JP7198621B2 - Conveyance control device, article conveyance system and program - Google Patents

Description

The present invention relates to a transport control device, an article transport system, and a program.

As a background art of this technical field, the summary of the following patent document 1 states that "Even if the self-position is at a position with poor estimation accuracy, it can autonomously move to a safe position with high estimation accuracy according to the past movement history. provide autonomous mobile robots." In addition, in paragraph 0013 of the specification of the same document, "The autonomous mobile robot 1 according to the embodiment of the present invention is a quad-rotor type small unmanned helicopter, as shown in the schematic diagram of FIG. The scope of application is not limited to quad-rotor type small unmanned helicopters, but can also be applied to single-rotor type small unmanned helicopters and autonomous mobile robots." ing.

JP 2016-173709 A

By the way, in Patent Document 1, there is no particular mention of applying the autonomous mobile robot as a transport device for a warehouse or the like. However, in a warehouse or the like, objects to be transported, conveying devices, and structures such as walls and pillars are arranged at a relatively high density. Therefore, when a transport task occurs, if the transport device to be started according to the transport task is inappropriate, the transport device may not be operated appropriately.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a transport control device, an article transport system, and a program capable of appropriately operating a transport device.

In order to solve the above-mentioned problems, the transport control device of the present invention has a function of acquiring the arrangement status of surrounding objects of a plurality of transport devices , and estimating the position information of each of the transport devices based on the arrangement status of the surrounding objects. a function of determining whether or not the position information can be estimated, and selecting one of the transport devices as a movement target transport device from among the transport devices determined to be capable of estimating the position information ; and a function of outputting a movement command.

ADVANTAGE OF THE INVENTION According to this invention, a conveying apparatus can be used appropriately.

1 is a perspective view showing a transport robot applied to a first embodiment of the present invention and a shelf to be transported; FIG. 1 is a perspective view of a transfer robot; FIG. It is a top view of a warehouse. It is a schematic diagram of environment map data. FIG. 4 is a schematic diagram of environment map data set in units of grids; 4 is a block diagram of a control unit arranged in the housing of the transfer robot; FIG. 3 is a block diagram of a general control device; FIG. FIG. 11 is an operation explanatory diagram showing the operation when the transport robot is brought into the storage space from the outside; FIG. 10 is an operation explanatory diagram of position detection using a bar code; It is a figure which shows the relationship between a conveyance robot and a laser measurement range. 4 is a flow chart of a transfer robot activation processing program; FIG. 10 is an operation explanatory diagram showing a method of determining a transport robot to be moved; FIG. 13 is a detailed view of the main part of FIG. 12; 4 is a flow chart of a transport task handling program in the general control device; 4 is a flow chart of a transfer task processing program in a transfer robot; It is a figure which shows the specific example of operation|movement of a conveyance robot. 10 is a flow chart of a transfer task handling program in the integrated control device of the second embodiment.

[First embodiment]
<Configuration of the first embodiment>
(Conveyor robot 102)
Hereinafter, the configuration of the warehouse system according to the first embodiment of the present invention will be described in detail. The warehouse system according to the present embodiment is applied to applications such as when a warehouse company stores goods in a mail-order warehouse and ships goods therefrom. However, the present invention can also be applied, for example, when a manufacturer or the like stores and manages parts in-house. It should be noted that the "goods" in the present embodiment is a concept that includes commodities to be traded, other products, parts, and the like.
FIG. 1 is a perspective view showing a transport robot 102 (transport device) applied to this embodiment and a shelf 111 to be transported. The shelf 111 includes an article storage section 112 in the shape of a substantially rectangular parallelepiped frame, and four support legs 114 protruding downward from four corners of the article storage section 112 .

As shown in FIG. 1, the transport robot 102 can crawl into the space below the article storage section 112 . The transport robot 102 can lift and move the shelf 111 by pushing up the article storage unit 112 from below. In this embodiment, when the transport robot 102 slips under the article storage section 112, the transport robot 102 slips in from one of the illustrated "front and back" or "left and right" directions. If an attempt is made to slip in from a direction oblique to the “front-rear” or “left-right” direction, the transport robot 102 and the support legs 114 may collide.

FIG. 2 is a perspective view of the transport robot 102. As shown in FIG. In FIG. 2, the transport robot 102 has a substantially rectangular parallelepiped housing 102a, and a pair of wheels 120 are attached to the bottom of the housing 102a. By rotating the pair of wheels 120 in the same direction, the transfer robot 102 can be moved on the floor surface. Further, by rotating the pair of wheels 120 in different directions, the transport robot 102 can be turned on the floor while maintaining the orientation of the shelf 111 (see FIG. 1) being transported. It is also possible to turn the transport robot 102 on the floor together with the shelf 111 . The height of the transport robot 102 is, for example, about 20 cm.

At the center of the upper surface of the transfer robot 102, a substantially disk-shaped shelf support portion 122 is provided. When the shelf support portion 122 is lifted upward, the shelf support portion 122 contacts the bottom plate of the article storage portion 112 (see FIG. 1) and pushes up the bottom plate, thereby pushing the shelf 111 upward. The transport robot 102 has collision detection units 124 on four sides. The collision detection unit 124 emits electromagnetic waves such as an infrared laser or radio waves to the surroundings. Then, when the radiated electromagnetic waves are reflected by surrounding obstacles, the collision detection unit 124 detects the position of the obstacles based on the reflection state. Thereby, collision between the transport robot 102 and the obstacle can be prevented.

