Method for storing containers in automatic storage and retrieval system and storage control system

Abstract

The invention relates to a method for storing containers in an automatic storage and retrieval system and a storage control system. The method comprises the steps of: defining a first storage area, where the first storage area comprises a particular storage column within a frame structure; setting a first maximum weight threshold for the first storage area; determining the total weight of all storage containers stored in the first storage area; a weight of another storage container to be stored within the frame structure is determined. The method then comprises the steps of determining that the storage location of the other storage container is within the first storage area if the sum of the total weight and the weight of the other storage container is below a first maximum weight threshold, or determining that the storage location of the other storage container is within the second storage area if the sum of the total weight and the weight of the other storage container is above the first maximum weight threshold. And if yes, determining that the storage position of the other storage container is outside the first storage area.

Description

[0001] This application is a divisional application of the Chinese national phase application with an international filing date of October 28, 2020, an international application number of PCT / EP2020 / 080295, and an invention name of “Method for allocating storage containers in an automatic storage and retrieval system”. The national phase entry date of the Chinese national phase application is May 20, 2022, the application number is 202080080526.9, and the invention name is “Method for allocating storage containers in an automatic storage and retrieval system”. Technical Field

[0002] The present invention relates to an automated storage and retrieval system for storing and retrieving containers, and more particularly to such a system, wherein the position of the containers is determined to prevent overloading of a predetermined storage area. The present invention also relates to a method for storing containers in such a system to prevent overloading of a predetermined storage area. Background Art

[0003] FIG. 1 discloses a typical prior art automated storage and retrieval system 1 having a frame structure 100 , and FIGS. 2 and 3 disclose two different prior art container handling vehicles 201 , 301 suitable for operating on such a system 1 .

[0004] The frame structure 100 comprises upright members 102, horizontal members 103 and a storage volume comprising storage columns 105 arranged in rows between the upright members 102 and the horizontal members 103. In these storage columns 105, storage containers 106 (also called boxes) are stacked on top of each other to form stacks 107. The members 102, 103 may typically be made of metal, such as extruded aluminum profiles.

[0005] The frame structure 100 of the automated storage and retrieval system 1 includes a rail system 108 arranged across the top of the frame structure 100, on which a plurality of container handling vehicles 201, 301 operate to lift and lower storage containers 106 from storage columns 105, and also to transport storage containers 106 onto storage columns 105. The rail system 108 includes a first set of parallel rails 110 arranged to guide movement of the container handling vehicles 201, 301 across the top of the frame structure 100 in a first direction X, and a second set of parallel rails 111 arranged perpendicular to the first set of rails 110 to guide movement of the container handling vehicles 201, 301 in a second direction Y perpendicular to the first direction X. The container handling vehicles access the containers 106 stored in the columns 105 through access openings 112 in the rail system 108. The container handling vehicles 201 , 301 can move laterally above the storage row 105 , ie in a plane parallel to the horizontal XY plane.

[0006] Upright members 102 of frame structure 100 may be used to guide storage containers during lifting and lowering of containers from and into row 105. Stack 107 of containers 106 is generally self-supporting.

[0007] Each prior art container handling vehicle 201, 301 comprises a vehicle body 201a, 301a and first and second sets of wheels 201b, 301b, 201c, 301c, which enable the container handling vehicle 201, 301 to move laterally in the X direction and the Y direction, respectively. In Figures 2 and 3, two wheels are fully visible in each set. The first set of wheels 201b, 301b is arranged to engage with two adjacent tracks in the first set of tracks 110, and the second set of wheels 201c, 301c is arranged to engage with two adjacent tracks in the second set of tracks 111. At least one of the wheel sets 201b, 301b, 201c, 301c is capable of rising and falling, so that the first wheel set 201b, 301b and / or the second wheel set 201c, 301c can engage with the corresponding track set 110, 111 at any time.

[0008] Each prior art container handling vehicle 201, 301 further comprises a lifting device (not shown) for vertically transporting storage containers 106, for example, lifting the storage containers 106 from the storage column 105 and lowering the storage containers 106 into the storage column 105. The lifting device comprises one or more gripping / engaging devices adapted to engage the storage containers 106 and which gripping / engaging devices can be lowered from the vehicle 201, 301 so that the position of the gripping / engaging devices relative to the vehicle 201, 301 can be adjusted in a third direction Z orthogonal to the first direction X and the second direction Y. The gripping device components of the container handling vehicle 301 are indicated by reference number 304 in FIG3. The gripping device of the container handling vehicle 201 is located within the vehicle body 301a in FIG2.

[0009] Conventionally, and also for the purposes of the present application, Z=1 identifies the uppermost layer of storage containers, i.e., the layer immediately below the rail system 108, Z=2 identifies the second layer below the rail system 108, Z=3 identifies the third layer, etc. In the exemplary prior art disclosed in FIG. 1 , Z=8 identifies the lowermost layer of storage containers. Similarly, x=1…n and y=1…n identify the position of each storage column 105 in the horizontal plane. Thus, as an example, for example, using the Cartesian coordinate system X, Y, Z shown in FIG. 1 , it can be said that the storage container identified as 106' in FIG. 1 occupies storage position X=10, Y=2, Z=3. It can be said that the container handling vehicle 201, 301 travels in layer Z=0, and each storage column 105 can be identified by its X and Y coordinates.

[0010] The storage volume of the frame structure 100 is generally referred to as a grid 104, wherein the possible storage locations within the grid are referred to as storage cells. Each storage column can be identified by a position in the X and Y directions, and each storage cell can be identified by a container number in the X, Y and Z directions.

