Method and system for autonomous control of the movement of a container handling vehicle operating within an automated warehouse system

Abstract

To provide a method and system for an autonomous control of movement of a container handling vehicle operating within an automatic warehouse system.SOLUTION: A method (200), a computer program product, or a system for controlling the movement of a container handling vehicle (150) is provided, wherein the container handling vehicle (150) operates within a warehouse system (10) that comprises a grid structure with a storage column (105) and a corresponding rail system (108) above the storage column (105) for guiding the movement of the vehicles (150) adapted for transporting a storage container (106) to the storage column (105) and from the storage column (105), each vehicle (150) comprises a vehicle controller (410) connected to drive means (420) and a sensor (430) for controlling the movement of the vehicle (150) along the rail system (108) relative to the movement of the other vehicle (150).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method, a system, and a computer program product for controlling the movement of a vehicle that loads and unloads storage containers within an automated warehouse system comprising a grid structure and a corresponding rail system for guiding the movement of the vehicle. More specifically, the present invention relates to a method and a computer program for providing autonomous operation of the movement of a vehicle that loads and unloads storage containers within a warehouse system.

Background Art

[0002] Warehouse systems are well-known. The vehicles that operate them are controlled by a central controller, also called a master controller, which communicates with the controllers within each vehicle.

[0003] FIG. 1 illustrates a typical prior art automated warehouse system 10 having a skeletal structure 100, and a container handling vehicle 150, also called a robot, is operating the automated warehouse system 10 while traveling on a rail system 108 above the skeletal structure 100.

[0004] The skeletal structure 100 comprises a plurality of upright members 102 and optionally a plurality of horizontal members 103 that support the upright members 102. The members 102, 103 may typically be made of metal (e.g., extruded aluminum profiles).

[0005] The skeletal structure 100 defines a storage grid 104 comprising storage columns 105 arranged in vertical rows, where storage containers 106, also known as containers, are stacked on top of each other to form a stack 107. Each storage container 106 may typically hold a plurality of product items.

[0006] The automated warehouse system 10 includes a rail system 108 for guiding the container handling vehicle 150. The rail system 108 is arranged in a grid pattern across the upper part of the storage grid 104. The container handling vehicle 150 travels on the rail system 108 and is operated to lower and raise the storage container 106 into and out of the storage column 105, and to transport the storage container 106 on the rail system 108. The horizontal range of the storage column 105 is defined by the grid cells 122 marked by the thick lines in FIG. 1. The grid cells 122 define the layout of the rail system 108.

[0007] The rail system 108 includes a first set 110 of parallel rails arranged to guide the movement of the container handling vehicle 150 in a first direction X across the upper part of the frame structure 100, and a second set 111 of parallel rails arranged at a right angle to the first set 110 of rails for guiding the movement of the container handling vehicle 150 in a second direction Y that is perpendicular to the first direction X. Thus, the rail system 108 defines grid columns above which the container handling vehicle 150 can move laterally above the storage columns 105 (i.e., in a plane parallel to the horizontal X-Y plane).

[0008] Each container handling vehicle 150 includes a vehicle body and a wheel arrangement of eight wheels, with a first set of four wheels enabling lateral movement of the container handling vehicle 150 in the X direction and a second set of the remaining four wheels enabling lateral movement in the Y direction. One or both sets of wheels within the wheel arrangement can be raised and lowered so that the first set of wheels and / or the second set of wheels can engage the individual sets 110, 111 of rails, which is defined by a controller that controls the drive means within the container handling vehicle 150 for controlled directional movement of the container handling vehicle 150.

[0009] Each container handling vehicle 150 further includes a lifting device (not shown) for vertical transportation of the storage container 106 (for example, raising the storage container 106 from the storage column 105 and lowering the storage container 106 into the storage column 105). The lifting device includes one or more gripping / engagement devices (not shown) adapted to engage the storage container 106. The gripping / engagement device can be lowered from the vehicle 150 by the lifting device to adjust the position of the gripping / engagement device in a third direction Z orthogonal to the first and second directions X, Y.

[0010] Each container handling vehicle 150 includes a storage compartment or space (not shown) for receiving and accommodating the storage container 106 when transporting the storage container 106 across the rail system 108. The storage space may include a cavity centrally arranged within the vehicle body, for example, as described in WO No. 2014 / 090684 A1, the content of which is incorporated herein by reference.

[0011] Alternatively, the container handling vehicle 150 may have a cantilever structure as described in NO No. 317366, the content of which is also incorporated herein by reference.

