Patent ID: 12210339

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

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.

An embodiment of a storage structure of an automated storage and retrieval system1according to the invention will now be discussed in more detail with reference toFIGS.1to8.

The storage structure comprises a framework2on which a plurality of container handling vehicles3a,3bare operated.

The framework2comprises a plurality of upright members4and a plurality of horizontal members5, which are supported by the upright members4. The members4,5may typically be made of metal, e.g. extruded aluminium profiles.

The framework2defines a three-dimensional storage grid comprising storage columns7arranged in rows, in which storage columns7storage containers8, also known as bins, are stacked one on top of another to form stacks9. Each storage container8may typically hold a plurality of product items (not shown), and the product items within a storage container8may be identical, or may be of different product types depending on the application of the system1. The framework2guards against horizontal movement of the stacks9of storage containers8, and guides vertical movement of the containers8, but does normally not otherwise support the storage containers8when stacked.

The horizontal members5comprise a rail or track system10arranged in a horizontal plane P above the storage columns7(seeFIGS.1and3), on which track system10the plurality of container handling vehicles3can move laterally above the storage columns7to raise storage containers8from and lower storage containers8into the storage columns7, and also to transport the storage containers8above the storage columns7.

The track system10comprises a first set of parallel rails or tracks11arranged to guide movement of the container handling vehicles3in a first direction X, and a second set of parallel rails or tracks12arranged perpendicular to the first set of tracks11to guide movement of the container handling vehicles3in a second direction Y, which is perpendicular to the first direction X.

The track system10forms a grid structure or grid pattern13in the horizontal plane P (seeFIG.3). The grid pattern13comprises a plurality of rectangular and uniform grid locations or grid cells14(seeFIG.8), where each grid cell14comprises a grid opening15which is delimited by a pair of tracks11a,11bof the first set of tracks11and a pair of tracks12a,12bof the second set of tracks12. InFIG.8, the grid cell14is indicated by a box having dashed borders and the grid opening15is indicated by a hatched area.

Consequently, tracks11aand11bform pairs of tracks defining parallel rows of grid cells running in the X direction, and tracks12aand12bform pairs of tracks defining parallel rows of grid cells running in the Y direction.

Each grid cell14has a width Wcwhich is typically within the interval of 30 to 150 cm, and a length Lcwhich is typically within the interval of 50 to 200 cm. Each grid opening15has a width Woand a length Lowhich is typically 2 to 10 cm less than the width Wc, and the length Lc, respectively, of the grid cell14.

In the X and Y directions, neighbouring grid cells are arranged in contact with each other such that there is no space there-between.

One embodiment of a container handling vehicle3according to the invention will now be discussed in more detail with additional reference toFIGS.10to12.

Each container handling vehicle3comprises a vehicle body17and a wheel assembly18arranged in a lower section or part17a(seeFIG.12) of the vehicle body17to enable the lateral movement of the container handling vehicle3, i.e. the movement of the vehicle3in the X and Y directions (seeFIG.4).

The wheel assembly18comprises a first set of wheels19, which is arranged to engage with a pair of tracks11a,11bof the first set of tracks11, and a second set of wheels20, which is arranged to engage with a pair of tracks12a,12bof the second set of tracks12(seeFIG.10). At least one of the set of wheels19,20can be lifted and lowered, so that the first set of wheels19and/or the second set of wheels20can be brought to engage with the respective set of tracks11,12at any one time.

Each set of wheels19,20comprises four wheels19a,19b,19c,19d;20a,20b,20c,20darranged along the sides of the vehicle (seeFIGS.4and7). Wheels19aand19bare arranged in a first vertical plane, and wheels19cand19dare arranged in a second vertical plane which is parallel to the first vertical plane and arranged at a distance from the first vertical plane which corresponds to the distance between rails11aand11b(seeFIG.8). Wheels20aand20bare arranged in a third vertical plane, which is orthogonal to the vertical planes in which wheels19a-19dare arranged, and wheels20cand20dare arranged in a fourth vertical plane which is parallel to the third vertical plane and arranged at a distance from the third vertical plane which corresponds to the distance between rails12aand12b.