[0011] Each prior art container handling vehicle 201, 301 includes a storage compartment or space for receiving and storing the storage container 106 while the storage container 106 is transported on the rail system 108. The storage space may include a cavity arranged in the center of the vehicle body 201a as shown in Figure 2 and as described, for example, in WO2015 / 193278A1, the contents of which are incorporated herein by reference.

[0012] Figure 3 shows an alternative configuration of a container handling vehicle 301 having a cantilever structure. Such a vehicle is described in detail in, for example, No. 317366, the contents of which are also incorporated herein by reference.

[0013] As described in WO 2015 / 193278 A1, the central cavity container handling vehicle 201 shown in Figure 2 may have an area covering dimensions in the X and Y directions substantially equal to the lateral area of ​​the storage column 105, the contents of which are incorporated herein by reference. The term "lateral" as used herein may mean "horizontally".

[0014] Alternatively, the central cavity container handling vehicle 101 may have an area that is larger than the lateral area defined by the storage columns 105, for example as disclosed in WO 2014 / 090684 A1.

[0015] The track system 108 typically includes a track with grooves in which the wheels of the vehicle travel. Alternatively, the track may include upwardly protruding elements, wherein the wheels of the vehicle include flanges to prevent derailment. These grooves and upwardly protruding elements are collectively referred to as tracks. Each track may include one rail, or each track may include two parallel rails.

[0016] WO2018146304, the contents of which are incorporated herein by reference, shows a typical configuration of a track system 108 comprising tracks and parallel rails in the X and Y directions.

[0017] In the frame structure 100, most of the columns 105 are storage columns 105, i.e., columns 105 in which storage containers 106 are stored in stacks 107. However, some columns 105 may have other purposes. In FIG. 1 , columns 119 and 120 are dedicated columns used by container handling vehicles 201, 301 to unload and / or pick up storage containers 106 so that they can be transported to access stations (not shown) where storage containers 106 can be accessed from the outside of the frame structure 100, or transported out of the frame structure 100 or into the frame structure 100. In the prior art, such a position is usually referred to as a "port", and the column where the port is located can be referred to as a "port column" 119, 120. The transportation to the access station can be in any direction, i.e., horizontal, inclined and / or vertical. For example, storage containers 106 may be placed in a random or dedicated row 105 within the frame structure 100 and then picked up by any container handling vehicle and transported to a port row 119, 120 for further transport to a storage and retrieval station. Note that the term "inclined" means that the transport of storage containers 106 has a general transport direction somewhere between horizontal and vertical.

[0018] In Figure 1, the first port column 119 can, for example, be a dedicated unloading port column, where container handling vehicles 201, 301 can unload storage containers 106 to be transported to an access station or a transfer station, and the second port column 120 can be a dedicated picking port column, where container handling vehicles 201, 301 can pick up storage containers 106 that have been transported from the access station or the transfer station.

[0019] The access station can generally be a picking station or a storage station for removing items from or placing items into the storage container 106. In the picking station or the storage station, the storage container 106 is generally not removed from the automated storage and retrieval system 1, but is returned again to the frame structure 100 after access. The port can also be used to transfer the storage container to another storage facility (e.g., to another frame structure or another automated storage and retrieval system), a transport vehicle (e.g., a train or a truck), or a production facility.

[0020] A conveyor system including a conveyor belt is typically used to transport storage containers between the port rows 119, 120 and the access station.

[0021] If the port rows 119, 120 and the access station are located at different levels, the conveying system may include a lifting device with a vertical component for transporting the storage containers 106 vertically between the port rows 119, 120 and the access station.

[0022] The conveying system may be arranged to convey the storage containers 106 between different frame structures, for example as described in WO 2014 / 075937 A1, 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 is instructed to retrieve the target storage container 106 from its location and transport the target storage container to the unloading port column 119. This operation includes moving the container handling vehicle 201, 301 to a position 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 201, 301, and transporting the storage container 106 to the unloading port column 119. If the target storage container 106 is located deep in the stack 107, i.e., one or more other storage containers 106 are located above the target storage container 106, the operation also involves temporarily moving the storage containers located above before lifting the target storage container 106 from the storage column 105. This step is sometimes referred to in the art as "digging" and can be performed by the same container handling vehicle that is subsequently used to transport the target storage container to the unloading port column 119, or by one or more other cooperating container handling vehicles. Alternatively, or in addition, the automated storage and retrieval system 1 may have a container handling vehicle dedicated to the task of removing storage containers from the storage column 105. Once the target storage container 106 has been removed from the storage column 105, the temporarily removed storage container may be relocated to the original storage column 105. Alternatively, however, the removed storage container may be relocated to another storage column.

[0024] When a storage container 106 is to be stored in one of the columns 105, one of the container handling vehicles 201, 301 is instructed to pick up the storage container 106 from the pick port column 120 and transport it to a position above the storage column 105 to be stored. After removing any storage containers located at or above the target position within the storage column stack 107, the container handling vehicle 201, 301 positions the storage container 106 at the desired position. The removed storage container can then be placed back into the storage column 105 or relocated to another storage column.

[0025] In order to monitor and control the automatic storage and retrieval system 1, for example, to monitor and control the position of each storage container 106 within the frame structure 100, the contents of each storage container 106, and the movement of the container handling vehicles 201, 301, so that the required storage containers 106 can be transported to the required location at the required time without the container handling vehicles 201, 301 colliding with each other, the automatic storage and retrieval system 1 includes a control system 500, which is typically computerized and the control system typically includes a database for tracking the storage containers 106.