In addition, the transport robot 102 is equipped with a laser scanner 130 (scanner) such as LIDAR (Laser Imaging Detection and Ranging) at one corner of the housing in order to detect conditions in a wider range. Since the laser scanner 130 is provided at one corner of the housing, the laser scanner 130 can detect the surrounding conditions within an angular range of approximately 270°.

The transport robot 102 also includes a wireless communication device 123, an infrared communication device 125, a camera 127, an operation/display unit 128, and a control unit 720 (transport control device, computer). The wireless communication device 123 performs wireless communication with an overall control device, which will be described later. Here, the integrated control device is a device that performs integrated control of the operations of the plurality of transport robots 102 .

The infrared communication device 125 also performs infrared communication with surrounding equipment such as a charging station (not shown). A camera 127 is installed at the bottom of the transfer robot 102 . The camera 127 has a function of reading a bar code (not shown) displayed on the floor, and the transport robot 102 can thereby recognize its own position. The operation/display unit 128 includes various push buttons, lamps, and the like operated by the operator.

(Warehouse 100)
FIG. 3 is a plan view of the warehouse 100 applied to this embodiment.
In the illustrated example, the warehouse 100 is a one-story building comprising a storage space 202 (floor surface), a work space 203, and a partition wall 204 separating them. A plurality of shelves 111 and a plurality of transport robots 102 that transport the shelves 111 are arranged in the storage space 202 . A work space 203 is a space where workers work.

The partition wall 204 is, for example, a wire mesh, and includes an entry gate 205 for entering articles into the storage space 202 and an exit gate 206 for exiting the article from the storage space 202 . Here, "warehousing" means, for example, storing an article purchased from a supplier in the storage space 202 . Also, "delivery" means, for example, taking out an article from the storage space 202 according to a customer's order.

The storage space 202 has a substantially rectangular shape, and walls 142, 144, and 146 (objects) indicated by broken lines are erected at locations corresponding to the upper, right, and left sides in the figure, respectively. Walls 142, 144, and 146 are walls extending from the floor to the ceiling. A wall 148 indicated by a dashed line is erected at a location corresponding to the lower side of the storage space 202 in the drawing. The wall 148 is a low wall, and has a height (for example, about 20 cm) that can be detected by the transport robot 102 with the collision detector 124 and the laser scanner 130 (see FIG. 1).

In addition, five pillars 132, 134, 136, 138, 140 (objects) for supporting the building are erected inside the storage space 202. As shown in FIG. In addition, the storage space 202 is virtually partitioned into grids 107 that are a plurality of square areas. In the illustrated example, a total of "84" square grids 107 are formed with "12" columns in the X direction and "7" rows in the Y direction. Each grid 107 can be identified by grid coordinates of the form "(X,Y)". In other words, in the illustrated example, the grid 107 is formed in the range of grid coordinates (1,1) to (12,7).

The positions of the racks 111 and the transport robots 102 in the storage space 202 are managed in units of grids. Here, since the grid demarcates the storage space 202 virtually, lines or the like demarcating the grid are not drawn on the floor surface of the storage space 202 . However, in order to allow the transport robot 102 to accurately grasp its own position, a bar code 208 indicating its position is affixed to some of the grids. Note that in the example shown in FIG. 3, the barcode 208 is shown only in one grid, and illustration of the other barcodes 208 is omitted.

Storage space 202 and working space 203 may have any size. The shape and area of the grid 107 are also arbitrary, but one grid preferably has a shape and area that allow one shelf 111 to fit without gaps. In the storage space 202, the plurality of shelves 111 are arranged so that 2 columns×3 rows=6 pieces form one “island”. However, the shape of the island and the number of shelves 111 belonging to one island are arbitrary.

In FIG. 3, the shelf 111 is represented by a “bold square with crosshairs”. In addition, the transport robot 102 is represented by a “slightly small chamfered square with a circle drawn in the center”. Further, as shown in FIG. 1, the transport robot 102 crawls under the shelf 111 to transport the shelf 111. As shown in FIG. The transport robot 102 and shelf 111 in that state are called a "collection". In FIG. 3, the aggregate 211 is expressed as a figure in which "a thick square with a cross line" and "a slightly smaller chamfered square with a circle drawn in the center" are superimposed.

(environmental map data)
FIG. 4 is a schematic diagram of the environment map data 180 applied to this embodiment.
The environment map data 180 is map data used by the transport robot 102 to estimate its own position. Environment map data 180 includes position information corresponding to walls 142, 144, 146, 148, columns 132, 134, 136, 138, 140, and grid 107 shown in FIG. The environment map data 180 may be generated by measuring the internal structure of the storage space 202, or may be generated based on CAD data when the warehouse 100 was constructed.

In FIG. 4, columns 132-140 and walls 142-148 are shown in solid lines. These pillars and walls indicated by solid lines are elements that can be detected by the laser scanner 130 (see FIG. 2) of the transfer robot 102 . The transport robot 102 can estimate the current position of the robot by collating the surrounding state of the robot detected by the laser scanner 130 with the environment map data 180 .

In addition to the pillars 132 to 140 and the walls 142 to 148, markers for the transfer robot 102 to detect its own position may be placed anywhere in the storage space 202. FIG. This marker can be composed of, for example, a signboard temporarily installed in the storage space 202 and a reflective material attached to the signboard. Unlike the pillars 132-140 and the walls 142-148, etc., this type of marker is not fixed to the building, so the installation arrangement can be changed according to the situation.

