System and method of determining charging errors in an automated storage and retrieval system

Abstract

The present invention relates to a system, method and computer program product for determining charging problems in an automated storage and retrieval system. The method comprising instructing a plurality of vehicles (501) to move to a plurality of charging stations (10) for charging of the energy source, receiving status messages of the charging of each of the plurality of vehicles (501) on each of the plurality of charging stations (10). When for one of the plurality of charging stations (10), a ratio of the received status messages of charging a plurality of unique vehicles (501) on the one of the plurality of charging stations (10) that is indicating a problem with charging is exceeding a first threshold (CTH), the one of the plurality of charging stations (10) is blocked from further usage. When for one of the plurality of vehicles (501), a ratio of the received status messages of charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) that is indicating a problem with charging is exceeding a second threshold (VTH), the one of the plurality of vehicles is instructed to move to a service area.

Description

System and method of determining charging errors in an automated storage and retrieval systemFIELD OF THE INVENTION

[0001] The present invention relates to an automated storage and retrieval system for storage and retrieval of containers, in particular to a system and method of determining charging errors.BACKGROUND AND PRIOR ART

[0002] Fig. 1 discloses a prior art automated storage and retrieval system 1 with a framework structure 100 and Figs. 2, 3 and 4 disclose three different prior art container handling vehicles 201,301,401 suitable for operating on such a system 1.

[0003] The framework structure 100 comprises upright members 102 and a storage volume comprising storage columns 105 arranged in rows between the upright members 102. In these storage columns 105 storage containers 106, also known as bins, are stacked one on top of one another to form stacks 107. The members 102 may typically be made of metal, e.g. extruded aluminum profiles.

[0004] 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 201,301,401 maybe operated to raise storage containers 106 from, and lower storage containers 106 into, the storage columns 105, and also to transport the storage containers 106 above the storage columns 105. The rail system 108 comprises a first set of parallel rails no arranged to guide movement of the container handling vehicles 201,301,401 in a first direction X across the top of the frame structure 100, and a second set of parallel rails 111 arranged perpendicular to the first set of rails no to guide movement of the container handling vehicles 201,301,401 in a second direction Y which is perpendicular to the first direction X. Containers 106 stored in the columns 105 are accessed by the container handling vehicles 201,301,401 through access openings 112 in the rail system 108. The container handling vehicles 201,301,401 can move laterally above the storage columns 105, i.e. in a plane which is parallel to the horizontal X-Y plane.

[0005] The upright members 102 of the framework structure 100 may be used to guide the storage containers during raising of the containers out from andlowering of the containers into the columns 105. The stacks 107 of containers 106 are typically self-supporting.[oo6] Each prior art container handling vehicle 201,301,401 comprises a vehicle body 201a, 301a, 401a and first and second sets of wheels 201b, 201c, 301b, 301c, 401b, 401c which enable the lateral movement of the container handling vehicles 201,301,401 in the X direction and in the Y direction, respectively. In Figs. 2, 3 and 4 two wheels in each set are fully visible. The first set of wheels 201b, 301b, 401b is arranged to engage with two adjacent rails of the first set no of rails, and the second set of wheels 201c, 301c, 401c is arranged to engage with two adjacent rails of the second set 111 of rails. At least one of the sets of wheels 201b, 201c, 301b, 301c, 401b, 401c can be lifted and lowered, so that the first set of wheels 201b, 301b, 401b and / or the second set of wheels 201c, 301c, 401c can be engaged with the respective set of rails no, 111 at any one time.

[0007] Each prior art container handling vehicle 201,301,401 also comprises a lifting device for vertical transportation of storage containers 106, e.g. raising a storage container 106 from, and lowering a storage container 106 into, a storage column 105. The lifting device comprises one or more gripping / engaging devices which are adapted to engage a storage container 106, and which gripping / engaging devices can be lowered from the vehicle 201,301,401 so that the position of the gripping / engaging devices with respect to the vehicle 201,301,401 can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y. Parts of the gripping device of the container handling vehicles 301,401 are shown in Figs. 3 and 4 indicated with reference number 304,404. The gripping device of the container handling device 201 is located within the vehicle body 201a in Fig. 2 and is thus not shown.