[0026] FIG. 4 illustrates an example of product items 80 stored in storage container 106 .

[0027] Nowadays, storage container 106 is usually designed to carry not only the product items stored in storage container 106 itself, but also the storage containers stacked above it. Therefore, the worst case for storage container 106 is to be the lowest storage container in the column.

[0028] Therefore, existing storage and retrieval systems 100 have limitations in the number of storage containers that can be stacked on top of each other and the weight of each storage container. The current limitations of the prior art storage system in FIG. 1 are that the maximum weight of each storage container (i.e., the weight of the storage container 106 and its product items 80) is 30 kg, and a maximum of 14 storage containers 106 can be stacked per column. These limitations also affect the maximum height of the grid, where the height of the grid generally corresponds to the height of 14 storage containers. Until recently, these limitations have been sufficient for most storage systems.

[0029] Nowadays, overloading of the storage containers 106 is avoided by calculating the maximum number of product items per storage container 106, because in most cases the weight of each product item is provided by the manufacturer. In some storage systems, when there is a question about the 30 kg load limit, the weight of the storage container 106 can be measured. One type of storage container currently used in storage systems weighs about 4 kg to 5 kg. Therefore, each storage container can carry a maximum of 25 kg to 26 kg of product items.

[0030] In NO 20180124, a method for allocating storage containers in an automated storage and retrieval system is described. Here, the total weight of some storage containers can exceed the 30kg limit as long as the other storage containers in the same stack have a lower weight. Therefore, the total load on the lowest storage container is still within the maximum load threshold of the storage container. The method first measures the weight of another storage container to be stored in the grid. Then, the target column for storage is determined based on the weight of the other storage container and the other storage containers to prevent overloading of the storage container at the lowest level.

[0031] Similar to the above-mentioned prior art, the object of the present invention is also to provide an automatic storage and retrieval system and method for storing storage containers, which can handle storage containers with a weight higher than a previously determined maximum weight. Therefore, in the above example, the goal is to be able to store storage containers with a total weight of more than 30 kg. Therefore, the object is to provide an alternative solution to the above-mentioned prior art.

[0032] Another object is to provide a method and system in which the weight of each storage container including its product items (i.e., the weight of the storage container itself and the weight of the product items stored in the storage container) can be increased without reducing the height of the stack of storage containers in each column.

[0033] In some buildings where automated storage and retrieval systems are installed, the interior height allows for grids with more than 14 storage containers on each grid. It is therefore another object of the present invention to be able to better utilize the available space for storage.

[0034] Another object of the present invention is to achieve the above objects of the present invention without significantly increasing the cost of each storage container and thus enabling the use of storage containers of this type.Another object is that the method and system can be implemented in already existing storage systems without much modification. Summary of the invention

[0035] The invention is set forth and characterized in the independent claim, while the dependent claims describe further characteristics of the invention.

[0036] The present invention relates to a method for storing containers in an automated storage and retrieval system, the system comprising a frame structure comprising upright members, horizontal members and storage columns arranged between the members; wherein the storage containers can be stacked in stacks of the storage columns;

[0037] The method is performed by a control system and comprises the following steps:

[0038] - defining a first storage area, wherein the first storage area includes a specific storage column within the frame structure;

[0039] - setting a first maximum weight threshold for the first storage area;

[0040] - determining the total weight of all storage containers stored in the first storage area;

[0041] - determining the weight of another storage container to be stored within the frame structure;

[0042] - if the sum of the total weight and the weight of the further storage container is below a first maximum weight threshold, determining that the storage location of the further storage container is within the first storage area, or

[0043] If the sum of the total weight and the weight of the further storage container is above a first maximum weight threshold, it is determined that the storage location of the further storage container is outside the first storage area.

[0044] In one aspect, the step of determining the weight of the other storage container comprises the steps of:

[0045] - The weight is calculated or measured at the port where the product item is added to or retrieved from another storage container.

[0046] In one aspect, the step of determining the weight of the other storage container comprises the steps of:

[0047] - Weighing the other storage container with the aid of a weight sensor.

[0048] The weight sensor may be provided as part of a port. The weight sensor may be provided as part of a container handling vehicle. The weight sensor may be positioned as part of a conveyor belt, roller, or other transport device provided for transporting containers and / or product items to and / or from an automated storage and retrieval system, i.e., in a system where such transport devices are used in addition to or as an alternative to a port. The transport device may transport the container to a specific storage location within the frame structure, from which the container handling vehicle may pick up the storage container.

[0049] In one aspect, the method comprises the steps of:

[0050] - Transporting another storage container to the storage location by means of a container transporter.

[0051] The weight sensor may be located in the port. The weight sensor may be located on the container handling vehicle.

[0052] Alternatively, the weight may be calculated by the step of estimating the weight of each product item and the number of product items added to or retrieved from the storage container. The step of estimating the weight may include using a predetermined weight for each product item. In another alternative, each or all product items may be weighed by weight before being added to or after being retrieved from the storage container, as the weight of the storage container is assumed to be known.

[0053] In one aspect, the method further comprises:

[0054] -determining the maximum load that can be stacked above the storage container; wherein the step of determining the storage location further comprises:

[0055] If the sum of the weight of another storage container and the weight of other storage containers above a storage container in a stack within the same column does not exceed the maximum load of a storage container in the stack, the storage position of another storage container is determined to be within a specific column inside or outside the first storage area.

