SYSTEM, METHOD AND MAIN CONTROL SYSTEM FOR HANDLING MALFUNCTIONING VEHICLES IN AN AUTOMATED STORAGE AND RETRIEVAL SYSTEM COMPRISING A RAIL SYSTEM
20220392273 · 2022-12-08
Assignee
Inventors
Cpc classification
International classification
Abstract
An automated storage and retrieval system includes a rail system with perpendicular tracks in X and Y direction. The storage and retrieval system includes a plurality of remotely operated container handling vehicles configured to move laterally on the rail system; and a main control system using a first communication system for communicating with the plurality of remotely operated container handling vehicles. The main control system monitors and controls the movement of the plurality of container handling vehicles via the first communication system. At least one service vehicle is movable on the rail system. The at least one service vehicle is configured to bring a malfunctioning remotely operated container handling vehicle to a service area outside of the rail system where the remotely operated container handling vehicles operate. The system further includes a secondary control system using a second communication system. The second communication system is independent of the main communication system. The secondary control system is communicating with the at least one service vehicle on the rail system such as to monitor and control the movement of the at least one service vehicle.
Claims
1. An automated storage and retrieval system comprising a rail system with perpendicular tracks in X and Y direction, wherein the storage and retrieval system comprises: a plurality of remotely operated container handling vehicles configured to move laterally on the rail system; a main control system using a first communication system for communicating with the plurality of remotely operated container handling vehicles, wherein the main control system monitors and controls the movement of the plurality of container handling vehicles via the first communication system; at least one service vehicle movable on the rail system, wherein the at least one service vehicle is configured to bring a malfunctioning remotely operated container handling vehicle to a service area outside of the rail system where the remotely operated container handling vehicles operate; and a secondary control system using a second communication system, wherein the second communication system is independent of the main communication system, and wherein the secondary control system is communicating with the at least one service vehicle on the rail system such as to monitor and control the movement of the at least one service vehicle.
2. The automated storage and retrieval system according to claim 1, wherein the the main control system is configured to perform, by wireless data communication, at least the following steps: determining an anomaly in an operational condition of a vehicle on the rail system, registering the vehicle with the anomalous operational condition as a malfunctioning vehicle, registering a position of the malfunctioning vehicle relative to the supporting rail system.
3. The automated storage and retrieval system according to claim 2, wherein the main control system is further configured to perform: setting up a two-dimensional exclusion zone extending from the malfunctioning vehicle to a position of the service vehicle.
4. The automated storage and retrieval system according to claim 3, wherein the main control system is further configured to perform: updating movement pattern of the plurality of remotely operated vehicles by instructing any remotely operated vehicles positioned within the two-dimensional exclusion zone to move outside the two-dimensional exclusion zone and avoiding entry of any of the remaining remotely operated vehicles into the two-dimensional exclusion zone.
5. The automated storage and retrieval system according to claim 4, wherein, when the main control system has performed the above steps, the secondary control system is configured to perform, by wireless data communication, at least the following step: operating the at least one service vehicle to move from an initial position to a position next to the malfunctioning vehicle along the exclusion zone.
6. The automated storage and retrieval system according to claim 1, wherein the first communication system and the second communication system are the same communication system or different communication systems.
7. The automated storage and retrieval system according to claim 6, wherein the first communication system and the second communication system operate with different frequencies.
8. The automated storage and retrieval system according to claim 6, wherein the first communication system and the second communication system have different coding and de-coding processes.
9. The automated storage and retrieval system according to claim 1, wherein the main control system is wireless fidelity and the second system is light fidelity.
10. The automated storage and retrieval system according to claim 1, wherein the service vehicle comprises wheels which are guided for movement along the rails in X and Y directions.
11. The automated storage and retrieval system according to claim 1, wherein the service vehicle comprises caterpillar tracks for movement over a top surface of the rail system independent of the X and Y directions of the rail system.
12. The automated storage and retrieval system according to claim 1, wherein an initial position of the service vehicle is in a service area outside of the rail system where the remotely operated vehicles operate.
13. The automated storage and retrieval system according to claim 1, wherein the rail system is at a top level of a storage grid.
