JP7623928B2 - MOBILE BODY CONTROL DEVICE, METHOD FOR CONTROLLING MOBILE BODY, AND MOBILE BODY SYSTEM - Google Patents

Description

This disclosure relates to control of movement of a moving device.

Mobile robots such as automated guided vehicles are being used to resolve labor shortages and improve efficiency in goods transportation operations in logistics warehouses and manufacturing plants. These mobile robots may have their movement path and speed remotely controlled by a central control device, or each mobile robot may control its movement path and speed autonomously. In either case, safe and efficient goods transportation is required. In other words, the movement of mobile robots must be controlled to prevent collisions and improve transportation efficiency.

Regarding this safe movement control, for example, there is a technology disclosed in Patent Document 1. Specifically, it discloses that "each autonomous moving device 2 in the autonomous moving system 1 is equipped with an autonomous driving means 3 for autonomous movement, a device information storage means 4 that stores its own identification information and information indicating its own operating status, an interface 5 for communication with other autonomous moving devices 2 and for the user to input destinations and driving commands, a target device extraction means 6 that extracts other autonomous moving devices moving on a route that intersects with the route of the autonomous moving device when heading to the next node, a time determination means 7 that determines whether the time when both devices reach the intersection will be within a predetermined time when another autonomous moving device 2 is extracted, and a movement determination means 8 that determines which device should move first based on the priority of both devices when the time ...

However, with the above technology, information on the other mobile robot is collected through communication, and if this communication fails and the information on the other mobile robot cannot be obtained, collisions between the mobile robots cannot be prevented. In particular, when using wireless communication means, there may be areas where communication is temporarily difficult, such as behind obstacles, and it is necessary to prepare for communication failures. Although this is not disclosed in Patent Document 1, it is easy to imagine ensuring safety by stopping on the spot when it detects that communication is difficult, or by moving at an extremely slow speed that will not break even if it collides, but in such cases, transportation efficiency will decrease.

Regarding the occurrence of areas where communication is difficult, for example, Patent Document 2 discloses a technology in which "a mobile object management system (100, 200) has a plurality of mobile objects (10) each moving according to a guidance command, a traffic management device (50) that transmits guidance commands to each mobile object, and at least one wireless access point (2) that is connected wirelessly to each mobile object and wirelessly or wired to the traffic management device and relays communication between each mobile object and the traffic management device. Each mobile object generates status data (32) indicating a communication status by communicating with a specified wireless access point, and transmits the status data to the outside via the specified wireless access point. The traffic management device uses the status data acquired from each mobile object to change the first guidance command to a second guidance command when the first guidance command meets a condition indicating that communication is difficult to maintain." This allows the mobile robot to travel safely while avoiding areas where communication is difficult.

However, the above technology does not improve transportation efficiency.

Patent Application No. 2006-113687 Patent Application No. 2019-148870

Therefore, there is a need for technology that can control the movement of mobile robots, such as automated guided vehicles, to prevent collisions between mobile robots even when the robots are traveling in areas where communication is difficult, and that can improve transportation efficiency when preventing collisions.

One aspect of the present disclosure is a mobile object control device that uses wireless communication to control the movement of multiple mobile objects within a mobile object control area. The mobile object control device includes one or more arithmetic devices and one or more storage devices. The one or more storage devices store management information indicating the current position of each of the multiple mobile objects. The one or more arithmetic devices identify an exclusive control area based on a measurement result of wireless communication quality within the mobile object control area, and control the movement of the multiple mobile objects based on the management information so that the number of mobile objects simultaneously present within the exclusive control area is equal to or less than a specified number.

Collisions can be prevented even when a mobile object moves through an area where wireless communication is difficult, and transportation efficiency can be improved when collisions are prevented.

FIG. 1 is a block diagram of a mobile control system according to an embodiment of the present specification. Functional configuration diagram of a mobile control device according to an embodiment of the present specification FIG. 1 is a hardware configuration diagram of a mobile control device according to an embodiment of the present specification. Functional configuration diagram of a moving body according to an embodiment of the present specification A communication sequence diagram between a mobile object and a mobile object control device in an embodiment of this specification, Part 1 A communication sequence diagram 2 between a mobile object and a mobile object control device in an embodiment of this specification Example of transportation information table in mobile control device Example of a mobile unit state table in a mobile unit control device Warehouse MAP information table in the mobile control device Information on items in a moving vehicle Mobile vehicle operation status table Flowchart of the mobile control function No. 1 Flowchart of the mobile control function, part 2 Flowchart of the route calculation function Flowchart of mobile state management function Routing control diagram Example 1 of exclusive control according to the embodiment of this specification Example 2 of exclusive control according to the embodiment of this specification Exclusive control diagram

First, the common parts of the following embodiments will be described. FIG. 1 is a configuration diagram of a mobile body system for a logistics warehouse according to an embodiment of this specification. Note that the mobile body system of the embodiment of this specification can be applied to sites other than logistics warehouses. The mobile body system includes multiple mobile bodies 101 and a mobile body control device 102 that controls the movement of the multiple mobile bodies 101 within a movement control area.

