Abstract
A two-dimensional rail system includes a first set of parallel rails arranged to guide movement of container handling vehicles in a first direction across the top of the frame structure, and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the container handling vehicles in a second direction, which is perpendicular to the first direction. The first and second sets of parallel rails divide the rail system into a plurality of grid cells. A container handling vehicle for operation on the two-dimensional rail system includes: a wheel base unit, a body unit, a support section, a cantilever section, and a lifting device. The wheel base unit includes first and second sets of wheels for guiding the container handling vehicle along the rail system in the first and second directions respectively. The first and second sets of wheels form outer peripheries of the wheel base unit. The body unit includes a lower section, which is provided on the wheel base unit. The lower section has a footprint with a horizontal extent which is equal to or less than the wheel base unit. The lower section has an upper surface. The upper surface provides a first container carrying position for carrying a storage container. The support section extends vertically from the lower section. The support section has a footprint with a horizontal extent which is smaller than the footprint of the lower section. The cantilever section extends horizontally from the support section beyond the footprint of the lower section. The lifting device includes a lifting frame that is suspended from the cantilever section.
Claims
1. A container handling vehicle for operation on a two-dimensional rail system comprising a first set of parallel rails arranged to guide movement of container handling vehicles in a first direction across the top of the frame structure, and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the container handling vehicles in a second direction which is perpendicular to the first direction, the first and second sets of parallel rails dividing the rail system into a plurality of grid cells, wherein the container handling vehicle comprises: a wheel base unit comprising first and second sets of wheels for guiding the container handling vehicle along the rail system in the first and second directions respectively, wherein the first and second sets of wheels form outer peripheries of the wheel base unit; a body unit (410) comprising: a lower section which is provided on the wheel base unit, the lower section having a footprint with a horizontal extent which is equal to or less than the wheel base unit, the lower section having an upper surface, wherein the upper surface provides a first container carrying position for carrying a storage container; a support section extending vertically from the lower section, the support section having a footprint with a horizontal extent which is smaller than the footprint of the lower section; and a cantilever section extending horizontally from the support section beyond the footprint of the lower section; and a lifting device comprising a lifting frame that is suspended from the cantilever section.
2. The container handling vehicle according to claim 1, wherein, when a storage container is positioned on the upper surface, an uppermost part of the storage container represents a first height; and the lifting device comprises a lifting frame that is suspended from the cantilever section, the lifting frame having a lowermost part at a second height when the lifting frame is docked in an upper position adjacent the cantilever section; wherein the second height, when the lifting frame is docked in its upper position, is above the first height, such that the lowermost part of a docked lifting frame of a first container handling vehicle can pass over the uppermost part of a storage container positioned on the upper surface of a lower section of the body unit of a second container handling vehicle when the first and second container vehicles pass one another on adjacent grid cells.
3. The container handling vehicle according to claim 1, wherein the first container carrying position is recessed to provide sideways support for a storage container positioned on the first container carrying position.
4. The container handling vehicle according to claim 1, wherein the lifting device comprises a lifting device motor and at least two lifting shafts, and wherein the at least two lifting shafts are arranged in the cantilever section and the lifting device motor is arranged in the lower section, and wherein the lifting device motor and at least two lifting shafts are connected to each other via a drive coupling.
5. The container handling vehicle according to claim 1, wherein the lifting device comprises a lifting device motor and at least two lifting shafts arranged in the cantilever section.
6. The container handling vehicle according to claim 1, wherein the body unit comprises an S-shaped housing linking the lower section, the support section and the cantilever section together.
7. The container handling vehicle according to claim 1, wherein the first container carrying position comprises a conveyor for transferring a storage container between the first container carrying position and an external support.
8. The container handling vehicle according to claim 1, wherein a footprint of the lower section of the body unit is displaced with respect to the footprint of the wheel base unit by substantially or equally a width of a wheel.
9. The container handling vehicle according to claim 1, wherein the lifting frame is suspended on lifting bands, and wherein the lifting frame extends horizontally and comprises gripping devices and corner guides, wherein a lowermost point of the corner guides provides the lowermost part of the lifting frame.
10. The container handling vehicle according to claim 1, wherein the container handling vehicle comprises a support surface, wherein the support surface provides a second container carrying position.
11. The container handling vehicle according to claim 10, wherein the second container carrying position is arranged above the first container carrying position.
12. The container handling vehicle according to claim 10, wherein the second container carrying position is movable between: a retracted position where the second container carrying position is beyond a vertical projection of the first container carrying position, and an extended position where the second container carrying position is at or within the vertical projection of the first container carrying position.
13. The container handling vehicle according to claim 12, wherein the second container carrying position is movable between the retracted position and the extended position via a pivot connection.
14. The container handling vehicle according to claim 12, wherein the second container carrying position is linearly movable between the retracted position and the extended position via a linear movement arrangement.
15. An automated storage and retrieval system comprising a two-dimensional rail system comprising a first set of parallel rails arranged to guide movement of container handling vehicles in a first direction across the top of the frame structure, and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the container handling vehicles in a second direction which is perpendicular to the first direction, the first and second sets of parallel rails dividing the rail system into a plurality of grid cells, wherein the automated storage and retrieval system comprises a plurality of container handling vehicles according to claim 1.