At least one of the wheels in each set19,20is motorized in order to propel the vehicle3along the track system10. Advantageously, the at least one motorized wheel in each set comprises a hub motor, i.e. an electric motor that is coupled to, or incorporated into, the hub of a wheel and drives the wheel directly. An example of a container handling vehicle with such a motor is disclosed in WO2016/120075A1, the contents of which are incorporated herein by reference.

Each container handling vehicle3comprises a storage compartment or storage space24arranged centrally within the lower part7aof the vehicle body17for receiving and holding a storage container8when transporting the storage container8across the track system10. The storage space24is arranged within the vehicle body17and can be accessed from below, i.e. from an opening (not shown) at the bottom of the container handling vehicle3.

Each container handling vehicle3also comprises a lifting device21(seeFIG.10) for vertical transportation of a storage container8, e.g. lifting a storage container8from a storage column7and bringing it into the storage space24, and also for lowering a storage container8from the storage space24into a storage column7. The lifting device21comprises a latching or gripping device22which is arranged to releasably engage with a storage container8. The lifting device also comprises a lifting motor23for lowering and raising the gripping device22so that the position of the gripping device22with respect to the vehicle body17can be adjusted in a third direction Z, which is orthogonal to the first direction X and the second direction Y (see alsoFIG.4).

Conventionally, and also for the purpose of this application, Z=1 identifies the uppermost layer of the storage grid, i.e. the layer immediately below the track system10, Z=2 identifies the second layer below the track system10, Z=3 identifies the third layer etc. The container handling vehicles3can be said to travel in layer Z=0. Consequently, each storage column can be identified by its X and Y coordinates, and each storage position in the storage grid can be identified by its X, Y and Z coordinates.

The lifting motor23is arranged in a second, upper part or section17bof the vehicle body17(seeFIG.12), which upper part17bis located above the lower part17a.

When a storage container8stored in the storage grid is to be accessed, one of the container handling vehicles3is instructed to retrieve the target storage container8from its position in the storage grid and to transport the target storage container8to an access station (not shown) where it can be access from outside of the storage grid or transferred out of the storage grid. This operation involves moving the container handling vehicle3to the grid cell14above the storage column7in which the target storage container is positioned and retrieving the storage container from the storage column7using the container handling vehicle's lifting device21. This step involves using the lifting device21to lift the storage container from the storage column7through the grid opening15of the grid cell14and into the storage space24of the vehicle3.

If the target storage container is located deep within a stack9, i.e. with one or a plurality of other storage containers positioned above the target storage container, the operation also involves temporarily moving the above-positioned storage containers prior to lifting the target storage container from the storage column7. 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 access station, or with one or a plurality of other cooperating container handling vehicles. Alternatively, or in addition, the automated storage and retrieval system may have container handling vehicles specifically dedicated to the task of temporarily removing storage containers from a storage column. Once the target storage container has been removed from the storage column, the temporarily removed storage containers can be repositioned into the original storage column. However, the removed storage containers may alternatively be relocated to other storage columns.

Once the target storage container has been brought into the storage space24of the container handling vehicle3, the vehicle transports the storage container to the access station where it is unloaded. The access station may typically comprise a grid location at the periphery of the storage grid where the storage container can be accessed manually or transported further using a suitable conveyor system.

When a storage container8is to be stored in the storage grid, one of the container handling vehicles3is instructed to pick up the storage container from a pick-up station (not shown), which may also double as an access station, and transport it to a grid cell above the storage column7where it is to be stored. After any storage containers positioned at or above the target position within the storage column stack have been removed, the container handling vehicle3positions the storage container at the desired position. The removed storage containers may then be lowered back into the storage column7, or relocated to other storage columns within the storage grid.

For monitoring and controlling the automated storage and retrieval system so that a desired storage container can be delivered to the desired location at the desired time without the container handling vehicles3colliding with each other, the automated storage and retrieval system comprises a control system (not shown), which typically is computerised and comprises a database for monitoring and controlling e.g. the location of the respective storage containers8within the storage grid, the content of each storage container8and the movement of the container handling vehicles3.