[0056] In many automated storage and retrieval systems, only one type of storage container is used. In such systems, the maximum load is often determined to be the same for all storage containers. In such systems, the lowest storage container will always be the storage container with a load closest to its maximum load.

[0057] However, some systems may use two or more types of storage containers, where the maximum load is different for the different types of storage containers. An example may be having two types of storage containers, a first type having a first maximum load, and a second type having a second maximum load, where the first maximum load is significantly higher than the second maximum load. Here, the first type of storage container may be the lowest storage container, and the second type of storage container is located above the lowest storage container. Here, the second type of storage container may be closer to its maximum load than the lowest container of the first type.

[0058] In one aspect, the method further comprises:

[0059] -determine a column with available storage space; wherein the step of determining the storage location further comprises:

[0060] - Determine that the storage location is within one of the columns that has available storage space.

[0061] In one aspect, the step of determining a column with available storage space comprises:

[0062] - Determine the height of each storage container;

[0063] -Determine the available height of each column;

[0064] The step of determining the storage location further includes:

[0065] - If the height of the other storage container is lower than the available height in the specific column (105), determining the storage position of the other storage container in the specific column inside or outside the first storage area.

[0066] The available height is typically calculated as the total height of the stored column minus the height of all containers currently stored in that column's stack.

[0067] This is of particular interest in automated storage and retrieval systems having two or more types of storage containers, wherein the types of storage containers have different heights.

[0068] In one aspect, the method further comprises:

[0069] determining a horizontal distance from another storage container to a corresponding column having available storage space;

[0070] The step of determining the storage location includes:

[0071] - Determine that the storage location is within a column that has the shortest horizontal distance among the columns.

[0072] The horizontal distance is determined based on the location where the container handling vehicle is picking up another storage container.

[0073] In one aspect, the step of defining a first storage area comprises:

[0074] - defining the first storage area as a specific storage column in which the lowest storage position is arranged at a height higher than the lowest part of the frame structure.

[0075] In one aspect, the step of defining a first storage area comprises:

[0076] -Define the first storage area to a specific storage column suspended above the lowest part of the frame structure.

[0077] In one aspect, the step of defining a first storage area comprises:

[0078] -Defining the first storage area to a specific storage column under which the building floor has a weight constraint.

[0079] In one aspect, the method further comprises:

[0080] defining a second storage area, wherein the second storage area includes a specific storage column of the frame structure or a specific storage column of another frame structure;

[0081] - setting a second maximum weight threshold for the second storage area;

[0082] - determining the total weight of all storage containers stored in the second storage area;

[0083] Wherein, the step of determining the storage location of another storage container further comprises:

[0084] - if the sum of the total weight and the weight of the further storage container is below a second maximum weight threshold, determining that the storage location of the further storage container is within the second storage area;

[0085] If the sum of the total weight and the weight of the further storage container is above a second maximum weight threshold, it is determined that the storage location of the further storage container is outside the second storage area.

[0086] The present invention also relates to an automatic storage and retrieval system comprising:

[0087] - a frame structure comprising: upright members, horizontal members and storage columns arranged between said members; wherein storage containers can be stacked in stacks within the storage columns; wherein the frame structure comprises: a rail system arranged on top of the upright members and the horizontal members;

[0088] - a port at which product items are added to or retrieved from a storage container;

[0089] - a container handling vehicle configured to move horizontally along a track system;

[0090] - a weight estimation or measurement device for estimating or measuring the weight of each storage container after one or more product items have been inserted into or retrieved from the storage container;

[0091] - a storage control system arranged to communicate with the container handling vehicle and the weight estimation or measurement device, wherein the storage control system is configured to:

[0092] - defining a first storage area, wherein the first storage area includes a specific storage column of the frame structure;

[0093] - setting a first maximum weight threshold for the first storage area;

[0094] - determining the total weight of all storage containers stored in the first storage area;

[0095] - determining the weight of another storage container to be stored within the frame structure;

[0096] - if the sum of the total weight and the weight of the further storage container is below a first maximum weight threshold, determining that the storage location of the further storage container is within the first storage area, or

[0097] If the sum of the total weight and the weight of the further storage container is above a first maximum weight threshold, it is determined that the storage location of the further storage container is outside the first storage area. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] To facilitate understanding of the present invention, the following drawings are attached. The drawings illustrate embodiments of the present invention, which will now be described by way of example only, wherein:

[0099] FIG. 1 is a perspective view of a frame structure of a prior art automated storage and retrieval system.

[0100] 2 is a perspective view of a prior art container handling vehicle having a centrally disposed cavity for carrying storage containers therein.

[0101] 3 is a perspective view of a prior art container handling vehicle having a cantilever for carrying storage containers underneath.

[0102] 4 is a perspective view of a storage container and product items stored in the storage container.

[0103] Figure 5 A portion of an automated storage and retrieval system is illustrated in which some of the lowermost storage containers are supported by a frame rather than on the floor.

[0104] Figure 6 An automated storage and retrieval system is illustrated in which all storage containers are suspended above the building floor by a frame structure. DETAILED DESCRIPTION

[0105] In the following, embodiments of the present invention will be discussed in more detail with reference to the accompanying drawings. It should be understood, however, that the drawings are not intended to limit the invention to the subject matter depicted in the drawings.

[0106] The frame structure 100 of the automatic storage and retrieval system 1 is constructed according to the prior art frame structure 100 described above in conjunction with Figures 1 to 3, that is, a plurality of upright members 102 and a plurality of horizontal members 103 supported by the upright members 102, and the frame structure 100 includes a first top rail system 108 in the X direction and the Y direction.