16. The automated storage and retrieval system according to claim 15, wherein the wheel base unit with the first and second sets of wheels is equal to a grid cell.
17. The automated storage and retrieval system according to claim 15, wherein two container handling vehicles, which have the same orientation, occupy only three grid cell spaces.
18. A method of transferring a storage container between a first and second container handling vehicle according to claim 1 operating on an automated storage and retrieval system comprising a two-dimensional rail system comprising a first set of parallel rails arranged to guide movement of container handling vehicles in a first direction across the top of the frame structure, and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the container handling vehicles in a second direction which is perpendicular to the first direction, the first and second sets of parallel rails (110,111) dividing the rail system into a plurality of grid cells, wherein the method comprises: utilizing a main control system to instruct the first and second container handling vehicles to position themselves in neighboring grid cells such that the lifting device of the first container handling vehicle is directly above the upper surface of the lower section of the second container handling vehicle; transferring a storage container between the first container carrying position of the lower section of the second container handling vehicle and the lifting device of the first container handling vehicle.
19. The method according to claim 18, wherein transferring a storage container between the upper surface of the lower section of the second container handling vehicle and the lifting device of the first container handling vehicle comprises: setting the container handling vehicle carrying or supporting the storage container as a master vehicle; setting the other container handling vehicle as a slave vehicle; sending a get_bin command to the slave vehicle; the slave vehicle performs the get_bin command and updates an internal status of the slave vehicle when the storage container is confirmed positioned on vehicle; the slave vehicle sends a confirmation to the control system when the storage container is in the confirmed positioned on vehicle such that the storage container is sufficiently clear from the first container carrying position of the master vehicle; the master vehicle detects that the storage container is gone and sends a bin_update status to the control system; the control system updates the logic state to match with the physical state of the master vehicle and the slave vehicle.
20. The method according to claim 19, wherein the get_bin command includes a parameter defining a height of the storage container to be transferred such that the lifting device of the master vehicle is lowered to a position equal to an uppermost part of the storage container positioned on the first container carrying position.
21. The method according to claim 18, wherein the step of setting the other container handling vehicle as a slave vehicle includes the step of sending a synchronize_to_master command to the slave vehicle such that the slave vehicle moves with and follows the master vehicle.
22. The method according to claim 21, further comprising: sending a message from the slave vehicle to the main control system when the slave vehicle moves with and follows the master vehicle.
23. A method of transferring a storage container between a container handling vehicle according to claim 1 and an external container carrying position, the container handling vehicle operating on an automated storage and retrieval system comprising a two-dimensional rail system comprising a first set of parallel rails arranged to guide movement of container handling vehicles in a first direction across the top of the frame structure, and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the container handling vehicles in a second direction which is perpendicular to the first direction, the first and second sets of parallel rails dividing the rail system into a plurality of grid cells, wherein the method comprises: utilizing a conveyor on the first container carrying position of the lower section to transfer a storage container between the container handling vehicle and an external position outside the container handling vehicle.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0080] Following drawings are appended to facilitate the understanding of the invention.
[0081] FIG. 1A is a perspective view of a framework structure of a prior art automated storage and retrieval system;
[0082] FIGS. 1B-D are top views of a container handling vehicle rail system, where FIG. 1B shows a single track rail system, FIG. 1C shows a double track rail system and FIG. 1D shows a double rail system with the width and length of a container handling vehicle grid cell indicated;
[0083] FIG. 2 is a perspective view of a prior art container handling vehicle having a centrally arranged cavity for carrying storage containers therein;
[0084] FIG. 3A is a perspective view of a prior art container handling vehicle having a cantilever for carrying storage containers underneath;
[0085] FIGS. 3B and 3C show an exemplary wheel base unit for the container handling vehicle;
[0086] FIG. 4A is a simplified side-view of a container handling vehicle according to an embodiment of the invention comprising a wheel base unit and a body unit, where the body unit comprises a lower section, a support section and a cantilever section;
[0087] FIG. 4B is a perspective view of a container handling vehicle according to an embodiment of the invention where protective covers have been removed to better illustrate the setup of the components in a lower section, support section and cantilever section of a body unit of the container handling vehicle;
[0088] FIG. 4C is a top view of FIG. 4B;
[0089] FIGS. 4D-4I are exemplary side views of different setups providing opposite rotation of the lifting shafts;
[0090] FIG. 5 is an example of the cantilever section of the body unit, and indicates which parts that may form part of the cantilever section;
[0091] FIG. 6 is a simplified side-view of a container handling vehicle according to an embodiment of the invention supporting one storage container on a first container carrying position and one storage container by the lifting device, the container handling vehicle comprising a wheel base unit and a body unit, where the body unit comprises a lower section, a support section and a cantilever section;
[0092] FIGS. 7A-7D show step-by-step an example method of transferring a storage container between a first and a second container handling vehicle operating on an automated storage and retrieval system comprising a two-dimensional rail system;
[0093] FIGS. 8A-8D show examples of a container handling vehicle according to the invention with a conveyor on the first container carrying position, where FIG. 8A shows a situation when not carrying a storage container on the first container carrying position, FIG. 8B shows a situation with a storage container on the first container carrying position, and FIG. 8C shows a possible transfer of the storage container from the conveyor on the first container carrying position and to an external conveyor, and FIG. 8D show the conveyor oriented 90 degrees relative the conveyor on FIG. 8A;
[0094] FIG. 9 shows an example of a container handling vehicle according to the invention comprising an upper surface providing a first container carrying position and a support surface providing a second container carrying position;
[0095] FIG. 10A shows the second container carrying position 426 of FIG. 9 in a retracted position via a pivot connection such that in the retracted position the second container carrier position is directed upwards.