A mobile object 101 carries goods within a warehouse 107. The mobile object control system includes a mobile object control device (WCS) 102, a user interface 103 for inputting setting values and displaying the operating status of the mobile object, and a wireless base station 104. In the warehouse 107, shelves 105 for storing goods are installed, and there are difficult-to-communicate areas (hereinafter referred to as NG areas) 106 caused by the shadows of the shelves and stored goods.

The mobile object control device 102 divides the entire warehouse 107 into mesh-like partial areas as shown by dotted lines in Figure 1, and manages communication quality on an area-by-area basis. This enables efficient management. For example, the minimum length of the sides of a mesh area can be determined based on the accuracy of the position coordinate measurement of the mobile object (A), the stopping ability of the mobile object (B), and the size of the mobile object (C). The shape (size) of each mesh area is determined, for example, so that each mobile object can automatically avoid collisions with other mobile objects. Note that wireless communication quality does not have to be managed for each mesh area.

More specifically, for example, the greater of (A) and (B) + (C) may be set as the minimum value of the length of the mesh sides. By making the mesh smaller to the extent that it is possible to guarantee that moving bodies will not collide, it is possible to manage areas where communication is difficult in smaller units, and the number of times that the movement exclusion control in the embodiments of this specification is executed can be reduced. This makes it possible to further suppress the decrease in efficiency of transportation work caused by movement exclusion control for ensuring safety.

The communication quality is constantly measured while the mobile object 101 is transporting goods. This allows the communication quality of the area in which the mobile object moves to be measured efficiently. Note that the communication quality may also be measured by another device installed in the warehouse. The mobile object 101 may measure the communication quality multiple times while moving within one area. Methods for determining the communication quality measurement value of the area from multiple measurement values include using the average value or the maximum value.

Details will be described in the explanation of Figure 2A, but an area where the communication quality measurement value has deteriorated and communication is determined to be difficult is an NG area 106. For safety reasons, in this area, moving objects may be made to travel at a low speed or stopped temporarily to prevent collisions between moving objects. However, this may reduce the efficiency of transporting goods.

In the embodiment of this specification, exclusive control of the movement of each moving body 101 is realized so that there is always a specified number or less of moving bodies within the NG area 106. The NG area 106 is an example of an exclusive control area. This can reduce the possibility of collisions between moving bodies within the NG area. The specified number is, for example, one body, which can more reliably prevent collisions between the moving bodies 101 within the NG area. In addition, transportation efficiency is improved by moving at the same speed as outside the NG area. An example of this method will be explained in more detail below. In the following, it is assumed that the number of moving bodies permitted to be present in the NG area is one.

Figure 2A is a functional configuration diagram of the mobile object control device 102. It implements a mobile object control function 201, a setting value retention function 202, a communication function 203, a mobile object status table 204, a transportation information table 205, a warehouse MAP information table 206, a communication quality determination function 207, and a movement route calculation function 208. The mobile object status table 204, the transportation information table 205, and the warehouse MAP information table 206 are examples of management information for controlling and managing the mobile object 101.

The mobile unit control function 201 is a function that mainly calculates the moving path and speed of the mobile unit 101, creates transportation information and a moving path notification message, and transmits them to the mobile unit 101. The processing of the mobile unit control function 201 will be described in detail in Figures 11 and 12.

The setting value retention function 202 is a function that retains and manages setting values input from the user interface 103. The setting values include, for example, the total number of moving objects, the moving object stopping performance of the moving object (the number of seconds from receiving a stop instruction to stopping), the high speed of the moving object, the low speed of the moving object, the communication quality threshold (communication delay time, communication data loss rate, etc.), and a movement route recalculation instruction.

The movement path recalculation instruction is normally off, but is turned on when the user issues a command from the user interface 103. When it is on, exclusive movement control of the moving object according to this embodiment is immediately executed, and when this control is completed, the movement path recalculation instruction is turned off. This is because the user is monitoring the movement status of the moving object displayed on the user interface 103, and when the user determines it is necessary, the moving object movement control system according to this embodiment is forced to execute exclusive movement control of the moving object.