[0107] The frame structure 100 further comprises storage compartments in the form of storage columns 105 arranged between the members 102 , 103 , wherein storage containers 106 are stackable in stacks 107 within the storage columns 105 .

[0108] The frame structure 100 can be of any size. In particular, it should be understood that the frame structure can be wider and / or longer and / or deeper than that disclosed in Figure 1. For example, the frame structure 100 can have a horizontal range of more than 700x700 columns and a storage depth of more than 12 containers.

[0109] Now refer to Figures 5 and 6 One embodiment of an automated storage and retrieval system according to the present invention is discussed in more detail.

[0110] First, refer to Figure 5 , wherein the system 1 comprises a frame structure 100 including vertical members 102, horizontal members 103 and an upper rail system 108 arranged above the members 102, 103. Here too, the frame 100 comprises a storage column 105, wherein storage containers 106 can be stacked in stacks 107. A container handling vehicle 40 similar to the container handling vehicle 301 of the prior art operates on the upper rail system 108. As in the prior art system, the containers stacked in the storage column 105 are accessed by means of the container handling vehicle 40 operating on the upper rail system 108.

[0111] However, in contrast to Figure 1, Figure 5 The heights of the different storage rows 105 in the embodiment are different due to a second lower rail system 108 arranged below a portion of the frame structure 100 . Figure 5 The second type of container handling vehicle (reference number 42) transports storage containers horizontally on the lower rail system 108.

[0112] Different storage areas in Figure 5 denoted by the letters SA, where each storage area includes a plurality of predefined columns indicated by their respective X and Y positions. As shown, the first storage area SA1 has two columns in the X direction and twelve columns in the Y direction. Each column within the first storage area SA1 can have three storage containers stacked on top of each other, indicated as storage positions Pz1 (top layer), Pz2 and Pz3 (bottom layer). It should be noted that in Figure 5 Only the Z direction is represented in the memory locations in . In most cases, each memory location has a unique memory location reference given by its X, Y, and Z positions respectively. Typically, most memory locations will be occupied. Figure 5 In FIG, some available storage locations are represented by dashed rectangles denoted as P?.

[0113] The second storage area SA2 can only have two stacked storage containers in each column. The same is true for the third storage area SA3.

[0114] The fourth storage area SA4 may have six storage containers stacked together.

[0115] It should be noted that some storage areas may be defined such that the columns are not adjacent to each other. It should also be noted that the storage columns within the same storage area may have different heights, i.e., a storage area may have some columns where three storage containers can be stacked together, and other columns where more or less than three storage containers can be stacked together.

[0116] exist Figure 5 In FIG. 1 , it is also noted that the system 1 includes ports 60a, 60b, in which product items 80 ( FIG. 4 ) are added to or removed from the storage container. The storage container is lifted directly from the port 60a to the top rail system by means of the lifting device (shown as 304 in FIG. 3 ) of the container handling vehicle 40, 201, 301. From the port 60b, the storage container is moved horizontally along the lower rail system 108 to a position below the container handling vehicle 40 on the upper rail system 108 by means of the container handling vehicle 42. Then, the storage container is lifted from the container handling vehicle 42 to the container handling vehicle 40 by means of the lifting device of the upper container handling vehicle 40.

[0117] As product items are added to or removed from the storage container at ports 60a, 60b, the total weight of the storage container (i.e., the weight including the product items within the storage container) changes. The storage container that most recently visited port 60b is shown being transported by a container handling vehicle 42 operating on the lower track system 108. Figure 5In the illustrated system 1 , the weight Wf of the storage container is estimated or measured and used when determining a new storage position P in one of the storage areas of the frame structure 100 .

[0118] The weight Wf of the storage container can be measured by a weight sensor 65 disposed in the port 60b. In addition, the port 60a may also include such a weight sensor. Alternatively, the weight sensor may be provided as a part of the container handling vehicle 40, 42. In another alternative, the weight Wf may be calculated by estimating the weight of each product item and the number of product items added to or retrieved from the storage container. The step of estimating the weight may include using a predetermined weight for each product item. In another alternative, each or all product items may be weighed by weight before being added to the storage container or after being retrieved from the storage container, because the weight of the empty storage container is considered to be known.

[0119] exist Figure 5 In the system 1 shown, there are some restrictions on the weight of the stacks in the columns of some storage areas. Therefore, it is impossible to store storage containers of full height carrying their maximum weight in all columns of some storage areas. Some examples will be discussed below. In these examples, storage containers with a maximum weight of 30 kg including the product items discussed in the above introduction were used. It should be noted that the invention of the present application is not limited to this particular type of storage container. The present invention can be used in systems with other types of storage containers, which have different net weights, different load capacities and different strengths relative to the number of containers that can be stacked on top of each other.

[0120] Example 1:

[0121] The frame structure 100 has a limitation on the total weight of the first storage area SA1. As shown, the first storage area 1 is suspended within the frame structure 100, and the weight of the storage containers in the first storage area is carried by the members 102,103.

[0122] Here, the term "hanging" is used to describe that the lowest storage position Pzn of the column is set at a height H1 higher than the lowest part 102l of the frame structure 100. The symbol "zn" refers to the depth or z level within each column, where n is a number. For example, n=2 in the second storage area SA2, n=3 in the first storage area SA1, and n=6 in the fifth storage area SA5.