[0096] FIG. 10B shows another example of a possible extended position of the second container carrier position;
[0097] FIG. 10C shows the example of FIG. 10B where the second container carrier position has been pivoted 180 degrees and rests upside down on the cantilever section when in the retraced position;
[0098] FIGS. 11A and 11B show yet another example of the second container carrier position, where, in FIG. 11A the second container carrier position is in the extended position directly above the first container carrying position, and in FIG. 11B, the second container carrying position is moved to a retracted position by means of a linear movement arrangement;
[0099] In the drawings, like reference numerals have been used to indicate like parts, elements or features unless otherwise explicitly stated or implicitly understood from the context.
DETAILED DESCRIPTION OF THE INVENTION
[0100] In the following, embodiments of the invention will be discussed in more detail by way of example only and with reference to the appended drawings. It should be understood, however, that the drawings are not intended to limit the invention to the subject-matter depicted in the drawings.
[0101] The framework structure 100 of the automated storage and retrieval system 1 is constructed in accordance with the prior art framework structure 100 described above in connection with FIGS. 1A-1D, i.e. a number of upright members 102 and a number of horizontal members 103, which are supported by the upright members 102, and further that the framework structure 100 comprises a first, upper rail system 108 in the X direction and Y direction.
[0102] The framework structure 100 further comprises storage compartments in the form of storage columns 105 provided between the members 102, 103, where storage containers 106 are stackable in stacks 107 within the storage columns 105.
[0103] The framework structure 100 can be of any size. In particular it is understood that the framework structure can be considerably wider and/or longer and/or deeper than disclosed in FIG. 1A. For example, the framework structure 100 may have a horizontal extent of more than 700×700 columns and a storage depth of more than twelve containers.
[0104] The rail system 108 may be a single rail (also denoted single track) system, as is shown in FIG. 1B. Alternatively, the rail system 108 may be a double rail (also denoted double track) system, as is shown in FIG. 1C, thus allowing a container handling vehicle 201 having a footprint generally corresponding to the lateral area defined by an access opening/grid column 112 to travel along a row of grid columns even if another container handling vehicle 201 is positioned above a grid column neighboring that row. Both the single and double track system, or a combination comprising a single and double track arrangement in a single rail system 108, forms a grid pattern in the horizontal plane P comprising a plurality of rectangular and uniform grid locations or grid cells 122, where each grid cell 122 comprises a grid opening 115 being delimited by a pair of tracks 110a,110b of the first set of rails 110 and a pair of tracks 111a,111b of the second set of rails 111. In FIG. 1C the grid cell 122 is indicated by a dashed box. For example, the sections of the rail-based system being made of aluminium are the rails, and on the upper surface of the rails, there are a pair of tracks that the wheels of the vehicle run in. However, the sections could be separate rails each with a track.
[0105] Consequently, tracks 110a and 110b form pairs of rails defining parallel rows of grid cells running in the X direction, and tracks 111a and 111b form pairs of rails defining parallel rows of grid cells running in the Y direction.
[0106] As shown in FIG. 1D, each grid cell 122 has a width W.sub.c which is typically within the interval of 30 to 150 cm, and a length L.sub.c which is typically within the interval of 50 to 200 cm. Each grid opening 115 has a width W.sub.o and a length L.sub.o which is typically 2 to 10 cm less than the width W.sub.c and the length L.sub.c of the grid cell 122.
[0107] In the X and Y directions, neighboring grid cells are arranged in contact with each other such that there is no space therebetween.
[0108] FIG. 3A is a perspective view of a prior art container handling vehicle 301 having a cantilever for carrying storage containers underneath.
[0109] An exemplary wheel base unit for a container handling vehicle 401 according to the invention is shown in FIGS. 3B and 3C. The wheel base unit 2 features a wheel arrangement 32a,32b having a first set of wheels 32a for movement in a first direction upon a rail system 108 and a second set of wheels 32b for movement in a second direction perpendicular to the first direction. Each set of wheels comprises two pairs of wheels arranged on opposite sides of the wheel base unit 2. To change the direction in which the wheel base unit may travel upon the rail system, one of the sets of wheels 32b is connected to a wheel displacement assembly 7. The wheel displacement assembly is able to lift and lower the connected set of wheels 32b relative to the other set of wheels 32a such that only the set of wheels travelling in a desired direction is in contact with the rail system. The wheel displacement assembly 7 is driven by an electric motor 8. Further, two electric motors 4,4′, powered by a rechargeable battery 6, are connected to the set of wheels 32a,32b to move the wheel base unit in the desired direction.
