JP7779481B2 - Logistics warehouse control device and logistics warehouse control method - Google Patents

Description

The present invention relates to a logistics warehouse control device and a logistics warehouse control method.

Conventionally, a logistics warehouse for storing items is known, for example, as described in Patent Document 1. This logistics warehouse carries in items via a transport lane and stores them in an automated warehouse. This logistics warehouse also transports and removes items stored in the automated warehouse at predetermined times.

JP 2018-81008 A

Now, a large number of items are stored in an automated warehouse. Therefore, when an item is stored in or removed from the warehouse, the control device must calculate an efficient transport route. However, calculating such a transport route poses the problem of imposing a huge computational load. Furthermore, there is a need to calculate a transport route that is efficient while reducing the computational load.

Therefore, the present invention aims to provide a logistics warehouse control device and logistics warehouse control method that can calculate a transport route for transporting goods with high transport efficiency while reducing the calculation load when calculating the transport route.

A logistics warehouse control device according to one aspect of the present invention is a logistics warehouse control device equipped with an automated warehouse for storing items, an in-stock lane for storing multiple lined-up items, and a conveyor installed between the in-stock lane and the automated warehouse. The device includes: an item information acquisition unit that acquires item information indicating the initial and completed states of the items as they move through the in-stock lane, the conveyor, and the automated warehouse in that order; and a route calculation unit that calculates transport route information from the item information to satisfy a reference logical expression based on constraints. When multiple items are lined up consecutively in the initial state, the route calculation unit performs a first process of grouping all of the items in the line together and treating them as a single first integrated item, thereby calculating first candidate route information for the transport route information; and a second process of separating the first end item at one end of the line and treating a group including items in the line other than the first end item as a single item, thereby calculating second candidate route information for the transport route information. The device adopts the first candidate route information or the second candidate route information, whichever is more highly evaluated, as the transport route information.

In a logistics warehouse control device, an item information acquisition unit acquires item information indicating the initial and completed states of an item as it moves through the storage lane, conveyor, and automated warehouse in that order. Furthermore, a route calculation unit calculates transport route information from the item information to satisfy a reference logical expression based on constraint conditions. In this case, the route calculation unit can calculate the transport route that should be taken between the initial state of the item and the completed state. By performing calculations to satisfy the reference logical expression based on constraint conditions, the route calculation unit can easily eliminate constrained actions on the transport route by calculating the reference logical expression. As a result, the route calculation unit can calculate an appropriate transport route with a low computational load. Furthermore, the route calculation unit performs a first process to calculate first candidate route information for the transport route information by grouping all of the multiple items in a row together and treating them as a single first integrated item. As a result, the route calculation unit can calculate first candidate route information that will bring the items to the completed state in fewer phases by treating multiple consecutively arranged items as a single first integrated item. However, among multiple consecutively lined items, allowing an end item at the end of the row to operate differently from the other items in the row can sometimes create a route that requires fewer conveyor operations. Therefore, the route calculation unit performs a second process in which the first end item at one end of the row is separated, and a group including the items in the row other than the first end item is treated as a single item, thereby calculating second candidate route information for the conveyance route information. This allows the route calculation unit to calculate second candidate route information that treats the group other than the first end item as a single item while allowing the first end item to operate differently from the items in the group. The route calculation unit can then calculate more efficient conveyance route information by adopting the first candidate route information or the second candidate route information, whichever is more highly evaluated, as the conveyance route information. As described above, it is possible to calculate an efficient conveyance route while reducing the computational load when calculating a conveyance route for conveying items.

The queue may include three or more consecutive items, and in the second process, the route calculation unit may separate the second end item at the other end of the queue, and calculate second candidate route information by treating the group including the items in the queue other than the first end item and the second end item as a single item. This allows the route calculation unit to calculate second candidate route information without restricting the movement of the end items at both ends of the queue.

The sequence may include three or more consecutive items, and the group may be composed of a single second integrated item that combines all items in the sequence except for the first end item. In this case, the path calculation unit can calculate second candidate path information by removing the restriction on the movement of only the first end item at one end, and combining all other items together.

A queue may consist of two consecutive items, and a group may consist of one item other than the first end item. In this case, when a queue consists of two items, the route calculation unit can calculate first candidate route information that combines the two items, and second candidate route information that separates the two items.

One aspect of the present invention provides a control method for a logistics warehouse equipped with an automated warehouse for storing items, an in-stock lane for receiving a plurality of lined-up items, and a conveyor provided between the in-stock lane and the automated warehouse. The method includes: an item information acquisition step for acquiring item information indicating the initial and completed states of the items as they move through the in-stock lane, the conveyor, and the automated warehouse in that order; and a route calculation step for calculating transport route information from the item information so as to satisfy a reference logical expression based on constraints. When a plurality of items are lined up consecutively in the initial state, the route calculation step includes a first process for calculating first candidate route information for the transport route information by grouping all of the items in the line together and treating them as a single first integrated item; and a second process for separating the first end item at one end of the line and treating a group including the items in the line other than the first end item as a single item and calculating second candidate route information for the transport route information. The first candidate route information or the second candidate route information, whichever is more highly evaluated, is adopted as the transport route information.

This logistics warehouse control method can achieve the same effects and benefits as the control device described above.

This invention makes it possible to calculate a transport route that is efficient for transporting items while reducing the computational load when calculating the transport route for transporting items.

1 is a schematic side view showing a logistics warehouse equipped with a control device according to an embodiment of the present invention. 1 is a schematic diagram illustrating a configuration of a logistics warehouse according to an embodiment of the present invention. This is a diagram modeling a logistics warehouse. FIG. 2 is a block diagram of a control device according to the present embodiment. This is a diagram modeling a logistics warehouse. This is a diagram modeling a logistics warehouse. FIG. 10 is a diagram illustrating specific examples of logical expressions. FIG. 10 is a diagram illustrating specific examples of logical expressions. FIG. 10 is a diagram illustrating specific examples of logical expressions. 1A is a diagram showing the relationship between phases and movement directions, and FIG. 1B is a diagram showing a model of a logistics warehouse. 1A is a diagram illustrating the specific content of a logical expression, and FIGS. 1B and 1C are diagrams illustrating a model of a distribution warehouse. 1A is a diagram illustrating the specific content of a logical expression, and FIGS. 1B and 1C are diagrams illustrating a model of a distribution warehouse. This is a diagram modeling a logistics warehouse. 1A is a diagram illustrating the specific content of a logical expression, and FIGS. 1B and 1C are diagrams illustrating a model of a logistics warehouse. This is a diagram modeling a logistics warehouse. 1A is a diagram illustrating the specific content of a logical expression, and FIGS. 1B and 1C are diagrams illustrating a model of a distribution warehouse. 1A is a diagram illustrating the specific content of a logical expression, and FIGS. 1B and 1C are diagrams illustrating a model of a distribution warehouse. 1A is a diagram illustrating the specific content of a logical expression, and FIGS. 1B and 1C are diagrams illustrating a model of a distribution warehouse. This is a diagram modeling a logistics warehouse. This is a diagram modeling a logistics warehouse. This is a diagram modeling a logistics warehouse. FIG. 10 is a diagram illustrating specific examples of logical expressions. FIG. 10 is a diagram illustrating specific examples of logical expressions. FIG. 10 is a diagram illustrating specific examples of logical expressions. This is a diagram modeling a logistics warehouse. This is a diagram modeling a logistics warehouse. FIG. 10 is a diagram illustrating specific examples of logical expressions. This is a diagram modeling a logistics warehouse. FIG. 10 is a diagram illustrating specific examples of logical expressions. 10 is a flowchart showing the processing contents of the control device. 1A is a diagram showing pattern A1, which is a method of sorting articles in the first process, and FIG. 1B is a diagram showing pattern A2, which is a method of sorting articles in the second process. (a) is a diagram showing pattern B1, which is a way of sorting items in the first process, and (b), (c), and (d) are diagrams showing patterns B2, B3, and B4, which are ways of sorting items in the second process. This is a diagram modeling three consecutive items in the initial state of movement. FIG. 10 is a diagram showing a model of an example of first candidate route information. FIG. 10 is a diagram showing a model of an example of first candidate route information. FIG. 10 is a diagram illustrating a model of an example of second candidate route information. FIG. 10 is a diagram illustrating a model of an example of second candidate route information. 10 is a flowchart showing the processing content of a path calculation unit.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 is a schematic side view showing a logistics warehouse 1 equipped with a control device according to an embodiment of the present invention. As shown in Figure 1, the logistics warehouse 1 is a system that receives and stores multiple items 150 and is capable of retrieving stored items 150 that need to be retrieved. The logistics warehouse 1 comprises an automated warehouse 100, an outgoing elevator 104 (conveyor), an incoming elevator 105 (conveyor), an outgoing lane 121 (conveyor lane), and an incoming lane 21 (conveyor lane). The automated warehouse 100 is a warehouse that stores items 150. The automated warehouse 100 comprises a warehouse main body 101, an outgoing transfer aisle 102, and an incoming transfer aisle 103. The warehouse main body 101 has multiple shelves 110. The shelves 110 extend from one end of the warehouse main body 101 to the other end. On the shelves 110, a transfer device 111 transfers items from the inbound path to the outbound path. The inbound transfer aisle 103 is located at one end of the warehouse main body 101 and is a mechanism for loading items 150 onto each shelf 110. The outbound transfer aisle 102 is located at the other end of the warehouse main body 101 and is a mechanism for unloading items 150 from each shelf 110. The inbound elevator 105 raises and lowers items 150 loaded from the inbound lane 21 and supplies the items 150 to the inbound transfer aisle 103 corresponding to the desired shelf 110. The outbound elevator 104 receives items 150 to be unloaded from the shelves 110 and the outbound transfer aisle 102 and raises and lowers them to an unloading port (not shown). The items 150 unloaded from the outbound elevator 104 are transported to the outbound lane 121.