(Environmental map data in grid units)
FIG. 5 is a schematic diagram of the environmental map data 182 set in grid units.
In the environment map data 180 shown in FIG. 4, the walls 142-148 were treated as "straight lines" reflecting the laser from the laser scanner 130. In FIG. On the other hand, in the environment map data 182 shown in FIG. 5, the walls 142 to 148 are expressed as planes having a width of 1 grid. For this reason, the environment map data 182 shown in FIG. 5 has an area expanded by one grid each in the vertical and horizontal directions as compared with the environment map data 180 .

A grid is formed in the environment map data 182 in the range of grid coordinates (-1, -1) to (13, 8). The grid coordinates to the left of the grid coordinates (1, 1) are (-1, 1), and the grid coordinates immediately below the grid coordinates (1, 1) are (1, -1). Each grid also stores a value called "object level".

Each transport robot 102 estimates its own position according to surrounding objects such as walls and pillars. However, the accuracy of position estimation differs depending on the type of object. The “object level” is a value that increases as the accuracy of position estimation that can be expected for each transport robot 102 to estimate its own position increases.

First, the object level of the grid corresponding to walls 142-148 (see FIG. 4) is "1". Also, the object level of the grid corresponding to columns 132-140 in storage space 202 is "2". Further, the object level of other grids, that is, the simple floor surface is "0". Here, when the pillar or wall is irradiated with the laser from the laser scanner 130, the reflected light from the pillar is more useful than the reflected light from the wall for estimating the position of the target transport robot 102. likely to be useful information. Therefore, in the present embodiment, the pillars are given a higher object level than the walls.

(goods receipt and goods issue)
The chronological movements of the transport robot 102 and the like at the time of warehousing of articles are outlined below.
- As shown in FIG. 1, the transfer robot 102 moves to the space below the target shelf 111 .
- The transport robot 102 lifts the shelf 111, moves in the storage space 202 shown in FIG.
- The worker stores the article on the shelf 111 through the entrance gate 205 .
• The transport robot 102 transports the shelf 111 containing the item to its original position or to another position within the storage space 202 .
- After lowering the shelf 111 to the floor, the transport robot 102 goes out to the aisle or the like and waits for the next transport.

In addition, the chronological movements of the transport robot 102 and the like at the time of unloading of articles are outlined below.
- The transport robot 102 moves to the space below the shelf 111 where the target article is stored.
- The transport robot 102 lifts the shelf 111 , moves in the storage space 202 , and transports it to the exit gate 206 .
- The worker takes out the article from the shelf 111 through the delivery gate 206 .
- The transport robot 102 transports the shelf 111 from which the item has been taken to its original position or another position within the storage space 202 .
- After lowering the shelf to the floor, the transport robot 102 goes out to the aisle or the like and waits for the next transport.

(Control device for transport robot)
FIG. 6 is a block diagram of the controller 720 arranged in the housing of the transfer robot 102. As shown in FIG.
The control unit 720 includes a central processing unit 732, a storage unit 733, a communication unit 735, an antenna 736, a collision detection control unit 740, a laser scanner control unit 742, a camera control unit 744, and a wheel control device 746. , a shelf support controller 748 and an input/output controller 750 .

The storage unit 733 stores control programs and various data. The central processing unit 732 controls each unit in the transport robot 102 based on the control program or the like stored in the storage unit 733 . Therefore, the control unit 720 has a function as a computer. The communication unit 735 controls the wireless communication device 123 and the infrared communication device 125 (see FIG. 2) to perform various communications with external devices. The collision detection control section 740 controls the collision detection section 124 (see FIG. 2).

The laser scanner control section 742 controls the laser scanner 130 (see FIG. 2), and the camera control section 744 controls the camera 127 (see FIG. 2) provided on the bottom of the transport robot 102. FIG. The wheel control device 746 controls the rotation state of the wheels 120 (see FIG. 2) of the transfer robot 102 . The shelf support controller 748 vertically moves the shelf support 122 (see FIG. 2) at the center of the upper surface. The input/output control unit 750 uses the operation/display unit 128 (see FIG. 2) to input/output various data to/from the outside.

(Integrated control device)
FIG. 7 is a block diagram of the integrated control device 230 (conveyance control device, computer) applied to this embodiment.
The overall control device 230 is arranged in, for example, an office space (not shown) of a warehouse company, and performs overall control of the operations of a plurality of transport robots 102 operated in the storage space 202 . The integrated control device 230 includes a central processing unit 232 , a storage unit 233 , an input/output unit 234 , a communication unit 235 and an antenna 236 . The storage unit 233 stores control programs, various data, and the like. In particular, the storage unit 233 stores environment map data 180 and 182 (see FIGS. 4 and 5). The central processing unit 232 controls the multiple transport robots 102 based on control programs and the like stored in the storage unit 233 . Therefore, the general control device 230 also has a function as a computer.

<Operation of the first embodiment>
(Initial operation of transfer robot 102)
FIG. 8 is an operation explanatory diagram showing the operation when the transport robot 102 is brought into the storage space 202 from the outside.
The operator carries the transport robot 102 into the storage space 202 through the entrance gate 205 and operates the operation/display unit 128 (see FIG. 2) to turn on the power. When the power is turned on, the transfer robot 102 establishes communication with the general control device 230 (see FIG. 6), and receives environment map data 180 and 182 (see FIGS. 4 and 5) from the general control device 230. to download.