[0008] Conventionally, and also for the purpose of this application, Z=i identifies the uppermost layer available for storage containers below the rails 110,111, i.e. the layer immediately below the rail system 108, =2 the second layer below the rail system 108, =3 the third layer etc. In the exemplary prior art disclosed in Fig. 1, =8 identifies the lowermost, bottom layer of storage containers. Similarly, X=i...n and Y=i...n identifies the position of each storage column 105 in the horizontal plane. Consequently, as an example, and using the Cartesian coordinate system X, Y, Z indicated in Fig. 1, the storage container identified as 106’ in Fig. 1 can be said to occupy storage position X=i , Y=i, Z=6. The container handling vehicles 201,301,401 can be said to travel in layer Z=o,and each storage column 105 can be identified by its X and Y coordinates. Thus, the storage containers shown in Fig. 1 extending above the rail system 108 are also said to be arranged in layer Z=o.

[0009] 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.

[0010] Each prior art container handling vehicle 201,301,401 comprises a storage compartment or space for receiving and stowing a storage container 106 when transporting the storage container 106 across the rail system 108. The storage space may comprise a cavity arranged internally within the vehicle body 201a, 401a as shown in Figs. 2 and 4 and as described in e.g. WO2O15 / 193278A1 and W02019 / 206487A1, the contents of which are incorporated herein by reference.

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

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

[0013] Alternatively, the cavity container handling vehicles 401 may have a footprint which is larger than the lateral area defined by a storage column 105 as shown in Fig. 1 and 4, e.g. as is disclosed in W02014 / 090684A1 or W02019 / 206487A1.

[0014] The container handling vehicles 201,301,401 are typically powered by an energy source in the form of a rechargeable battery. The rechargeable battery powers the wheels for moving the vehicle along the rail system, it powers the lifting device and gripper of the vehicle for handling the storage containers, it powers the control system of the vehicle and the communication interface of the vehicle. The container handling vehicles 201,301,401 comprise a charginginterface (indicated as 630 in fig. 3) to make electrical contact with a battery charger.

[0015] The rail system 108 typically comprises rails with grooves in which the wheels of the vehicles run. Alternatively, the rails may comprise upwardly protruding elements, where the wheels of the vehicles comprise flanges to prevent derailing. These grooves and upwardly protruding elements are collectively known as tracks. Each rail may comprise one track, or each rail 110,111 may comprise two parallel tracks. In other rail systems 108, each rail in one direction (e.g. an X direction) may comprise one track and each rail in the other, perpendicular direction (e.g. a Y direction) may comprise two tracks. Each rail 110,111 may also comprise two track members that are fastened together, each track member providing one of a pair of tracks provided by each rail.

[0016] W02018 / 146304A1, the contents of which are incorporated herein by reference, illustrates a typical configuration of rail system 108 comprising rails and parallel tracks in both X and Y directions.

[0017] In the framework structure 100, a majority of the columns are storage columns 105, i.e. columns 105 where storage containers 106 are stored in stacks 107. In addition to storage columns 105, there are special-purpose columns within the framework structure. In Fig. 1, columns 119 and 120 are such specialpurpose columns used by the container handling vehicles 201,301,401 to drop off and / or pick up storage containers 106 so that they can be transported to an access station (not shown) where the storage containers 106 can be accessed from outside of the 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. The transportation from the port to the access station may require movement along various different directions, by means such as delivery vehicles, trolleys or other transportation lines. Note that the term ‘tilted’ means transportation of storage containers 106 having a general transportation orientation somewhere between horizontal and vertical.[ooi8] In Fig. i, the first port column 119 may for example be a dedicated drop-off port column where the container handling vehicles 201,301,401 can drop off storage containers 106 to be transported to an access or a transfer station, and the second port column 120 may be a dedicated pick-up port column where the container handling vehicles 201,301,401 can pick up storage containers 106 that have been transported from an access or a transfer station.

[0019] 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.

[0020] A conveyor system comprising conveyors is normally employed to transport the storage containers between the port columns 119,120 and the access station.

[0021] 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.

[0022] The conveyor system may be arranged to transfer storage containers 106 between different framework structures, e.g. as is described in W02014 / 075937A1, the contents of which are incorporated herein by reference.

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

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

[0025] For monitoring and controlling the automated storage and retrieval system 1, e.g. monitoring and controlling the location of respective storage containers 106 within the framework structure 100, the content of each storage container 106, and the movement of the container handling vehicles 201,301,401 so that a desired storage container 106 can be delivered to the desired location at the desired time without the container handling vehicles 201,301,401 colliding with each other, the automated storage and retrieval system 1 comprises a control system 500 which typically is computerized and which typically comprises a database for keeping track of the storage containers 106.