[0012] In storage grid 104, most of the grid columns are storage columns 105 (i.e., the grid columns 105 where storage containers 106 are stored in stack 107). However, storage grid 104 is not normally used for storing storage containers 106. Instead, storage containers 106 can be unloaded and / or loaded by container handling vehicle 150 for use in at least one grid column such that the storage containers 106 can be transported to a second location (not shown) where the storage containers 106 can be accessed from outside storage grid 104 or transferred out of or into storage grid 104. In the art, such a location is typically referred to as a "port", and the grid column where the port is located can be referred to as a "delivery column" 119. The loading and unloading ports of container handling vehicle 150 are referred to as the "upper port of the delivery column" 119. On the other hand, the opposite end of the delivery column is referred to as the "lower port of the delivery column".

[0013] The storage grid 104 of FIG. 1 includes two delivery columns 119 and 120. The first delivery column 119 may include, for example, a dedicated unloading port through which container handling vehicle 150 can unload a storage container 106 to be transported to a further access station or transfer station (not shown) through delivery column 119, and the second delivery column 120 may include a dedicated loading port through which container handling vehicle 150 can load a storage container 106 being transported from an access station or transfer station (not shown) through delivery column 120. Each of the ports of the first and second delivery columns 119, 120 may include ports suitable for both loading and unloading of storage containers 106.

[0014] A second location where the storage container 106 can be accessed from outside the storage grid 104 may typically be a picking station or a reserve station where product items are removed from or positioned within the storage container 106. At the picking station or the reserve station, the storage container 106 is usually never removed from the automated warehouse system 10, but once accessed, it is returned into the storage grid 104. For the transfer of the storage container to the outside or inside of the storage grid 104, lower ports provided within the delivery column also exist. Such lower ports are used, for example, to transfer the storage container 106 directly to another storage facility (e.g., another storage grid), to a transport vehicle (e.g., a train or a large truck), or to a production facility.

[0015] To monitor and control the automated warehouse system 10, the system includes a central control system (not shown), which is typically computerized and includes a database for continuously tracking the location of the storage containers 106 as well as the storage containers 106 to be handled at any time (i.e., the storage containers 106 to be retrieved or stored within the storage grid 104). In addition to this, the control system monitors and controls the position and movement of each container handling vehicle 150 operating on the storage grid 104. Thus, each container handling vehicle 150 receives from the central control system movement instructions for transporting a specific storage container 106 from one location to another without colliding with each other.

[0016] To control the traffic flow of the container handling vehicles 150 operating on the storage grid 104, the control system must always have an up-to-date overview of the position and movement of all container handling vehicles 150.

[0017] When the storage container 106 stored within the storage grid 104 disclosed in FIG. 1 is to be accessed, the control system may, for example, instruct one of the container handling vehicles 150 to retrieve the storage container 106 from its current location within the storage grid 104 and transport it to or through the first delivery column 119. This operation involves moving the container handling vehicle 150 to the grid location above the storage column 105 where the target storage container 106 is located, retrieving the storage container 106 from the storage column 105 using a lifting device (not shown) of the container handling vehicle, and transporting the storage container 106 to the first delivery column 119. If the target storage container 106 is located deep within the stack 107 (i.e., one or more other storage containers are stacked above the target storage container 106), this operation involves temporarily moving the storage container 106 above the target storage container 106 prior to lifting the target storage container 106 out of the storage column 105. This step, sometimes referred to in the art as "digging out," may be performed using the same container handling vehicle 150 that is subsequently used to transport the target storage container 106 to the delivery column, or using one or more other cooperating container handling vehicles 150. Alternatively or in addition, the automated storage system 10 may specifically include a container handling vehicle 150 dedicated to the task of temporarily removing the storage container 106 from the storage column 105. Once the target storage container 106 has been removed from the storage column 105, the temporarily removed storage container 106 can be repositioned back into the original storage column 105 or, alternatively, repositioned into another storage column 105.

[0018] Once the storage container 106 is to be stored within the storage grid 104, one of the container handling vehicles 150 is instructed to load the storage container 106 from the second delivery column 120 shown in FIG. 1 and transport it to a grid location above the target storage column 105 where it is to be stored. After any storage container 106 positioned at or above the target position within the storage column stack 107 is removed, the container handling vehicle 150 installs the storage container 106 at the desired location. The removed storage container 106 can then be lowered back into the storage column 105 or repositioned to another storage column 105.