[0110] Further referring to FIGS. 3B and 3C, the horizontal periphery of the wheel base unit 2 is dimensioned to fit within the horizontal area defined by a grid cell, such that two wheel base units 2 may pass each other on any adjacent grid cells of the rail system 108. In other words, the wheel base unit 2 may have a footprint, i.e. an extent in the X and Y directions, which is generally equal to the horizontal area of a grid cell, i.e. the extent of a grid cell in the X and Y directions, e.g. as is described in WO2015/193278A1, the contents of which are incorporated herein by reference.
[0111] FIG. 4A is a simplified side-view of a container handling vehicle 401 according to an embodiment of the invention comprising a wheel base unit 2 and a body unit 410, where the body unit 410 comprises a lower section 411, a support section 412 and a cantilever section 413. The lower section 411 having an upper surface, wherein the upper surface 425 provides a first container carrying position 425 for carrying a storage container 106.
[0112] Referring to FIGS. 3B and 4A, the wheel base unit 2 has a top panel/flange 9 (i.e. an upper surface) configured as a connecting interface for connection to a body unit 410 of a container handling vehicle 401. The top panel 9 have a centre opening 20 and features multiple through-holes 10 (i.e. connecting elements) suitable for a bolt connection via corresponding through-holes in a lower section 411 of the body unit 401. In other embodiments, the connecting elements of the top panel 9 may for instance be threaded pins for interaction with the through-holes of the lower section 411. In yet another embodiment, the container handling vehicle 401 is not in this modular design, but rather made in one or a few pieces. The presence of a centre opening 20 is advantageous as it provides access to internal components of the wheel base unit 2, such as the rechargeable battery 6 and an electronic control system 21.
[0113] Further referring to FIG. 4A, the body unit 410 is disclosed as comprising an S-shaped housing linking the lower section 411, the support section 412 and the cantilever section 413 together. The container handling vehicle 401 of FIG. 4A is operable on a rail system 108 as described in connection with FIGS. 1A-1D, and comprises a wheel base unit 2 and a body unit 410. The wheel base unit 2 comprising sets of wheels 32a, 32b for guiding the container handling vehicle 401 along the rail system 108 in the first and second directions X, Y. The body unit 410 comprising a lower section 411, a support section 412 and a cantilever section 413. The lower section 411 is mounted on an upper surface of the wheel base unit 2. The lower section 411 may have a footprint with a horizontal extent which is equal to or less than the horizontal extent of one of the grid cells 122. The top of the storage container 106 is at a first height h1. I.e. the first height h1 is the distance from the top of the rail system 108 to the top of the storage container 106 positioned on the first container carrying position on the upper surface the lower section 411 when the lower section 411 is mounted on the wheel base unit 2. The support section 412 extends vertically from the lower section 411 and has a footprint with a horizontal extent which is smaller than the footprint of the lower section 411. The width of the support section 412 (i.e. the extension in the X direction) may be equal to the width of the lower section 411 (in the X direction). The extension of the support section 412 in the Y direction is smaller than the extension of the lower section 411 in the Y direction.
[0114] Furthermore, referring to FIG. 4C, when seen in a plan view from above, the footprint of the support section 412 falls within the footprint of the lower section 411. In other words, as disclosed in FIGS. 4A-4C, the support section 412 does not extend beyond the lower section 411. The cantilever section 413 extends horizontally from the support section 412 beyond the footprint of the lower section 411 and comprises a lifting device 414 suspended from the cantilever section 413.
[0115] The lifting device 414 comprising a lifting frame 415 having a lowermost part at a second height h2 when the lifting frame 415 is docked in an upper position adjacent the cantilever section 413 (FIGS. 4A and 4B show docked position of lifting frame 415). I.e. the second height h2 is the distance from the top of the rail system 108 to the lowermost part of the lifting frame 415. The lifting frame 415 is suspended from the cantilever section 413 via lifting bands 419. The lifting frame 415 may comprise gripping devices 420 extending from a lower surface thereof for connecting the lifting frame to complementary lifting holes of the storage containers 106 thereby rendering possible lifting and lowering of the storage containers 106. In addition, the lifting frame 415 may comprise guides 421 arranged in the corners of the lower surface of the lifting frame 415 to align the gripping devices 420 of the lifting frame 415 relative the complementary lifting holes on the storage containers 106. In many situations the guides 421 or the gripping devices 420 may constitute the lowermost part of the lifting frame 415 such that the second height h2 is the lowermost part of any of these components. However, according to an embodiment of the invention, the second height h2 of the lowermost part of the lifting frame 415, when the lifting frame 415 is docked in its upper position, is always above the first height h1 of the storage container 106 positioned on the first container carrying position.