The communication function 203 is a function for transmitting and receiving information to and from the mobile body 101. The mobile body status table 204, the transportation information table 205, and the warehouse MAP information table 206 are described in Figures 6, 7, and 8, respectively. The communication quality determination function 207 is a function for comparing the communication quality measurement value measured by the mobile body 101 with the communication quality threshold value stored in the setting value storage function 202, and determining that the area in which the mobile body 101 measured the communication quality is an NG area if the communication quality measurement value exceeds the communication quality threshold value, that is, if the measured communication quality is inferior to a predetermined communication quality. The movement route calculation function 208 is a function for realizing exclusive movement control of the mobile body. It will be described in detail in Figure 13.

FIG. 2B is a block diagram showing a schematic example of the hardware configuration of the mobile object control device 102. The mobile object control device 102 includes a calculation device 121 having calculation performance, and a main memory device 122 that provides a memory area for storing programs executed by the calculation device 121 and data to be processed. The calculation device 121 is, for example, a CPU including one or more cores, and the main memory device 122 is, for example, a RAM including a volatile memory area.

The mobile control device 102 further includes a communication interface 126 that performs data communication with other computing devices and external storage devices, and an auxiliary storage device 123 that provides a non-volatile storage area using a hard disk drive (HDD) or flash memory. The mobile control device 102 also includes an input device 124 that accepts operations from the user, and an output device 125 that presents the output results of each process to the user.

The input device 124 includes, for example, a keyboard and a mouse, and the output device 125 includes, for example, a monitor and a printer. These components of the mobile control device 102 can communicate with each other via an internal bus 127.

The programs executed by the arithmetic device 121 and the data to be processed are loaded, for example, from the auxiliary storage device 123 to the main storage device 122. Functional units such as the mobile object control function 201, the setting value retention function 202, the communication quality determination function 207, and the movement path calculation function 208 shown in FIG. 2A can be implemented by the arithmetic device 121 executing the corresponding programs. Furthermore, the communication function 203 can be implemented by the arithmetic device 121 using the communication interface 126. Various data or information such as the mobile object status table 204, the warehouse MAP information table 206, and the transportation information table 209 shown in FIG. 2A can be stored, for example, in the auxiliary storage device 123.

The mobile control device 102 may be a physical computer system (one or more physical computers) or a system built on a group of computing resources (multiple computing resources) such as a cloud platform. The mobile control device 102 may be a portable device such as a smartphone or tablet. The computer system or group of computing resources includes one or more interface devices, one or more storage devices (including, for example, a main storage device and an auxiliary storage device), and one or more arithmetic devices.

When a function is realized by a program being executed by a computing device, the defined processing is performed using a storage device and/or an interface device, etc., as appropriate, and therefore the function may be considered to be at least a part of the computing device. Processing described using the function as the subject may be considered to be processing performed by the computing device or a system having its processor.

The program may be installed from a program source. The program source may be, for example, a program distribution computer or a computer-readable storage medium (e.g., a computer-readable non-transitory storage medium). The description of each function is an example, and multiple functions may be combined into one function, or one function may be divided into multiple functions.

Figure 3 is a functional configuration diagram of the mobile object 101. The functional configuration of the mobile object 101 can be realized, for example, by a computer configuration such as that described with reference to Figure 2B. A status management function 301, an item information table 302, a wireless communication function 303, an operation status table 304, a communication quality measurement function 305, a position coordinate acquisition function 306, and a driving function 307 are implemented.

The status management function 301 is a function that creates and transmits a position and speed information notification message 401 that notifies the mobile control device 102 of its own current position, movement speed, and communication quality measurement value. It also has a function that creates and transmits an operation status notification message that notifies the mobile control device 102 of its own operation status, such as arrival at the movement destination.

The wireless communication function 303 is a function for performing wireless communication via a wireless LAN or the like. The item information table 302 and the operation status table 304 are described in Figures 9 and 10, respectively.

The communication quality measurement function 305 is a function that measures the communication delay time and communication data loss rate between the mobile control device 102. Generally, when transmitting information, a transmission time and a unique sequence number are assigned to each piece of information to be transmitted. When information is received, the communication delay time is calculated from the difference between the reception time and the assigned transmission time. In addition, the unique sequence number assigned to each piece of information is used to detect information loss, and the information loss rate is calculated. This calculation of the information loss rate is performed periodically, for example, every 10 seconds.