[0019] In addition to the warehouse system 10 described above with reference to FIG. 1, the applicant has also developed a warehouse system in which the container handling vehicle 150 operates both above and below the storage grid 104. The container handling vehicle operating below the storage grid 104 is called a drone. The solution including the drone improves the efficiency when handling the storage container 150, but requires further communication to and from the central control system and all the container handling vehicles 150.

[0020] This AutoStore system is controlled by a master controller that transmits operation and movement commands to all the container handling vehicles 150 to control all movements and operations on the warehouse system 10. To do so, the master controller always has an overall overview of the locations of all the vehicles 150 operating the warehouse system 10 as well as the locations of all the storage containers 106. The master controller instructs each vehicle 150 to store or retrieve the storage container 106. The current position of each vehicle is continuously communicated from the vehicle 150 to the master controller, thus enabling it to control the movement of all the vehicles 150 on the rail system 108 in an optimal manner without the vehicles 150 forming a queue or colliding.

[0021] In this solution, this requires continuous wireless communication with each container handling vehicle 150. In a larger system with multiple vehicles 150, the amount of wireless communication is enormous and can be vulnerable to noise and the like. Another problem is that the skeletal structure 100 itself can obscure communication signals. This is particularly problematic when there are container handling vehicles 150 (i.e., drones) operating below the grid 104.

[0022] The present invention alleviates this problem by a method and computer program product that require reduced wireless traffic between a master controller and container handling vehicles 150 operating on a warehouse system 10 to handle storage containers 106 of the warehouse system 10.

[0023] By causing all vehicles 150 operating the warehouse system 10 to make autonomous movement decisions, the master controller only needs to assign tasks to the vehicles, and each vehicle selects the best route to follow along the rail system 108 from its current position to the destination. This dramatically reduces the wireless communication between each container handling vehicle 106 and the master controller as well as the complexity of central processing.

[0024] However, when using vehicles that make autonomous movement decisions regarding movement on the rail system 108, there are challenges. Since the grid 104 is dense and other vehicles 150 can block the view for the vehicle 150, it is difficult to predict the movement of other vehicles 150. Using distance sensors makes it easier to follow other vehicles, but when traffic is dense and the speed of other vehicles 150 is potentially relatively high, crossing lanes can still be difficult. This entails the risk that some vehicles will be held up (i.e., due to high traffic load, they cannot enter the congested "main road" from the port position). These aspects are also addressed and solved by the present invention.

Prior Art Documents

Patent Documents

[0025] [Patent Document 1] International Publication No. 2014 / 090684 [Summary of the Invention] [Means for Solving the Problems]

[0026] Brief Description of the Invention The present invention is a method, a computer program product, and a system as defined in the independent claims and with additional features defined in the dependent claims.

[0027] More specifically, the present invention is defined by a method for autonomously controlling the movement of a container handling vehicle, the container handling vehicle operating within a warehouse system comprising a grid structure with storage columns and a corresponding rail system above the storage columns for guiding the movement of the vehicle adapted to transfer storage containers to and from the storage columns, each vehicle comprising a vehicle controller connected to drive means and sensors for controlling the movement of the vehicle along the rail system with respect to the movement of other vehicles. The method comprises, within the vehicle controller of each vehicle, a) using a map defining a rail layout and traffic rules regarding where and when a vehicle can move on the rail system, the map being the same for all vehicles operating within the warehouse system, b) synchronizing the vehicle controller to a common clock for all vehicles, c) receiving, from a master controller, an instruction to command the vehicle to move to a destination defined on the rail system with respect to the map, d) causing the vehicle controller to determine a path for following on the rail system from the current position of the vehicle to the defined destination based on the map, traffic rules, distance to other vehicles, and the movement of other vehicles, e) Controlling the movement of the vehicle along the rail system from its current position to a specified destination according to the determined route; f) Repeating steps d) and e) until the vehicle reaches the specified destination; characterized by performing the above.

[0028] According to an embodiment of the present invention, the rail layout in a common map is defined according to two-dimensional coordinates corresponding to grid cells defined by the horizontal extent of the storage columns of the warehouse system, and the traffic rules are defined for each grid cell and its corresponding rail.

[0029] This means that each grid cell is uniquely defined. Since all vehicles operating the warehouse system use the same map that defines the rules for movement, the vehicle controller in each vehicle can control the vehicle along the rail system without colliding with other vehicles.