The container handling vehicles3typically communicates with the control system via wireless communication means, e.g. via a WLAN operating under an IEEE 802.11 (WiFi) standard and/or utilising a mobile telecommunication technology such as 4G or higher.

Each container handling vehicle3comprises a battery25which provides power to onboard equipment, including the motorised wheels, the lifting motor and onboard control and communications systems.

Each container handling vehicle3has a footprint, i.e. a contact area against the track system10, which has a horizontal extension which is equal to or less than the horizontal extension of a grid cell14. In other words, when the vehicle3is positioned above a grid cell14, e.g. for lifting a storage container from or lowering a container into a storage column7, the footprint of the vehicle3will not extend beyond the grid cell into a neighbouring grid cell.

The wheels19a-19d,20a-20dare arranged around the periphery of the storage space24, and the footprint14of the vehicle3is larger than the storage space24only enough to accommodate the wheels19a-19d,20a-20d. In this way, the footprint14of the vehicle3takes up the minimum possible amount of space in the X-Y plane. Since the storage space24is positioned between the pair of wheels19a-19d,20a-20don each side of the vehicle3, the centre of gravity of the vehicle3will be located within the footprint14also when a storage bin is raised into the storage space24.

Further, the vehicle3comprises generally vertical side walls26a-26d(seeFIGS.4,6and7), which are co-planar to the vertical planes in which the wheels19a-19d;20a-20dare arranged. Consequently, the lower part of the container handling vehicle3has a generally cuboid shape.

However, the upper part17bof the vehicle3has a protruding section27which extends horizontally in the X direction beyond the otherwise generally vertical side wall26c(e.g. seeFIGS.2and4). This section27houses the battery25of the vehicle3(seeFIG.7). Positioning the battery in this manner is advantageous since it allows charging or battery exchange stations easy access to the battery for charging or battery replacement. In particular, if a battery exchange scheme is used, in which case the protruding section27comprises a battery compartment or slot28(e.g. seeFIG.12), the protruding character of section27provides advantageous guiding for the battery25during battery exchange operation.

The protruding section27also allows larger batteries to be mounted in the vehicle and may also be beneficial when operating the vehicles as a train of vehicles, e.g. as is disclosed in the international patent application PCT/EP2016/077300.

Alternatively, or in addition, the protruding section27may hold down-looking sensors, which may be used to establish the position of the vehicle on the track system10, e.g. the alignment of the vehicle vis-à-vis a grid cell14, or to establish the position of the vehicle vis-à-vis other vehicles on the track system10, e.g. when operating the vehicles as a train of vehicles.

When the vehicle3is positioned above a grid cell14, e.g. to access a container8in the storage column7located vertically below the grid cell14, the protruding section27will extend over a neighbouring grid cell. In other words, even though the vehicle3has a contact area against the rail system10which does not extend beyond the horizontal extent of one grid cell14, the vehicle has a vertical projection which occupies more than one grid cell.

Normally this would prevent a second vehicle from travelling over the neighbouring grid cell, i.e. the grid cell into which the protruding section27of the first vehicle extends. This could be a problem since it could reduce the overall capacity of the automated storage and retrieval system.

However, the container handling vehicle3comprises a recessed section29which is arranged in the upper part17bopposite to the protruding section27. In other words, the protruding section27and the recessed section29are arranged at opposite sides of the container handling vehicle3. The recessed section29is capable of accommodating the protruding sections27of other vehicles when they pass over a neighbouring grid cell. In particular, the recessed section29has a shape which is complementary to the shape of the protruding section27and extends across the whole width of the container handling vehicle3in the Y direction, thus allowing vehicles3to pass each other over adjacent grid cells.

This is illustrated inFIGS.4to6, which show a first vehicle3amoving in to operate over a grid cell while a second vehicle3bis positioned over a neighbouring grid cell while the protruding section27aof the first vehicle3ais accommodated in the recessed section29bof the second vehicle3b.