After communication with the general control device 230 is established, when the operator issues a predetermined “start command” on the operation/display unit 128, the transport robot 102 uses the laser scanner 130 (see FIG. 2) to scan the surroundings. Detect the position of existing objects. However, instead of the operator issuing the "start instruction", the integrated control device 230 may transmit the "start instruction" to the transport robot 102. FIG. A laser measurement range 150 , which is a hatched area, is a range in which the position of an object can be detected by the laser scanner 130 .

In the example shown in FIG. 8, the transport robot 102 irradiates a pillar 134 with a laser beam and obtains the position of the pillar 134 . After completing the position detection of the surrounding objects, the transport robot 102 detects the position of itself by comparing the position information of the surrounding objects with the environment map data 180 (see FIG. 4).

(Position detection using barcode)
The transport robot 102 can also detect its own position using a barcode. FIG. 9 is an operation explanatory diagram of position detection using a bar code.
In the example shown in FIG. 9, a bar code 208 is attached to the floor grid adjacent to the entrance gate 205 . After placing the transport robot 102 at the entrance gate 205, the operator performs a predetermined bar code reading command operation on the operation/display unit 128 (see FIG. 2).

However, reading of the barcode 208 may be executed according to a barcode reading command supplied from the central control device 230 (see FIG. 7). When a barcode reading command is supplied from the operation/display unit 128 or the integrated control device 230, the transport robot 102 advances by a distance corresponding to one grid. As a result, the transport robot 102 moves above the barcode 208 . Next, the transport robot 102 reads the bar code 208 using the camera 127 (see FIG. 2), recognizes its own position information, and transmits the content to the general control device 230 .

In the example described above, the transport robot 102 detects its own position using the bar code 208 on the floor, but the detection result from the laser scanner 130 may also be used to detect its own position. In this way, by detecting the position of one's own device using a plurality of methods, the accuracy and reliability of position detection can be improved. Also, in the above example, the operation at the initial stage when the transport robot 102 is carried into the storage space 202 has been described, but the same operation may be performed at stages other than the initial stage.

For example, when the transport robot 102 breaks down and is recovered and repaired, the same operation may be performed when the repaired transport robot 102 is carried into the storage space 202 again. Also, in the above example, the transport robot 102 starts its operation from the position of the grid adjacent to the storage gate 205, but the grid on which it starts its operation is not limited to this. That is, the transport robot 102 can initiate operations at any grid within the storage space 202 .

(Relationship between laser scanner and grid)
FIG. 10 is a diagram showing the relationship between the transport robot 102 and the laser measurement range 150. As shown in FIG.
The transfer robot 102-1 shown in FIG. 10 is moving upward in the drawing. In this case, the laser scanner 130 of the transport robot 102-1 is positioned in the upper right portion of the transport robot 102-1 in the figure. As a result, the laser measurement range 150-1 of the transport robot 102-1 becomes as shown. Further, among the grids around the transport robot 102-1, grids from which an object can be detected by the laser scanner 130 are called "search target grids". In FIG. 10, "1" is assigned to the search target grid, and "0" is assigned to other grids. Similarly, transport robot 102-2 is moving leftward in the drawing. In this case, the laser scanner 130 of the transfer robot 102-2 is positioned at the upper left portion of the transfer robot 102-2. As a result, the laser measurement range 150-2 of the transfer robot 102-2 and the search target grid are as shown.

Similarly, transport robot 102-3 is moving downward in the figure. In this case, the laser scanner 130 of the transfer robot 102-3 is positioned at the lower left portion of the transfer robot 102-3. As a result, the laser measurement range 150-3 of the transfer robot 102-3 and the search target grid are as shown. Similarly, transport robot 102-4 is moving rightward in the figure. In this case, the laser scanner 130 of the transfer robot 102-4 is positioned at the lower right portion of the transfer robot 102-4. As a result, the laser measurement range 150-4 of the transport robot 102-4 and the search target grid are as shown.

In FIG. 10, the position of the laser scanner 130 is represented by a small circle attached to one corner of the figure of the transfer robot. In other drawings to be described later, the symbol "130" may be omitted, but the small circle attached to one corner of the figure of the transfer robot indicates the position of the laser scanner 130, as in FIG. Then, as shown in FIG. 10 , the traveling direction of the transfer robot, the laser measurement range 150 and the search target grid are determined by the position of the laser scanner 130 . Note that the laser measurement ranges 150-1 to 150-4 shown in FIG. 10 may be downloaded from the general control device 230 to the control unit 720 of the transfer robot 102, and are held by the control unit 720 of the transfer robot 102 from the beginning. may

(Processing procedure when the transport robot starts up)
FIG. 11 is a flow chart of a transfer robot activation processing program executed by the controller 720 of the transfer robot 102 when each transfer robot 102 starts to operate. Note that this program is started, for example, when the transfer robot 102 is powered on or when the operator performs a predetermined reset operation on the operation/display unit 128 .

When the process proceeds to step S102 in FIG. 11, the communication unit 735 (see FIG. 6) of the transport robot 102 establishes communication with the communication unit 235 of the general control device 230. FIG. Next, when the process proceeds to step S104, the central processing unit 732 downloads and acquires the environment map data 180, 182 (see FIGS. 4 and 5) from the central control device 230 via the communication unit 735. FIG.