[0026] The above system comprises battery chargers in order to charge the batteries of the container handling vehicles. Problems with charging of batteries is a safety concern and may ultimately lead to fires in the system. It is therefore important to detect errors relating to the charging process and differentiatewhether the errors are related to the charging stations or the container handling vehicles, and to take the necessary measures to handle the errors.SUMMARY OF THE INVENTION

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

[0028] The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention.

[0029] In one aspect, the invention relates to an automated storage and retrieval system comprising: a plurality of vehicles, each of the plurality of vehicles comprising an energy source, and a local controller adapted to control movements of the vehicle, a plurality of charging stations adapted to charge the energy source of the plurality of vehicles, and a control system adapted to communicate with the local controller in each of the plurality of vehicles, instructing the plurality of vehicles to move to the plurality of charging stations for charging of the energy source, and receiving status messages of the charging of each of the plurality of vehicles on each of the plurality of charging stations, wherein the control system, is adapted to: when for one of the plurality of charging stations, a ratio of the received status messages of charging a plurality of unique vehicles on the one of the plurality of charging stations that is indicating a problem with charging is exceeding a first threshold, blocking the one of the plurality of charging stations from further usage, and / or when for one of the plurality of vehicles, a ratio of the received status messages of charging the one of the plurality of vehicles on a plurality of unique charging stations that is indicating a problem with charging is exceeding a second threshold, instructing the one of the plurality of vehicles to move to a service area.

[0030] The automated storage and retrieval system may comprise a rail system with a first set of parallel rails extending in a first direction and a secondset of parallel rails extending in second direction. The second direction may be perpendicular to the first direction. The plurality of vehicles maybe configured to operate on the rail system. The plurality of charging stations may be on or at the perimeter of the rail system. The service area may be on the rail system.

[0031] The first threshold may be that four out of the last five of the received status messages received for attempting charging the unique vehicles on the one of the plurality of charging stations are indicating a problem with charging of the energy source

[0032] The second threshold may be that four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles on a plurality of unique charging stations are indicating a problem with charging of the energy source.

[0033] When the system comprises less than five charging stations, the second threshold may be that all of the last received status messages for attempting charging the one of the plurality of vehicles on all of the plurality of charging stations are indicating a problem with charging of the energy source.

[0034] The status messages of the charging may be transmitted from the plurality of vehicles.

[0035] The control system may is adapted to transmit an error message when the first threshold or second threshold is exceeded.

[0036] The at least one vehicle may be a container handling vehicle operating on the rail system to receive storage containers from, and deliver storage containers into, storage columns arranged in rows between upright members and horizontal members of the framework structure, and also to transport the storage containers above or below the storage columns.

[0037] In a second aspect, the present invention relates to a method of determining charging problems in an automated storage and retrieval system comprising: a plurality of vehicles, each of the plurality of vehicles comprising an energy source, and a local controller adapted to control movements of the vehicle, a plurality of charging stations adapted to charge the energy source of the plurality of vehicles, anda control system adapted to communicate with the local controller in each of the plurality of vehicles, wherein the method comprising:-instructing the plurality of vehicles to move to the plurality of charging stations for charging of the energy source,-receiving status messages of the charging of each of the plurality of vehicles on each of the plurality of charging stations,-when for one of the plurality of charging stations, a ratio of the received status messages of charging a plurality of unique vehicles on the one of the plurality of charging stations that is indicating a problem with charging is exceeding a first threshold, blocking the one of the plurality of charging stations from further usage, and / or-when for one of the plurality of vehicles, a ratio of the received status messages of charging the one of the plurality of vehicles on a plurality of unique charging stations that is indicating a problem with charging is exceeding a second threshold, instructing the one of the plurality of vehicles to move to a service area on the rail system.

[0038] The automated storage and retrieval system may comprise a rail system with a first set of parallel rails extending in a first direction and a second set of parallel rails extending in second direction. The second direction may be perpendicular to the first direction. The plurality of vehicles maybe configured to operate on the rail system. The plurality of charging stations may be on or at the perimeter of the rail system. The service area may be on the rail system.

[0039] The first threshold may be that four out of the last five of the received status messages received for attempting charging the unique vehicles on the one of the plurality of charging stations are indicating a problem with charging of the energy source

[0040] The second threshold may be that four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles on a plurality of unique charging stations are indicating a problem with charging of the energy source.

[0041] When the system comprises less than five charging stations, the second threshold may be that all of the last received status messages forattempting charging the one of the plurality of vehicles on all of the plurality of charging stations are indicating a problem with charging of the energy source.