[0116] By ensuring that the lowermost part of a docked lifting frame 415 of a first container handling vehicle 401 can pass over a storage container 106 supported on the first container carrying position of a second container handling vehicle 401 when the first and second container vehicles 401 pass one another on adjacent grid cells 122, the first and second container handling vehicles 401 can pass each other while collectively occupying fewer grid cells than required in prior art solutions.
[0117] FIG. 4B is a perspective view of a container handling vehicle 401 according to the embodiment of the invention where protective covers have been removed to better illustrate the setup of the components in the lower section 411, the support section 412 and the cantilever section 413 constituting the body unit 410 of the container handling vehicle 401. In the embodiment of FIG. 4B, the lifting device 414 is disclosed as comprising a lifting device motor 416′ and at least two lifting shafts 417′,417″. The two lifting shafts 417′,417″ are arranged in parallel in the cantilever section 413. The lifting bands 419 connected to the lifting frame 415, are spooled onto and off the lifting shafts 417′,417″, thereby moving the lifting frame 416 and any storage container 106 carried by the lifting frame 415 up and down. Lifting shaft wheels 423′,423″ are arranged on each end of the lifting shafts 417 and operate together with the lifting shafts 417, respectively. As shown in FIG. 4B, the lifting device motor 416′ is arranged in the lower section 411. The lifting device motor 416′ and the two lifting shafts 417 are connected to each other via the lifting shaft wheels 423′, 423″ and an endless flexible force transferring element 418, such as e.g. belt, running via sheaves 422 to ensure that the first and second lifting shafts 417 rotate simultaneously in the same direction. Any necessary power source (not shown) for supplying power to the lifting device motor 416′ may be arranged in the lower section 413 in order to obtain a favorable center of gravity with reduced risk of tilting of the container handling vehicle in the event lifting a heavy storage container 106 and/or as a result of too high acceleration/deceleration of the container handling vehicle 401.
[0118] The lifting frame 415 is shown with guides 421 arranged in the corners of the lower surface of the lifting frame 415 to align the gripping devices 420 of the lifting frame 41 relative the complementary lifting holes on the storage containers 106.
[0119] Any necessary power source (not shown) for supplying power to the lifting device motor 416″ may be arranged in the lower section 413 in order to obtain a favorable center of gravity with reduced risk of tilting of the container handling vehicle in the event lifting a heavy storage container 106 and/or as a result of too high acceleration/deceleration of the container handling vehicle 401.
[0120] FIG. 4C is a top view of FIG. 4B, showing the lower section 411, the support section 412 and the cantilever section 413.
[0121] FIGS. 4D-41 are examples of different setups providing opposite rotation of the lifting shafts 417′,417″. As disclosed in all of the examples of FIGS. 4D-4I, common to all of the force transferring setups, is the presence of a rotatable lifting device motor 416′, a first and second lifting shaft wheel 423′, 423″ whereof each is connected for rotation with the respective lifting shafts 417′,417″, at least one sheave 422′, 422″, a force transferring element 418 in the form of an endless belt forming a closed loop and where at least one of sheaves 422′,422″ is arranged inside the closed loop. In addition, the first or second lifting shaft wheel 423′, 423″ is in contact with an inner surface of the endless belt 418 and the other of the first or second lifting shaft wheel 423′, 423″ is in contact with the outer surface of the endless belt 418. This is achieved by arranging one of the first or second lifting shaft wheels 423′, 423″ inside the closed loop formed by the force transferring element 418 and the other of the first or second lifting shaft wheel 423′, 423″ outside the closed loop formed by the force transferring element 418. The mutual setup of the first and second lifting shaft wheels 423′, 423″ (e.g., acting on opposite sides of the endless belt), the guide sheaves 422′, 422″ and the force transferring element 418, are such that the first and second lifting shafts 417′, 417″ (via first and second lifting shaft wheels 423′, 423″, respectively) rotate in opposite directions (counter rotates). The first and second lifting shaft wheels 423′, 423″ are preferably arranged in the same horizontal plane in order to ensure horizontal stability during lifting. The sheave(s) 422′, 422″ are arranged along the travel of the force transferring element 418 at fixed positions such that they provide for a “change” in the travel direction of the force transferring element 418. Each of the sheaves 422′, 422″ are arranged to lead the force transferring element 418 correctly onto the first and second lifting shaft wheel 423′, 423″ thereby allowing the first and second lifting shaft wheels 423′, 423″ (and thus the lifting shafts 417′, 417″) to rotate in opposite directions.
[0122] In the example in FIG. 4D, one sheave 422′ is shown.
[0123] In the examples of FIGS. 4E-41, a number of examples of force transferring setups comprising two sheaves 422′, 422″, are shown. The sheaves 422′, 422″ are arranged alternating along the path of the force transferring element 418 such that the first lifting shaft wheel 423′ is followed by a sheave 422′, 422″ and the second lifting shaft wheel 423″ is followed by a sheave 422′, 422″ in both directions of travel of the force transferring element 418.