Figure 2 is a schematic diagram showing the configuration of a logistics warehouse 1 equipped with a control device 10 according to an embodiment of the present invention. In the following description, the receiving elevator 105 and the outgoing elevator 104 may be simply referred to as "conveyors 22." Figure 2 shows the configuration of the receiving side of the logistics warehouse 1. Note that the outgoing side of the logistics warehouse 1 has a similar configuration to the receiving side, except that the flow of goods 150 is via the automated warehouse 100, the conveyor 22 (outgoing elevator 104), and the outgoing lane 121, and therefore will not be described here. As shown in Figure 2, the logistics warehouse 1 includes a conveyor system 2 that conveys goods 150 and a control device 10 that controls the conveyor system 2. The conveyor system 2 includes a receiving lane 21, a conveyor 22, and a conveyor 23 of the automated warehouse 100. Of these, the conveyor 22 is a component of the aforementioned receiving elevator 105. The receiving lane 21 is a device that transports goods 150 horizontally and hands them over to the conveyor 22. The receiving lanes 21 are provided for specific stages of the conveyors 22. The conveyors 23 are devices that receive items from the conveyors 22 and transport them horizontally on each floor of the automated warehouse 100. The conveyors 23 are provided on each floor (here, the fourth floor) of the receiving walkway 103.

The conveying machine 22 is equipped with horizontal movement means (e.g., a conveyor) and vertical movement means, and is a device that moves items 150 vertically and horizontally. Each item 150 to be stored is associated with a destination floor. As a result, the conveying machine 22 moves each item 150 to the destination floor in the storage linkage 103. Note that in the figure, items 150 whose destination is the "nth floor" are designated with the number "n". This also applies to subsequent figures. In the following explanation, items 150 whose destination is the nth floor may be referred to as "items to the nth floor".

The conveyor 22 is a vertical conveyor that performs vertical conveyance by alternately raising and lowering multiple adjacent transport boxes 22a and moving items 150 horizontally (sideways). The conveyor 22 is an alternating-operation lifting device and has a transport shelf 22A on the storage lane 21 side and a transport shelf 22B on the conveyor 23 side. Each transport shelf 22A, 22B has a storage area CE equal to the number of floors of the automated warehouse plus one floor. Each transport shelf has a number of consecutive transport boxes 22a equal to the number of floors of the automated warehouse (four in this case). The consecutive transport boxes 22a move up and down simultaneously. As the consecutive transport boxes 22a move downward, each transport box 22a is placed in the first to fourth storage area CE, starting from the bottom. As the consecutive transport boxes 22a move upward, each transport box 22a is placed in the second to fifth storage area CE, starting from the bottom. In the following description, when simply referring to the number of levels, unless otherwise noted, this refers to the number of levels counted from the bottom. Furthermore, the transport boxes 22a on transport shelves 22A and 22B alternately move up and down. That is, when the transport box 22a on transport shelf 22A moves upward, the transport box 22a on transport shelf 22B moves downward. This allows the item 150 on transport shelf 22A to be raised by one level (see operation M1). Furthermore, when the transport box 22a on transport shelf 22A moves downward, the transport box 22a on transport shelf 22B moves upward. This allows the item 150 on transport shelf 22B to be raised by one level. Furthermore, within the same number of levels, the item 150 can be moved horizontally between the transport boxes 22a on transport shelves 22A and 22a on transport shelves 22B, allowing for the exchange of the item 150 (see operation M2). Additionally, the item 150 can be transferred from the transport box 22a on the transport shelf 22B to the conveyor 23 on the destination floor (see operation M3).

In this embodiment, an input lane 21 is provided for the second-lowest storage area CE, and four conveyors 23 are provided for the first through fourth-lowest storage areas CE. Note that the areas marked "S1" and "S2" within the storage area CE in Figure 2 are spaces provided for the lifting and lowering of the transport shelves 22A and 22B. However, the positional relationship between the storage area CE, input lane 21, and conveyor 23 is not particularly limited and may be set appropriately depending on the configuration of the logistics warehouse 1. Note that in this embodiment, because items 150 are transported consecutively to two or more levels of the automated warehouse 100 to which the input lane 21 is connected, the entrance floor and the destination floor are the same.

In the following explanation, the logistics warehouse 1 may be modeled as shown in Figure 3. The transport box 22a of the transport machine 22 is represented by a single rectangle. Each item 150 can move horizontally simultaneously unless there is an obstruction. As for vertical movement, while the transport shelf of the transport machine 22 is moving vertically, the items 150 inside the transport machine 22 cannot move. While the transport machine 22 is moving vertically, the storage lane 21 and conveyor 23 can move horizontally. In the following explanation, the transport shelf 22A may be referred to as the "right (R) transport shelf," and the transport shelf 22B may be referred to as the "left (L) transport shelf." The state in which the left transport shelf 22B is raised, as shown in Figure 3(a), may be referred to as the "left transport shelf raised state," and the state in which the right transport shelf 22A is raised, as shown in Figure 3(b), may be referred to as the "right transport shelf raised state." Additionally, each transport box 22a on transport shelves 22A and 22B is assigned an identification number, "0, 1, 2, 3," in order from bottom to top. In the figure, the identification numbers are shown as numbers in circles inside the transport box 22a.

Next, the block configuration of the control device 10 will be described with reference to Figure 4. Figure 4 is a block configuration diagram of the control device 10 according to this embodiment. The control device 10 is a unit that controls the conveying system 2. The control device 10 includes an ECU (Electronic Control Unit) that performs overall management of the logistics warehouse 1. The ECU is an electronic control unit that includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and communication circuits such as a CAN (Controller Area Network). The ECU, for example, loads programs stored in the ROM into the RAM and executes the programs loaded into the RAM with the CPU, thereby achieving various functions. The control device 10 includes an operation control unit 11, an item information acquisition unit 12, and a path calculation unit 13.

The operation control unit 11 is a unit that controls the transport operation of the logistics warehouse 1 so that each item 150 is transported based on the transport route calculated by the route calculation unit 13. The operation control unit 11 controls the transport operation by sending control signals to the transport system 2. The operation control unit 11 operates each drive unit by sending control signals to the storage lane 21, transport machine 22, and conveyor 23 of the transport system 2.

The item information acquisition unit 12 acquires item information indicating the initial movement state and the completed movement state of the item 150 when the item 150 moves in the order of the receiving lane 21, the conveyor 22, and the automated warehouse 100, or when the item moves in the order of the automated warehouse 100, the conveyor 22, and the outgoing lane 121. The initial movement state is a state in which the item 150 to be transported is present in the receiving lane 21, as shown in FIG. 5(a). The completed movement state is a state in which all of the items 150 to be transported have been transported to the automated warehouse 100, as shown in FIG. 5(b). The item information includes information such as the destination floor number of the item 150 present in the receiving lane 21 at the time of storage, the number of items 150 for each floor, and the storage order. The item information also includes information such as the number of items 150 to be removed from which floor of the automated warehouse 100, and the order of removal.

The route calculation unit 13 is a unit that calculates transport route information from item status information so as to satisfy a reference logical expression based on constraint conditions. The route calculation unit 13 searches for a transport route for each item 150 in the transport system 2. Here, between the initial movement state and the completed movement state shown in FIG. 5(a), the transport system 2 simultaneously moves each item 150 horizontally and vertically, combining these operations to transport each item 150 to its destination. At this time, the control device 10 moves the items 150 within the operational constraints of the transport system 2 so that the items 150 do not interfere with each other and can be sorted quickly. At this time, the route calculation unit 13 calculates the route each item 150 will take within the transport system 2 to reach its destination. The route calculation unit 13 searches for a route for each item 150 for a predetermined number of items 150 using a shortest route search method or the like, with each part of the transport system 2 as a search node.

Here, the path calculation unit 13 defines the constraints as a satisfiability problem (SAT problem). A SAT problem is a problem that determines whether there is a value assignment to a propositional variable that makes a logical formula containing propositional variables true. A SAT problem is a problem that solves a decision problem, that is, it determines whether a solution that satisfies the constraints exists. For example, in response to the question, "Can all items 150 arrive at the destination floor in five or fewer up and down movements of the transport shelves 22A and 22B of the transport machine 22?", the answer given is "Yes. The specific schedule is..." The reference logical formula includes movement constraints regarding the movement of the items 150, initial constraints regarding the initial state of the items, and arrival constraints regarding the arrival of the items 150 at their destinations.

