Patent Description:
Recently, as the volume of objects such as cargo handled at distribution centers increases in the field of logistics, diligence is being made for greater efficiency in various approaches in relation to sorting and transporting of objects. As one approach, automated guided vehicles have been introduced to transport objects without requiring manpower. For instance, an automated guided vehicle ducks under a rack in which objects are contained, lifts the rack, and transports the rack to a targeted location.

<CIT> discloses a method for transporting inventory items includes moving a mobile drive unit to a first point within a workspace. The first point is a location of an inventory holder. The method further includes docking the mobile drive unit with the inventory holder and moving the mobile drive unit and the inventory holder to a second point within the workspace. The second point is associated with conveyance equipment. The method further includes moving the inventory holder to a third point within the workspace using the conveyance equipment.

<CIT> discloses a transport vehicle control device including: a storage portion that stores map information in which a state of a cell where a rack is arranged is saved for each cell; a data transceiver that receives the latest state of a cell from a transport vehicle which transports the rack; a map manager that updates the map information, each time the data transceiver receives the latest state of the cell, using the latest state of the cell received; and a route searcher that searches for a route for the transport vehicle transporting the rack based on the map information updated. The transport vehicle control device of the disclosure further includes a cell-for-rearranged-rack determiner that determines a cell into which the rack is rearranged on the basis of a usage frequency of articles to be stored on the rack.

<CIT> discloses a rack management system, including a processor and a storage unit. The storage unit stores information indicating positions of sections included in an area in which storage racks that store articles can be arranged. One of the storage racks can be arranged in each of the sections. At least one of the sections is surrounded by other adjacent sections without an aisle to convey the storage racks therebetween. The processor classifies the sections into sections assigned ranks indicating a degree of efficiency of an operation to convey the storage racks placed therein to a predetermined working area, and one or more empty sections into which, if there is a need to move one or more other storage racks in order to convey a storage rack placed in a given section, the other storage racks that were moved are placed, and outputs results of the classification.

<CIT> discloses an inventory system that has mobile drive units that freely and independently move about a facility to transport inventory holders. The mobile drive units may operate through communications with other drive units, or under a more centralized control of a management module. For various operating scenarios, the mobile drive units are directed to shuffle the inventory holders in a manner that minimizes travel of the mobile drive units, thereby improving overall system efficiency. One or more single mobile drive units may be used to transport inventory holders to and from a region, and to sequentially reposition or slide each of the inventory holders within the region according to a priority ordering.

As a volume of objects to be handled increases, the storage space for racks that store objects needs to be expanded, which increases costs. Aligning the racks at high density may be one solution; however, if the racks are simply placed with no space in-between, there may be a difficulty in retrieving a rack from the back or middle of the aligned rack group. Moreover, once the rack is retrieved, it may also become difficult to return it to the place. There is a demand from business operators for increasing the efficiency of storing, retrieving, and replacing objects.

The purpose of the embodiments is to offer a transport control device, a transport control method and program for improving efficiency in storing, retrieving and replacing objects.

An information processing apparatus according to an embodiment includes the features of claim <NUM>.

Hereinafter, the embodiment will be described with reference to the drawings.

<FIG> is a diagram for schematically showing an exemplary configuration of a transport control system according to an embodiment.

As illustrated in <FIG>, the transport control system <NUM> includes a host server <NUM> and an automated guided vehicle (AGV) controller <NUM> corresponding to a transport control device, where the AGV controller <NUM> controls an AGV <NUM>, which corresponds to a transport vehicle. In this embodiment, the AGV controller <NUM> controls multiple AGVs <NUM>. If the warehouse has multiple floors, an AGV controller <NUM> may be provided for a respective floor so that the AGV controller <NUM> of each floor can control the AGVs <NUM> allocated for the floor.