[0123] This limitation may exist throughout the life of the system 1. Alternatively, this type of limitation exists only for relatively short periods of time, for example, due to maintenance, repair, etc. of the frame structure 100, during which time the frame structure may carry less weight than normal.

[0124] For the reasons described above, a first maximum weight threshold Wmax1 is set for the first storage area SA1. Typically, the maximum weight threshold Wmax1 is lower than the maximum weight of a fully loaded storage container multiplied by the number of possible storage locations in the storage area. As described above, in one type of prior art storage system, the maximum weight of each storage container (i.e., the weight of the storage container 106 and its product items 80) is 30 kg. The storage area SA1 has two columns in the X direction, twelve columns in the Y direction, and n=3 in the Z direction. Therefore, it can be determined that the first maximum weight threshold Wmax1 for the first storage area SA1 is set to a specific weight lower than 30 kg * 2 * 12 * 3 = 2160 kg. For example, the first maximum weight threshold Wmax1 can be temporarily set to 1000 kg.

[0125] Example 2:

[0126] Here, the frame structure 100 has a limit relative to the total weight of the second storage area SA2. As shown, the second storage area 2 is also suspended in the frame structure 100, and the weight of the storage containers in the second storage area is borne by the members 102,103.

[0127] Here, the lowest storage position Pz0 of the column is arranged at a height H2 which is also higher than the lowest part 102 l of the frame structure 100 .

[0128] A second maximum weight threshold Wmax2 is set for the second storage area SA2. The storage area SA2 has 1 column in the X direction, 12 columns in the Y direction, and a maximum height of 2 containers. Therefore, the first maximum weight threshold Wmax1 of the first storage area SA1 can be set to be lower than 30 kg*1*12*2=720 kg. For example, the second maximum weight threshold Wmax2 can be temporarily set to 300 kg.

[0129] The second maximum weight threshold Wmax2 may also be temporarily set to 0 kg, ie, no storage space is provided for the storage container in the second storage area SA2.

[0130] Example 3:

[0131] Here, the frame structure 100 has a limitation on the total weight of the fourth storage area SA4. This is due to the weakness of the building floor BF supported by the beams B. As mentioned above, this weakness may be permanent or temporary. Another example of this situation is that the area around the building is flooded and the gravel or other materials under the building floor are partially washed away.

[0132] It should be noted that in this example, the lowest storage position Pzn of the row within the fourth storage area SA4 is set at the same height as the lowest part 102L of the frame structure. Therefore, in this example, the fourth storage area SA4 is not considered to be suspended within the frame structure 100. In addition, the weight of the storage containers within the fourth storage area SA4 is carried by the building floor BF, rather than by the members 102, 103 of the frame structure 100.

[0133] run

[0134] A method according to an exemplary embodiment of the present invention will now be described with reference to the first example above. The method is performed by a control system 50 in communication with the port 60a and / or the port 60a, the container handling vehicle 40, the delivery vehicle 42, etc. In general, the control system will correspond to the control system 500 of the prior art, but with additional functionality as described below.

[0135] Initially, as described above, the first maximum weight threshold Wmax1 of the first storage area SA1 has been determined. Figure 5 All other storage areas indicated in do not have such a weight threshold. Alternatively, a maximum weight threshold may also be set for other storage areas.

[0136] Additionally, the weight Wf of another storage container 6f that is closest to port 60b has been determined.

[0137] Since the weight Wf of all storage containers has been measured or calculated, the control system 50 has stored the storage position (X, Y and Z position) and weight of each storage container in the system 1. Of course, the control system 50 also stores a lot of other information.

[0138] Based on the information in the control system 50 , the total weight Wtot1 of all storage containers 6 currently stored in the first storage area SA1 is determined.

[0139] If the sum of the total weight Wtot1 and the weight Wf of the further storage container 6f is below the first maximum weight threshold WMAX1, the storage position P of the further storage container 6f is now determined to be within the first storage area SA1. However, if this condition is not met, i.e. the sum of the total weight Wtot1 and the weight Wf of the further storage container 6f is above the first maximum weight threshold Wmax1, the storage position P for the further storage container 6f is determined to be outside the first storage area SA1. In this way, overloading of the first storage area SA1 is avoided.

[0140] The above-mentioned weight consideration may be one step among many steps in determining the storage position P of the further storage container 6f.

[0141] In one aspect, a maximum load Wloadmax is determined for each storage container or each type of storage container used in the system 1 , wherein the maximum load Wloadmax defines the maximum weight that can be stacked above the storage container before it collapses due to the weight of the stack.

[0142] Here, a further step for determining the storage position P of the further storage container 6f may include checking whether the sum of the weight Wf of the further storage container 6f and the weights of the other storage containers 106 above one of the storage containers 106 in the stack in the same column 105 exceeds the maximum load Wloadmax of one of the storage containers 106 in the stack 107. If not, the storage position P will be determined to be in the column that meets this condition or in one of the columns that meets this condition. If no such storage position P is found in the first area SA1, a storage position P outside the first storage area SA1 must be considered.

[0143] In many automated storage and retrieval systems 1, only one type of storage container is used. In such a system, the maximum load Wloadmax is usually determined to be the same for all storage containers. In such a system, the lowest storage container is always a storage container 106 having a load that is closest to its maximum load Wloadmax.