The route calculation unit 13 also defines the multiple transport route information acquired as a Maximum Satisfaction Problem (MaxSAT). The MaxSAT problem is a problem of finding the variable ratio that maximizes the number of satisfied clauses for a set of clauses given as input. The MaxSAT problem is solving an optimization problem, i.e., finding an optimal solution that satisfies constraints. For example, to the question, "What is the shortest time for all 150 items to arrive at the destination floor?", the answer given is "10 seconds. The specific schedule is..." The route calculation unit 13 calculates at least one of a solution that satisfies all hard clauses and maximizes the sum of the weights of the satisfied soft clauses, and a solution that satisfies all hard clauses and minimizes the sum of the weights of the unsatisfied soft clauses. A hard clause is a clause that must be satisfied. A soft clause is one that should be filled as much as possible, and the degree of this is expressed as a weight (a positive integer).

[Preparation for explanation]
First, before explaining the constraints of SAT problems and MaxSAT problems, we will explain terminology. Hereinafter, we will explain the common points of SAT problems and MaxSAT problems. A "constraint" is expressed as a set of clauses. A "clause" is the logical sum of literals, and is shown in the following formula (1). A "literal" is a logical variable or its negation, and is shown in formula (2). A "variable" takes the value "True" or "False," and True can sometimes be considered as "1" and False as "0." In this specification, formulas (3), (4), and (5) are used in place of clauses. Formula (3) can also be shown as formula (6).

Equations (3) and (6) are interpreted as "If all of _a1 through _am are true in the current state, then one of _c1 through _cn must be true." Using equations (3) and (6), it is possible to express, for example, "If an item is in XX on the right-hand transport shelf (representing each a), then in the next state, it will either remain there or be in YY on the left-hand transport shelf (representing each c)." Equation (4) is interpreted as "At most one of _l1 through _ln will be True." If all _l1 through _ln are False, the left side of equation (4) will be "0." In other words, the left side of equation (4) will be either "1" or "0." Using equation (4), it is possible to express, for example, "At most one item can be placed in each transport box (each transport box represents l) on the transport shelf." This means that the same item 150 cannot be present in the same transport box 22a at the same time. If an item 150 does not fit into any of the transport boxes 22a, the left side of equation (4) is "0". Equation (5) is interpreted as "exactly one of _l1 to _ln is True". Using equation (5), it is possible to express, for example, that "an item is always present in either the storage lane, the storage shelf, or the destination floor (each location represents l)". In the following explanation, when simply referring to an "entrance" in explaining the constraints, this refers to the storage lane 21. Furthermore, when simply referring to a "baggage" in explaining the constraints, this refers to the item 150.

[Steps and Phases]
In this description, the initial state of the logistics warehouse 1 is assumed to be a state in which the left-side transport shelf 22B is raised and the right-side transport shelf 22A is lowered, as shown in FIG. 3( a). The route calculation unit 13 performs calculations by dividing the three-phase operation that enables the lateral movement of the item 150 and one lifting and lowering operation of the transport device 22 into one step. The route calculation unit 13 performs the "three-phase, one-step" operation as a basic operation, repeatedly performing this operation. As shown in FIG. 6, in each phase, the item 150 may move horizontally (laterally) to the next position. Note that the number of items that are horizontally moved in one phase is not particularly limited, and it is also possible for no items to be horizontally moved at all. Note that the route calculation unit 13 may omit phases in which no horizontal movement occurs without allocating time to them when calculating the transport route in a later calculation. When the three phases are completed, the step is switched. At the timing of the step switch, the transport shelves 22A and 22B are switched between the "left transport shelf raised state (see FIG. 3A)" and the "right transport shelf raised state (see FIG. 3B)." The inventors discovered that, while the movement of the item 150 does not progress even when the transport shelves 22A and 22B are switched repeatedly, the movement of the item 150 progresses even when the horizontal movement of the item 150 is performed repeatedly. Furthermore, the inventors adopted an appropriate number of phases in one step, 3, because the movement of the item 150 does not progress even when horizontal movement is performed four or more times consecutively (with some exceptions). The reason for the number of phases being three is that the horizontal movement during the period when vertical movement is not performed within the transport shelves 22A and 22B (during one step) can occur at most once for rightward movement and at most twice for leftward movement (with some exceptions), resulting in a total of three phases.

The variables used to indicate steps and phases will now be described. (7) shown below is a variable indicating that "the i-th package is lined up at the entrance in phase p of step t." (8) is a variable indicating that "the i-th package is at the destination floor in phase p of step t." (9) is a variable indicating that "the i-th package is in box j on the left-hand shelf in phase p of step t." Note that "j," which identifies box 22a, is the identification number shown in a circle in FIG. 3. (10) is a variable indicating that "the i-th package is in box j on the right-hand shelf in phase p of step t.""Phase p of step t" may be abbreviated as "(t, p)" to indicate time in the following explanation. Note that the index is "0-origin." The start is "step 0, phase 0." Therefore, (t, p) transitions as follows: "(0, 0) → (0, 1) → (0, 2) → (1, 0) → (1, 1) → ...." Note that the transport shelves 22A and 22B are switched at the timing of the change of step t. If step t is an even number, it indicates that the left transport shelf is in the "raised state (see FIG. 3(a))," and if step t is an odd number, it indicates that the right transport shelf is in the "raised state (see FIG. 3(b))." To express the transition of (t, p), the variable shown in (11) is adopted. (11) is a variable that returns the next step and phase of (t, p). Specifically, the variable (11) indicates the content shown in FIG. 7(a).

[Entrance constraints]
The constraints related to the entrance (i.e., the storage lane 21) will now be described. The reference logical formula includes the logical formulas (12) and (13) that indicate the entrance constraints as initial constraints related to the initial state. Formula (12) is interpreted as "if package i is lined up at the entrance at (t, p), it was also lined up before that." Formula (13) is interpreted as "if package i is lined up at the entrance at (t, p), package i+1 is also lined up." The specific content of formula (12) is shown in FIG. 7(b). The specific content of formula (13) is shown in FIG. 7(c). Note that "M" refers to the maximum value of the vertical movement of the transport shelves 22A and 22B. The same meaning of "M" will be used in the following explanations.

[Destination Floor Constraint]
The constraint conditions related to the destination floor of the automated warehouse 100 will be explained. The reference logical formula includes the logical formula of formula (14) which indicates the destination floor constraint as an arrival constraint related to the arrival of an item at the destination floor (destination). Formula (14) is interpreted as "if package i has arrived at the destination floor at (t, p), it will remain the same thereafter." The specific content of formula (14) is shown in FIG. 8(a).

[Conveyor box restrictions on transport shelves]
The constraints on the transport boxes 22a on the transport shelves 22A and 22B will now be explained. The reference logical formula includes logical formulas (15) and (16) that indicate transport box constraints as movement constraints on the movement of items. Formula (15) is interpreted as "at (t, p), two or more packages cannot be placed in transport box j on the left transport shelf." Formula (16) is interpreted as "two or more packages cannot be placed in transport box j on the right transport shelf." Note that "N" means the number of packages. This also applies to the subsequent logical formulas. Formula (17) indicates the range of values that (t, p) can take.

[Luggage presence constraints]
The constraints regarding the presence of luggage somewhere in the transport system 2 will be explained. The reference logical formula includes, as a movement constraint, the logical formula of formula (18) which indicates the presence constraint regarding the presence of luggage while the luggage is moving. Formula (18) is interpreted as "at (t, p), luggage i is either lined up at the entrance, in a transport rack, or has reached the destination floor." Formula (19) indicates the range of values that (t, p) can take.

[Auxiliary function (carton position)]
An auxiliary function is set that indicates the relationship between transport boxes 22a on transport shelves 22A and 22B. (20) shown below is an auxiliary function that indicates "a transport box on the left transport shelf that can be moved from transport box j on the right transport shelf." (21) shown below is an auxiliary function that indicates "a transport box on the right transport shelf that can be moved from transport box j on the left transport shelf." (22) shown below is an auxiliary function that indicates "a transport box on the left transport shelf that is stopped at the entrance floor at step t." (23) shown below is an auxiliary function that indicates "a transport box on the right transport shelf that is stopped at the entrance floor at step t."

The specific content of auxiliary function (20) is shown in Figure 9(a). The specific content of auxiliary function (21) is shown in Figure 9(b). The specific content of auxiliary function (22) is shown in Figure 9(c). The specific content of auxiliary function (23) is shown in Figure 9(d). If step t is an even number, the state is the "left transport shelf raised state (see Figure 3(a))". Therefore, the relationship between transport box 20a on right transport shelf 22A and transport box 22a on left transport shelf 22B is shown in Figure 3(a). Furthermore, for transport boxes 22a on transport shelves 22A and 22B parked on the second floor, which is the entrance floor, as shown in Figure 3(a), right transport shelf 22A has "identification number 1" and left transport shelf 22B has "identification number 0". If step t is an odd number, the state is the "right transport shelf raised state (see Figure 3(b))". Therefore, the relationship between the transport box 20a on the right transport shelf 22A and the transport box 22a on the left transport shelf 22B is shown in Figure 3(b). Also, for the transport boxes 22a on the transport shelves 22A and 22B parked on the second floor, which is the entrance floor, as shown in Figure 3(b), the right transport shelf 22A has "identification number 0" and the left transport shelf 22B has "identification number 1."