The host server <NUM> can be realized by a single computer or by combining multiple computers. The host server <NUM> can communicate with other devices such as the AGV controller <NUM> in a wired or wireless manner, receive information from these devices or transmit a control signal or the like to the devices to control the devices. The host server <NUM> stores load information relating to objects such as loads, rack information relating to a rack containing one or more objects, AGV information relating to the AGVs <NUM>, map data of the warehouse, and the like. The object information includes object identification information (ID) and the like, where each object has an object ID assigned. The rack information includes rack IDs and the like, where each rack has a rack ID assigned. The AGV information includes AGV IDs and the like, where each AGV <NUM> has an AGV ID assigned.

An object ID may be marked directly upon each object, or a tag on which an object ID is marked may be attached to each object. As a manner of marking the object ID, it may be printed visibly, or printed invisibly with an ink that absorbs infrared light. Alternatively, an electronic tag or wireless tag in which an object ID is stored may be attached to an object. An object ID includes at least identification information constituted by one selected from numerals, characters, symbols, a bar code, a two-dimensional code, and a QR code (trademark), or a combination of two or more selected therefrom. Similarly, a rack ID may be marked directly upon each rack, or a tag or the like on which a rack ID is marked may be attached to the rack. An AGV <NUM> has an AGV ID. The AGV ID may be marked directly on each AGV <NUM>, or a tag or the like on which an AGV ID is marked may be attached to the AGV <NUM>.

The transport control system <NUM> according to the embodiment includes a plurality of cameras for taking images inside the warehouse and a plurality of ID readers. The ID readers read object IDs, rack IDs, and AGV IDs. The host server <NUM> detects the position of each object, each rack and each AGV <NUM>, and traces the move thereof, based on the warehouse map data, positional information of each camera and each ID reader on the map, an image taken by each camera, and an ID read by each ID reader. The host server <NUM> further draws up schedules regarding which AGV <NUM> moves which rack at which timing, in response to an object retrieval request.

In accordance with the schedule received from the host server <NUM>, the AGV controller <NUM> transmits a control signal to each AGV <NUM> to control the travel of each AGV <NUM> and pickup and placement of a rack by the AGV <NUM>. Pickup of a rack includes lifting, retrieving, and loading a rack. Placement of a rack includes lowering a lifted rack, releasing a retrieved rack, and dropping a loaded rack off. In the embodiment, a case of the AGV <NUM> picking up and moving a rack will be discussed. The transport control system according to the present embodiment is equally applicable to a case of the AGV <NUM> picking up and moving an object.

<FIG> is a diagram for showing an example of an AGV and a rack to be transported by the AGV in the transport control system according to the embodiment.

An AGV <NUM> is a wheeled, self-propelled robot, which, in response to a control signal from the AGV controller <NUM>, travels toward a pickup position corresponding to a targeted rack R (e.g., directly under the rack R), picks up the targeted rack R at the pickup position, and travels toward a rack placement position. In response to the control signal from the AGV controller <NUM>, the AGV <NUM> places the targeted rack R at the rack placement position corresponding to the targeted rack.

A rack R may stand upright with its four legs, with a height of the clearance under the rack (from the floor surface to the bottom of the rack) being larger than the height of an AGV <NUM>. This allows the AGV <NUM> to duck under the rack. The AGV <NUM> that has ducked under the rack lifts the rack with the rack lifting mechanism <NUM> to the extent that the legs will be lifted several centimeters off the floor surface, and travels with the rack being lifted. In this manner, the AGV <NUM> can transport the rack.

For instance, the AGV <NUM> travels to the destination position, based on the map data, destination position data, and current position data. The AGV <NUM> travels to the destination position while detecting the moving distance and moving direction. Alternatively, the AGV <NUM> travels to the destination position while reading a magnetic tape or two-dimensional bar codes attached to the passageways. Furthermore, the AGV <NUM> may be provided with a laser detection sensor, a camera or the like to detect obstacles (including other AGVs <NUM>) so as to travel while avoiding the obstacles detected by the laser detection sensor or the obstacles detected through analysis of images taken by the camera.