[0030] The common map includes a set of traffic rules for each grid cell and its corresponding rail. Different sets of traffic rules may be used for different grid cells. The common map may define, for example, a series of connected cells as the "main road", while the cells connected to the "main road" are defined as "side roads". The map may further define some grid cells as "one-way traffic" in a specific direction. Another rule may be that one or more specified grid cells should not be used (i.e., passage or stop on the grid cell is prohibited). Yet another rule may be that the grid cell is defined with a restricted speed (i.e., passed only at the set maximum speed).

[0031] When different traffic rules are combined, the common map described in detail can be followed by all container handling vehicles operating on the same rail system. Each vehicle follows different rules according to their current location.

[0032] In addition to a common set of traffic rules, different sets of traffic rules may be applied over a certain time slot. In this way, traffic patterns can be changed according to, for example, specific needs and times.

[0033] The current position of each vehicle can be determined in different ways. One way is to determine the position by detecting the number of rail intersections passed and the direction in which the rail intersections are passed from the initial position. The initial position can preferably be obtained by external means that detect the current positions of all vehicles when all vehicles are stopped (typically when starting or resetting the system).

[0034] As described, one step of the method is to synchronize the vehicle controllers of each vehicle to the same common clock.

[0035] Each vehicle is instructed to move to a destination defined relative to a common map. At the destination, the vehicle performs tasks such as retrieving or storing storage containers.

[0036] When each vehicle receives an instruction including a destination grid cell, the vehicle controller determines a route for following from the current position of the vehicle to the defined destination based on the common map. The vehicle controller plans and creates the route according to traffic rules and the distance to other vehicles.

[0037] The vehicle controller may adjust and / or change the speed and movement of the vehicle according to traffic rules, the distance to other vehicles, and its movement.

[0038] The vehicle controller may further adjust and / or change the set route of the vehicle according to the current position of the vehicle, the distance to other vehicles, and the movement of other vehicles.

[0039] When all vehicles are synchronized to the same common clock, they are controlled according to a common map and all movements run smoothly without the need to be continuously controlled by a master controller. This dramatically reduces the communication and central processing complexity between the vehicles and the master controller.

[0040] The method according to the invention can be implemented in different types of vehicles (e.g., robots and drones) operating within a warehouse system. This is particularly suitable in a system where both robots and drones cooperate, especially when handling storage containers. A robot is an autonomous vehicle operating above the warehouse system, while a drone is an autonomous vehicle operating below the vehicle or at a level below the grid structure of the warehouse system.

[0041] Vehicles traveling on the same level must follow the same common map. Since robots and drones operate on different levels, they may follow maps that define different traffic rules.

[0042] The invention is further defined by a computer program product comprising instructions that, when executed in a processor of a vehicle controller provided within an autonomous container handling vehicle, implement the method described above for handling storage containers within a warehouse system.