[0042] The method may comprising transmitting the status messages of the charging from the plurality of vehicles.

[0043] The method may comprising transmitting an error message when the first threshold or second threshold is exceeded.

[0044] In a third aspect, the present invention relates to a computer program product for a control system in the system of the first aspect, wherein the computer program product comprises instructions which when executed on the control system performs the method of the second aspect.BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Following drawings are appended to facilitate the understanding of the invention. The drawings show embodiments of the invention, which will now be described by way of example only, where:

[0046] Fig. 1 is a perspective view of a framework structure of a prior art automated storage and retrieval system;

[0047] Fig. 2 is a perspective view of a prior art container handling vehicle having an internally arranged cavity for carrying storage containers therein;

[0048] Fig. 3 is a perspective view of a prior art container handling vehicle having a cantilever for carrying storage containers underneath;

[0049] Fig. 4 is a perspective view, seen from below, of a prior art container handling vehicle having an internally arranged cavity for carrying storage containers therein;

[0050] Figs. 5 is a perspective view of an container handling vehicle at a charging station.

[0051] Fig. 6 is a flowchart of an exemplary method of the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0052] In overview, a method for determining charging problems in an automated storage and retrieval system is provided. The method comprises instructing a plurality of vehicles (501) to move to a plurality of chargingstations (10) for charging of the energy source, receiving status messages of the charging of each of the plurality of vehicles (501) on each of the plurality of charging stations (10). When for one of the plurality of charging stations (10), a ratio of the received status messages of charging a plurality of unique vehicles (501) on the one of the plurality of charging stations (10) that is indicating a problem with charging is exceeding a first threshold (CTH), the one of the plurality of charging stations (10) is blocked from further usage. When for one of the plurality of vehicles (501), a ratio of the received status messages of charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) that is indicating a problem with charging is exceeding a second threshold (VTH), the one of the plurality of vehicles is instructed to move to a service area.

[0053] In the following, embodiments of the invention will be discussed in more detail with reference to the appended drawings. It should be understood, however, that the drawings are not intended to limit the invention to the subject-matter depicted in the drawings.

[0054] The framework structure 100 of the automated storage and retrieval system 1 is constructed in a similar manner to the prior art framework structure 100 described above in connection with Figs. 1-3. That is, the framework structure 100 comprises a number of upright members 102, and comprises a first, upper rail system 108 extending in the X direction and Y direction.

[0055] The framework structure 100 further comprises storage compartments in the form of storage columns 105 provided between the members 102 wherein storage containers 106 are stackable in stacks 107 within the storage columns 105.

[0056] The framework structure 100 can be of any size. In particular it is understood that the framework structure can be considerably wider and / or longer and / or deeper than disclosed in Fig. 1. For example, the framework structure 100 may have a horizontal extent of more than 700x700 columns and a storage depth of more than twelve containers.

[0057] It is now referred to fig. 5. Here a simplified version of the automated storage and retrieval system 1 is shown for the purpose of illustrating a charging station 10 and the interaction between the charging station and a container handling vehicle 501. The framework structure 100 here comprises twelve upright members 102 defining six storage columns 105. Similar to prior art, therail system 108 is provided on top of the upright members 102. The container handling vehicle 501 is here illustrated as being of the cantilever type similar to, but not necessarily identical to, the container handling vehicle 301 of fig. 3. However, the container handling vehicle may be also similar to the prior art vehicles 201, 401 described in the introduction above.

[0058] The vehicle 501 comprises a charging interface for connection to the charging station 10. Inside the vehicle, the vehicle 501 comprises an energy source in the form of a rechargeable battery, chargeable via the charging interface. It should be noted that the vehicle 501 may use other energy sources, such as an ultracapacitor type of energy source. The vehicle 501, maybe similar to the prior art vehicles 201, 301, 401 described in the introduction above. The vehicle 501 communicates with the control system 500 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.

[0059] The system comprises a plurality of charging stations 10 on or at the perimeter of the rail system 108 adapted to be electrically connected with the energy source of the plurality of vehicles 501. The electrical connection maybe provided by any suitable connectors, such as a plug and socket, surface to surface etc. as known by the skilled person.

[0060] The control system 500 is instructing the plurality of vehicles 501 to move to the plurality of charging stations 10 for charging of the energy source. The control system is receiving status messages of the charging of each of the plurality of vehicles 501 on each of the plurality of charging stations 10. The status messages of the charging may be transmitted from the plurality of vehicles 501. If the status messages indicate that it is a problem with the charging it may be difficult to determine if there is a fault with the charger or the vehicle.