14. The automated storage and retrieval system according to claim 1, wherein the rail system is a delivery rail system.
15. A method for handling malfunctioning vehicles on a rail system wherein the storage and retrieval system comprises: a plurality of remotely operated container handling vehicles configured to move laterally on the rail system; and a main control system using a first communication system for communicating with the plurality of vehicles wirelessly, wherein the main control system monitors and controls the movement of the plurality of container handling vehicles via the first communication system; at least one service vehicle positioned at an initial position, wherein the service vehicle is movable on the rail system, and wherein the at least one service vehicle is configured to bring a malfunctioning remotely operated container handling vehicle to a service area outside of the rail system where the remotely operated container handling vehicles operate; a secondary control system, using a second communication system which is independent of the main control system for communicating with the at least one service vehicle on the rail system wirelessly, and wherein the secondary control system monitors and controls the movement of the at least one service vehicle; the main control system performs at least the following steps: determining an anomaly in an operational condition of a vehicle on the rail system, registering the vehicle with the anomalous operational condition as a malfunctioning vehicle, registering a position of the malfunctioning vehicle relative to the supporting rail system.
16. The method according to claim 15, wherein the method further comprises utilizing the main control system to perform: setting up a two-dimensional exclusion zone extending from the malfunctioning vehicle to the position of the service vehicle.
17. The method according to claim 16, wherein the method further comprises utilizing the main control system to: updating a movement pattern of the plurality of remotely operated vehicles outside the two-dimensional exclusion zone such that entrance into the two-dimensional exclusion zone is avoided.
18. The method according to claim 17, wherein the method further comprises, when the main control system has performed the above steps, the secondary control system performs by wireless data communication at least the following step: operating the at least one service vehicle to move from an initial position to the position where the malfunctioning vehicle is halted along the exclusion zone.
19. A main control system for an automated storage and retrieval system, the automated storage and retrieval system comprising: a rail system with horizontal tracks extending in perpendicular X and Y directions; a plurality of remotely operated container handling vehicles configured to operate on the rail system; a service vehicle; and a secondary control system for the service vehicle, wherein the secondary control system is communicating with the at least one service vehicle on the rail system such as to monitor and control the movement of the at least one service vehicle, and wherein the at least one service vehicle is configured to bring a malfunctioning remotely operated container handling vehicle to a service area (160) outside of the rail system where the remotely operated container handling vehicles operate, wherein the main control system is configured to route the plurality of remotely operated vehicles across a working zone of the rail system, the main control system further being configured to detect if a remotely operated vehicle is malfunctioning, and if a remotely operated vehicle is malfunctioning, the main control system being configured to: reconfigure the working zone to divide off an exclusion zone, the exclusion zone defining an area of the rail system containing the malfunctioning remotely operated vehicle and providing a path for the service vehicle to reach the malfunctioning remotely operated vehicle; reroute other remotely operated vehicles operating in the exclusion zone and in the reconfigured working zone so that they avoid the area of the rail system defined by the exclusion zone; and hand over control of the area of the rail system in the exclusion zone to the secondary control system.
20. The main control system according to claim 19, wherein the main control system is configured, once the service vehicle has moved out of the exclusion zone of the rail system, to: take back control of the area of the rail system within the exclusion zone from the secondary control system; reconfigure the working zone to include the area of the rail system that was previously in the exclusion zone; and reroute remotely operated vehicles to take account of the increased working zone with the area of the rail system previously in the exclusion zone included as part of the working zone.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0080] The following drawings are appended to facilitate the understanding of the invention:
[0081]
[0082]
[0083]
[0084]
[0085]
[0086]
[0087]
[0088]
[0089]
[0090]
[0091]
[0092]
[0093]
[0094]
[0095]
[0096]
[0097]
[0098]
[0099]
[0100]
[0101]
[0102]
[0103]
[0104]
[0105]
[0106]
[0107] In the drawings, the same 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
[0108] 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.
[0109] With reference to
[0110] The framework structure 100 may be constructed in accordance with the prior art framework structure 100 described above, i.e. a plurality of upright members 102 and a plurality of horizontal members 103 which are supported by the upright members 102.
[0111] The rail system 108 includes parallel rails 110,111 along the X direction and the Y direction, respectively, arranged across the top of storage columns 105. The horizontal area of a grid cell 122 delimiting the opening into the storage column 105 may be defined by the distance between adjacent rails 110 and 111, respectively.
[0112] In
[0113] The rail system 108 allows the container handling vehicles 250 to move horizontally between different grid locations, where each grid location is associated with a grid cell 122.