[0043] The master controller is - transmitting a map to the vehicle controllers of all vehicles operating within the warehouse system, the map defining a rail layout and traffic rules regarding where and when the vehicles can move on the rail system, the map being the same for all vehicles, and - transmitting a synchronization signal to all vehicle controllers so that all vehicle controllers are synchronized to a common clock for all vehicles adapted for, Each vehicle controller - Receiving, from a master controller, a command to command a vehicle to move to a destination defined on a rail system with respect to a map - Determining a route for following on the rail system from a current position of the vehicle to a defined destination based on the map, traffic rules, distance to other vehicles, and movement of other vehicles - Controlling the movement of the vehicle along the rail system from its current position to a defined destination according to the determined route is adapted for. The present invention provides, for example, the following. (Item 1) A method for autonomously controlling the movement of a container handling vehicle (150), wherein the container handling vehicle (150) operates within a warehouse system (10) comprising a grid structure with storage columns (105) and a corresponding rail system (108) above the storage columns (105) for guiding the movement of the vehicle (150) adapted to transfer storage containers (106) to and from the storage columns (105), each vehicle (150) comprising a vehicle controller (410) connected to drive means (420) and sensors (430) for controlling the movement of the vehicle (150) along the rail system (108) with respect to the movement of other vehicles (150), the method comprising, within the vehicle controller (410) of each vehicle (150), a) Using a map defining a rail layout and traffic rules regarding where and when a vehicle (150) can move on the rail system (108), the map being the same for all vehicles (150) operating within the warehouse system (10) b) Synchronizing the vehicle controller (410) to a common clock for all vehicles (150) c) Receiving, from a master controller (400), a command to command the vehicle (150) to move to a destination defined on the rail system (108) with respect to the map d) causing the vehicle controller (410) to determine a route for following on the rail system (108) from the current position of the vehicle (150) to the specified destination based on the map, the traffic rules, the distance to another vehicle (150), and the movement of the other vehicle (150); e) controlling the movement of the vehicle (150) along the rail system (108) from its current position to the specified destination according to the determined route; f) repeating steps d) and e) until the vehicle (150) reaches the specified destination. A method, characterized by performing the above steps. (Item 2) Defining the rail layout according to two-dimensional coordinates corresponding to grid cells (122) defined by the perimeter of the horizontal range of the storage column (105) of the warehouse system (10), and defining traffic rules for each grid cell (122) and its corresponding rail. The method according to item 1. (Item 3) Further defining a time slot for each grid cell (122) with respect to when the traffic rules are applicable. The method according to item 2. (Item 4) The traffic rules include that a grid cell (122) should be used for one-way driving only in a specified direction, that a grid cell (122) should not be used, that a grid cell (122) can only pass through, that a grid cell (122) can be used only in a specified direction within a set time slot, or that a grid cell (122) can only pass through at a specified speed, including one or more of these. The method according to item 3. (Item 5) Determining the position of the vehicle (150) by detecting the number of rail crossings passed through and the direction in which the rail crossings are passed through. The method according to any one of the above items. (Item 6) The method according to any one of the preceding items, characterized in that the vehicle controller (410) adjusts and / or changes the speed and movement of the vehicle (150) according to the traffic rules, the distance to another vehicle (150), and the movement of the other vehicle (150). (Item 7) The method according to any one of the preceding items, characterized in that the vehicle controller (410) adjusts and / or changes the route of the vehicle (150) according to the current position of the vehicle (150), the distance to another vehicle (150), and the movement of the other vehicle (150). (Item 8) A computer program product comprising instructions which, when executed in a processor of a vehicle controller (410) provided in an autonomous container handling vehicle (150), implement the method according to items 1 to 7 for controlling the movement of the container handling vehicle (150) within a warehouse system (10). (Item 9) A system for autonomously controlling the movement of a container handling vehicle (150), the container handling vehicle (150) operating within a warehouse system (10) comprising a grid structure with storage columns (105) and a corresponding rail system (108) above the storage columns (105) for guiding the movement of the vehicle (150) adapted to transfer storage containers (106) to and from the storage columns (105), each vehicle (150) comprising a vehicle controller (410) connected to drive means (420) and sensors (430) for controlling the movement of the vehicle (150) along the rail system (108) with respect to the movement of other vehicles (150), the system comprising a master controller (400) adapted to communicate with the vehicle controller (410) within each vehicle (150), wherein the master controller,[[]] - Transmitting a map to the vehicle controllers (410) of all vehicles (150) operating within the warehouse system (10), wherein the map defines a rail layout and traffic rules regarding locations and times at which a vehicle (150) can move on the rail system (108), and the map is the same for all the vehicles (150), - Transmitting a synchronization signal to all the vehicle controllers (410) such that all the vehicle controllers (410) are synchronized to a common clock for all vehicles (150), adapted for, Each vehicle controller (150) is, - Receiving, from a master controller (400), an instruction to command the vehicle (150) to move to a specified destination on the rail system (108) with respect to the map, - Determining a route for following on the rail system (108) from the current position of the vehicle (150) to the specified destination based on the map, the traffic rules, the distance to other vehicles (150), and the movement of the other vehicles (150), - Controlling the movement of the vehicle (150) along the rail system (108) from its current position to the specified destination in accordance with the determined route, characterized by being adapted for.

[0044] The master controller is, - Transmitting a map to the vehicle controllers of all vehicles operating within the warehouse system, wherein the map defines a rail layout and traffic rules regarding locations and times at which a vehicle can move on the rail system, and the map is the same for all vehicles, - Transmitting a synchronization signal to all the vehicle controllers such that all the vehicle controllers are synchronized to a common clock for all vehicles, adapted for, Each vehicle controller is, - Receiving, from a master controller, a command to instruct a vehicle to move on a rail system to a destination defined for a map; - Determining a route for following on a rail system from a current position of the vehicle to a defined destination based on a map, traffic rules, distance to other vehicles, and movement of other vehicles; - Controlling movement of the vehicle along the rail system from its current position to a defined destination in accordance with the determined route is adapted for.

Brief Description of the Drawings

[0045] Embodiments of the present invention are provided here, with reference to the figures, in more detail and by way of example only.