Next, when the process proceeds to step S106, the process waits until a predetermined "start command" is supplied. The start command may be supplied by the operator operating the operation/display unit 128 (see FIG. 2), or may be supplied from the central control device 230 to the transport robot 102 by communication. However, if the position of the transport robot 102 is out of the predetermined start position (for example, the position of the transport robot 102 shown in FIG. 8) at this time, the operator pushes the transport robot 102 by hand, for example, to the start position. Can be moved to position.

Then, when a start command is supplied to the transport robot 102, the process proceeds to step S108. Here, the central processing unit 732 causes the laser scanner 130 to scan the surroundings, and stores the resulting scan data in the storage unit 733 . Next, when the process proceeds to step S110, the central processing unit 732 collates the environment map data 180 and 182 stored in the storage unit 733 with the scan data to estimate the position of the transport robot 102. , determine the position information of the aircraft.

Here, "self-machine position information" is a set of the following four types of data.
(1) own aircraft coordinates, which are the coordinates where the own aircraft is located in the environment map data 180 (see FIG. 4); (2) own aircraft grid positions, which are the grid positions to which the own aircraft belongs in the environment map data 182 (see FIG. 5);
(3) Grid positions of objects (columns 132 to 140, walls 142 to 148, etc. in FIG. 4) belonging to the laser measurement range 150 and their object levels (4) Self-machine direction

Next, when the process proceeds to step S<b>112 , the transport robot 102 transmits its own position information acquired in step S<b>110 to the central control device 230 via the communication unit 735 . With the above, the processing of this program ends.

(Method for Determining Transfer Robot to be Moved)
FIG. 12 is an operation explanatory diagram showing a method of determining a transfer robot to be moved. Moreover, FIG. 13 is a detailed view of the main part of FIG. Here, the transfer robot to be moved is a transfer robot to which the general control device 230 outputs a movement command.
In FIG. 12, six transport robots 504, 506, 508, 510, 512, 514 are constructed in the same manner as the transport robot 102 described above. These transport robots 504 to 514 are scheduled to be unloaded from the warehouse 100 through the unloading gate 206 for periodic inspection, for example, and are on standby for unloading.

First, the transfer robots 504 to 514 are on standby at grids (8,2) to (6,2) and grids (6,1) to (8,1) (see FIG. 13) to receive regular inspections. there is These transport robots 504 to 514 are scheduled to move between grids in the order indicated by the arrows in the figure, and finally to be carried out of the warehouse 100 through the exit gate 206 .

In FIG. 13, the transfer robot 504 positioned at grid (8, 2) is in a waiting state with its traveling direction directed downward in the drawing. Similarly, the transport robots 506 and 510 positioned at grids (7, 2) and (6, 1) are also on standby with their traveling direction directed downward in the figure. Also, the transfer robot 508 of grid (6, 2) is in a standby state with its traveling direction directed leftward in the figure. Also, the transfer robots 512 and 514 of the grids (7, 1) and (8, 1) are in a waiting state with their advancing directions directed to the right in the figure.

In FIG. 13, laser measurement ranges 152, 154 and 156 are laser measurement ranges by the laser scanners 130 of the transfer robots 508, 510 and 514, respectively. In the illustrated state, the laser beams of the transport robots 504, 506, and 512 are blocked by the other transport robots, and useful data cannot be obtained. More specifically, the transport robot 512 does not have a movement path because it is surrounded by other objects (transport robots and walls) on all sides.

In addition, since the laser scanner 130 is surrounded by other objects (transport robots), the transport robots 504 and 506 cannot move while checking the surrounding conditions. In this embodiment, each transport robot moves while checking the surrounding conditions by itself, so the transport robots 504 and 506 are also excluded from the candidate transport robots to be moved. Also, the laser measurement range 152 of the transfer robot 508 includes a portion of the pillar 140 , and the laser measurement ranges 154 and 156 of the transfer robots 510 and 514 include a portion of the wall 148 .

Here, for example, it is assumed that there is an urgent need to move one of the shelves 111 (transportation task). In such a case, the overall control device 230 preferentially selects a transport robot capable of specifying its own position with high accuracy among the transport robots 504 to 514 as the transport robot to be moved. As shown in FIG. 5, the object level of column 140 (=2) is higher than the object level of wall 148 (=1). Then, as shown in FIG. 13 , the transport robot 508 estimates its position from the pillar 140 . Therefore, the overall control device 230 selects the transport robot 508 as the transport robot to be moved, and outputs a move command. Details of the operation of the overall control device 230 will be described below.

(Operation of integrated control device 230 for transport task)
FIG. 14 is a flow chart of a transport task handling program executed in the integrated control device 230 when a transport task occurs.
When the process proceeds to step S202 in FIG. 14, the central control device 230 identifies one or more transport robots in standby state. Next, when the process proceeds to step S204, the central control device 230 commands the transfer robot in the standby state to transmit "state information".

Here, the "status information" is "own device position information" or "movement control disabled information". "Own aircraft position information" includes, as described above, (1) own aircraft coordinates, (2) own aircraft grid position, (3) object grid position and its object level, and (4) own aircraft There are four types of orientation data. "Movement control disabled information" is information indicating that movement control is not supported.

Next, when the process proceeds to step S206, the process waits until the communication unit 235 receives status information from any transport robot. Here, when the communication unit 235 receives state information (self-position information or movement control disabled information) from any of the transport robots, the process proceeds to step S208, and the state information of the transport robot is stored in the storage unit 233. . Next, when the process proceeds to step S210, the central processing unit 232 determines whether state information has been received from all the transport robots in the standby state. If "No" is determined here, the process proceeds to step S212, and the central processing unit 232 determines whether or not the time has expired, that is, whether or not a predetermined time has elapsed after step S204 described above ends. judge.