In the disclosed embodiment, the protruding section27of each container handling vehicle3extends in the X direction and the recessed section29extends across the whole width of the vehicle3in the Y direction. However, it is understood that the protruding section may alternatively extend in the Y direction and the recessed section extend across the whole width of the vehicle in the X direction.

Each container handling vehicle may alternatively have two protruding sections27′,27″ extending in two orthogonal directions and two opposite, complementary recessed sections29′,29″, as is schematically illustrated by the container handling vehicle shown inFIG.13. This configuration will also allow two vehicles to operate over neighbouring grid cells without the protruding sections27′ and27″ hindering the movement of other vehicles on the track system.

In the track system10shown inFIG.8, each horizontal member making up the tracks comprises two tracks. Consequently, each horizontal member is capable of accommodating two wheels in parallel. In such a track system, the borders between neighbouring grid cells run along the centre-line of the horizontal members, as is indicated inFIG.8.

FIG.9shows an alternative rail or track system16which is made up by elongated members each forming a single track, i.e. a track configured to accommodate only one wheel. In such a track system the borders between neighbouring grid cells run midway between neighbouring elongated members forming the single tracks.

InFIG.9, grid cell14comprises a grid opening15. To the left (West) of grid cell14, there is an adjacent grid cell14W comprising a grid opening15W. Likewise, to the right (East) of grid cell14, there is an adjacent grid cell14E comprising a grid opening15E. Also, below grid cell14(South), there is an adjacent grid cell14S comprising a grid opening15S, and above grid cell14(North), there is an adjacent grid cell14N comprising a grid opening15N.

InFIG.9, a footprint30of a container handling vehicle is schematically illustrated. In this embodiment the footprint30is defined by the horizontal extension of the wheels of the vehicle. As is evident from the figure, the footprint30has a horizontal extent which is less than the horizontal extent of a grid cell.

InFIG.9, a footprint30′ of a container handling vehicle according to an alternative embodiment is also schematically illustrated. In this case the lower part of the vehicle extends beyond the wheels and the footprint30′ has a horizontal extension which is equal to than the horizontal extension of a grid cell.

As previously mentioned, the protruding section27may comprise a battery compartment or slot28for a rechargeable or a replaceable battery25. In the following, such an embodiment and an associated battery exchange scheme will be discussed in more detail with reference toFIGS.14to19.

An example of a charging and/or battery exchange station40, hereinafter referred to as a charging station, is shown inFIG.14, both in a perspective view (FIG.14A) and in side views along X direction (FIG.14B) and along Y direction (FIG.14C).

The charging station40is mounted on a charging station base plate41, which is fixed (directly or indirectly) to neighbouring rails11a,11b,12a,12bof the track system above a grid column at or near the perimeter of the framework structure. The particular grid column containing the charging station40will hereinafter be referred to as a charging station cell.

The charging station40shown comprises a vertical charging station column42fixed at a lower end42ato the based plate41. A charging socket45is arranged at or near an upper end42bof the column42, i.e. opposite to the lower end42a, and electrically connected to a power supply44, possibly via a power transformer transforming the charging power to the desired power level.

The charging socket45is further configured to receive a charging plug46of the battery25installed on each vehicle3(see.FIG.18), thereby allowing flow of electric power when the charging plug46is electrically coupled to the charging socket45.

In a preferred configuration, the charging socket45is resiliently attached to the charging station42, for example such that the position of the charging socket45is fixed in an upper (unloaded) position when no external force act on the charging socket45and in a lower (loaded) position when the charging socket is exposed to the weight of the electrically connected battery25.

The charging socket45and the charging plug46may of course be interchanged.

In general, any kind of disconnectable electrical connections between the charging station40and the battery25is possible.

An automated storage and retrieval system as described herein may comprise a plurality of such charging stations40, typically arranged along the perimeter of the track system. However, one or more charging stations40may alternatively or additionally be placed further into the track system and/or fully outside of the track system. In the latter configuration, the charging station(s)40should be connected to the track system by additional rails in order to allow the vehicles3to travel to their respective charging station40.