[0114] In
[0115] All container handling vehicles 250 may be controlled by a main control system with a first communication system as indicated with reference numeral 109′.
[0116] The container handling vehicles 250 may be of any type known in the art, e.g. any one of the automated container handling vehicles disclosed in WO2014/090684 A1, in NO317366 or in WO2015/193278A1.
[0117]
[0118] In
[0119] The service areas 160a-c may be adjacent to a mezzanine outside the boundary of the rail systems 108, for supporting the service vehicle 20 while it is inactive.
[0120] In
[0121] A different automated storage and retrieval system 1 is shown in part in
[0122] Below this transport rail system 108, near the floor level, another framework structure 300 is shown which partly extends below some of the storage columns 105 of the framework structure 100. As for the other framework structure 100, a plurality of vehicles 330,340,350 may operate on a rail system 308 comprising a first set of parallel rails 310 directed in a first direction X and a second set of parallel rails 311 directed in a second direction Y perpendicular to the first direction X, thereby forming a grid pattern in the horizontal plane P.sub.L comprising a plurality of rectangular and uniform grid locations or grid cells 322. Each grid cell of this lower rail system 308 comprises a grid opening 315 being delimited by a pair of neighboring rails 310a,310b of the first set of rails 310 and a pair of neighboring rails 311a, 311b of the second set of rails 311.
[0123] The part of the lower rail system 308 that extends below the storage columns 105 are aligned such that its grid cells 322 are in the horizontal plane P.sub.L coincident with the grid cells 122 of the upper rail system 108 in the horizontal plane P.
[0124] Hence, with this particular alignment of the two rail systems 108,308, a storage container 106 being lowered down into a storage column 105 by a container handling vehicle 250 can be received by a delivery vehicle 350 configured to run on the rail system 308 and to receive storage containers 106 down from the storage column 105. In other words, the delivery vehicle 350 is configured to receive storage containers 106 from above, preferably directly from the container handling vehicle 250.
[0125]
[0126] After having received a storage container 106, the delivery vehicle 350 may drive to an access station adjacent to the rail system 308 (not shown) for delivery of the storage container 106 for further handling and shipping.
[0127] Hereinafter, the upper and lower rail systems 108,308 are called the transport rail system 108 and the delivery rail system 308. Likewise, the vehicle shown in
[0128]
[0139]
[0140] In
[0141] In
[0142] In
[0143] The exclusion zone 225 has been created at the boundary of the rail system 108 in order to minimize the impact on the remaining container handling vehicles 250 operating on the rail system 108. However, it will be understood that the exclusion zone 225 can be created anywhere on the rail system 108, whatever is most expedient in the specific situation and preferably along a path which minimizes the interruption of the other container handling jobs.
[0144] In
[0145] In
[0146] In
[0147] Once the malfunctioning container handling vehicle 240,X is within the service area 160, the main control system 109′ may be used to re-classify the exclusion zone 225 allowing the operative vehicles 250 to enter the previously existed exclusion zone 225.
[0148] It shall be noted that in the example of
[0149]
[0150] In
[0151] In
[0152] In
[0153]
[0154] The service vehicle 20 of
[0155]
[0156] The transfer device 8 comprises a lifting mechanism 8c which includes one or more vertical linear actuators 8f. Each of the actuators 8f has one end connected to a pivot support 8h that pivotally couples to the vehicle body 3 with a rotational axis parallel to the underlying rail system 108 and the other end to a lifting claw 8d. The lifting claws 8d may be displaceable in a horizontal direction relative to the vehicle body 3 by use of horizontal linear actuators 8i, i.e. with a horizontal non-zero component.
[0157] The service vehicle 20 is remotely operated by a remote control system via one or more onboard transmitters 36. Alternatively, or in addition, similar transmitters 36 may be arranged on the vehicle body 3, within the registration unit 9, on one or both of the rollers 6,7, etc.
[0158] As for the above disclosed embodiments the caterpillar tracks/rollers 6,7 have a length L extending across a plurality of grid cells 122, preferably four or more.
[0159] The opening of the vertical containing handling vehicle receiving side of the vehicle body 3, including any guiding pins 35, has a minimum width G being equal to, or larger than, the overall width of the malfunctioning vehicle(s) 240,340 to be serviced.