<FIG> is a block diagram for schematically showing an exemplary configuration of an AGV controller in the transport control system according to the embodiment.

The AGV controller <NUM> corresponds to a transport control device configured to control the travel of the AGV <NUM> and pickup and placement of a rack by the AGV <NUM>. For instance, the AGV controller <NUM> controls the operations of the AGV <NUM> including traveling to the rack pickup position, picking the rack up, moving the rack to the rack placement position, and dropping the rack off at the rack placement position. As illustrated in <FIG>, the AGV controller <NUM> includes a processor <NUM>, a ROM <NUM>, a RAM <NUM>, an auxiliary memory device <NUM>, a communication interface <NUM>, and an input/output unit <NUM>.

The processor <NUM> serves as the central portion of the computer configured to execute processing such as calculations and controls required for the travel of the AGVs <NUM> and the pickup and placement of racks by the AGVs <NUM>. The processor <NUM> executes control to implement various functions of the AGV controller <NUM>, based on the system software programs, application software programs, firmware programs stored in the ROM <NUM>, auxiliary memory device <NUM> or the like. The processor <NUM> may be a central processing unit (CPU), a micro processing unit (MPU), or a digital signal processor (DSP). Alternatively, the processor <NUM> may be a combination of any of these.

The ROM <NUM> is a non-transitory computer-readable storage medium, serving as the main memory device of the computer having the processor <NUM> as the central unit. The ROM <NUM> is a nonvolatile memory exclusively used for data reading. The ROM <NUM> stores therein the above-mentioned programs. Furthermore, the ROM <NUM> stores data and various setting values used by the processor <NUM> for performing various kinds of processing.

The RAM <NUM> serves as the main memory device of the computer having the processor <NUM> as the central unit. The RAM <NUM> is a memory used for data reading and writing. The RAM <NUM> is used, for example, as what is called a work area to temporarily store data when the processor <NUM> performs various kinds of processing.

The auxiliary memory device <NUM> is a non-transitory computer-readable storage medium, serving as an auxiliary memory device of the computer having the processor <NUM> as the central unit. The auxiliary memory device <NUM> may store therein the above-mentioned programs. The auxiliary memory device <NUM> also stores the data used when the processor <NUM> performs various kinds of processing, as well as the data and various setting values produced through the processing of the processor <NUM>.

The programs stored in the ROM <NUM> or auxiliary memory device <NUM> include a program for controlling the travel of the AGVs <NUM> and pickup and placement of racks by the AGVs <NUM>. For instance, the AGV controller <NUM> may be transferred to a manager of the AGV controller <NUM> or the like with the programs stored in the ROM <NUM> or auxiliary memory device <NUM>. Alternatively, the AGV controller <NUM> may also be transferred to the manager or the like with the programs not stored in the ROM <NUM> or auxiliary memory device <NUM>. The programs may be separately transferred to the manager so that they can be written into the auxiliary memory device <NUM> under the manipulation of the manager or a service provider. The transfer of the programs may be realized, for example, through a removable storage medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory, or through downloading via a network or the like.

The communication interface <NUM> communicates via a network or the like with other devices such as the host server <NUM> and AGVs <NUM> in a wired or wireless manner, receives various kinds of information transmitted from these devices, and transmits various kinds of information to the devices. For instance, the communication interface <NUM> receives a schedule from the host server <NUM>, and transmits to the AGVs <NUM> a control signal for controlling the travel of the AGVs.

The input/output unit <NUM> includes a keyboard, a numeric keyboard, a mouse, a touch panel display, and the like. The input/output unit <NUM> receives an instruction input by the operator, and informs the processor <NUM> of the instructions. The touch panel display presents to the operator various types of information.

<FIG> is a block diagram for schematically showing an exemplary configuration of an AGV according to the embodiment.