One possible battery exchange process will now be described with particular reference toFIGS.15to17.

A vehicle3, having transferred its discharged, or partly discharged, main battery from its battery compartment or slot within a battery cover31to a first charging station for charging, approaches a second charging station40containing a charged, or partly charged, main battery25(seeFIG.15AandFIG.16C).

To allow the vehicle to enter the charging station storage cell, the first set of wheels19a-dshould contact the underlying track system (seeFIG.15A-15D) and the second set of wheels20a-dclosest to the charging station30should be sufficiently high above the track system in order not to interfere with the tracks along the Y direction.

When wheels20aand20bof the second set of have entered the charging station storage cell, and prior to reaching the horizontal position where the charging station40is contacting the approaching vehicle3, the vehicle3is lowered towards the track system. The lowering is performed to allow correct alignments with the main battery25during the battery exchange process since the weight of the battery25forces the charging socket45down to its lower (loaded) position as explained above. A lowering of the vehicle3also increases the overall stability of the exchange procedure. Typical vertical displacement of the vehicle3is 5-15 mm, for example 10 mm.

The charging station40should thus be configured such that the height of the main battery25under charge, relative to the track system, is approximately equal to the corresponding height of the battery compartment on the vehicle3when the vehicle3is in a lowered position.

To allow movements of the vehicle3being void of a main battery25, an auxiliary battery may be installed, for example in the same or similar way as disclosed in the patent publication WO 2015/104263 A1, the contents of which are incorporated herein by reference. Other solutions may also be envisaged, for example use of external power sources such as live rails, manual interference, etc.

Alternative embodiments in which either the charging station40or the vehicle3or a combination of both contain a plurality of batteries, thereby avoiding the need of vehicle movements between charging stations40during battery exchange. A multi-battery charging station applicable for the above mentioned storage system1is disclosed in WO 2017/220627 A1, the contents of which are incorporated herein by reference.

The available charged battery25on the second charging station40is mounted onto a battery support43, which in the example shown inFIGS.14A-16Dis in form of two guiding pins43a,43bextending laterally into the track system from each side of the charging station column's42upper end42b.

When the vehicle3is contacting the charging station40, a release mechanism50(seeFIG.17) is activated, allowing the battery cover31to be tilted around a rotational axis.

The release mechanism50comprises a pivot arm51arranged at both sides of the opening of the battery compartment into which the battery25is to be inserted.

Further, each of the protruding ends of the guiding pins43a,43b(constituting the battery support43) displays a tapered section52(seeFIGS.14A and14C). Upon contact between the pivot arm51and the guiding pins43, a pivot arm contact element51aof each pivot arm51is pushed towards the tapered section52, thereby enforcing an upward directed pivoting movement of the pivot arm51(seeFIG.15A,FIG.16DandFIG.17). This pivot movements releases a security lock51b(seeFIGS.15and19) allowing the above mentioned tilt of the battery cover31.

The operation of the release mechanism50is illustrated in each of the sequence drawings inFIG.15A-15Fand inFIG.17. To increase clarity, enlarged area drawings of the release mechanism50is added inFIG.15A-15CandFIG.15F. The enlarged area drawings clearly show the activation of the pivot arm movement upon contact with the tapered section52moving the security lock51baway from the battery cover27and the subsequent entry of the battery25.

When the guiding pins43with the attached battery28has entered a certain distance into the battery compartment27a(seeFIGS.15Band C), the guiding pins43releases a battery lock27b,27cthat allows further entry until the battery25is fully in its end position within the battery compartment.

InFIG.19, the battery lock27b,ccomprises a battery lock activator27bin the form of a wheel and one or more blocking teeth27cextending from the inner walls of the battery cover and into the battery compartment. When the tapered ends52of the guiding pins43a,bcontacts the battery lock activator27b, the battery cover27is tilted upwards, thereby displacing the one or more teeth27csuch that the battery25and the guiding pins43a,bmay continue the movement deeper into the battery compartment.