[Movement Constraints (Entrance)]
The constraints on the movement of luggage when luggage is lined up at the entrance will be explained. The reference logical formula includes, as a movement constraint, the logical formula of formula (24) which indicates the movement constraint of luggage on the entrance side. Formula (24) is interpreted as "if luggage i is lined up at the entrance at (t, p), then in the next phase next(t, p), it will be on the transport shelf on the right or will remain lined up at the entrance." The specific content of formula (24) is shown in Figure 8(b).

[Movement constraints (transport shelf)]
Constraints on the movement of packages when they are on shelves 22A and 22B are described below. Here, the basic conditions for the movement constraints on shelves 22A and 22B are described. A condition is set for the first two of the three phases, in which packages move to the left, and for the last phase, in which they move to the right. The specific relationship between the phases and the movement direction is shown in FIG. 10(a). By setting such conditions, it is possible to prevent a situation in which package A on shelf 22B and package B on shelf 22A are suddenly swapped in the next phase while packages A and B are moving horizontally, as shown in FIG. 10(b). The reference logical formula includes, as movement constraints, logical formulas (25) and (26), which indicate movement constraints for packages placed in immovable containers on the right-hand shelf 22A. Formula (25) can be interpreted as: "When package i is in container "0" on the right-hand shelf at (t, p) where t is even, it will be in the same container "0" in the next phase, next(t, p)." Equation (26) is interpreted as "When package i is in box "3" on the right-side transport shelf at (t, p) where t is odd, it will be in the same box "3" in the next phase, next(t, p)." The specific content of equations (25) and (26) is shown in FIG. 11(a). When t is even, the bottommost transport box 22a with "identification number 0" on the right-side transport shelf 22A is not adjacent to any other transport boxes 22a, the automated warehouse 100, or the storage lane 21 (see FIG. 11(b)). When t is odd, the topmost transport box 22a with "identification number 3" on the right-side transport shelf 22A is not adjacent to any other transport boxes 22a, the automated warehouse 100, or the storage lane 21 (see FIG. 11(c)). Therefore, packages placed on those transport boxes 22a with "identification numbers 1 and 3" cannot be moved to any other location in the next phase and will remain in place.

The reference logical formula includes, as movement constraints, logical formulas (27) and (28) that indicate movement constraints for packages placed in transport boxes that can move left on the right-side transport shelf 22A, except for the entrance floor. Formula (27) is interpreted as "package i in transport box j on the right-side transport shelf moves left or remains in the same transport box j when the transition from (t, 0) to (t, 1) occurs." Formula (28) is interpreted as "package i in transport box j on the right-side transport shelf remains in the same transport box j when the transition from (t, 1) to (t, 2) occurs or when the transition from (t, 2) to (t+1, 0) occurs." The specific content of formulas (27) and (28) is shown in FIG. 12(a). When t is an even number, as shown in FIG. 12(b), transport boxes 22a with "identification numbers 2 and 3" on the right-side transport shelf 22A correspond to transport boxes 22a that can move left on floors other than the second floor, which is the entrance floor. When t is an odd number, as shown in FIG. 12(c), the transport boxes 22a with "identification numbers 1 and 2" on the right transport shelf 22A correspond to the transport boxes 22a that can move left to floors other than the second floor, which is the entrance floor.

The reference logical formula includes, as movement constraints, the logical formulas of formulas (29), (30), and (31) which indicate movement constraints for packages placed in a transport box stopped at the entrance floor of the right-side transport shelf 22A. Formula (29) is interpreted as "package i in transport box j on the right-side transport shelf moves to the left or remains in the same transport box j when transitioning from (t, 0) to (t, 1)." Formula (30) is interpreted as "package i in transport box j on the right-side transport shelf remains in the same transport box j when transitioning from (t, 1) to (t, 2) or from (t, 2) to (t+1, 0) if it was there immediately before." Equation (31) is interpreted as "when package i in box j on the right-hand transport shelf transitions from (t, 1) to (t, 2) or from (t, 2) to (t+1, 0), if package i was not there immediately before, it moves to the left or remains in the same box j." When t is an even number, as shown in FIG. 13(a), the box 22a with "identification number 1" on the right-hand transport shelf 22A corresponds to the box 22a parked on the second floor, which is the entrance floor. When t is an odd number, as shown in FIG. 12(b), the box 22a with "identification number 0" on the right-hand transport shelf 22A corresponds to the box 22a parked on the second floor, which is the entrance floor.

The reference logical formula includes, as a movement constraint, the logical formula (32) that indicates the movement constraint of the parcel placed in the immovable transport box on the left transport shelf 22B. Equation (32) is interpreted as follows: "If parcel i is in transport box "3" on the left transport shelf at (t, p) where t is even, then in the next phase, next(t, p), it will be in the same transport box "3." The specific content of equation (32) is shown in FIG. 14(a). When t is even, the topmost transport box 22a with "identification number 3" on the left transport shelf 22B is not adjacent to any other transport boxes 22a, the automated warehouse 100, or the storage lane 21 (see FIG. 14(b)). Therefore, the parcel placed in the transport box 22a with "identification number 3" cannot be moved to any location in the next phase and will remain there. Note that when t is odd, there are no immovable transport boxes 22a on the left transport shelf 22B (see FIG. 14(c)).

The reference logical formula includes, as movement constraints, the logical formulas of formulas (33), (34), and (35) which indicate movement constraints for packages placed in transport boxes on the left transport shelf 22B at the destination floor. Formula (33) is interpreted as "package i in transport box j on the left transport shelf moves to the left or remains in the same transport box j when transitioning from (t, 0) to (t, 1)." Formula (34) is interpreted as "package i in transport box j on the left transport shelf remains in the same transport box j when transitioning from (t, 1) to (t, 2) or from (t, 2) to (t+1, 0) if it was there immediately before." Equation (35) is interpreted as "when the load i in the container j on the left-hand transport shelf transitions from (t, 1) to (t, 2) or from (t, 2) to (t+1, 0), if the load i was not there immediately before, it moves to the left or remains in the same container j." When t is an even number, as shown in FIG. 15(a), the container 22a with the "identification number 0, 1, 2" on the left-hand transport shelf 22B corresponds to the container 22a stopped at the target floor. When t is an odd number, as shown in FIG. 15(b), the container 22a with the "identification number 0, 1, 2, 3" on the left-hand transport shelf 22B corresponds to the container 22a stopped at the target floor.

The reference logical formula includes, as a movement constraint, the logical formula (36) which indicates the movement constraint of the parcel placed in the transport box that is stopped at a floor other than the destination floor on the left transport shelf 22B. Equation (36) is interpreted as "parcel i in transport box j on the left transport shelf remains in the same transport box j when transitioning from (t, 0) to (t, 1) or when transitioning from (t, 1) to (t, 2)." The specific content of equation (36) is shown in FIG. 16(a). When t is an even number, as shown in FIG. 16(b), the transport boxes 22a with "identification numbers 0, 1, 2" on the left transport shelf 22B correspond to the transport boxes 22a that are stopped at a floor other than the destination floor. When t is an odd number, as shown in FIG. 16(c), the transport boxes 22a with "identification numbers 0, 1, 2, 3" on the left transport shelf 22B correspond to the transport boxes 22a that are stopped at a floor other than the destination floor.

The reference logical formula includes, as a movement constraint, the logical formula (37) which indicates the movement constraint of a package placed on a transport box that is stopped at a floor that is not the destination floor of the left transport shelf 22B and cannot be moved to the right. Equation (37) is interpreted as "package i in transport box j on the left transport shelf remains in the same transport box j when the transition from (t, 2) to (t+1, 0) occurs." The specific content of equation (37) is shown in FIG. 17(a). When t is an even number, as shown in FIG. 17(b), there is no floor on the left transport shelf 22B that is not the destination floor and cannot be moved to the right. When t is an odd number, as shown in FIG. 17(c), the transport box 22a with "identification number 0" on the left transport shelf 22B is not the destination floor and cannot be moved to the right.

The reference logical formula includes, as movement constraints, logical formulas (38) and (39) that indicate movement constraints for packages placed in transport boxes that are parked at floors other than the destination floor of the left-side transport shelf 22B, that are allowed to move to the right, and that are not the entrance floor. Formula (38) is interpreted as "if package i in transport box j on the left-side transport shelf is not present in phase 0 when the transition from (t, 2) to (t+1, 0) occurs, it will remain in the same transport box j." Formula (39) is interpreted as "if package i in transport box j on the left-side transport shelf is present in phase 0 when the transition from (t, 2) to (t+1, 0) occurs, it will either move to the right or remain in the same transport box j." Specific contents of formulas (38) and (39) are shown in FIG. 18(a). When t is an even number, as shown in Figure 18(b), the transport boxes 22a with "identification numbers 1 and 2" on the left transport shelf 22B are not the destination floor, can be moved to the right, and are not the entrance floor. When t is an odd number, as shown in Figure 18(c), the transport boxes 22a with "identification numbers 2 and 3" on the left transport shelf 22B are not the destination floor, can be moved to the right, and are not the entrance floor.