[0061] The control system 500 for each one of the plurality of charging stations 10 adapted to determining a ratio of the received status messages of charging a plurality of unique vehicles 501 on the one of the plurality of charging stations 10 that is indicating a problem with charging. Repeated errors for the same robot and same charger are ignored by the control system 500. When the ratio of messages indicating a problem is exceeding a first threshold CTH, the control system is blocking the one of plurality of charging stations 10 fromfurther usage. The control system 500 may transmit an error message, e.g. to a super user or service operator, when the first threshold CTH is exceeded.

[0062] The first threshold CTH may in one embodiment be that that four out of the last five of the received status messages received for attempting charging the unique vehicles 501 on the one of the plurality of charging stations 10 are indicating a problem with charging of the energy source.

[0063] Example 1: Recurring charging issues at Charger Ci1. Vehicle Vi fails to charge.2. Vehicle V2 fails to charge.3. Vehicle V3 successfully charges.4. Vehicle V4 fails to charge.5. Vehicle V4 fails to charge.6. Vehicle V4 fails to charge.7. Vehicle V5 fails to charge.8. Charger Ci is blocked from further usage.

[0064] In this example four vehicles, Vi, V2, V4 and V5, out of five unique vehicles fails to charge on charger Ci. Ci is thus blocked from further usage. Vehicle V4 fails to charge three times but is only counted as one unique vehicle when determining the ratio of messages indicating a problem.

[0065] The control system 500 is for each of the one of the plurality of vehicles 501 adapted to determining a ratio of the received status messages of charging the one of the plurality of vehicles 501 on a plurality of unique charging stations 10 that is indicating a problem with charging. Repeated errors for the same robot and same charger are ignored by the control system 500. When the ratio of messages indicating a problem is indicating a problem is exceeding a second threshold VTH, the control system 500 is instructing the one of the plurality of vehicles 501 to move to a service area on the rail system 108. The control system 500 may transmit an error message, e.g. to a super user or service operator, when the second threshold VTH is exceeded.

[0066] The second threshold VTH may in one embodiment be that four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles 501 on a plurality of unique charging stations 10 are indicating a problem with charging of the energy source.

[0067] Example 2: Recurring charging issues with Vehicle Vi1. Vehicle Vi fails at Charger Ci.2. Vehicle Vi fails at Charger C2.3. Vehicle Vi succeeds at Charger C3.4. Vehicle Vi fails at Charger C4.5. Vehicle Vifails at Charger C4.6. Vehicle Vi fails at Charger C4.7. Vehicle Vi fails at Charger C5.8. Vehicle Vi is deactivated from further usage.

[0068] In this example four, Ci, C2, C4 and C5, out of five unique chargers fails to charge one vehicle Vi. Vi is thus blocked from further usage. Charger C4 fails to charge three times but is only counted as one unique charger when determining the ratio of messages indicating a problem.

[0069] If the system comprises less than five charging stations 10, the second threshold VTH is that all of the last received status messages for attempting charging the one of the plurality of vehicles 501 on all of the plurality of charging stations 10 are indicating a problem with charging of the energy source.

[0070] Example 3: Recurring charging issues with Vehicle 1 on system with only 3 chargers1. Vehicle Vi fails at Charger Ci.2. Vehicle Vi fails at Charger C2.3. Vehicle Vi succeeds at Charger C3.4. Vehicle Vifails at Charger Ci.5. Vehicle Vi fails at Charger C2.6. Vehicle Vi fails at Charger C3.7. Vehicle Vi is deactivated from further usage.

[0071] In this example three, Ci, C2 and C3, out of three unique chargers fails to charge one vehicle Vi. Vi is thus blocked from further usage.

[0072] Fig. 6 is a flowchart of a method 600 of determining charging problems in an automated storage and retrieval system 1 described above. In a first step 601 the control system 500 is instructing the plurality of vehicles 501 to move to the plurality of charging stations 10 for charging of the energy source

[0073] In step 602 the control system 500 is receiving status messages of the charging of each of the plurality of vehicles 501 on each of the plurality of charging stations 10. The status messages of the charging maybe transmitted from the plurality of vehicles 501.