[0160] The procedure for picking up a malfunctioning vehicle 240,340 by the service vehicle 20 may proceed in the following way: [0161] (
[0166] In all embodiments, the rollers 6,7 comprise endless tracks (i.e. looped chains) 6d driven by toothed belt wheels 6a,6b arranged within the chains 6d. However, it may be envisaged configuration where one or more of the toothed wheels 6a,6b are arranged outside the looped chain 6d. Instead of toothed wheels 6,7, the rollers 6,7 may comprise alternative drive mechanism such as wheels having other types of means for meshing or coupling to their respective chains 6d. Further, the rollers 6,7 may be composed of components other than endless belts, for example a set of wheels wide enough to cover at least one grid cell 122.
[0167] All the embodiments of the service vehicle 20 in
[0168] Embodiments may also be envisaged where the full operation of the service vehicle 20 is partly due to the operation of an onboard operator and partly due to a remotely located human operator or alternatively a combination between the operation of an onboard operator and a fully or partly automated control system.
[0169] It is now referred to
[0170] The service vehicle 20 comprises a vehicle body 3 with a central cavity 25 (
[0171] The service vehicle 20 further comprises a connection system 30 provided on a first side 3A of the vehicle body 3. The connection system 30 is connectable to, and disconnectable from, a connection interface CI, for example a connection interface CI of an additional support unit (see
[0172] First, it should be noted that the embodiment of the service vehicle 20 shown in the drawings comprises one connection system 30 provided on a first side 3A of the vehicle body 3 and an additional connection system 30 provided on a second side 3B, opposite of the first side 3A (se
[0173] Now, the connection system 30 will be described in detail with reference to
[0174] In
[0175] In the present embodiment, the slot 24 is a vertical slot 24, in which the connector pin 31 can be moved vertically by means of an actuator 34. The actuator 34 is an electric linear actuator 34.
[0176] On the outside of the vehicle body 3, a first contact body 32 is provided. The first contact body 32 can be connected to the connector pin 31 or to the vehicle body 3 at a horizontal distance from the pin head 31a. In the present embodiment, the first contact body 32 is connected to and around the connector pin 31.
[0177] In addition to the first contact body 32, the connection system 30 comprises a second contact body 33 provided at a vertical distance from the first contact body 32.
[0178] A rigid member 38 is provided on the inside of the vehicle body 21. The rigid member 38 is used to connect the actuator 34 to the connector pin 31 and also to the first contact body 32. Moreover, the second contact body 33 is connected to the rigid member 38 by means of a connector 39. Hence, when the actuator 34 is moving vertically, also the rigid member 38, the connector pin 31 and the first and second contact bodies 32, 33 are moving vertically.
[0179] In
[0180] It is now referred to
[0181] It is now referred to
[0182] It should be noted that in
[0183] In
[0184] It is now referred to
[0185] The further connection system 30 on the second side 3b of the vehicle body 21 also comprises two such connector pins 31 provided in two spaced apart slots 24.
[0186] The rigid member 38 described above with reference to
[0187] The service vehicle 20 is based on the type of prior art container handling vehicle 250 shown in
[0188] Only minor modifications are needed to manufacture a service vehicle 20 from such a container handling vehicle 250. One modification is that slots must be provided in the vehicle body 3 and that the different parts of the connection system 30 must be mounted to the vehicle. Preferably, the container lifting device of the prior art container handling vehicle 250 is removed to save costs and also to provide sufficient space for the actuators 34. In some applications, it may be required to modify the drive system, as the service vehicle 20 may be designed to handle a larger total weight than a typical container handling vehicle. Hence, a more powerful motor of the drive system 40 may be needed, possibly also more robust bearings for the wheels may be used etc. All in all, the number of modifications are still relatively low. In addition, relatively small modifications in the control system are needed, for controlling the actuators 34.
[0189] The automated storage and retrieval system 1 may comprise one or more service vehicles 20 and at least one additional support unit. The additional supporting unit comprises a connection interface CI to which the service vehicle 20 can connect to and disconnect from. Together, the service vehicle 20 and the additional supporting units form a support system for an automated storage and retrieval system 1.
[0190] In general, the connection system 30 may be configured to be connected to the connection interface CI of the additional support unit by the following operation: [0191] moving the connector pin 31 to a first (here: lower) position aligned with the keyhole KH of the connection interface CI of the unit; [0192] moving the connector pin 31 horizontally into the keyhole KH by moving the service vehicle 20 along the track system towards the unit; [0193] moving the connector pin 31 to a second (here: upper) position different from the first position.