Here, (40) shown below is an auxiliary variable indicating that "package is contained in transport box j on the entrance floor of the right-hand transport shelf (p = 2)." Using this auxiliary variable and based on De Morgan's law, equations (41) and (42) show that a package is contained in transport box 22a on the second entrance floor of right-hand transport shelf 22A. When t is an even number, as shown in FIG. 19(a), transport box 22a with "identification number 1" on right-hand transport shelf 22A corresponds to transport box 22a on the entrance floor. When t is an odd number, as shown in FIG. 19(b), transport box 22a with "identification number 0" on right-hand transport shelf 22A corresponds to transport box 22a on the entrance floor.

The reference logical formula includes, as movement constraints, logical formulas (43), (44), and (45) that indicate movement constraints for packages placed in transport boxes that are parked at the entrance floor and that are not the destination floor of the left-side transport shelf 22B but are allowed to move to the right. Formula (43) is interpreted as "if package i in transport box j on the left-side transport shelf is not present in phase 0 when the transition from (t, 2) to (t+1, 0) occurs, it will remain in the same transport box j." Formula (44) is interpreted as "if package i in transport box j on the left-side transport shelf is present in phase 0 when the transition from (t, 2) to (t+1, 0) occurs, and the transport box to the right is empty, it will either move to the right or remain in the same transport box j." Equation (45) is interpreted as "when the transition from (t, 2) to (t+1, 0) occurs, if package i in box j on the left-hand transport shelf is there in phase 0, if there is something in the box to the right, it will remain in the same box j." When t is an even number, as shown in FIG. 20(a), box 22a with "identification number 0" on left-hand transport shelf 22B corresponds to box 22a that is not the destination floor but can move to the right and is parked at the entrance floor. When t is an odd number, as shown in FIG. 20(b), box 22a with "identification number 1" on left-hand transport shelf 22B corresponds to box 22a that is not the destination floor but can move to the right and is parked at the entrance floor.

[Initial and Arrival Constraints]
The initial constraint will be explained. The following (46) indicates that "all baggage items are initially lined up at the entrance," and is therefore True. The arrival constraint will be explained. The following (47) indicates that "all baggage items must have arrived at the destination floor after M up-and-down movements of the transport rack," and is therefore True.

[When there is a continuous load of luggage going to the second floor]
When two consecutive parcels with the same entrance and destination floors pass through the conveyor 22, four phases are required (for example, when there are two parcels) to pass through the conveyor 22. For example, as shown in FIG. 21( a), the front parcel can reach the destination floor, the second floor, with three phases of horizontal movement, while the rear parcel cannot reach the destination floor without four phases of horizontal movement. Thus, a three-phase, one-step schedule does not allow such a passing through. Therefore, the route calculation unit 13 regards multiple consecutive parcels as one parcel. As shown in FIG. 21( b), the route calculation unit 13 regards two parcels as one parcel, as indicated by "150B." In this case, "150B" can reach the destination floor with three phases of horizontal movement. The number of parcels to be grouped together is not particularly limited, and three or more parcels may be grouped together.

[Movement Constraints (Entrance)]
The reference logical formula includes, as movement constraints, the logical formulas of formula (48), formula (49), and formula (50) which indicate movement constraints at the entrance. Formula (48) is interpreted as "package i at the entrance can move to the right-hand transport shelf only in phase 0." Formula (49) is interpreted as "package i at the entrance remains at the entrance in phase 1." Formula (50) is interpreted as "package i at the entrance remains at the entrance in phase 2."

[Movement constraints (right shelf)]
The reference logical formula includes, as movement constraints, logical formulas (51) and (52) that indicate movement constraints for a transport box on the entrance floor of the right-side transport shelf. Formula (51) is interpreted as "package i on a transport box on the entrance floor of the right-side transport shelf is always moved to the left-side transport shelf when t is even and the transition from (t, 1) to (t, 2) occurs." Formula (51) is interpreted as "package i on a transport box on the entrance floor of the right-side transport shelf is always moved to the left-side transport shelf when t is odd and the transition from (t, 1) to (t, 2) occurs." Note that there is "no constraint" when the transition occurs from (t, 0) to (t, 1) or from (t, 2) to (t+1, 0). When t is even, as shown in FIG. 19(a), the transport box 22a with "identification number 1" on the right-side transport shelf 22A corresponds to the transport box 22a on the entrance floor. When t is an odd number, as shown in FIG. 19(b), the transport box 22a with "identification number 0" on the right transport shelf 22A corresponds to the transport box 22a on the entrance floor.

[Movement constraints (left shelf)]
The reference logical formula includes, as movement constraints, logical formulas (53) and (54) that indicate movement constraints on the containers on the destination and entrance floors of the left-side conveying shelf. Formula (53) is interpreted as "package i on a container on the destination and entrance floors of the left-side conveying shelf must move to the left when t is even and transitions from (t, 2) to (t + 1, 0)." Formula (54) is interpreted as "package i on a container on the destination and entrance floors of the left-side conveying shelf must move to the left when t is odd and transitions from (t, 2) to (t + 1, 0)." Note that there is "no constraint" when transitioning from (t, 0) to (t, 1) or from (t, 1) to (t, 2). As shown in FIG. 20(a), container 22a with "identification number 0" on left-side conveying shelf 22B corresponds to container 22a parked at the destination and entrance floors. When t is an odd number, as shown in FIG. 20(b), the transport box 22a with "identification number 1" on the left transport shelf 22B corresponds to the transport box 22a parked on the destination floor and the entrance floor.

[Optimal solution search possible with SAT]
Next, we will explain the optimal solution search unique to SAT. Let "S _M " be "the set of constraints (clauses) obtained when M is given." If _{S M} has a "solution," it can be interpreted as "all packages can reach the destination floor within M up and down movements of the rack." If _{S M} has a "no solution," it can be interpreted as "not all packages will reach the destination floor within M up and down movements of the rack." For example, if "S ₀ , S ₁ , ... S _m-1 " has a "no solution" and "S _m , ..." has a "solution," then "m" is the optimal value.

[MaxSAT]
Next, the contents unique to MaxSAT will be explained. To explain MaxSAT, variables (55) and (56) are prepared. (55) shown below is a variable indicating that "all baggage has arrived at the destination floor by phase 0 of step t." (56) shown below is a variable indicating that "during the transition from (t, 0) to (t, 1) to (t, 2) to (t+1, 0), the baggage has made horizontal movement k+1 times." Note that when the path calculation unit 13 calculates the MaxSAT problem, it also calculates the above-mentioned constraints calculated as the SAT problem.

[Soft clause and associated hard clause]
The hard clauses related to the soft clauses will be explained. First, the variables in (55) above will be explained. (55) indicates the cost of the up and down movement of the transport shelves 22A and 22B, and a "weight: 1" can be set. The logical formula shown in formula (57) holds for this variable. "N" means the number of pieces of luggage. The meaning of "N" will remain the same in the following explanations. Formula (57) can be interpreted as "by phase 0 of step t, all luggage has arrived at the destination floor." The specific content of formula (57) is shown in Figure 22(a).

The variable in (56) above will be explained. This variable is used in a negative form as shown in (58). (58) indicates the cost of horizontal movement of luggage, and "weight: 1" can be set. Equation (59) is interpreted as "during the transition from (t, 0) → (t, 1) → (t, 2) → (t+1, 0), no horizontal movement of luggage occurs."

Regarding horizontal movement from the entrance, equation (60) holds. Equation (60) can be interpreted as "if package i is lined up at the entrance at (t, 0) and is on the right-hand transport shelf at the next step (t+1, 0), the horizontal movement cost is 1." A specific example of equation (60) is shown in FIG. 22(b). When t is an even number, as shown in FIG. 19(a), the transport box 22a with "identification number 1" on the right-hand transport shelf 22A corresponds to the transport box 22a from which packages are being moved from the entrance. When t is an odd number, as shown in FIG. 19(b), the transport box 22a with "identification number 0" on the right-hand transport shelf 22A corresponds to the transport box 22a from which packages are being moved from the entrance.

Regarding horizontal movement from the entrance, equation (61) holds. Equation (61) can be interpreted as "if package i is lined up at the entrance at (t, 0) and is on the left-hand transport shelf at the next step (t+1, 0), the horizontal movement cost will be 2." A specific example of equation (61) is shown in FIG. 23(a). When t is an even number, as shown in FIG. 20(a), the transport box 22a with "identification number 0" on the left-hand transport shelf 22B corresponds to the transport box 22a from which the package is moved from the entrance. When t is an odd number, as shown in FIG. 20(b), the transport box 22a with "identification number 1" on the left-hand transport shelf 22B corresponds to the transport box 22a from which the package is moved from the entrance.

Regarding horizontal movement from the entrance, equation (62) holds. Equation (62) can be interpreted as "if baggage i is lined up at the entrance at (t, 0) and arrives at the destination floor at the next step (t+1, 0), the horizontal movement cost will be 3." A specific example of equation (62) is shown in Figure 23(b).

Regarding horizontal movement from the entrance, equation (63) holds. Equation (63) can be interpreted as "if package i is on the right-hand transport shelf at (t, 0) and is on the left-hand transport shelf at the next step (t+1, 0), the horizontal movement cost is 1." A specific example of equation (63) is shown in FIG. 24(a). When t is an even number, as shown in FIG. 25(a), the transport boxes 22a with "identification numbers 1, 2, 3" on the right-hand transport shelf 22A are the source transport boxes 22a, and the transport boxes 22a with "identification numbers 0, 1, 2" on the left-hand transport shelf 22B are the destination transport boxes 22a. When t is an odd number, as shown in FIG. 25(b), the transport boxes 22a with "identification numbers 0, 1, 2" on the right-hand transport shelf 22A are the source transport boxes 22a, and the transport boxes 22a with "identification numbers 1, 2, 3" on the left-hand transport shelf 22B are the destination transport boxes 22a.