As illustrated in <FIG>, the AGV <NUM> includes a processor <NUM>, a ROM <NUM>, a RAM <NUM>, an auxiliary memory device <NUM>, a communication interface <NUM>, and a driving unit <NUM>.

The processor <NUM> serves as the central portion of the computer configured to execute processing such as calculations and controls required for travel and pickup/drop-off of racks. The processor <NUM> executes control to implement various functions of the AGV <NUM>, based on the system software programs, application software programs, and firmware programs stored in the ROM <NUM>, auxiliary memory device <NUM> or the like. The processor <NUM> may be a CPU, MPU, or DSP. Alternatively, the processor <NUM> may be a combination of any of these. For instance, the AGV controller <NUM> transmits a control signal for moving the AGV <NUM> to a destination position, and the processor <NUM> outputs a drive signal corresponding to map data included in the control signal transmitted from the AGV controller <NUM>, destination position data, and current position data. Alternatively, the processor <NUM> outputs a drive signal corresponding to a rack pickup and drop-off instruction included in the control signal transmitted from the AGV controller <NUM>.

The auxiliary memory device <NUM> is a non-transitory computer-readable storage medium, serving as an auxiliary memory device of the computer having the processor <NUM> as the central unit. The auxiliary memory device <NUM> may store therein the above-mentioned programs. The auxiliary memory device <NUM> also stores the data used when the processor <NUM> performs various kinds of processing, as well as data and various setting values produced through the processing of the processor <NUM>.

The communication interface <NUM> communicates via a network or the like with other devices such as the AGV controller in a wireless manner, receives various types of information transmitted from these devices, and transmits various types of information to the devices. For instance, the communication interface <NUM> receives a control signal from the AGV controller <NUM>. The communication interface <NUM> also transmits completion notices to the AGV controller <NUM> to report the completion of travel to the destination position, completion of a pickup of a rack, or completion of a placement of a rack.

The driving unit <NUM> includes wheels configured to be rotated by a motor, a steering mechanism for switching the traveling direction, a rack lifting mechanism configured to be vertically moved by a motor, and the like. In response to a drive signal output by the processor <NUM>, the driving unit <NUM> rotates or stops the motor and controls the steering mechanism to move the AGV <NUM> to a destination position. With the AGV <NUM> ducking under the rack, the driving unit <NUM> rotates the motor (for a forward rotation) in response to a drive signal output by the processor <NUM> so that the rack lifting mechanism can ascend and lift the rack. After the AGV <NUM> reaches the destination position, the driving unit <NUM> rotates the motor (for an inverse rotation) in response to a drive signal output by the processor <NUM> so that the rack lifting mechanism can descend and place the rack down to the floor.

Next, the environment of the warehouse in which the AGVs <NUM> travels around will be described.

<FIG> is a diagram for showing an exemplary warehouse environment for which the transport control system according to the embodiment is adopted.

In the warehouse, a plurality of racks are aligned. A plurality of aligned racks form a row of racks, and a plurality of rows of racks form a group of racks. Groups of racks that are formed are positioned at predetermined intervals, and racks in one group are aligned at predetermined intervals.

For instance, as illustrated in <FIG>, rack groups <NUM> and <NUM> are formed and positioned at predetermined intervals in the warehouse <NUM>. The rack group <NUM> includes rack rows <NUM> and <NUM>, where the rack row <NUM> includes racks A4, B4, C4, and D4, and the rack row <NUM> includes racks A3, B3, C3, and D3. Furthermore, the rack group <NUM> includes rack rows <NUM> and <NUM>, where the rack row <NUM> includes racks A2, B2, C2, and D2, and the rack row <NUM> includes racks A1, B1, C1, and D1. A rack that can be any rack will be referred to as a "rack R".

The warehouse <NUM> includes an outer aisle <NUM> at the peripheries of the rack groups <NUM> and <NUM>, under-rack aisles <NUM> under the racks R, and a pickup station <NUM> (rack area) where a rack R carried from the rack groups <NUM> and <NUM> by the AGV <NUM> is placed. Under each rack R, an under-rack aisle <NUM> is formed to allow the AGV <NUM> to pass.