[0046]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0047] As described above with reference to FIG. 1, vehicles operating within a prior art warehouse system are controlled by a master controller that has, at all times, an overall overview of the movement of all vehicles. In a larger system involving multiple vehicles, having this overall overview requires extensive continuous communication between the master controller and the vehicles that can make signals vulnerable to interference and subject to signal loss.

[0048] The present invention addresses and solves this problem by means of a method, a system, and a computer program product that enable each vehicle to control its own movement with respect to the movement of other vehicles.

[0049] Figure 2 illustrates different steps 200 implemented in a method for autonomously controlling the movement of a vehicle traveling on rails within a grid system.

[0050] As described above, the container handling vehicle 150 operates within a warehouse system 10 comprising a grid structure with grid cells 122 and a corresponding rail system 108 for guiding the movement of vehicles for transferring storage containers to and from the grid cells 122. Each vehicle 150 comprises a vehicle controller 410 (see Figure 4) connected to drive means 420 and sensors 430 for controlling the movement of the vehicle 150 along the rail system 108 with respect to the movement of other vehicles 150. The vehicle controller 410 is a signal connected to a master controller 400 for exchanging information.

[0051] According to the present invention, a method 200 for autonomously controlling the movement of the vehicle 150 comprises different steps implemented within the vehicle controller 410 of each vehicle 150.

[0052] A first step 210 is to use a map defining the rail layout and the traffic rules regarding the rail system 108. Each vehicle is provided with the same map with information on the rail layout of the warehouse system and the same traffic rules defining where and when the vehicle can move on the rails. An example of the traffic rules is described below with reference to Figure 3.

[0053] The map can be provided to each vehicle 150 in different ways. When setting up a new warehouse system, each vehicle operating on the system may have a map pre-installed in a non-volatile memory connected to its controller. An updated version of the map may be transmitted to each vehicle 150 and installed in each vehicle 150 after each vehicle 150 becomes operational.

[0054] In addition to the track layout of the rail system 108 and the traffic rules for each grid cell 122, the common map also defines, for each grid cell 122, a time slot that defines the time interval during which different traffic rules are effective for each grid cell 122. Each time, the slot can define a "virtual traffic signal" for movement on each grid cell 122. For example, a "blue traffic signal" means that vehicle 150 can move, while a "red traffic signal" means that vehicle 150 must wait. For this to work, all vehicles must operate according to the same time reference (i.e., a common clock).

[0055] The second step 220 of the method is to synchronize the clocks in the vehicle controllers 410 of each vehicle according to the common clock. When the first step 210 and the second step 220 are executed, all vehicles 150 are prepared for normal operation and to receive instructions containing information adapted for each vehicle (e.g., the destination grid cell 122 and the task to be performed). The task may be, for example, to load a specific storage container 150 stored in the storage column 105 corresponding to the grid cell 122 where it is instructed to move.

[0056] The next step is repeated and executed during normal operation (i.e., when all vehicle controllers 410 are provided with the common map and their clocks are synchronized).

[0057] During normal operation, each vehicle controller 410 receives from the master controller 400 an instruction including the destination grid cell 122 to which it should move and the operation to be performed. This is illustrated by step 230 in FIG. 2. When the vehicle controller 410 receives this information, the next step 240 is to cause the vehicle controller 410 in the vehicle 150 to determine the route that the vehicle 150 should follow on the rail system 108 from its current location to the destination grid cell 122. All movements along the track are made according to a common map. During that movement along the track, it is constantly checked whether other vehicles are too close or will become too close and whether it should stop (see step 250). The proximity of one vehicle to another can be determined by distance sensors disposed within the vehicle. By constantly detecting and updating the current distance to other vehicles 150, their movements (e.g., the speed at which they are traveling, whether they are moving away from the determined route of the vehicle 150, or whether they are moving towards the determined route of the vehicle 150) can be determined.

[0058] If it is determined that it must stop, it returns to step 240 again and the route is determined again. This may be a new route or the same route that the vehicle 150 previously followed and that is clear after the stop.

[0059] If it is determined that the vehicle 150 can follow the determined route to the destination grid cell 122 without stopping (see step 260), the vehicle controller 410 controls the vehicle 150 to drive it to the destination grid cell 122 and perform its commanded operation. This then prepares to receive a new instruction or to plan a new route to another destination grid cell 122 according to a previously received instruction.

[0060] Each container handling vehicle 150 is provided with a controller synchronized with (a clock synchronized with the same common clock) and sensor means for determining its position and the distance to other container handling vehicles 150. When controlled according to the same common map that defines traffic rules, the vehicle can move safely without the need to be controlled by an external master controller.