[0144] However, some systems may use two or more types of storage containers, where the maximum loads Wloadmax1, Wloadmax2, ... WloadmaxN are different for different types of storage containers 106. An example may be that there are two types of storage containers, the first type having a first maximum load Wloadmax1 and the second type having a second maximum load Wloadmax2, where the first maximum load Wloadmax1 is significantly higher than the second maximum load Wloadmax2. Here, the first type of storage container may be the lowest storage container, and the second type of storage container is located above the lowest storage container. Here, the second type of storage container may be closer to its maximum load Wloadmax2 than the lowest container of the first type.

[0145] Before or after checking the maximum load Wloadmax of the containers in each column, it is determined that the storage position P must be within a column 105 with available storage space. In particular, this is very important in systems with more than one type of storage container, in which the different types of containers have different heights.

[0146] First, the height Hf of each storage container 6f, 106 is determined. Then the available height Hav of each column 105 is determined. The available height Hav is usually calculated as the total height of the storage column 105 minus the heights of all containers 106 currently stored in the stack 107 in that column 105.

[0147] Now, the step of determining a storage position P further comprises determining a storage position P of a further storage container 6f within a particular column 105, if the height Hf of the further storage container 6f is lower than the available height Hav in the particular column 105. If no such storage position P is found within the first area SA1, a storage position P outside the first storage area SA1 has to be considered.

[0148] As mentioned above, there may be two (or even more) storage areas with weight constraints in System 1. Now assume Figure 5 The second storage area SA2 also has a weight constraint, ie the second maximum weight threshold Wmax2 is set lower than the maximum weight of one container multiplied by the number of possible storage locations in the second storage area SA2.

[0149] After the second storage area SA2 and its second maximum weight threshold Wmax2 are determined as described above, if it is determined that the storage location P cannot be within the first storage area SA1, the following steps are performed: Then, it is checked whether the storage location can be within the second storage area SA2.

[0150] In a similar manner to the above-described first storage area SA1 , the total weight Wtot2 of all storage containers 106 stored in the second storage area SA2 is determined.

[0151] Then, if the sum of the total weight Wtot2 and the weight Wf of the other storage container 6f is lower than the second maximum weight threshold WMAX2, the storage position P of the other storage container 6f is determined to be within the second storage area SA2. Otherwise, that is, if the sum of the total weight Wtot2 and the weight Wf of the other storage container 6f is higher than the second maximum weight threshold Wmax2, the storage position P for the other storage container 6f is determined to be outside the second storage area SA2.

[0152] However, a further step for determining the storage position P of the further storage container 6f may comprise taking the horizontal transport distance into account.

[0153] Here, if Figure 5 As shown, the horizontal distance Dxy from another storage container 6f to each column 105 having available storage space is determined. The horizontal distance Dxy is determined from the column where the container handling vehicle 40 is picking up another storage container 6f. The storage position P is then determined to be within the one column 105 having the shortest horizontal distance Dxy.

[0154] According to the above, prevention of overloading of the storage area is achieved. In addition, several other factors are taken into account, such as the maximum load that can be stacked above the storage containers in the storage column, the available height of each column and the horizontal transport distance.

[0155] As a result, even if some parts of the frame structure are temporarily or permanently weaker than other parts of the frame structure, or even if some areas of the building floor are temporarily or permanently weaker than other parts of the building floor, the system 1 can continue its operation without a significant reduction in efficiency.

[0156] In the foregoing description, various aspects of the method and automatic storage and retrieval system have been described with reference to illustrative embodiments. For the purpose of explanation, specific numbers, systems and configurations are listed to provide a thorough understanding of the system and its working principle. However, this description is not intended to be interpreted in a limiting sense. Various modifications and variations of the illustrative embodiments and other embodiments of the system that are obvious to those skilled in the art to which the disclosed subject matter belongs are considered to fall within the scope of the present invention.

[0157] Reference Numbers List

[0158] (1) Automated storage and retrieval system

[0159] (6) Storage container

[0160] (6F) Another storage container

[0161] (40)Container transporter

[0162] (42) Delivery vehicles

[0163] (50) Control system

[0164] (60a)Port

[0165] (60b)Port

[0166] (65)Weight sensor

[0167] (80)Product Projects

[0168] (100)Frame structure

[0169] (102) Upright members

[0170] (102l) The lowest part of the vertical member

[0171] (103) Horizontal member of the frame structure

[0172] (104) Storage Grid

[0173] (105) Storage Column

[0174] (106) Storage Container

[0175] (106') Specific location of storage container

[0176] (107) Stack

[0177] (108) Track system

[0178] (110) parallel tracks in the first direction (x)

[0179] (110a) The first track in the first direction (x)

[0180] (110B) A second track in the first direction (x)

[0181] (111) parallel tracks in the second direction (y)

[0182] (111a) The first track in the second direction (y)

[0183] (111b) The second track in the second direction (y)

[0184] (112) Access opening

[0185] (119) First port column

[0186] (120) Second port column

[0187] (201) Prior Art Storage Container Vehicle

[0188] (201a) Vehicle body of storage container vehicle 101

[0189] (201b) Drive unit / wheel arrangement, first direction (x)

[0190] (201c) Drive device / wheel arrangement, second direction (y)

[0191] (301) Prior Art Cantilever Storage Container Vehicle

[0192] (301a) Vehicle body of storage container vehicle 101

[0193] (301b) Driving device in the first direction (x)

[0194] (301c) driving device in the second direction (y)

[0195] (304) Grip device

[0196] (500) Prior Art Control Systems

[0197] (bf) Building floor

[0198] (sa1) First storage area

[0199] (sa2) Second storage area

[0200] (sa3) Third storage area

[0201] (sa4) Fourth storage area

[0202] (sa5) Fifth storage area

[0203] (h1)Height

[0204] (h2)Height.