[0124] In the examples of FIGS. 4G, 4H, 4I, there are disclosed examples comprising a tightening wheel 424 for tensioning of the force transferring element 418. The tightening wheel 424 may for example be an eccentric tensioning mechanism comprising a rotatable sheave with an axle that can be adjusted within an opening in a fixed bracket. The location of the tightening wheel 424 along the path of the force transferring element 418 is preferably at a location where the path length of the force transferring element 418 can be affected (i.e. the path of the force transferring element can be shortened or prolonged in order to further tension or reduce tension in the force transferring element). The tightening wheel 424 can be arranged inside (FIGS. 4G and 41) or outside (FIG. 4H) the closed loop formed by the force transferring element 418.
[0125] In the examples in FIGS. 4D-4F, a dedicated tensioning mechanism such as a tightening wheel is not shown; however, if a tensioning mechanism is required, one of the sheaves 422′ or 422″ may be a tensioning mechanism and can be replaced by a tightening wheel 424.
[0126] FIG. 5 is an example of another setup of the lifting device 414, where, in addition to the lifting shafts 417 and the lifting bands spoolable onto and off the lifting shafts 417′, 417″, also the lifting device motor 416″ is arranged in the cantilever section 413 of the body unit 410. The lifting device motor(s) 416″ in FIG. 5 is a brushless DC motor encircling one of the lifting shafts 417′, 417″. Synchronous operation of the lifting shafts 417′, 417″ can be obtained by a synchronization element such as a force transferring element as disclosed in FIGS. 5A-5E and 6A-6H in WO 2019/137870 A1 (Applicant: Autostore Technology AS), the contents of which are incorporated herein by reference.
[0127] FIG. 6 is a simplified side-view of a container handling vehicle 401 according to an embodiment of the invention supporting one storage container 106 on a first container carrying position 425 and one storage container 106 by the lifting device 415, the container handling vehicle 401 comprising a wheel base unit 2 and a body unit, where the body unit comprises a lower section 411, a support section 412 and a cantilever section 413. The components of the container handling vehicle in FIG. 6 are similar to the container handling vehicle in FIG. 4A. The first container carrying position 425 is preferably recessed to provide sideways support for a storage container 425 positioned on the first container carrying position 425.
[0128] FIGS. 7A-7D show step-by-step an exemplary method of transferring a storage container 106 between a first and a second container handling vehicle 401 operating on an automated storage and retrieval system 1 comprising a two-dimensional rail system 108. Referring to FIG. 7A, a first container handling vehicle 401 (i.e. the vehicle to the right in the figure not carrying a storage container 106) is positioned in a distance from the second container handling vehicle 401 (i.e. the vehicle to the left in the figure carrying a storage container 106 in the lifting device and carrying a storage container 106 on the first container carrying position 425). The first container handling vehicle 401 and the second container handling vehicle 4011 operate in neighboring rows on the rail system 108.
[0129] In FIG. 7B the first and second container handling vehicles 401 have moved closer to each other compared to the situation in FIG. 7A and the lifting device 414 of the first container handling vehicle 401 is almost above the upper surface/first container carrying position 425 of the lower section 411 of the second container handling vehicle 401.
[0130] In FIG. 7C the first and second container handling vehicles 401 have positioned themselves in neighboring grid cells 122 such that the lifting device 414 of the first container handling vehicle 401 is directly above the upper surface/first container carrying position 425 of the lower section 411 of the second container handling vehicle 401.
[0131] In FIG. 7D the lifting device 414 of the first container handling vehicle 401 has been lowered down to lift the storage container 106 positioned on the first container carrying position 425 on the second container handling vehicle 401 and lifted the storage container 106 off the first container carrying position 425. The transfer of the storage container 106 is now complete.
[0132] Referring to FIGS. 7A-7D, the method of transferring the storage container may comprise the steps of: [0133] utilizing a main control system to instruct the first and second container handling vehicles 401 to position themselves in neighboring grid cells 122 such that the lifting device 414 of the first container handling vehicle 401 is directly above the upper surface of the lower section 411 of the second container handling vehicle 401; [0134] transferring a storage container 106 between the first container carrying position 425 of the lower section 411 of the second container handling vehicle 401 and the lifting device 414 of the first container handling vehicle 401. The step of transferring a storage container 106 between the upper surface of the lower section 411 of the second container handling vehicle 401 and the lifting device 414 of the first container handling vehicle 401 may comprise the steps of: [0135] setting the container handling vehicle 401 carrying or supporting the storage container 106 as a master vehicle; [0136] setting the other container handling vehicle 401 as a slave vehicle; [0137] sending a get_bin command to the slave vehicle; [0138] the slave vehicle performs the get_bin command and updates its internal status when the storage container 106 is confirmed positioned on vehicle 401; [0139] the slave vehicle sends a confirmation to the control system when the storage container is in the confirmed positioned on vehicle such that the storage container 106 is sufficiently clear from the first container carrying position 425 of the master vehicle; [0140] the master vehicle detects that the storage container 106 is gone and it will send a bin_update status to the control system 500; [0141] the control system 500 updates the logic state to match with the physical state of the master vehicle and the slave vehicle.