Regarding horizontal movement from the entrance, equation (64) holds. Equation (64) can be interpreted as "if package i is on the right-hand transport shelf at (t, 0) and arrives at the destination floor in the next step (t+1, 0), the horizontal movement cost is 2." A specific example of equation (64) is shown in FIG. 24(b). When t is an even number, as shown in FIG. 26(a), the transport boxes 22a with "identification numbers 1, 2, 3" on the right-hand transport shelf 22A are the source transport boxes 22a. When t is an odd number, as shown in FIG. 26(b), the transport boxes 22a with "identification numbers 0, 1, 2" on the right-hand transport shelf 22A are the source transport boxes 22a.

Regarding horizontal movement from the entrance, equation (65) holds. Equation (65) can be interpreted as "if package i is on the left transport shelf at (t, 0) and is on the right transport shelf at the next step (t+1, 0), the horizontal movement cost is 1." A specific example of equation (65) is shown in FIG. 27(a). When t is an even number, as shown in FIG. 28(a), the transport boxes 22a with "identification numbers 0, 1, 2" on the left transport shelf 22B are the source transport boxes 22a. When t is an odd number, as shown in FIG. 28(b), the transport boxes 22a with "identification numbers 1, 2, 3" on the left transport shelf 22A are the source transport boxes 22a.

Regarding horizontal movement from the entrance, equation (66) holds. Equation (66) can be interpreted as "if package i is on the left-hand transport shelf at (t, 0) and arrives at the destination floor in the next step (t+1, 0), the horizontal movement cost is 1." A specific example of equation (66) is shown in FIG. 29. When t is an even number, as shown in FIG. 28(a), the transport boxes 22a with "identification numbers 0, 1, 2" on the left-hand transport shelf 22B are the source transport boxes 22a. When t is an odd number, as shown in FIG. 28(b), the transport boxes 22a with "identification numbers 1, 2, 3" on the left-hand transport shelf 22A are the source transport boxes 22a.

Regarding horizontal movement when multiple pieces of luggage are going consecutively from the entrance to the destination floor on the second floor (the situation shown in FIG. 21 above), a variable (67) is prepared. This variable is set to "weight: s-1". Here, s is the number of consecutive pieces of luggage. Furthermore, equations (68) and (60) hold true. "Luggage i" is a bundle of multiple consecutive pieces of luggage. Equations (68) and (69) are interpreted as "the horizontal movement cost of s consecutive pieces of luggage going to the second floor is S+2". Equation (68) is set to "weight: s-1", and equation (69) is set to "weight: 3".

Next, with reference to Figure 30, an example of processing content showing a control method by the control device 10 will be described. As shown in Figure 30, the item information acquisition unit 12 acquires item information indicating the initial movement state and the completed movement state of the item 150 when the item 150 moves through the storage lane 21, conveyor 22, and automated warehouse 100 in that order, or when the item moves through the automated warehouse 100, conveyor 22, and outgoing lane 121 in that order (step S10). Next, the path calculation unit 13 calculates transport path information from the item information acquired in step S10 so as to satisfy a reference logical expression based on constraint conditions (step S20).

At this time, the route calculation unit 13 calculates whether scheduling can be achieved with M or fewer up and down movements of the transport shelves 22A and 22B as a SAT problem. The route calculation unit 13 calculates the reference logical formula to include movement constraints regarding the movement of the item 150, initial constraints regarding the initial state of the item 150, and arrival constraints regarding the arrival of the item 150 at the destination. In other words, the route calculation unit 13 calculates transport route information to satisfy the reference logical formula based on the basic constraints (entrance, destination floor, lift box, and presence of luggage) and movement constraints (entrance → transport shelf → movement to destination floor). Furthermore, the route calculation unit 13 calculates the multiple transport route information obtained as a MaxSAT problem. The route calculation unit 13 calculates at least one of a solution that satisfies all hard clauses and maximizes the sum of the weights of the satisfied soft clauses, and a solution that satisfies all hard clauses and minimizes the sum of the weights of the unsatisfied soft clauses. The path calculation unit 13 calculates the software clauses (the costs of vertical movement of the transport shelves 22A and 22B and horizontal movement of the item 150) in addition to the constraints calculated as the SAT problem described above.

The operation control unit 11 controls the transport operation of the item 150 based on the transport route information calculated in step S20 (step S30). This completes the control process shown in Figure 30.

Next, we will explain the operation and effects of the control device 10 and control method of the logistics warehouse 1 described above.

In the control device 10 of the logistics warehouse 1, the item information acquisition unit 12 acquires item information indicating the initial movement state and the completed movement state of the item 150 when the item 150 moves through the storage lane 21, the conveyor 22, and the automated warehouse 100 in that order, or when the item moves through the automated warehouse 100, the conveyor 22, and the outgoing lane 121 in that order. The route calculation unit 13 also calculates transport route information from the item information so as to satisfy a reference logical expression based on the constraint conditions. In this case, the route calculation unit 13 can calculate the transport route that should be taken between the initial movement state of the item 150 and the completed movement state. By performing calculations to satisfy the reference logical expression based on the constraint conditions, the route calculation unit 13 can easily eliminate operations that are constrained on the transport route by calculating the reference logical expression. As a result, the route calculation unit 13 can calculate an appropriate transport route with a small computational load. This reduces the computational load when calculating a transport route for transporting the item 150.

The path calculation unit 13 defines the constraints as a satisfiability determination problem, and the reference logical formula may include a movement constraint regarding the movement of the item 150, an initial constraint regarding the initial state of the item 150, and an arrival constraint regarding the arrival of the item 150 at the destination.

The conveyor 22 is a vertical conveyor that performs vertical conveyance by moving the item 150 horizontally while alternately raising and lowering the conveyor boxes 22a on adjacent conveyor shelves 22A and 22B. The path calculation unit 13 may perform calculations using a three-phase operation that enables the horizontal movement of the item 150, and one lifting and lowering operation of the conveyor 22 as one step. Thus, due to the structure of the vertical conveyor, there are cases where efficient movement is possible by performing about three consecutive horizontal movements, but consecutive lifting and lowering operations do not result in the item moving. Therefore, by dividing the horizontal movement into an appropriate number of phases, such as three, while treating the lifting and lowering operation as one step, the path calculation unit 13 can more easily calculate an efficient conveyance path.

The route calculation unit 13 may define the multiple transport route information obtained as a satisfiability maximization problem and calculate at least one of a solution that satisfies all hard clauses and maximizes the sum of the weights of the satisfied soft clauses, and a solution that satisfies all hard clauses and minimizes the sum of the weights of the unsatisfied soft clauses. In this case, the route calculation unit 13 can select the transport route that satisfies the hard clauses and can move items most efficiently based on the weights of the soft clauses, among the transport routes that can clear the necessary constraints.

When items whose target location in the automated warehouse 100 has the same floor number as the storage lane 21 and the outgoing lane 121 pass consecutively through the conveyor 22, the path calculation unit 13 may treat the consecutive items 150 as a single item (see FIG. 21). For example, if there is a restriction on the number of consecutive lateral movements of the items 150, it is possible that the rearmost item 150 of the consecutive items 150 may not be able to reach the target location as is. In contrast, by treating the consecutive items 150 as a single item, the path calculation unit 13 can allow the rearmost item 150 to reach the target location as is.

The control method for the logistics warehouse 1 includes an item information acquisition step S10 for acquiring item information indicating the initial movement state and the completed movement state of the item 150 when the item 150 moves through the receiving lane 21, the conveyor 22, and the automated warehouse 100 in that order, or when the item moves through the automated warehouse 100, the conveyor 22, and the outgoing lane 121 in that order; a route calculation step S20 for calculating transport route information from the item information so as to satisfy a reference logical expression based on constraint conditions; and a transport control step S30 for controlling the transport operation of the item 150 based on the transport route information.

This control method for logistics warehouse 1 can achieve the same effects and benefits as the control device 10 described above.

Next, we will explain, with reference to Figures 32 to 38, the processing details that can further improve transport efficiency while reducing the computational load by calculating transport route information to satisfy the reference logical expression based on the constraint conditions, as described above.

As explained with reference to Figure 21, when two or more consecutive items 150 are transported to a destination floor on the same floor as the entrance floor (here, the second floor) of the automated warehouse 100 to which the storage lane 21 is connected, the multiple items 150 are considered to be a single item. In this case, when a row of items 150 considered to be a single item passes through the conveyor 22, vertical movement of the conveyor shelves 22A, 22B is not permitted. However, even when transporting consecutive items 150, there are cases where allowing vertical movement of the conveyor shelves 22A, 22B along the way improves transport efficiency. Therefore, the path calculation unit 13 performs calculations by dividing the grouping of consecutive items 150 into multiple patterns. Furthermore, the path calculation unit 13 performs calculations by dividing the pattern according to the number of consecutive items 150. Note that Figure 31 shows a row of two consecutive items 150. These two items 150 are assumed to be in the initial movement state shown in Figure 21(a). Figure 32 shows an example of three or more consecutive items 150. These three or more items 150 (for example, three) are assumed to be in the initial movement state shown in Figure 33.