[0074] In step 603 it is checked when for one of the plurality of charging stations 10, a ratio of the received status messages of charging a plurality of unique vehicles 501 on the one of the plurality of charging stations 10 that is indicating a problem with charging is exceeding the first threshold CTH. Then if that is the case, in step 604, the control system 500 is blocking the one of the plurality of charging stations 10 from further usage.

[0075] The first threshold CTH may be that four out of the last five of the received status messages received for attempting charging the unique vehicles 501 on the one of the plurality of charging stations 10 are indicating a problem with charging of the energy source

[0076] In step 605 it is checked when for one of the plurality of vehicles 501, a ratio of the received status messages of charging the one of the plurality of vehicles 501 on a plurality of unique charging stations 10 that is indicating a problem with charging is exceeding a second threshold VTH. Then if that is the case, in step 606 the control system 500 is instructing the one of the plurality of vehicles to move to a service area on the rail system 108.

[0077] The second threshold VTH may be four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles 501 on a plurality of unique charging stations 10 are indicating a problem with charging of the energy source.

[0078] When the system 1 comprises less than five charging stations 10, the second threshold VTH may be that all of the last received status messages for attempting charging the one of the plurality of vehicles 501 on all of the plurality of charging stations 10 are indicating a problem with charging of the energy source.

[0079] The control system may transmit an error message, e.g. to super user or service personnel, when the first threshold or second threshold is exceeded.

[0080] In the preceding description, various aspects of the charging station 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 embodiments, as well asother 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.

[0081] Aspects and features of the present invention are defined in the following numbered clauses.