The outer aisle <NUM> includes an outbound passageway <NUM>, a return passageway <NUM> (first return passageway), a return passageway <NUM> (second return passageway), a return passageway <NUM> (second return passageway), and a return passageway <NUM> (second return passageway), each having a passageway width corresponding to a rack transported by an AGV <NUM>.

The outbound passageway <NUM> is defined in the proximity of the rack row <NUM> (first rack row) of the rack group <NUM> (specific rack group), and the AGV <NUM> travels through this outbound passageway <NUM> from the pickup station <NUM> to a targeted rack R, which is included in the rack row <NUM> of the rack group <NUM> (outbound trip). The AGV <NUM> also travels through the outbound passageway <NUM> and under-rack aisle <NUM> from the pickup station <NUM> to a targeted rack R included in the rack row <NUM> of the rack group <NUM> or to a targeted rack R included in the rack row <NUM> or rack row <NUM> of the rack group <NUM> (outbound trip). The return passageway <NUM> is defined in the proximity of the rack row <NUM> (first rack row) of the rack group <NUM> (specific rack group), and the AGV <NUM> travels through this return passageway <NUM> from the targeted rack included in the rack row <NUM> to the pickup station <NUM> (return trip).

The return passageway <NUM> is defined in the proximity of the rack row <NUM> (second rack row) of the rack group <NUM>, and the AGV <NUM> travels through this return passageway <NUM> and the return passageway <NUM> from the targeted rack included in the rack row <NUM> to the pickup station <NUM> (return trip). The return passageway <NUM> is defined in the proximity of the rack row <NUM> (second rack row) of the rack group <NUM>, and the AGV <NUM> travels through this return passageway <NUM> and the return passageway <NUM> from the targeted rack included in the rack row <NUM> to the pickup station <NUM> (return trip). As described above, all of the outer aisles <NUM> are determined to have one-way traffic in order to avoid collisions of AGVs <NUM> and to simplify the transport management of the multiple AGVs <NUM>. In addition, waiting of an AGV <NUM> for another AGV to pass can be reduced.

The auxiliary memory device <NUM> of the AGV controller <NUM> stores the map data of the warehouse <NUM>, where the map data includes positional information relating to the racks R of the rack groups <NUM> and <NUM>, pickup station <NUM>, outer aisles <NUM>, and under-rack aisles <NUM>. The auxiliary memory device <NUM> further stores management information for managing the racks R and objects contained in each rack R. The management information includes rack information including rack IDs and object information including object IDs.

Next, rack retrieval and rack sliding by the transport control system according to the embodiment will be described.

For instance, the AGV controller <NUM> selects one or more AGVs <NUM> from multiple AGVs <NUM> in the warehouse <NUM>. If one AGV <NUM> is selected, the AGV controller <NUM> transmits to the selected AGV <NUM> a first control signal including a rack retrieval instruction, a second control signal including a rack sliding instruction, and a third control signal including a rack returning instruction for returning the rack placed in the pickup station <NUM> to a vacant space. If multiple AGVs <NUM> are selected, the AGV controller <NUM> transmits the first control signal to one of the selected AGVs <NUM>, and the second control signal to another one of the selected AGVs <NUM>.

First, by referring to <FIG>, a rack retrieval will be described. <FIG> are diagrams showing the transition of an exemplary rack retrieval by the transport control system according to the embodiment.

As illustrated in <FIG>, it is assumed that the rack groups <NUM> and <NUM> are positioned side by side. The AGV controller <NUM> selects a single AGV <NUM> from multiple AGVs <NUM> in the warehouse <NUM>, and instructs the selected AGV <NUM> to retrieve the rack C1. For instance, the processor <NUM> of the AGV controller <NUM> selects an AGV <NUM> on standby in the pickup station <NUM> and outputs a first control signal, and thereby the communication interface <NUM> transmits the first control signal to the selected AGV <NUM>.

