
               
                 709 
                 Shelf guide 
               
               
                 709′ 
                 Horizontal movement shelf roller 
               
               
                 710 
                 Guiding tracks (configured to receive shelf rollers 709, 
               
               
                   
                 709′) 
               
               
                 710′ 
                 Guiding track, vertical part 
               
               
                 710″ 
                 Guiding track, horizontal part 
               
               
                 711 
                 Bracket (for connection of the container support 402 to the 
               
               
                   
                 second belt/chain 707) 
               
               
                 712 
                 Bracket (for drive shaft 702) 
               
               
                 713 
                 Bracket (for electric motor 701) 
               
               
                 X 
                 First direction 
               
               
                 Y 
                 Second direction 
               
               
                 Z 
                 Third direction 
               
               
                 P rs   
                 Horizontal plane 
               
               
                 W f   
                 Width of storage container 
               
               
                 L f   
                 Length of storage container 
               
               
                 H f   
                 Height of storage container 
               
               
                 A f   
                 Areal of storage container 
               
               
                 Wr 
                 Width of one rail 
               
               
                 V r1   
                 Offset between lower edge of rail system and lower edge 
               
               
                   
                 of first container supporting framework 
               
               
                 ΔdV, 
                 Offsets between lower edge of container supporting 
               
               
                 ΔdVb-n 
                 framework below the first container supporting framework 
               
               
                 CP 
                 Cantilever part of the rail system (108) or traveling crane 
               
               
                   
                 system (601)