[0082] Clauses1. An automated storage and retrieval system (1) comprising: a rail system (108) with a first set of parallel rails (110) extending in a first direction (X) and a second set of parallel rails (111) extending in second direction (Y), wherein the second direction (Y) is perpendicular to the first direction (X); a plurality of vehicles (501) operating on the rail system (108), each of the plurality of vehicles (501) comprising an energy source, and a local controller adapted to control movements of the vehicle (501); a plurality of charging stations (10) on or at the perimeter of the rail system (108) adapted to charge the energy source of the plurality of vehicles (501); and a control system (500) adapted to communicate with the local controller in each of the plurality of vehicles (501), instructing the plurality of vehicles (501) to move to the plurality of charging stations (10) for charging of the energy source, and receiving status messages of the charging of each of the plurality of vehicles (501) on each of the plurality of charging stations (10); wherein the control system, (500) is adapted to: when for one of the plurality of charging stations (10), a ratio of the received status messages of charging a plurality of unique vehicles (501) on the one of the plurality of charging stations (10) that is indicating a problem with charging is exceeding a first threshold (CTH), blocking the one of the plurality of charging stations (10) from further usage; or when for one of the plurality of vehicles (501), a ratio of the received status messages of charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) that is indicating a problem with charging is exceeding a second threshold (VTH), instructing the one of the plurality of vehicles to move to a service area on the rail system (108).2. The system of clause 1, wherein the first threshold (CTH) is that four out of the last five of the received status messages received for attempting charging the unique vehicles (501) on the one of the plurality of charging stations (10) are indicating a problem with charging of the energy source.3. The system of clause 1 or 2, wherein the second threshold (VTH) is four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) are indicating a problem with charging of the energy source.4. The system of clause 1 or 2, wherein the system comprises less than five charging stations (10), the second threshold (VTH) is that all of the last received status messages for attempting charging the one of the plurality of vehicles (501) on all of the plurality of charging stations (10) are indicating a problem with charging of the energy source.5. The system of any of clauses 1 - 4, wherein the status messages of the charging are transmitted from the plurality of vehicles (501).6. The system of any of clauses 1 - 5, wherein the control system (500) is adapted to transmit an error message when the first threshold or second threshold is exceeded.7. The system of any of the preceding clauses, wherein the at least one vehicle (501) is a container handling vehicle (301, 401, 501) operating on the rail system (108) to receive storage containers (106) from, and deliver storage containers (106) into, storage columns (105) arranged in rows between upright members (102) and horizontal members (103) of the framework structure (100), and also to transport the storage containers (106) above or below the storage columns (105).8. A method of determining charging problems in an automated storage and retrieval system (1) comprising: a rail system (108) with a first set of parallel rails (110) extending in a first direction (X) and a second set of parallel rails (111) extending in second direction (Y), wherein the second direction (Y) is perpendicular to the first direction (X);a plurality of vehicles (501) operating on the rail system (108), each of the plurality of vehicles (501) comprising an energy source, and a local controller adapted to control movements of the vehicle (501); a plurality of charging stations (10) on or at the perimeter of the rail system (108) adapted to charge the energy source of the plurality of vehicles (501); and a control system (500) adapted to communicate with the local controller in each of the plurality of vehicles (501); wherein the method comprising:-instructing the plurality of vehicles (501) to move to the plurality of charging stations (10) for charging of the energy source;-receiving status messages of the charging of each of the plurality of vehicles (501) on each of the plurality of charging stations (10);-when for one of the plurality of charging stations (10), a ratio of the received status messages of charging a plurality of unique vehicles (501) on the one of the plurality of charging stations (10) that is indicating a problem with charging is exceeding a first threshold (CTH), blocking the one of the plurality of charging stations (10) from further usage; or-when for one of the plurality of vehicles (501), a ratio of the received status messages of charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) that is indicating a problem with charging is exceeding a second threshold (VTH), instructing the one of the plurality of vehicles to move to a service area on the rail system (108).9. The method of clause 8, wherein the first threshold (CTH) is that four out of the last five of the received status messages received for attempting charging the unique vehicles (501) on the one of the plurality of charging stations (10) are indicating a problem with charging of the energy source.10. The method of clause 8 or 9, wherein the second threshold (VTH) is four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) are indicating a problem with charging of the energy source.n. The method of clause 8 or 9, wherein the system (1) comprises less than five charging stations (10), the second threshold (VTH) is that all of the last received status messages for attempting charging the one of the plurality of vehicles (501) on all of the plurality of charging stations (10) are indicating a problem with charging of the energy source.12. The method of any of clauses 8 - 11, comprising transmitting the status messages of the charging from the plurality of vehicles (501).13. The method of any of clauses 8 - 12, comprising transmitting an error message when the first threshold or second threshold is exceeded.14. A computer program product for a control system (500) in the system of clauses 1 - 7, wherein the computer program product comprises instructions which when executed on the control system (500) performs the method of any of clauses 8 - 13.LIST OF REFERENCE NUMBERS1 Prior art automated storage and retrieval system 10 charging station 100 Framework structure 102 Upright members of framework structure 104 Storage grid 105 Storage column 106 Storage container 106’ Particular position of storage container 107 Stack 108 Rail system no Parallel rails in first direction (X) 112 Access opening 119 First port column 120 Second port column 201 Prior art container handling vehicle 201a Vehicle body of the container handling vehicle 201 201b Drive means / wheel arrangement / first set of wheels in first direction (X) 201c Drive means / wheel arrangement / second set of wheels in second direction (Y) 301 Prior art cantilever container handling vehicle 3Oia Vehicle body of the container handling vehicle 301 3Oib Drive means / first set of wheels in first direction (X) 3Oic Drive means / second set of wheels in second direction (Y) 304 Gripping device 401 Prior art container handling vehicle 401a Vehicle body of the container handling vehicle 401 401b Drive means / first set of wheels in first direction (X) 401c Drive means / second set of wheels in second direction (Y) 404 Gripping device 404a Lifting band 404b Gripper 404c Guide pin 404b Lifting frame 500 Control system 501 Container handling vehicle 600 Method of determining charging problems 601 Move vehicles to charging station for charging 602 Receive charging status messages 603 Ratio exceeding first threshold CTH 604 Block charger station 605 Ratio exceeding second threshold VTH606 Move vehicle to service areaX First directionY Second directionZ Third direction

Claims

CLAIMS1. An automated storage and retrieval system (1) comprising: a plurality of vehicles (501), each of the plurality of vehicles (501) comprising an energy source, and a local controller adapted to control movements of the vehicle (501); a plurality of charging stations (10) adapted to charge the energy source of the plurality of vehicles (501); and a control system (500) adapted to communicate with the local controller in each of the plurality of vehicles (501), instructing the plurality of vehicles (501) to move to the plurality of charging stations (10) for charging of the energy source, and receiving status messages of the charging of each of the plurality of vehicles (501) on each of the plurality of charging stations (10); wherein the control system, (500) is adapted to: when for one of the plurality of charging stations (10), a ratio of the received status messages of charging a plurality of unique vehicles (501) on the one of the plurality of charging stations (10) that is indicating a problem with charging is exceeding a first threshold (CTH), blocking the one of the plurality of charging stations (10) from further usage; and / or when for one of the plurality of vehicles (501), a ratio of the received status messages of charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) that is indicating a problem with charging is exceeding a second threshold (VTH), instructing the one of the plurality of vehicles to move to a service area.