The first control signal controls the travel of the AGV <NUM> through the outbound passageway <NUM> and under-rack aisle <NUM> from the pickup station <NUM> to the pickup position corresponding to the rack C1 (e.g., directly below the rack C1), controls the pickup of the rack C1 by the AGV <NUM>, controls the travel of the AGV <NUM> through the under-rack aisle <NUM>, return passageway <NUM>, and return passageway <NUM> from the pickup position corresponding to the rack C1 to the predetermined position of the pickup station <NUM>, and controls the placement of the rack C1 at the predetermined position by the AGV <NUM>.

In accordance with the first control signal, the AGV <NUM> travels from the pickup station <NUM> to the pickup position corresponding to the rack C1 through the outbound passageway <NUM> (<NUM> cells upward) and under-rack aisle <NUM> (<NUM> cells leftward), where it lifts the rack C1 with the rack lifting mechanism <NUM>, and completes the pickup of the rack C1. Furthermore, as illustrated in <FIG>, in accordance with the first control signal, the AGV <NUM> travels from the pickup position corresponding to the rack C1 to the predetermined position of the pickup station <NUM> through the under-rack aisle <NUM> (<NUM> cell leftward), the return passageway <NUM> (<NUM> cells downward), and the return passageway <NUM> (<NUM> cells rightward and <NUM> cell downward), where it places the rack C1 at the predetermined position. As shown in <FIG>, the space <NUM> where the rack C1 of the rack group <NUM> was placed becomes a vacant space, created by the transport of the rack C1.

With reference to <FIG>, the rack sliding will now be described. <FIG> are diagrams showing the transition of an exemplary rack sliding process in the transport control system according to the embodiment.

The AGV controller <NUM> selects a single AGV <NUM> or multiple AGVs <NUM> from the AGVs <NUM> in the warehouse <NUM>, and instructs the selected AGV <NUM> to perform the rack sliding. The processor <NUM> of the AGV controller <NUM> determines, based on the operational state of each AGV <NUM> in the warehouse <NUM>, whether to have a single AGV <NUM> perform a rack retrieval and rack sliding, or to have multiple AGVs <NUM> (first and second transport vehicles) perform a rack retrieval and rack sliding.

If a single AGV <NUM> (first transport vehicle) is slated to perform the rack retrieval and rack sliding, the processor <NUM> selects the same AGV <NUM> as the AGV <NUM> that transports the rack C1 in <FIG>. If two different AGVs <NUM> (first and second transport vehicles) are slated to perform the rack retrieval and rack sliding, the processor <NUM> selects AGVs <NUM> that differ from the AGV <NUM> carrying the rack C1 in <FIG>. Furthermore, if the rack sliding is performed multiple times, the processor <NUM> may determine, based on the operational state of each AGV <NUM> in the warehouse <NUM>, whether to have the same AGV <NUM> perform the rack sliding multiple times, or to have different AGVs <NUM> perform the rack sliding multiple times, and then select AGVs <NUM>.

When multiple AGVs <NUM> are selected, the rack sliding can be planned at the timing at which the rack retrieval is determined so that the rack sliding can be efficiently implemented. The AGV <NUM> for performing the rack sliding can be kept on standby near the vacant space before the vacant space is ready. In this manner, the rack sliding can be realized as soon as the vacant space is ready.

The processor <NUM> of the AGV controller <NUM> outputs a second control signal to perform rack sliding once or multiple times, and the communication interface <NUM> thereby transmits the second control signal to the selected AGV <NUM>. For instance, the second control signal includes a signal for performing rack sliding by the AGV <NUM> to carry the rack C2, which was adjacent to the rack C1, to the space <NUM> so that the vacancy in the space <NUM> created by the transport of the rack C1 can be shifted to the adjacent space <NUM> to create a vacant space <NUM>.