The position coordinate acquisition function 306 is a function for acquiring the current position of the mobile object within the warehouse. For example, a marker such as a QR code (registered trademark) indicating the position information within the warehouse can be placed in each area, and the marker can be photographed with a camera mounted on the mobile object to acquire the position information. The travel function 307 is a function for the mobile object to travel under remote instructions or autonomously.

Figure 4 is a sequence diagram of a position and speed information notification message 401 and a transportation information and movement route notification message 402. Details will be explained in Figure 11, but when the mobile body control device 102 receives a position and speed information notification message 401 from the mobile body 101, it judges the communication quality of the area. If a normal area changes to a NG area as a result, or conversely, if a NG area changes to a normal area, it executes route control for the associated mobile body 101. The mobile body control device 102 creates a transportation information and movement route notification message 402 and transmits it to the associated mobile body 101.

Figure 5 is a sequence diagram of an operating status notification message 501 and a transportation information and movement route notification message 402. This transportation information and movement route notification message 402 has the same content as that in Figure 4, and is also used in Figure 5. Details will be explained in Figure 12, but when the mobile body control device 102 receives an operating status notification message 501 from a mobile body 101, it executes route control for the mobile body 101. The mobile body control device 102 creates a transportation information and movement route notification message 402 and transmits it to the mobile body 101.

Figure 6 is an example of a transport information table 205 held by the mobile object control device 102. The transport information table 205 indicates, for each item stored in the warehouse, the transport order 601, a unique item number 602, item shelf coordinates 603 indicating the storage location, destination coordinates 604, and allocation status 605. The allocation status 605 indicates whether the transport of the item has already been assigned to any mobile object.

The mobile object control device 102 assigns a mobile object 101 to transport each item based on the transport information table 205, and calculates the travel route and travel speed. For example, among the mobile objects waiting to be transported, the mobile object control device 102 assigns the mobile object that is closest to the item shelf coordinates 603 where the item is located to transport the item. It also calculates the travel route that will result in the shortest travel distance, and calculates the travel speed, including deceleration around curves, so as to minimize the travel time.

Figure 7 shows an example of a mobile object status table 204 held by the mobile object control device 102. The mobile object status table 204 shows a unique mobile object ID 701, a status 702, a position coordinate 703, a speed 704, a transported item number 705, and a moving path and speed 706.

The status 702 holds whether the mobile object 101 is transporting an item, is stopped, or is moving toward the item to be transported. The position coordinates 703 indicate the current position of the mobile object 101, are managed separately from the mesh that manages communication quality, and indicate the physical position within the warehouse. Generally, a certain point within the warehouse is taken as the reference point, and the position is expressed in relative planar coordinates (unit: meters) from that point.

Speed 704 is the moving speed of the moving body when it passes through position coordinate 703, that is, the current moving speed. Transported item number 705 is the number of the item transported by the moving body, which is item number 602 in FIG. 6. If the transported item number 705 is not assigned, it means that the moving body 101 is waiting. Movement path and speed 706 indicates the movement path and movement speed of each moving body 101 for transporting items, and is the calculation result of the movement path calculation function 208. After the three numbers in parentheses, the first two indicate the position coordinates, and the third number indicates the movement speed to the next position coordinate.

Figure 8 is an example of a warehouse MAP information table 206 held by the mobile object control device 102. The warehouse MAP information table 206 shows objects 801, start point coordinates 802, and end point coordinates 803. The object 801 indicates whether each object is an item shelf 105 in the warehouse, a mobile object passage, or a NG area 106. The start point coordinates 802 and end point coordinates 803 indicate the size of the object (unit: meters). These coordinates are in the same coordinate system as the position coordinates 703 in Figure 7. Note that each time the communication quality determination described in Figure 4 is performed, the number of NG area rows increases or decreases depending on the result. Details of this will be explained in Figure 11.

Figure 9 is an example of an item information table 302 held by the mobile body 101. The item information table 302 shows information on items transported by the mobile body 101. The item information table 302 shows an item number 901, item shelf coordinates 902, and destination coordinates 903. These are the same as the item number 602, item shelf coordinates 603, and destination coordinates 604 in Figure 6, respectively, and are notified by the mobile body control device 102 using the transportation information and movement route notification message 402. The mobile body 101 moves to the location indicated by the item shelf coordinates 902 and loads the item. It then moves to the location indicated by the destination coordinates 903 and unloads the item. The mobile body 101 repeats this operation.