[0061] The drones operating below the warehouse system 10 do not have excavation activities and typically have a lower density grid. The set of traffic rules for the drones may thus be simpler than the traffic rules defined for the vehicles 150 operating above the warehouse system. When using both vehicles 150 and drones to operate the warehouse system, wireless access points are provided both above and below the grid structure. By using vehicles controlled according to the method described above, fewer wireless access points are required due to the lower need for communication between the master controller and the vehicles.

[0062] The virtual time slot-based "traffic lights" and traffic rules within the common map enable autonomous traffic decisions for each vehicle 150 when moving from its current location to the destination grid cell 122. This does not require communication with a central controller or other vehicles. The route that each vehicle should follow to its destination is determined by the vehicle controller 410 within each vehicle 150. Guiding the vehicle along the track thus does not require continuous communication with the master controller 400 or other vehicles.

[0063] When the vehicle 150 arrives at its destination, it reports this to the master controller 400 and is then ready to receive new instructions (e.g., the next destination and tasks to be performed).

[0064] The present invention is further defined by a computer program product comprising instructions that, when executed within a processor of a vehicle controller 410 provided within the autonomous vehicle 150, implement the method described above for controlling the movement of the container handling vehicle 150 within the warehouse system 10.

[0065] FIG. 3 illustrates an example of the movement of the vehicle 150 according to a central map that defines traffic rules. Different traffic rules (e.g., speed limits, the vehicle 150 can pass through the grid cell 122 but cannot stop on the grid cell 122, the vehicle can pass only in a defined direction, etc.) may be applied to each grid cell 122.

[0066] The map shows only a part of the rail system 108 above each grid cell 122 of the grid 104 of the warehouse system 10. Each vehicle 150 in the figure is a container handling vehicle 150 identified by a number (i.e., 01 - 08). The map shows a series of grid cells 122 defined as the "main road" in each x - direction. This means that these grid cells 122 are used as the main transportation route for the container handling vehicle 150.

[0067] Vehicles 150 marked as 01, 02, 05, and 08 are driving on the main transportation route (i.e., the "main road"). Since traffic rules are applied to each grid cell 122 at specific time slots, the specific time slots define the "traffic signal lights" for the grid cell 122 and thus the traffic situation regarding the vehicle 150.

[0068] To access the "main road", vehicles 150 marked as 03, 04, 06, and 07 located at the upper port positions need a time slot with a "blue traffic signal light" to enter the grid cell 122 on the main road by moving in the y - direction, and the grid cell 122 they are moving into should not be occupied by another vehicle 150.

[0069] The figure illustrates one specific time slot in which vehicle 04 has a "blue traffic signal" for moving in the y direction on grid cell 122 on the "main road", while vehicles 01 and 02 that are already moving on the "main road" have "red traffic signals" and must stop on their current grid cell 122. Vehicle 04 can then move onto the "main road".

[0070] Vehicles 06 and 07 are currently busy with their operations at their port positions and thus are not moving on the rail even if they have a "blue traffic signal". Vehicles 06 and 07 must first wait until a time slot has a "blue traffic signal" in the direction they are to drive when they are ready to move to another grid cell 122.

[0071] Figure 4 illustrates that each vehicle 150 comprises a vehicle controller 410 connected to a drive means 420 and a sensor 430 for autonomous control of the movement of the container handling vehicle. Each vehicle controller 410 communicates with a master controller 400 for receiving and responding to operation commands.

[0072] According to the present invention, vehicles 150 operating within the warehouse system 10 each receive from the master controller 400 a command that includes the grid cell 122 in which the vehicle 150 is to move, without any further information about the path or speed to follow. Based on a common map that defines traffic rules and its distance sensors, each vehicle 150 makes its own determination about the path and speed to follow. The vehicle can change or optimize its current path while en route to the destination location (e.g., grid cell 122). If the current path is blocked, a new path may be planned. All vehicles move safely when their vehicle controllers follow the same common map that is temporally synchronized and defines traffic rules for each grid cell 122, and when they use distance sensors to continuously update their current distance to other vehicles 150.

[0073] The context used when explaining the above invention can be an AutoStore warehouse system that can consist of a conventional AutoStore grid where container handling vehicles operate on the retrieval and storage grid, and a grid for drone traffic that operates at or below the lower level of the retrieval and storage grid. The grid for drone traffic typically connects multiple AutoStore grids but can also be used for transportation to a picking station or an external handling area.