In this end position, and before retraction of the vehicle3, the battery25can be electrically connected two both the charging station40and i.e. the drive motors for the wheels19a-d,20a-d.

When the battery is in its end position inside the battery compartment and in electrical contact with the corresponding electrical connector of the vehicle3, the battery compartment tilts back to its initial position such that the teeth27cphysically locks or holds the battery25within the battery compartment. As an example, the teeth27cmay enter dedicated recesses49awithin support rails49arranged at both sides of the battery28(seeFIG.17).

The battery lock27b,cmay be any physical hindrance within the battery compartment. As an alternative to the above-mentioned teeth27c, the battery lock may comprise one or more protruding wedges that the battery25may surpass in one direction, but not in the other. In this configuration, the wedge shape would act as the battery lock activator27b.

When the battery25is in its end position and successfully locked into the battery compartment by the battery lock27b,c, the second set of wheels20a-dof the vehicle3is lifted from the track system (typically between 5-15 mm), thereby lifting the overall height of the vehicle3. This operation causes the battery25to be released from the battery support43, for example from dedicated pockets or tracks within the first and second guiding pins43a,b(seeFIG.14A).

Since now the battery lock27b,cis locking the battery25into the battery compartment, and the battery25has been lifted free from the battery support43, a retraction of the vehicle3out of the charging station storage cell leaves the battery25electrically connected to the vehicle3.

In addition to allowing successful exchange of battery, the blocking of the battery28into the battery compartment27ahas the advantage that the battery28cannot be unintentionally displaced within the battery cover27during operation.

When the control system has sent an instruction to the vehicle3to place its battery28into a charging station40for charge, the steps for transferring the battery28from the vehicle3to the charging station40are essentially equal or similar to the opposite sequence and direction of the above-mentioned steps of transferring the battery28from the charging station40to the vehicle3.

Hence, the vehicle3is first raised to both allow the vehicle to enter the charging station storage cell without interference of the second set of wheels20with the tracks11in the second direction (Y) and to align the operative battery25with the charging plug45of the charging station40. As mentioned above, the charging plug45is in the exemplary configuration ofFIGS.14-17in an upper, unloaded position.

During the approach of the vehicle3towards the charging station40, the wedged ends52of the first and second guiding pins43a,bfirst activate the tilt of the battery compartment via the release mechanism51, then activate the battery lock27b,ccausing the battery cover to tilt upwards, thereby removing the blocking teeth27cfrom the corresponding recesses49ain the support rail49.

By lowering the vehicle3towards the track system, the support rails49of the battery28mesh with the battery support43. A subsequent retraction of the vehicle3would thus leave the battery in the desired charging position on the charging station40.

To allow larger batteries within the vehicle3, both the battery cover and the optional release mechanism50may be arranged so that they protrude horizontally in the X direction beyond the otherwise generally vertical side walls26cand26d. In this way, the overall capacity of each vehicle3in the system1may be increased significantly without necessitating making the tracks11,12wider.

In case there is a need of manual interference for removing the battery from the battery compartment, for example due to general maintenance or accidental battery jamming, a configuration with a protruding release mechanism50has an additional advantage in that it allows easy manual unlocking of the battery. That is, the protruding arrangement allows for exertion of sufficient manual force on the release mechanism50, an operation that would be difficult if for example the release mechanism50was arranged deep within the battery cover27.

The protruding configuration described above is also beneficial for ensuring early engagement in the charging station40.

An example of a battery25is shown in perspective inFIG.18. One of two support rails49is shown protruding from a side wall of the battery25. And identical support rail is protruding from the opposite side wall. The purpose of the support rails49is to both ensure a stable support of the battery25on the battery support/guiding pins43and to ensure an accurate guiding of the battery25into and out of the battery compartment during exchange.FIG.19shows the battery25with support rails49being inserted fully within the battery compartment. In the particular configuration shown inFIG.19, the battery25is approximately half the maximum allowable volume of a battery.

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.