If "No" is determined in step S212, the process returns to step S206. On the other hand, if the determination is "Yes" in either step S210 or S212, the process proceeds to step S214. Here, the target object level included in the own position information of each transport robot is referred to, and a transport robot to be moved, which is one of the transport robots to be moved, is selected from transport robots having a high target object level. Next, when the process proceeds to step S216, a movement command is transmitted to the transfer robot to be moved. With the above, the processing of this program ends.

(Operation of transport robot for transport task)
FIG. 15 is a flow chart of a transport task handling program executed in each transport robot when a transport task occurs.
This program is started in the transport robot that has received the instruction when the central control device 230 issues a command to transmit its own position information (see FIG. 14, step S206). When the process proceeds to step S302 in FIG. 15 , the central processing unit 732 causes the laser scanner 130 to scan the surroundings, and stores the resulting scan data in the storage unit 733 .

Next, when the process proceeds to step S304, the central processing unit 732 determines whether movement control is possible. Here, the case where movement control is possible means the case where self-machine position information can be estimated based on scan data. More specifically, the central processing unit 732 determines whether an effective laser measurement range can be secured.

In the example shown in FIG. 13, transfer robots 508, 510, 514 have effective laser measurement ranges 152, 154, 156 with the beam of laser scanner 130 not completely blocked. Accordingly, in these transport robots, the central processing unit 732 determines "Yes" (possible to estimate position information based on scan data=possible to control movement) in step S304.

On the other hand, transfer robots 504, 506, and 512 do not have effective laser measurement ranges because the beam of laser scanner 130 is completely blocked. Therefore, in these transport robots, the central processing unit 732 determines "No" (the position information cannot be estimated based on the scan data=the movement control is impossible) in step S304. If "No" is determined in step S304, the process proceeds to step S320. Here, the central processing unit 732 transmits "movement control disabled information" indicating that "movement control is not possible" to the overall control device 230, and the processing of this program ends.

On the other hand, if determined as "Yes" in step S304, the process proceeds to step S306. Here, the central processing unit 732 determines own device position information in the same manner as in step S110 (see FIG. 11) described above. That is, the environment map data 180 and 182 stored in the storage unit 733 and the scan data are collated to estimate the position of the transport robot 102 . Next, when the process proceeds to step S<b>308 , the central processing unit 732 transmits the self-machine position information to the central control device 230 via the communication unit 735 .

Next, when the process proceeds to step S310, it is determined whether or not the communication unit 735 has received a movement command addressed to itself (see step S216 in FIG. 14). If "No" is determined here, the process proceeds to step S312, and it is determined whether or not time has expired, that is, whether or not a predetermined time has elapsed after step S308 described above ends.

If "No" is determined in step S312, the process returns to step S310, and thereafter the loop of steps S310 and S312 is repeated until a movement command is received or the time expires. Then, when the time is up, it is assumed that the transfer robot has not been selected as a movement target, and the processing of this program ends. Also, when the communication unit 735 receives the movement command addressed to itself, a determination of "Yes" is made in step S310, and the process proceeds to step S314. In step S314, the wheels 120 (see FIG. 2) and the like are driven according to the received movement command, and the transport robot moves. With the above, the processing of this program ends.

(Concrete example of movement of transfer robot)
FIG. 16 is a diagram showing a specific example of the operation of the transport robot.
In FIG. 16, patterns P508, P510 and P514 represent patterns of search target grids in the transport robots 508, 510 and 514, respectively. In these patterns, grids marked with "1" are search target grids, that is, grids in which objects can be detected by the laser scanner 130. FIG. Grids marked with "0" are other grids.

In the pattern P508, the transport robot 508 corresponds to the transport robot 102-2 shown in FIG. 10, because its advancing direction is the left direction in the figure. Therefore, the search target grid in the transport robot 508 is the same as that of the laser measurement range 150-2 in FIG. Also, the search target grid includes the pillar 140 as an object for position measurement.

In pattern P510, transport robot 510 corresponds to transport robot 102-3 shown in FIG. 10, because its advancing direction is downward in the figure. Therefore, the search target grid in the transfer robot 510 is the same as the laser measurement range 150-3 in FIG. In addition, the search target grid includes the wall 148 as an object for position measurement.

10. Further, the transport robot 514 corresponds to the transport robot 102-4 shown in FIG. 10, since its advancing direction is the right direction in the drawing. Therefore, the search target grid in the transfer robot 510 is the same as the laser measurement range 150-4 in FIG. In addition, the search target grid includes the wall 148 as an object for position measurement.

In the illustrated example, the transport robots 508, 510, and 514 transmit their own position information to the general control device 230 through the processing of steps S306 and S308 in FIG. On the other hand, the transport robots 504, 506, and 512 transmit movement control disabled information to the general control device 230 by the process of step S320. The overall control device 230 determines the transfer robot to be moved based on the object level of the position measurement object by the process of step S214 in FIG. As described above, in the example shown in FIG. 16, the pattern P508 of the transfer robot 508 includes the pillar 140 (see FIG. 5) whose object level is "2". Therefore, the overall control device 230 selects the transport robot 508 as the transport robot to be moved.