Claims

A method for autonomously controlling the movement of a container handling vehicle (150) operating within a warehouse system (10), wherein the warehouse system comprises a grid structure with storage columns (105) and a corresponding rail system (108) above the storage columns (105) for guiding the movement of the container handling vehicle (150), each container handling vehicle (150) comprises a vehicle controller (410), and the method comprises, within the vehicle controller (410) of each vehicle (150), a) using a map, the map defining traffic rules and a rail layout for all the container handling vehicles operating on the warehouse system, the rail layout according to two-dimensional coordinates corresponding to grid cells (122) defined by the perimeter of the horizontal extent of the storage columns (105) of the warehouse system (10), the traffic rules defining where and when a container handling vehicle (150) can move on the rail system (108); b) synchronizing the vehicle controller (410) to a common clock for all vehicles (150); c) receiving, from a master controller (400), an instruction to command the vehicle (150) to move to a specified destination on the rail system (108) relative to the map; d) causing the vehicle controller (410) to determine a route for following the rail system (108) from the current position of the vehicle (150) to the specified destination based on the map, the traffic rules, the distance to other vehicles (150), and the movement of the other vehicles (150); e) controlling the movement of the vehicle (150) along the rail system (108) from its current position to the specified destination according to the determined route; f) repeating steps d) and e) until the vehicle (150) reaches the specified destination. A method comprising performing the above. The method according to claim 1, further comprising defining a time slot for each grid cell with respect to when the traffic rules are applicable. The method according to claim 1, wherein the container handling vehicle is adapted to transfer storage containers to and from the storage columns. **Claim 4**: The method according to claim 1, wherein the vehicle controller is connected to drive means (420) and sensors (430) for controlling the movement of the container handling vehicle along the rail system relative to the movement of other container handling vehicles. **Claim 5**: The method according to claim 1, wherein the map is the same for all vehicles moving on the warehouse system. **Claim 6** The traffic rules should include one or more of the following: the grid cell (122) should be used only for one-way driving in the specified direction, the grid cell (122) should not be used, the grid cell (122) can only pass through, the grid cell (122) can be used only in the specified direction within the set time slot, the grid cell (122) can pass through only at the specified speed. The method according to claim 1. **Claim 7** The method according to claim 1, further comprising determining the position of the vehicle (150) by detecting the number of rail crossings passed and the direction in which the rail crossings are passed. **Claim 8** The method according to any one of claims 1 to 7, further comprising causing the vehicle controller (410) to adjust and / or change the speed and movement of the vehicle (150) according to the traffic rules, the distance to other vehicles (150), and the movement of the other vehicles (150). **Claim 9** The method according to any one of claims 1 to 8, further comprising causing the vehicle controller (410) to adjust and / or change the route of the vehicle (150) according to the current position of the vehicle (150), the distance to other vehicles (150), and the movement of the other vehicles (150). **Claim 10** A computer program product comprising instructions which, when executed in a processor of a vehicle controller (410) provided in an autonomous container handling vehicle (150), implement the method according to claims 1 to 9 for controlling the movement of the container handling vehicle (150) within a warehouse system (10).

11. A system for autonomously controlling the movement of a container handling vehicle (150) operating within a warehouse system (10), wherein the warehouse system includes a grid structure with storage columns (105) and a corresponding rail system (108) above the storage columns (105) for guiding the movement of the container handling vehicle (150), each container handling vehicle (150) includes a vehicle controller (410), and the system includes a master controller (400) adapted to communicate with the vehicle controller (410) within each container handling vehicle (150). The master controller (400) is configured to transmit a map to the vehicle controllers (410) of all vehicles (150) operating within the warehouse system (10), the map defining traffic rules and a rail layout for all the container handling vehicles operating within the warehouse system, the rail layout corresponding to two-dimensional coordinates of grid cells (122) defined by the perimeter of the horizontal extent of the storage columns (105) of the warehouse system (10), and the traffic rules defining where and when a vehicle (150) can move on the rail system (108). configured to transmit a synchronization signal to all the vehicle controllers (410) so that all the vehicle controllers (410) are synchronized to a common clock for all vehicles (150). and is adapted for Each vehicle controller (410) is configured to receive from the master controller (400) an instruction to command the vehicle (150) to move to a specified destination on the rail system (108) with respect to the map. configured to determine a route for following on the rail system (108) from the current position of the vehicle (150) to the specified destination based on the map, the traffic rules, the distance to other vehicles (150), and the movement of the other vehicles (150). configured to control the movement of the vehicle (150) along the rail system (108) from its current position to the specified destination according to the determined route. and is a system adapted for.

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