2. The system of claim 1, wherein the automated storage and retrieval system comprises a rail system (108) with a first set of parallel rails (110) extending in a first direction (X) and a second set of parallel rails (111) extending in second direction (Y), wherein the second direction (Y) is perpendicular to the first direction (X), wherein the plurality of vehicles operate on the rail system (108), wherein, optionally, the plurality of charging stations (10) are on or at the perimeter of the rail system (108), and wherein, optionally, the service area is on the rail system (108).

3. The system of claim 1 or claim 2, wherein the first threshold (CTH) is that four out of the last five of the received status messages received for attempting charging the unique vehicles (501) on the one of the plurality of charging stations (10) are indicating a problem with charging of the energy source.

4. The system of any preceding claim, wherein the second threshold (VTH) is four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) are indicating a problem with charging of the energy source.

5. The system of any of claims 1 to 3, wherein the system comprises less than five charging stations (10), the second threshold (VTH) is that all of the last received status messages for attempting charging the one of the plurality of vehicles (501) on all of the plurality of charging stations (10) are indicating a problem with charging of the energy source.

6. The system of any of claims 1 to 5, wherein the status messages of the charging are transmitted from the plurality of vehicles (501).

7. The system of any of claims 1 to 6, wherein the control system (500) is adapted to transmit an error message when the first threshold or second threshold is exceeded.

8. The system of any preceding claim, wherein the at least one vehicle (501) is a container handling vehicle (301, 401, 501) operatable (108) to receive storage containers (106) from, and deliver storage containers (106) into, storage columns (105) arranged in rows between upright members (102) and horizontal members (103) of the framework structure (100), and also to transport the storage containers (106) above or below the storage columns (105).

9. A method of determining charging problems in an automated storage and retrieval system (1) comprising: a plurality of vehicles (501), each of the plurality of vehicles (501) comprising an energy source, and a local controller adapted to control movements of the vehicle (501); a plurality of charging stations (10) adapted to charge the energy source of the plurality of vehicles (501); and a control system (500) adapted to communicate with the local controller in each of the plurality of vehicles (501); wherein the method comprising:-instructing the plurality of vehicles (501) to move to the plurality of charging stations (10) for charging of the energy source;-receiving status messages of the charging of each of the plurality of vehicles (501) on each of the plurality of charging stations (10);-when for one of the plurality of charging stations (10), a ratio of the received status messages of charging a plurality of unique vehicles (501) on the one of the plurality of charging stations (10) that is indicating a problem with charging is exceeding a first threshold (CTH), blocking the one of the plurality of charging stations (10) from further usage; and / or-when for one of the plurality of vehicles (501), a ratio of the received status messages of charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) that is indicating a problem with charging is exceeding a second threshold (VTH), instructing the one of the plurality of vehicles to move to a service area.

10. The method of claim 9, wherein the automated storage and retrieval system comprises a rail system (108) with a first set of parallel rails (110) extending in a first direction (X) and a second set of parallel rails (111) extending in second direction (Y), wherein the second direction (Y) is perpendicular to the first direction (X), wherein the plurality of vehicles operate on the rail system (108), wherein, optionally, the plurality of charging stations (10) are on or at the perimeter of the rail system (108) and wherein, optionally, the service area is on the rail system (108).

11. The method of claim 9 or claim 10, wherein the first threshold (CTH) is that four out of the last five of the received status messages received for attempting charging the unique vehicles (501) on the one of the plurality of charging stations (10) are indicating a problem with charging of the energy source.

12. The method of any of claims 9 to 11, wherein the second threshold (VTH) is four out the last five of the received status messages received for attempting charging the one of the plurality of vehicles (501) on a plurality of unique charging stations (10) are indicating a problem with charging of the energy source.

13. The method of any of claims 9 to 11, wherein the system (1) comprises less than five charging stations (10), the second threshold (VTH) is that all of the last received status messages for attempting charging the one of the plurality of vehicles (501) on all of the plurality of charging stations (10) are indicating a problem with charging of the energy source.

14. The method of any of claims 9 to 13, comprising transmitting the status messages of the charging from the plurality of vehicles (501).15- The method of any of claims 9 to 14, comprising transmitting an error message when the first threshold or second threshold is exceeded.

16. A computer program product for a control system (500) in the system of any of claims 1 to 8, wherein the computer program product comprises instructions which when executed by the control system (500) performs the method of any of claims 9 to 15.

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