If a single AGV <NUM> on standby in the pickup station <NUM> is selected, the selected AGV <NUM> travels based on the second control signal through the outbound passageway <NUM> and under-rack aisle <NUM>, from the pickup station <NUM> to the pickup position corresponding to the rack C2 adjacent to the rack C1, where it lifts the rack C2 with the rack lifting mechanism <NUM>, and completes the pickup of the rack C2. As illustrated in <FIG>, the AGV <NUM> transports the rack C2 from the pickup position to the space <NUM>, and places the rack C2 in the space <NUM>.

Furthermore, in accordance with the second control signal, the AGV <NUM> returns through the under-rack aisle <NUM> and return passageway <NUM> to the pickup station <NUM>, and travels through the outbound passageway <NUM> and under-rack aisle <NUM> from the pickup station <NUM> to the pickup position corresponding to the rack C3 adjacent to the rack C2, where it lifts the rack C3 with the rack lifting mechanism <NUM>, and completes the pickup of the rack C3. The AGV <NUM> transports the rack C3 from the space <NUM> to the space <NUM>, and places the rack C3 in the space <NUM> (see <FIG>). Alternatively, in accordance with the second control signal, the AGV <NUM> travels through the under-rack aisle <NUM> from the space <NUM> to the space <NUM>, lifts the rack C3 with the rack lifting mechanism <NUM>, completes the pickup of the rack C3, transports the rack C3 from the space <NUM> to the space <NUM>, and places the rack C3 in the space <NUM> (see <FIG>).

In accordance with the second control signal, the AGV <NUM> also returns through the under-rack aisle <NUM> and return passageway <NUM> to the pickup station <NUM>, and travels through the outbound passageway <NUM> and under-rack aisle <NUM> from the pickup station <NUM> to the pickup position corresponding to the rack C4 adjacent to the rack C3, where it lifts the rack C4 with the rack lifting mechanism <NUM>, and completes the pickup of the rack C4. The AGV <NUM> transports the rack C4 from the space <NUM> to the space <NUM>, and places the rack C4 in the space <NUM> (see <FIG>). Alternatively, in accordance with the second control signal, the AGV <NUM> travels through the under-rack aisle <NUM> from the space <NUM> to the space <NUM>, lifts the rack C4 with the rack lifting mechanism <NUM>, completes the pickup of the rack C4, transports the rack C4 from the space <NUM> to the space <NUM>, and places the rack C4 in the space <NUM> (see <FIG>). In the above manner, the vacancy in the space <NUM> can be shifted over to a targeted position (i.e., the rack row <NUM> of the rack group <NUM> closest to the pickup station <NUM>).

In accordance with the third control signal, the AGV <NUM> travels through the under-rack aisle <NUM> and return passageway <NUM> to the pickup position corresponding to the rack C1 of the pickup station <NUM>, where it lifts the rack C1 with the rack lifting mechanism <NUM> and completes the pickup of the rack C1. The AGV <NUM> transports the rack C1 from the pickup position to the space <NUM> through the outbound passageway <NUM>, and places the rack C1 in the space <NUM> (see <FIG>). In the above manner, the retrieved rack C1 can be replaced in the rack row <NUM> of the rack group <NUM> closest to the pickup station <NUM>.

<FIG> is a flowchart showing exemplary rack retrieving and rack sliding operations in the transport control system according to the embodiment.

For instance, the host server <NUM> designates a targeted rack to be retrieved from groups of racks, and the communication interface <NUM> of the AGV controller <NUM> receives the designation of the targeted rack (ST1). Based on the operational states of the AGVs <NUM>, the processor <NUM> selects one or more AGVs <NUM> slated to control the transport of a rack and sliding of the rack (ST2), and generates a first control signal for controlling the transport of a rack and a second control signal for controlling the sliding of the rack. The communication interface <NUM> transmits the first control signal to the selected AGV <NUM>, and transmits the second control signal to the selected AGV <NUM>. The AGVs <NUM> to which the first and second control signals are transmitted may be the same AGV <NUM>, or different AGVs <NUM>.