[0194] In this second position, movement of the service vehicle 20 away from the unit will cause the unit to be pulled by the service vehicle. Movement of the service vehicle 20 towards the unit will cause the unit to be pushed by the service vehicle. In the two directions mentioned here, the service vehicle 20 and the unit will move along tracks 110 of
[0195] Movement of the service vehicle in a direction perpendicular to the push/pull direction will cause the unit to be dragged or pushed in parallel with the service vehicle 20. This last movement will, as described in the introduction above, require that the correct set of wheels become in contact with tracks 111, or tracks parallel with tracks 111, in
[0196] In general, the connection system 30 is configured to be connected from the connection interface CI by the following operation: [0197] lowering the connector pin 31 to its first (here: lower) position again; [0198] moving the connector pin 31 horizontally out of the keyhole KH by moving the service vehicle 20 along the rails track system 108 away from the unit.
[0199] Examples of different support units will be described through the following examples:
EXAMPLE 1
[0200] It is here referred to
[0201] As shown in
[0202] The connector pins 31 of the connection system 30 of the service vehicle 20 are connected to the connection interface CI and the connector pins 31 are in their upper and locked position. It can also be seen in
[0203] The distance between the respective downwardly protruding supporting elements 64 are adapted to the track system 108. Hence, by lowering the connector pins 31 of the service vehicle 20, the downwardly protruding supporting elements 64 will come into contact with the track system 108 and the service vehicle 20 can disconnect from the unit 60. The service vehicle 20 can re-connect to the unit 60 by moving towards the unit 60 with its connector pins 31 in their lower position and then elevate the connector pins 31 when they have been inserted into the keyhole of the connection interface again.
[0204] In
[0205] It should be noted that the connection system 30 of the service vehicle 20 in this example may have a third position. In the first position, as described above, the connection system 30 has lowered the unit and the unit is in contact with the track system 108. Here, the service vehicle may move the connector pin 31 into or out from the keyhole KH of the connection interface CI. In the second position, the connection system 30 has lifted the unit and the unit is no longer in contact with the track system 108. However, the pull body 76 is not sufficiently elevated to be moved over the vehicle 240,250. Hence, to engage the additional connection system 70 with the vehicle 240,250, the connector pins 31 and hence the unit 60 is elevated to a third position above the second position. Now, the pull body 76 of the unit can be moved over the vehicle 240,250 and then the connection system 30 can be lowered to the second position again. Now, the pull body 76 is engaged with the vehicle 240,250. To disconnect from the vehicle 240,250, the unit 60 is elevated from the third position and moved away from the vehicle 240,250, as the pull body 76 is not engaged with the vehicle 240,250 in the third position.
[0206] The wheel actuator 72 is connected to a mechanical interface 72a of the container handling vehicle 240,250 for adjusting wheel elevation of the container handling vehicle 240,250, i.e. to mechanically control if the wheels should be in contact with tracks 110 or tracks 111 of the track system. The wheel actuator 72 is driven by an electric motor controlled by the control system of the service vehicle 20 or by a control system of the entire system 1.
[0207] It should be noted that the length of the elongated bar elements 62 is adapted to the length between the rails 111. Hence, when moving along tracks 111, four tracks 11 are in contact with the wheels of the service vehicle 20 and the wheels of the vehicle 301, while when moving along tracks 110, the same two tracks are used both by the service vehicle 20 and the vehicle 240,250.
[0208] It should be noted that in this example, no modification of the vehicle 340,350 is needed.
EXAMPLE 2
[0209] It is now referred to
[0210] The purpose of the counterweight unit 60d is to enable the service vehicle 20 to lift and transport a failed container handling vehicle 240,250 of the type shown in
[0211] In
[0212] In
Alternative Embodiments
[0213] In the above embodiments, the connector pin 31 including the pin head 31a was rotationally symmetrical around its longitudinal axis.
[0214] It is now referred to
[0215] In
[0216] In
[0217] In
[0218] In
[0219] It should be noted that all of the above connector pins 31 may be used in combination with all of the above keyholes KH. It should be noted that the present invention is not limited to the specific examples described and shown in the drawings, many other alternatives are considered to be within the scope of the invention as defined by the claims.