Claims

1. A method for storing containers (6f, 106) in an automated storage and retrieval system (1), the system (1) comprising a frame structure (100) comprising upright members (102), horizontal members (103) and storage columns (105) disposed between the members (102, 103); wherein: The storage containers (106) can be stacked in a stack (107) within the storage column (105); The method is executed by a control system (50), and comprises the following steps: - defining a first storage area (SA1), wherein the first storage area (SA1) comprises a specific storage column (105) within the frame structure (100); - setting a first maximum weight threshold (Wmax1) for said first storage area (SA1); - determining the total weight (Wtot1) of all storage containers (106) stored in said first storage area (SA1); - determining the weight (Wf) of another storage container (6f) to be stored in the frame structure (100); - if the sum of the total weight (Wtot1) and the weight (Wf) of the further storage container (6f) is below the first maximum weight threshold (Wmax1), determining that the storage position (P) of the further storage container (6f) is within the first storage area (SA1), or - if the sum of the total weight (Wtot1) and the weight (Wf) of the further storage container (6f) is higher than the first maximum weight threshold (Wmax1), it is determined that the storage position (P) of the further storage container (6f) is outside the first storage area (SA1).

2. The method according to claim 1, wherein: Under that particular storage column, the building floor (BF) has a tighter weight constraint either temporarily or permanently.

3. The method according to claim 1 or 2, wherein: The step of determining said weight (Wf) of said further storage container (6f) comprises the following steps: - calculating or measuring said weight (Wf) at the port (60) where the product item (80) is added to or retrieved from said further storage container (6f).

4. The method according to claim 1 or 2, wherein: The step of determining said weight (Wf) of said further storage container (6f) comprises the following steps: The further storage container (6f) is weighed by means of a weight sensor (70).

5. The method according to claim 1 or 2, wherein: The method further comprises the following steps: - transporting the further storage container (6f) to the storage location (P) by means of a container handling vehicle (40; 40, 42).

6. The method according to claim 1 or 2, wherein: The method further comprises: - determining the maximum load (Wloadmax) that can be stacked above the storage container (106); Wherein, the step of determining the storage position (P) further comprises: - If the sum of the weight (Wf) of the other storage container (6f) and the weight of the other storage containers (106) above a storage container (106) in the stack within the same column (105) does not exceed the maximum load (Wloadmax) of a storage container (106) in the stack (107), it is determined that the storage position (P) of the other storage container (6f) is within a specific column (105) inside or outside the first storage area (SA1).

7. The method according to claim 1 or 2, wherein: The method further comprises: - determining the columns with available storage space (105); Wherein, the step of determining the storage position (P) further comprises: - determining that said storage location (P) is within one of said columns (105) having available storage space.

8. The method according to claim 7, wherein: The step of determining a column with available storage space (105) comprises: - Determine the height (H) of each storage container (6f, 106); - Determine the available height (Hav) of each column (105); Wherein, the step of determining the storage position (P) further comprises: -If the height (Hf) of the other storage container (6f) is lower than the available height (Hav) in the specific column (105), it is determined that the storage position (P) of the other storage container (6f) is within the specific column (105) inside or outside the first storage area (SA1).

9. The method according to claim 7, wherein: The method further comprises: - determining the horizontal distance (Dxy) from the further storage container (6f) to each column (105) having available storage space; The step of determining the storage position (P) comprises: - determining that said storage position (P) is within a column having the shortest horizontal distance (Dxy) among said columns.

10. The method according to claim 1 or 2, wherein: The step of defining the first storage area (SA1) comprises: - defining the first storage area (SA1) as a specific storage column (105) in which the lowest storage position (Pz0) is arranged at a height (H1) higher than the lowest part (102L) of the frame structure (100).

11. The method according to claim 10, wherein: The step of defining the first storage area (SA1) comprises: - defining the first storage area (SA1) as a specific storage column (5) suspended above the lowest part (102L) of the frame structure (100).

12. The method according to claim 1 or 2, wherein: The method further comprises: - defining a second storage area (SA2), wherein the second storage area (SA2) comprises a specific storage column (105) of the frame structure (100) or a specific storage column (105) of another frame structure (100); - setting a second maximum weight threshold (Wmax2) for said second storage area (SA2); determining the total weight (Wtot2) of all storage containers (6) stored in the second storage area (SA2); Wherein, the step of determining the storage position (P) of the other storage container (6f) further comprises: - if the sum of the total weight (Wtot2) and the weight (Wf) of the further storage container (6f) is below the second maximum weight threshold (Wmax2), determining that the storage position (P) of the further storage container (6f) is within the second storage area (SA2); - If the sum of the total weight (Wtot2) and the weight (Wf) of the further storage container (6f) is higher than the second maximum weight threshold (Wmax2), it is determined that the storage position (P) of the further storage container (6f) is outside the second storage area (SA2).

13. A storage control system (50) configured to perform the method of any one of claims 1 to 12.

14. An automatic storage and retrieval system (1), comprising: - a frame structure (100) comprising: upright members (102), horizontal members (103) and storage columns (105) arranged between said members (102, 103); wherein storage containers (106) can be stacked in stacks (107) within said storage columns (105); - a weight estimation or measurement device (65) for estimating or measuring the weight of each storage container after one or more product items (80) have been inserted into or retrieved from said storage container; The storage control system (50) of claim 13.

15. A computer program which, when executed by a control system (50), causes the control system (50) to perform the method of any one of claims 1 to 12.

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