[0142] The get_bin command may include a parameter defining a height of the storage container 106 to be transferred such that the lifting device 414 of the master vehicle is lowered to a position equal to an uppermost part of the storage container positioned on the first container carrying position.
[0143] The step of setting the other container handling vehicle 401 as a slave vehicle may comprise the step of sending a synchronize_to_master command to the slave vehicle, such that the slave vehicle moves with and follows the master vehicle. This allows for transferring the storage container 106 between the upper surface of the lower section 411 of the second container handling vehicle 401 and the lifting device 414 of the first container handling vehicle 401 in motion. The slave vehicle may optionally send a message to the main control system when synchronization has been obtained. Alternatively, the main control system may determine that synchronization has been obtained based on positional information of the slave vehicle and the master vehicle. Synchronization has been obtained when the slave vehicle moves with and follows the master vehicle.
[0144] The master vehicle may send movement data, such as speed, acceleration, and position data to the slave vehicle. The slave vehicle may use the movement data to synchronize its own movements to the received movement data. The master vehicle may send the movement data via the main control system. The master vehicle may alternatively, or additionally send the movement data directly to the slave vehicle using local communication between the master vehicle and the slave vehicle. The local communication may be any suitable means of local wireless communication, such as near field communication (NFC) or infrared (IR).
[0145] Synchronized movement of the slave vehicle and the master vehicle may include a train-like synchronization where the slave vehicle follows behind the master vehicle, or the synchronized movement may include a parallel synchronization where the slave vehicle moves with the master vehicle side by side.
[0146] The automated storage and retrieval system may comprise a positioning system using multilateration techniques, such as a Time of Flight (TOF) measurement system, for determining the position of both the master vehicle and the slave vehicle. The main control system continuously receives position data from the positioning system of a position of the first container handling vehicle and position data of a position of the second container handling vehicle. The main control system may use the position data to instruct slave vehicle to move with and follow the master vehicle within a predetermined separation from the master vehicle. The movement of the master vehicle and the slave vehicle is thereby synchronized such that the step of transferring the storage container 106 between the upper surface of the lower section 411 of the second container handling vehicle 401 and the lifting device 414 of the first container handling vehicle 401 may be performed in motion.
[0147] The container handling vehicles may be arranged with sensors that can detect the position of the container handling vehicles on the rail system, and/or proximity sensors that detects the distance to nearby container handling vehicles. The main control system may instruct the slave vehicle to move with and follow the master vehicle within a predetermined separation from the master vehicle based on received distance data from the proximity sensor of the slave vehicle. The movement of the master vehicle and the slave vehicle is thereby synchronized such that the step of transferring the storage container 106 between the upper surface of the lower section 411 of the second container handling vehicle 401 and the lifting device 414 of the first container handling vehicle 401 may be performed in motion.
[0148] The container handling vehicles may be adapted to move together in physical contact with one another. The main control system may instruct the slave vehicle to move with and follow the master vehicle by first moving into physical contact of the master vehicle, and after contact continue to apply a push force on the master vehicle to maintain physical contact. The movement of the master vehicle and the slave vehicle is thereby synchronized such that the step of transferring the storage container 106 between the upper surface of the lower section 411 of the second container handling vehicle 401 and the lifting device 414 of the first container handling vehicle 401 may be performed in motion.
[0149] FIGS. 8A-8D show examples of a container handling vehicle 401 according to an embodiment of the invention with a conveyor 427 on the first container carrying position 425 adapted to transfer the storage container 106 backwards onto another container handling vehicle or to an external conveyor. through any of the short sides of the container handling vehicle 401. The conveyor 427 could also have been oriented 90 degrees relative the embodiment of FIG. 8A such that storage containers 106 could be transferred directly backwards onto another container handling vehicle or to an external conveyor (see FIG. 8D). FIG. 8A shows a situation when not carrying a storage container on the first container carrying position 425, while FIG. 8B shows a situation with a storage container 106 on the first container carrying position 425, and FIG. 8C shows a possible transfer of the storage container 106 from the conveyor 427 on the first container carrying position 425 and to an external conveyor 428. An upper surface of the external conveyor 428 is preferably arranged at the substantially same height as an upper surface of the conveyor 427 on first container carrier position 425.
[0150] Referring to FIGS. 7A, 7B and 8A the lower section 411 has an upper surface 425 which is recessed with respect to a pair of support webs 429, wherein the upper surface 425 provides the first container carrying position 425 for carrying a storage container 106. The support section 412 extends vertically from the pair of support webs 429 of the lower section 411, the support section 412 having a footprint with a horizontal extent which is smaller than the footprint of the lower section 411.
[0151] FIG. 9 shows an example of a container handling vehicle 401 according to an embodiment of the invention comprising an upper surface 425 providing a first container carrying position 425 and a support surface 426 providing a second container carrying position 426. The container handling vehicle 401 of FIG. 9 comprises similar components as the container handling vehicle of FIGS. 4A and 6, which will not be repeated herein. However, the container handling vehicle 401 in FIG. 9 additionally comprises the second container carrying position 426. The second container carrying position 426 is disclosed as being arranged above the first container carrying position 425. Preferably, the first and second container carrying positions 425, 426 form the same vertical projection on the underlying rail system 108.