Then, in step S216 of FIG. 14, the overall control device 230 transmits a movement command task to the transport robot 508, which is the transport robot to be moved, to transport the shelf 111 (see FIG. 1) urgently, for example. On the other hand, the transfer robot 508, which is the transfer robot to be moved, receives the movement command in step S310 of FIG. 15, and moves itself to the target grid in step S314.

<Effect of the first embodiment>
As described above, the transport control device (230, 720) of the present embodiment has a function (S204 to S208, S304 to S308, S320) of acquiring the arrangement status of surrounding objects of a plurality of transport devices (102), A function (S214) for selecting one transport device from among a plurality of transport devices (102) as a transport device to be moved (transport robot to be moved) based on the arrangement of objects; , and a function of outputting a movement command (S216).
As a result, the transport device to be moved can be appropriately selected based on the arrangement of surrounding objects of the transport device (102), so that the transport device can be appropriately operated.

Further, the transport control device (230, 720) has a function of selecting a transport device to be moved while excluding a transport device (512) whose movement path is blocked by surrounding objects from candidates for the transport device to be moved (S214). ).
As a result, it is possible to select a more appropriate transport device to be moved while suppressing the possibility of driving the transport device (102) whose movement path is blocked by surrounding objects by mistake.

In addition, the surrounding objects are other transport devices (102) or objects (132 to 146), and the object levels of the objects (132 to 146) are determined according to their types, and the transport control device ( 230, 720) further comprises a function (S214) of selecting a transport to be moved according to the object level of the objects (132-146) around each transport (102).
This makes it possible to more appropriately select the transport device to be moved according to the object level.

Further, the transport device (102) includes a housing (102a) that is substantially rectangular in plan view, and a scanner (130) that is arranged at one corner of the housing (102a) and detects surrounding objects. The control device (230, 720) has a function ( S214).
This makes it possible to more appropriately select the transport device to be moved while excluding the transport device (102) surrounded by surrounding objects.

In addition, the objects (132 to 146) can increase the accuracy of position estimation of the surrounding transport device (102) as the corresponding object level is higher.
As a result, the transport device (102) with high position estimation accuracy can be selected and used as the transport device to be moved. As a result, for example, even if there is an urgent task to move the shelf 111 or the like, it is possible to select and move a transport device that has a high possibility of accurately recognizing its own position as the transport device to be moved. It is possible to process the generated tasks with high reliability.

[Second embodiment]
Next, a warehouse system according to a second embodiment of the present invention will be described.
The configuration and operation of the second embodiment are substantially the same as those of the first embodiment (see FIGS. 1 to 16). However, when a transport task occurs in this embodiment, the program shown in FIG. 17 is activated in the central control device 230 instead of the program shown in FIG. A transport robot is identified.

FIG. 17 is a flow chart of a transfer task processing program in the integrated control device of this embodiment.
As a premise for executing the program shown in FIG. 17, the program shown in FIG. remembered.

When the process proceeds to step S402 in FIG. 17, the overall control device 230 receives state information (own machine position information or movement control disabled information) from each of the transport robots 102, 504 to 514, and stores it in the storage unit 233. . "Own aircraft position information" includes, as described above, (1) own aircraft coordinates, (2) own aircraft grid position, (3) object grid position and its object level, and (4) own aircraft There are four types of orientation data.

Next, when the process proceeds to step S<b>404 , the overall control device 230 receives the “task completion status” from each transport robot 102 and stores the content thereof in the storage section 233 . Here, the "task completion status" is information indicating whether or not the last task given to each transport robot 102 by the overall control device 230 has been completed. Also, in step S404, all the transport robots that have completed the last given task are identified as the transport robots in the waiting state.

Next, when the process proceeds to step S406, one or a plurality of transfer robots whose movement can be controlled are specified among the transfer robots in the standby state. In other words, a transport robot whose own position information is stored in the storage unit 233 (no movement control disabled information is stored) is extracted. As in the first embodiment described above, the transport robots whose own position information is stored in the storage unit 233 are transport robots that have an effective laser measurement range.

For example, in the example shown in FIG. 13, the storage unit 233 of the integrated control device 230 stores the position information of the transport robots 508 , 510 , 514 . Therefore, the transfer robots identified in step S406 are the transfer robots 508, 510, and 514 in the example of FIG.

Next, when the process proceeds to step S408, a transfer robot to be moved is selected from among the transfer robots specified in step S406 according to the object level. In the example shown in FIG. 13, the laser measurement range 152 of the transfer robot 508 includes a portion of the column 140, and the laser measurement ranges 154, 156 of the transfer robots 510, 514 include a portion of the wall 148. part is included. As shown in FIG. 5, the object level (=2) of the pillar 140 is higher than the object level (=1) of the wall 148. Therefore, in this embodiment, as in the first embodiment, The transport robot 508 is selected as the transport robot to be moved.

Next, when the process proceeds to step S410, the central control device 230 transmits a move command to the transport robot to be moved. After receiving this movement command, the transport robot moves itself to the target grid. With the above, the processing of this program ends.

As described above, the transport control device (230, 720) of the present embodiment appropriately transports the object to be moved based on the arrangement of surrounding objects of the transport device (102), as in the first embodiment. Since the device can be selected, the transport device can be operated appropriately. Furthermore, according to this embodiment, the frequency of communication between the central control device 230 and each transport robot can be reduced, so the transport device can be operated at a higher speed.