Specifically, when, in the initial state of movement, multiple items 150 are lined up consecutively to form a line, the route calculation unit 13 performs a first process and a second process. The first process is a process of grouping all of the multiple items 150 in the line together, treating them as a single first integrated item, and calculating first candidate route information for the transport route information. The second process is a process of separating the first end item at one end of the line, treating the group including the items in the line other than the first end item as a single item, and calculating second candidate route information for the transport route information. In addition, the route calculation unit 13 adopts the first candidate route information or the second candidate route information, whichever is more highly rated, as the transport route information.

Referring to Figure 31, we will explain the case where a row is composed of two consecutive items 150. Figure 31(a) is a diagram showing pattern A1, which is a method of dividing items 150 in the first process. Figure 31(b) is a diagram showing pattern A2, which is a method of dividing items 150 in the second process. In the case of two items 150, the item 150 on the upstream side in the conveying direction corresponds to end item 150EA, and the item 150 on the downstream side corresponds to end item 150EB. As shown in Figure 31(a), in the first process, the path calculation unit 13 combines the two items 150 and considers them as a single first integrated item 150UNA (pattern A1). As shown in Figure 31(b), in the second process, the path calculation unit 13 separates end item 150EA at the upstream end of the row and considers group G, including items 150 in the row other than end item 150EA, as a single item 150 (pattern A2). Here, group G is composed of one item 150 other than end item 150EA, downstream end item 150B.

When the train is made up of two consecutive items 150, the route calculation unit 13 calculates first candidate route information for one item, "first integrated item 150UNA," and calculates a second candidate route for two items, "end item 150EA" and "end item 150EB."

In this explanation, end item 150EA at the upstream end corresponds to the "first end item" in the claims, and end item 150EB at the downstream end corresponds to one item that makes up the "group" in the claims. However, end item 150EB at the downstream end may also correspond to the "first end item" in the claims, and end item 150EA at the upstream end may also correspond to one item that makes up the "group" in the claims.

Referring to Figure 32, we will explain the case where a row is made up of three or more consecutive items 150. Figure 32(a) is a diagram showing pattern B1, which is a method of dividing items 150 in the first process. Figures 32(b), (c), and (d) are diagrams showing patterns B2, B3, and B4, which are methods of dividing items 150 in the second process. In the case of two items 150, the item 150 located most upstream in the conveying direction corresponds to end item 150EA, and the item 150 located most downstream corresponds to end item 150EB. As shown in Figure 32(a), in the first process, the path calculation unit 13 combines all three or more items 150 and considers them to be a single first integrated item 150UNA (pattern A1).

Pattern B2 will be described with reference to Figure 32 (b). In the second process, the path calculation unit 13 separates end item 150EA at the upstream end of the line. The path calculation unit 13 separates end item 150EB at the downstream end of the line. The path calculation unit 13 considers group G, which includes items 150 in the line other than end item 150EA and end item 150EB, to be a single item. Note that if the line is made up of four or more consecutive items 150, group G is made up of a single third integrated item 150UNC that combines multiple items 150 other than end items 150EA and 150EB. If the line is made up of three consecutive items 150, group G is made up of a single item 150 other than end items 150EA and 150EB.

In this description, end item 150EA at the upstream end corresponds to the "first end item" in the claims, and end item 150EB at the downstream end corresponds to the "second end item" in the claims. However, end item 150EB at the downstream end may also correspond to the "first end item" in the claims, and end item 150EA at the upstream end may also correspond to the "second end item" in the claims.

Pattern B3 will be described with reference to Figure 32 (c). In the second process, the path calculation unit 13 separates the end item 150EA at the upstream end of the row. The path calculation unit 13 considers group G, which includes the items 150 in the row other than end item 150EA, to be a single item. Group G is composed of a single second integrated item 150UNB, which combines multiple items 150 other than end item 150EA. Here, the second integrated item 150UNB includes end item 150EB at the downstream end.

Pattern B4 will be described with reference to Figure 32 (d). In the second process, the path calculation unit 13 separates the end item 150EB at the downstream end of the row. The path calculation unit 13 considers a group G including the items 150 in the row other than the end item 150EB as a single item. Group G is composed of a single second integrated item 150UNB that combines multiple items 150 other than the end item 150EB. Here, the second integrated item 150UNB includes the end item 150EA at the upstream end.

When a train is made up of three or more consecutive items 150, the route calculation unit 13 calculates first candidate route information for one item, "first integrated item 150UNA." The route calculation unit 13 also calculates a second candidate route for three items, "end item 150EA," "group G (third integrated item 150UNC)," and "end item 150EB." The route calculation unit 13 calculates a second candidate route for two items, "end item 150EA" and "group G (second integrated item 150UNB)." The route calculation unit 13 calculates a second candidate route for two items, "group G (second integrated item 150UNB)" and "end item 150EB." In this way, the route calculation unit 13 can calculate three second candidate routes. However, in the second process, the path calculation unit 13 only needs to adopt at least one of patterns B2, B3, and B4, and may omit some patterns.

Next, an example of the processing content of the route calculation unit 13 will be described with reference to Figures 33 to 38. Figure 33 is a diagram modeling three consecutive items 150 in an initial state of movement. Figures 34 and 35 are diagrams modeling an example of first candidate route information. Figures 36 and 37 are diagrams modeling an example of second candidate route information. Figure 38 is a flowchart showing the processing content of the route calculation unit 13. Figure 38 is executed at a predetermined timing in step S20 of Figure 30.

As shown in FIG. 38, first, the route calculation unit 13 determines, based on the acquired item information, whether there are any consecutive items 150 heading to the second floor in the storage lane 21 (step S110). If it is determined in step S110 that there are no consecutive items 150, the route calculation unit 13 calculates a transport route assuming that the items 150 heading to the second floor are a single, discontinuous item 150 (step S120). Once the calculation of the transport route in step S120 is complete, the processing shown in FIG. 38 ends.

If it is determined in step S110 that there are consecutive items 150, the path calculation unit 13 determines whether there are three or more consecutive items 150 (step S130). If the determination in step S130 is NO, this means that there are two consecutive items 150. Therefore, the path calculation unit 13 divides the two consecutive items 150 into pattern A1 and pattern A2, as shown in FIG. 31 (step S140). If the determination in step S130 is YES, the path calculation unit 13 divides the three or more consecutive items 150 into patterns B1 to B4, as shown in FIG. 32 (step S150). In the example shown in FIG. 33, there are three consecutive items 150 heading to the second floor. Therefore, the determinations in steps S110 and S130 are YES.

Next, the route calculation unit 13 performs a first process to calculate first candidate route information and a second process to calculate second candidate route information (step S160). For example, the route calculation unit 13 creates the candidate route information shown in Figures 34 and 35 as the first candidate route information. The first integrated item 150UNA, which is formed by integrating three items 150, is stored on the second floor of the automated warehouse 100 by horizontal movement from the initial movement position shown in Figure 33 (see Figures 34(a) and (b)). At this time, because vertical movement of the transport shelves 22A and 22B is restricted, the item 150 heading to the fourth floor remains on the transport shelf 22A (see Figures 34(a) and (b)). Once all of the items 150 in the first unified item 150UNA have been stored, the conveyor 22 combines vertical and horizontal movement on the conveyor shelves 22A and 22B to store the items 150 bound for the fourth floor on the fourth floor of the automated warehouse 100 (FIG. 34(c), FIG. 35(a)(b)(c)). In this way, after the state shown in FIG. 34(a) in which two items 150 bound for the second floor have been stored, the storage of all of the items 150 is completed through the five operations of FIG. 34(b)(c) and FIG. 35(a)(b)(c).

For example, the route calculation unit 13 creates the candidate route information shown in Figures 36 and 37 as second candidate route information. Here, two items 150 are combined into a second integrated item 150UNB, and an end item 150EB. The route calculation unit 13 stores the second integrated item 150UNB on the second floor of the automated warehouse 100 by moving it horizontally from the initial movement position shown in Figure 33 (Figure 36(a)). At this time, the end item 150EB remains on the transport shelf 22B, but because it is a different item from the second integrated item 150UNB, vertical movement of the transport shelves 22A and 22B is permitted. Therefore, the transport shelves 22A and 22B move vertically (see Figure 36(b)). Thereafter, by combining vertical and horizontal movement by transport shelves 22A and 22B, end item 150EB bound for the second floor is stored there, and item 150 bound for the fourth floor is stored on the fourth floor of the automated warehouse 100 (FIG. 36(c), FIG. 37(a)(b)). In this way, after the state shown in FIG. 36(a) in which two items 150 bound for the second floor have been stored, the four operations shown in FIG. 36(b)(c) and FIG. 37(a)(b) complete the storage of all items 150.

Next, the route calculation unit 13 adopts the higher-rated one of the first and second candidate route information as the transport route information (step S170). In the example shown in Figures 33 to 37, the second candidate route information allows all of the items 150 to be stored with fewer operations than the first candidate route information. Therefore, the route calculation unit 13 adopts the second candidate route information because it has better transport efficiency and a higher rating. This completes the processing shown in Figure 38.