[0152] FIG. 10A shows the second container carrying position of FIG. 9 in a retracted position via a pivot connection 430 such that in the retracted position the second container carrier position 426 is directed upwards. The arrow A shows the direction of movement from a horizontal extended position (in FIG. 9) and a vertical retracted position in FIG. 10A. The pivot connection 430 shows the axle of rotation of the second container carrier 426.
[0153] FIG. 10B shows another example of a possible extended position of the second container carrier position 426. In FIG. 10B the second container carrier position 426 is in the extended horizontal position where it can receive a storage container (not shown).
[0154] FIG. 10C shows the example of FIG. 10B where the second container carrier position 426 has been pivoted 180 degrees and rests upside down on the cantilever section 413 of the container handing vehicle 401 when in the retraced position. The second container carrying position 426 has been pivoted from the retracted position to the extended position around the pivot connection arrangement 430 as shown with the arrow A.
[0155] FIGS. 11A and 11B show yet another example of the second container carrier position 426, where, in FIG. 11A the second container carrier position 426 is in the extended position directly above the first container carrying position 425, and in FIG. 11B, the second container carrying position is moved linearly (as indicated with arrow A) to a retracted position by means of a linear movement arrangement (not shown).
[0156] Thus, referring to FIGS. 10A, 10B, 10C and 11A and 11B, in order to obtain access to a storage container 106 positioned on the first container carrying position 425, the second container carrying position 426 is preferably movable between: [0157] a retracted position where the second container carrying position 426 is beyond a vertical projection of the first container carrying position 425, providing access to the upper surface of the first container carrying position 425 and or the storage container 106 positioned on the first container carrying position 425, and [0158] an extended position where the second container carrying position 426 is at or within the vertical projection of the first container carrying position 425. The second container carrying position 426 can be movable between the retracted position and the extended position via a pivot connection arrangement 430 (FIGS. 10A-10C)) or a linear movement arrangement (FIGS. 11A and 11B) where it is linearly movable between the retracted position and the extended position via a linear movement arrangement.
[0159] If using a pivot connection (see FIGS. 10A-10C), the pivot connection 430 can be arranged such that: [0160] in the retracted position the second container carrying position 426 is substantially vertical, and [0161] in the extended position the second container carrier position 426 extends substantially horizontally.
[0162] If using a linear movement arrangement (see FIGS. 11A and 11B), the linear movement arrangement can be arranged such that: [0163] in the retracted position the second container carrying position 426 is moved to a position beyond the first container carrying position 425 and above the cantilever section 413, and [0164] in the extended position the second container carrying position 426 is above the first container carrying position 425.
[0165] In the preceding description, various aspects of an automated storage and retrieval system according to the invention have been described with reference to the illustrative embodiment. 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, are deemed to lie within the scope of the present invention as defined by the following claims.
TABLE-US-00001 List of reference numbers 1 Automated storage and retrieval system 2 Wheel base unit 4, 4′ Electric motor 6 Rechargeable battery 7 Wheel displacement assembly 8 Electric motor for wheel displacement assembly 9 Top panel/flange 10 Through-holes 20 Centre opening 21 Electronic control system 30 Remotely operated delivery vehicle 32a, 32b Wheel arrangement, first and second set of wheels 100 Framework structure 102 Upright members of framework structure 103 Horizontal members of framework structure 104 Storage grid 105 Storage column 106 Storage container 106′ Particular position of storage container 107 Stack 108 Rail system 110 First set of parallel rails in first direction (X) 110a, 110b Tracks of first set of rails 111 Second set of parallel rail in second direction (Y) 111a, 111b Tracks of second set of rails 112 Access opening/grid column 115 Grid opening 119 First port column 120 Second port column 122 Grid cell 201 Prior art storage container vehicle 201a Vehicle body of the storage container vehicle 201 201b Drive means/wheel arrangement, first direction (X) 201c Drive means/wheel arrangement, second direction (Y) 301 Prior art cantilever storage container vehicle 301a Vehicle body of the storage container vehicle 301 301b Drive means in first direction (X) 301c Drive means in second direction (Y) 304 Parts of the gripping device of the container handling vehicle 301 401 Container handling vehicle 410 Body unit 411 Lower section of body unit 412 Support section of body unit 413 Cantilever section of body unit 414 Lifting device 415 Lifting frame 416′, 416″ Lifting device motor 417′, 417″ Lifting shaft 418 Force transferring element 419 Lifting band 420 Gripping device 421 Guide 422′, 422″ sheaves 423′, 423″ Lifting shaft wheels 424 Tightening wheel 425 Upper surface/first container carrying position 426 Support surface/second container carrying position 427 Conveyor 428 External conveyor 429 Support webs 430 Pivot connection arrangement 500 Control system A Arrow showing movement direction(s) X First direction Y Second direction Z Third direction C clearance h1 First height h2 Second height