[Modification]
The present invention is not limited to the embodiments described above, and various modifications are possible. The above-described embodiments are illustrated for easy understanding of the present invention, and are not necessarily limited to those having all the described configurations. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Also, it is possible to delete part of the configuration of each embodiment, or to add or replace other configurations. Also, the control lines and information lines shown in the drawings are those considered to be necessary for explanation, and do not necessarily show all the control lines and information lines necessary on the product. In practice, it may be considered that almost all configurations are interconnected. Possible modifications to the above embodiment are, for example, the following.

(1) Since the hardware of the control unit 720 and the general control device 230 in the above embodiment can be realized by a general computer, the programs and the like shown in FIGS. may be distributed as

(2) The processing shown in FIGS. 11 and 12 has been described as software processing using a program in the above embodiment, but part or all of it is an ASIC (Application Specific Integrated Circuit). Alternatively, hardware processing using an FPGA (field-programmable gate array) or the like may be substituted.

(3) As shown in step S104 in FIG. 11, the transfer robot 102 in the above embodiment downloads the environment map data 180 and 182 from the central control unit 230, but the transfer robot 102 has the environment map data 180 from the beginning. , 182 may be stored.

(4) In the examples shown in FIGS. 12 and 13, the transfer robot to be moved is selected from a group of transfer robots 504 to 514 that are gathered while being adjacent to each other in order to undergo periodic inspection. . However, the transfer robot to be moved may be selected from among the transfer robots in the stand-by state individually.

(5) In each of the above embodiments, both the environment map data (FIG. 4) and the environment map data (FIG. 5) set in units of grids are applied, but only one of the two may be applied. .

(6) In each of the above embodiments, the division of roles of the control unit 720 in the overall control device 230 and the transport robots 102, 504 to 514 is not limited to that in each of the above embodiments. That is, in each of the above embodiments, the control unit 720 in the transport robot 102 may execute part of the processing executed by the central control device 230, and part of the processing executed by the control unit 720 may be executed by the central control device 230. can be run with

102, 102-1 to 102-4, 504 to 514 transport robot (transport device)
102a housing 130 laser scanner (scanner)
132-140 pillars (object)
142-148 wall (object)
230 integrated control device (conveyance control device, computer)
720 control unit (conveyance control device, computer)

Claims (10)

A function to acquire the arrangement status of surrounding objects of a plurality of transport devices;
It is determined whether or not the position information of each of the transport devices can be estimated based on the arrangement of the surrounding objects, and one transport device is selected from the transport devices for which it is determined that the position information can be estimated. as a transport device to be moved; and
and a function of outputting a move command to the movement target transport apparatus. 2. The method according to claim 1, further comprising a function of selecting the transport device to be moved while excluding the transport device whose moving path is blocked by the surrounding object from candidates for the transport device to be moved. transport control device. the surrounding object is another transport device or object;
An object level , which is a value indicating the expected accuracy of position estimation, is defined for the object according to its type including at least a wall, a pillar, or a floor surface ;
further comprising a function of preferentially selecting, as the movement target transport device, the transport device capable of specifying its own position with high accuracy according to the target object level of the target object around each of the transport devices. 3. The transfer control device according to claim 2. The transport device includes a housing that is substantially rectangular in plan view, and a scanner that is arranged at one corner of the housing and detects the surrounding object,
4. The scanner according to claim 3, further comprising a function of selecting the transport device to be moved while excluding the transport device surrounded by the surrounding objects from candidates for the transport device to be moved. transport control device. 5. The transport control device according to claim 4, wherein the higher the object level corresponding to the target object, the higher the accuracy of position estimation of the transport device existing in the surroundings. a plurality of conveying devices for conveying articles;
A function of acquiring the placement status of surrounding objects of a plurality of said transport devices , and determining whether or not position information of each of said transport devices can be estimated based on said placement status of said surrounding objects, and said position information is estimated. A transport comprising a function of selecting one transport device from among a plurality of transport devices determined to be possible as a transport device to be moved, and a function of outputting a movement command to the transport device to be moved. and a control device. the computer,
Means for acquiring the arrangement status of surrounding objects of a plurality of transport devices;
determining whether or not the position information of each of the transport devices can be estimated based on the arrangement status of the surrounding objects; means for selecting a device as a transport device to be moved;
means for outputting a move command to the transport device to be moved;
program to function as a . A function to acquire the arrangement status of surrounding objects of a plurality of transport devices;
a function of selecting one of the transport devices as a movement target transport device from among the plurality of transport devices based on the arrangement of the surrounding objects;
a function of outputting a move command to the transport device to be moved;
a function of selecting the transport device to be moved while excluding the transport device whose movement path is blocked by the surrounding object from candidates for the transport device to be moved;
the surrounding object is another transport device or object;
An object level, which is a value indicating the expected accuracy of position estimation, is defined for the object according to its type including at least a wall, a pillar, or a floor surface;
It further comprises a function of preferentially selecting, as the movement target transport device, the transport device that can specify its own position with high accuracy according to the target object level of the target object around each of the transport devices.
A transport control device characterized by: The transport device includes a housing that is substantially rectangular in plan view, and a scanner that is arranged at one corner of the housing and detects the surrounding object,
The scanner further comprises a function of selecting the transport device to be moved while excluding the transport device surrounded by the surrounding objects from candidates for the transport device to be moved.
9. The transfer control device according to claim 8, characterized in that: The higher the target object level corresponding to the target object, the higher the accuracy of position estimation of the transport device existing in the surroundings.
10. The transfer control device according to claim 9, characterized in that:

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