The processor <NUM> of the AGV controller <NUM> transmits the first control signal to the selected AGV <NUM> via the communication interface <NUM> to control the transport of the rack (ST3), and transmits the second control signal to the selected AGV <NUM> via the communication interface <NUM> to control the rack sliding (ST5).

That is, the processor <NUM> controls the travel of the AGV <NUM> to a targeted rack with the first control signal (ST31), controls the pickup of the targeted rack by the AGV <NUM> (ST32), controls the travel of the AGV <NUM> toward the pickup station <NUM> (ST33), and controls the placement of the targeted rack in the pickup station <NUM> by the AGV <NUM> (ST34).

If the targeted position (e.g., the rack row <NUM> of the rack group <NUM> closest to the pickup station <NUM>) does not become vacant under the control of the rack transport at ST3 (no at ST4), the processor <NUM> controls the travel of the AGV <NUM> toward a sliding-targeted rack, which is adjacent to the transported rack, using the second control signal (ST51), the pickup of the sliding-targeted rack by the AGV <NUM> (ST52), the travel of the AGV <NUM> toward the vacant space (ST53), and the placement of the sliding-targeted rack in the vacant space by the AGV <NUM> (ST54).

If the targeted position does not become vacant (no at ST4), the rack sliding is repeated (ST5). If the targeted position becomes vacant (yes at ST4), the processing is terminated.

As described above, the embodiment offers the transport control device, transport control method, and program, which can improve efficiency in storing, retrieving and replacing objects.

Claim 1:
A transport control device (<NUM>) comprising:
a storage unit (<NUM>) configured to store positional information relating to racks (R) included in a plurality of rack groups (<NUM>, <NUM>) provided at predetermined intervals, an outer aisle (<NUM>) around the rack groups (<NUM>, <NUM>), an under-rack aisle (<NUM>) under each of the racks (R), and a rack area (<NUM>) in which a rack retrieved from the rack groups (<NUM>, <NUM>) by a transport vehicle (<NUM>) is placed, and management information for managing the racks (R);
a control unit configured to output a control signal for controlling the transport vehicle (<NUM>) based on the positional information and the management information; and
a communication unit configured to transmit the control signal to the transport vehicle (<NUM>),
wherein each of the rack groups (<NUM>, <NUM>) includes a first rack row (<NUM>) and a second rack row (<NUM>),
the outer aisle (<NUM>) includes an outbound passageway (<NUM>), a first return passageway (<NUM>), and a second return passageway (<NUM>, <NUM>, <NUM>), the outbound passageway (<NUM>) and the first return passageway (<NUM>) being in proximity to the first rack row (<NUM>) in a predetermined rack group of the rack groups (<NUM>, <NUM>), and the second return passageway (<NUM>, <NUM>, <NUM>) being in proximity to the second rack row (<NUM>) of each of the rack groups (<NUM>, <NUM>), and
the control unit outputs a first control signal for controlling a travel of the transport vehicle (<NUM>) toward a first pickup position corresponding to a first rack included in the rack groups (<NUM>, <NUM>), controlling a pickup of the first rack by the transport vehicle (<NUM>), and controlling the travel of the transport vehicle (<NUM>) by way of the first or second return passageway (<NUM>, <NUM>, <NUM>) from the first pickup position to the rack area (<NUM>),
characterized in that the control unit further outputs a second control signal for performing rack sliding once or a plurality of times, wherein in the rack sliding, a second rack previously adjacent to the first rack is transported by the transport vehicle (<NUM>) to a vacant space (<NUM>) created after transport of the first rack, and
the second control signal includes a signal for repeating the rack sliding until the vacant space (<NUM>) moves to a position included in the first rack row (<NUM>) of the predetermined rack group.