[0220] It should also be noted that the operation of the actuator 34 may be dependent on, or independent of, the operation of the drive system 40. In one embodiment, the vertical distance between the slot 24 and the track system will be the same when the service vehicle is moving along tracks 110 and when the service vehicle is moving along tracks 110. In such a case, the operation of the actuator 34 can be independent from the drive system 40. However, in case the vertical distance between the slot 24 and the track system is different when the service vehicle is moving along tracks 110 and when the service vehicle is moving along tracks 111 (due to different elevation of the vehicle body 3 and the different sets of wheels), then the actuator may be operated to change the height of the connector pins based on the travel direction.
[0221] In the preceding description, various aspects of the method and its related system according to the invention have been described with reference to the illustrative embodiment. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the system and its workings. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the illustrative embodiment, as well as other embodiments of the method and 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.
TABLE-US-00001 1 Automated storage and retrieval system 3 Service vehicle body 3A First side of service vehicle body 3B Second side of service vehicle body 6 First propulsion means/propulsion mechanism/rolling means/ roller/caterpillar track 6a First toothed belt wheel for each endless belt 6, 7 6b Second toothed belt wheel for each endless belt 6, 7 6d Endless tracks/Looped chain/endless belt 7 Second propulsion means/propulsion mechanism/rolling means/ roller/caterpillar track 8 Transfer device 8c Transfer motor/lifting mechanism 8d Attachment device/lifting hook/lifting claw 8f Vertical linear actuator 8h Pivot support for vertical linear actuator 8i Horizontal linear actuator 9 Registration unit/image capturing unit 9a Forward camera 9b Rearward camera 20 Service vehicle 22 A support base for malfunctioning vehicle 23 Driving means service vehicle 24 Aperture/slot 25 Central cavity 30 Connection system 31 Connector member/connector pin 31a First section/pin head X31 Longitudinal axis 31b Second elongated section or shank 32 First contact body 33 Second contact body 34 Actuator 35 Guiding pin 36 Transmitter 37 Stopper 38 Rigid member 39 connector 40 Drive system service vehicle/motor/power source 42 First set of wheels service vehicle 44 Second set of wheels service vehicle 60 Intermediate support unit/additional support unit 60d Counterweight unit 61 Elongated bar element 62 Cross bar element 64 supporting elements 70 connection system of additional support unit 72 Wheel actuator 72a Mechanical interface 74, 75 Push body 76 Pull body 108 Rail system 108a First transport rail system 108b Second transport rail system 108c Third transport rail system 109′ Main Control system/first communication system 109″ Secondary control system/second communication system 110 First set of parallel rails in first direction (X) 111 Second set of parallel rails in second direction (Y) 115 Grid opening in transport rail system 119 Delivery column/transfer column 120 Delivery column/transfer column 122 Grid cell of transport rail system 125 Vehicle blocking barrier 130a First vehicle passage between transport rail systems 130b Second vehicle passage between transport rail systems 160 Service area to transport rail system for service vehicle 160a First service area 160b Second service area 160c Third service area 225 Exclusion zone on transport rail system 230 Parked container handling vehicle 230′ Boundary defining, parked vehicle 230″ Non-boundary defining, parked vehicle 240 Malfunctioning container handling vehicle 250 Operative container handling vehicle 251 Wheel assembly for container handling vehicle 252 Vehicle body for container handling vehicle 300 Delivery framework structure 308 Delivery rail system 310 First set of parallel rails in first direction (X) on delivery rail system 311 Second set of parallel rails in second direction (Y) on delivery rail system 315 Grid opening in delivery rail system 322 Grid cell of delivery rail system 330 Parked container delivery vehicle 330′ Boundary defining, parked vehicle 330″ Non-boundary defining, parked vehicle 340 Malfunctioning container delivery vehicle 350 Operative container delivery vehicle 351 Wheel assembly for container delivery vehicle 352 Storage container support X First direction Y Second direction Z Third direction P Horizontal plane of rail system A1, A2 Arrow indicating movement of container handling vehicle A3, A4 Arrow indicating movement of service vehicle A5 Arrow indicating movement of service vehicle with malfunctioning container handling vehicle CI Connection interface CS Connection structure G Minimum width KH Keyhole Kha Circular opening KHb slot RS Rear side FS Front side Lcs Longitudinal distance Tcs Thickness connection structure