Next, we will explain the functions and effects of the control device 10 and control method of the logistics warehouse 1 according to this embodiment.

The route calculation unit 13 performs a first process to calculate first candidate route information for the transport route information by grouping all of the multiple items 150 in the row and treating them as a single first integrated item 150UNA. By treating multiple consecutively arranged items 150 as a single first integrated item 150UNA, the route calculation unit 13 can calculate first candidate route information that allows the items 150 to reach an item completion state in fewer phases. However, for end items at the end of a row of multiple consecutively arranged items 150, allowing them to operate differently from the other items 150 in the row may result in creating a route with fewer conveyor 22 operations. Therefore, the route calculation unit 13 performs a second process to separate the first end item at one end of the row (end item 150EA or end item 150EB) and treat the group including the items 150 in the row other than the first end item as a single item to calculate second candidate route information for the transport route information. As a result, the route calculation unit 13 can calculate second candidate route information that considers group G other than the first end item as a single item, while allowing the first end item to behave differently from the items in group G. The route calculation unit 13 can then calculate more efficient transport route information by adopting the higher-rated one of the first and second candidate route information as the transport route information. As described above, it is possible to calculate an efficient transport route while reducing the computational load when calculating a transport route for transporting item 150.

The row may include three or more consecutive items, and in the second process, the route calculation unit 13 may separate the second end item (end item 150EA or end item 150EB) at the other end of the row, and calculate second candidate route information by treating group G including items 150 in the row other than the first end item and second end item as a single item. This allows the route calculation unit 13 to calculate second candidate route information without restricting the movement of end items 150EA, 150EB at both ends of the row.

The row may include three or more consecutive items, and the group G may be composed of a single second integrated item UNB that combines all of the items 150 in the row other than the first end item. In this case, the route calculation unit 13 can calculate second candidate route information by removing the restriction on the movement of only the first end item at one end, and combining all of the other items 150.

A queue may consist of two consecutive items, and group G may consist of one item 150 other than the first end item. In this case, when a queue consists of two items 150, the route calculation unit 13 can calculate first candidate route information that combines both items, and second candidate route information that separates them.

A control method for a logistics warehouse 1 according to one aspect of this embodiment includes an item information acquisition step S10 for acquiring item information indicating the initial and completed states of an item 150 as the item 150 moves through the storage lane 21, conveyor 22, and automated warehouse 100 in that order, and a route calculation step S20 for calculating transport route information from the item information so as to satisfy a reference logical expression based on constraints. When multiple items are lined up consecutively in the initial state, the route calculation step S20 performs two processes: a first process for calculating first candidate route information for the transport route information by grouping all of the multiple items 150 in the line and treating them as a single first integrated item 150UNA; and a second process for calculating second candidate route information for the transport route information by separating the first end item at one end of the line and treating a group G including the items in the line other than the first end item as a single item. The first candidate route information or the second candidate route information, whichever is more highly evaluated, is adopted as the transport route information.

This control method for logistics warehouse 1 can achieve the same effects and benefits as the control device 10 described above.

The present invention is not limited to the above-described embodiments.

The above-mentioned SAT problem and the various constraints for MaxSAT are merely examples and can be changed as appropriate. Furthermore, the number of floors of the automated warehouse 100, the number of floors of the conveyors 22, the inbound lanes 21, and the outbound lanes 121 can also be changed as appropriate, and the constraints can be changed accordingly.

For example, the logistics warehouse is not limited to the one shown in Figure 1. For example, multiple automated warehouses may be installed in parallel with a pair of receiving lanes 21 and outgoing lanes 121. Furthermore, the conveyor does not have to be a vertical conveyor with a pair of storage shelves that move up and down alternately as shown in Figure 2. For example, a rotary-type conveyor (a conveyor in which the storage shelves move in a fixed direction one level at a time and, when the shelves are not moving in a circular direction, items can be moved between the shelves) may be used. Alternatively, an escalator-type or traction-type conveyor may be used. In this case, the control device may calculate the conveyor route information to satisfy a reference logical expression based on the constraints applicable to the conveyor.

[Form 1]
an automated warehouse for storing goods;
a storage lane for storing the arranged plurality of articles;
A control device for a logistics warehouse including a conveyor provided between the storage lane and the automated warehouse,
an item information acquisition unit that acquires item information indicating an initial state and a completed state of movement of the item when the item moves through the storage lane, the conveyor, and the automated warehouse in this order;
a route calculation unit that calculates transport route information from the item information so as to satisfy a reference logical expression based on constraint conditions;
In the initial state of movement, when a plurality of the articles are lined up in succession to form a line, the path calculation unit:
a first process for calculating first candidate route information of the transport route information by grouping all of the plurality of articles in the row together and regarding them as a single first integrated article;
a second process of separating a first end item at one end of the row, and calculating second candidate route information for the conveyance route information by treating a group including the items in the row other than the first end item as one item;
A control device for a logistics warehouse that adopts, as the transport route information, one of the first candidate route information and the second candidate route information that has a higher evaluation.
[Form 2]
the row includes three or more consecutive articles;
A control device for a logistics warehouse as described in form 1, wherein in the second processing, the route calculation unit separates a second end item at the other end of the row, and calculates the second candidate route information by treating a group including the items in the row other than the first end item and the second end item as a single item.
[Form 3]
the row includes three or more consecutive articles;
A control device for a logistics warehouse as described in form 1 or 2, wherein the group is composed of a single second integrated item that combines all of the items in the row other than the first end item.
[Form 4]
said row consisting of two consecutive said articles;
A control device for a logistics warehouse as described in any one of aspects 1 to 3, wherein the group is composed of one item other than the first end item.
[Form 5]
an automated warehouse for storing goods;
a storage lane for storing the arranged plurality of articles;
a conveyor provided between the storage lane and the automated warehouse,
an item information acquisition step of acquiring item information indicating an initial movement state and a movement completion state of the item when the item moves in the order of the storage lane, the conveyor, and the automated warehouse;
a route calculation step of calculating transport route information from the item information so as to satisfy a reference logical expression based on a constraint condition,
In the initial state of movement, when a plurality of the articles are lined up in succession to form a line, in the path calculation step,
a first process for calculating first candidate route information of the transport route information by grouping all of the plurality of articles in the row together and regarding them as a single first integrated article;
a second process is performed in which a first end item at one end of the row is separated, and a group including the items in the row other than the first end item is regarded as one item, and second candidate route information of the conveying route information is calculated;
A control method for a logistics warehouse, wherein one of the first candidate route information and the second candidate route information, whichever has a higher evaluation, is adopted as the transport route information.

1...logistics warehouse, 10...control device, 12...item information acquisition unit, 13...route calculation unit, 21...storage lane (transport lane), 22...conveyor, 100...automated warehouse, 121...outlet lane (transport lane), 150...item

Claims (5)

an automated warehouse for storing goods;
a storage lane for storing the arranged articles;
A control device for a logistics warehouse including a conveyor provided between the storage lane and the automated warehouse,
an item information acquisition unit that acquires item information indicating an initial state and a completed state of movement of the item when the item moves through the storage lane, the conveyor, and the automated warehouse in this order;
a route calculation unit that calculates transport route information from the item information so as to satisfy a reference logical expression based on a constraint condition;
In the initial state of movement, when a plurality of the articles heading to the same floor of the conveyor are lined up in succession to form a queue, the path calculation unit:
a first process for calculating first candidate route information of the transport route information by grouping all of the plurality of articles in the row together and regarding them as a single first integrated article;
a second process of separating a first end item at one end of the row, and calculating second candidate route information for the conveyance route information by treating a group including the items in the row other than the first end item as one item;
A control device for a logistics warehouse that adopts, as the transport route information, one of the first candidate route information and the second candidate route information that has a higher evaluation. the row includes three or more consecutive articles;
2. The control device for a logistics warehouse according to claim 1, wherein in the second processing, the route calculation unit separates a second end item at the other end of the row, and calculates the second candidate route information by treating a group including the items in the row other than the first end item and the second end item as one item. the row includes three or more consecutive articles;
The control device for a logistics warehouse according to claim 1 , wherein the group is configured as a single second integrated item that combines all of the items in the row other than the first end item. said row consisting of two consecutive said articles;
The control device for a logistics warehouse according to claim 1 , wherein the group is made up of one of the items other than the first end item. an automated warehouse for storing goods;
a storage lane for storing the arranged plurality of articles;
a conveyor provided between the storage lane and the automated warehouse,
an item information acquisition step of acquiring item information indicating an initial movement state and a movement completion state of the item when the item moves in the order of the storage lane, the conveyor, and the automated warehouse;
a route calculation step of calculating transport route information from the item information so as to satisfy a reference logical expression based on constraint conditions,
In the initial state of movement, when a plurality of the articles heading to the same floor of the conveyor are lined up in succession to form a queue, in the path calculation step,
a first process for calculating first candidate route information of the transport route information by grouping all of the plurality of articles in the row together and regarding them as a single first integrated article;
a second process is performed in which a first end item at one end of the row is separated, and a group including the items in the row other than the first end item is regarded as one item, and second candidate route information of the conveying route information is calculated;
A control method for a logistics warehouse, wherein one of the first candidate route information and the second candidate route information, whichever has a higher evaluation, is adopted as the transport route information.