Figure 10 shows the operation status table 304 held by the mobile unit 101. The operation status table 304 shows a status 1001, a position coordinate 1002, a speed 1003, and a communication quality measurement value 1004. These are notified to the mobile unit control device 102 in a position and speed information notification message 401. The status 1001, the position coordinate 1002, and the speed 1003 have the same contents as the status 702, the position coordinate 703, and the speed 704 in Figure 7.

Figures 11 and 12 are flowcharts of the mobile unit control function 201 of the mobile unit control device 102. In Figure 11, in step 1101, the mobile unit control function 201 waits for a position and speed information notification message 401 from the mobile unit 101. Upon receiving the message in step 1102, the mobile unit control function 201 updates the mobile unit status table 204 in step 1103 and updates the warehouse MAP information table 206 in step 1104 based on the message contents.

In step 1103, the mobile object control function 201 updates the status 702, position coordinates 703, and speed 704 in the mobile object status table 204. In step 1104, the mobile object control function 201 adds and deletes rows related to NG areas in the warehouse MAP information table 206.

Specifically, as described in FIG. 2A, the mobile object control function 201 uses the communication quality determination function 207 to determine an NG area based on the communication quality measurement value notified from the mobile object 101. If an existing NG area changes to a normal area as a result, the mobile object control function 201 deletes the row in question in the warehouse MAP information table 206. Conversely, if the number of NG areas increases, a new row is added to the warehouse MAP information table 206. At this time, the area including the position coordinates 703 of the mobile object 101 is regarded as the newly increased NG area.

In step 1105, when the NG area is reduced as a result of judging the communication quality, the mobile object control function 201 checks the movement path and speed 706 column of the mobile object status table 204 in FIG. 7 to see if there is a mobile object 101 that has the area on its movement path. If there is, proceed to step 1106, and if there is not, proceed to step 1107.

In step 1106, the mobile object control function 201 cancels the exclusive control of the mobile object 101. In other words, the moving speed that was reduced while waiting for the exclusive control on the moving route is updated to the maximum speed. Next, the process proceeds to step 1108.

In step 1107, it is confirmed in the same manner as in step 1105 whether the NG area has increased as a result of the communication quality determination in step 1104, and if so, whether there is a moving body 101 that has the NG area on its movement route. If NO, the process returns to step 1101. If YES, in step 1301, the movement route of the moving body 101 is calculated by the movement route calculation function 208. Details of this movement route calculation will be explained in FIG. 13.

In step 1108, the mobile control function 201 creates a transportation information and movement route notification message 402 including the calculated or updated movement route and movement speed, and transmits it to the mobile unit 101.

In FIG. 12, in step 1201, the mobile object control function 201 waits for an operating status notification message 501 from the mobile object 101. When the message is received in step 1202, in step 1301, the mobile object control function 201 calculates the movement route of the mobile object 101 using the movement route calculation function 208 based on the message contents. Details of this will be explained in FIG. 13. Next, in step 1203, transportation information and movement route notification message 402 including the calculated movement route and movement speed are created and transmitted to the mobile object 101.

Figure 13 is a flowchart of the movement path calculation function 208 of the mobile object control device. A conceptual diagram of the movement path calculation is shown in Figure 15. The process of Figure 13 is executed for one target mobile object 101. As explained with reference to Figure 11, when a new NG area occurs, the process of Figure 13 is executed for each mobile object 101 that passes through the NG area. Also, as explained with reference to Figure 12, a movement path is calculated for a mobile object 101 that has received an operating status notification message 501.

In step 1302, the movement path calculation function 208 calculates the shortest route with the shortest movement distance from the position coordinates 703 of the moving body 101 and the position coordinates of the destination point. For the destination point, if a transported item has already been assigned to the moving body 101, the transported item number 705 in Figure 7 is referenced to obtain the item number. The destination coordinates 604 in the row with the same item number 602 in Figure 6 becomes the destination point. If a transported item has not been assigned, the function refers to Figure 6 to find the item number 602 with the smallest transport order 601 among those with an assignment status 605 of Not Assigned. At this time, the item shelf coordinates 603 becomes the destination point.

In step 1303, the movement route calculation function 208 refers to the warehouse MAP information table 206 to check whether the shortest route includes an NG area. If an NG area is included (1303: YES), the process proceeds to step 1306. If an NG area is not included (1303: NO), there is no problem with always traveling at maximum speed on the shortest route, so the shortest route and maximum speed are set as the movement route and movement speed, and the process proceeds to step 1304.

In step 1306, the travel route calculation function 208 calculates the second shortest route that bypasses the no-go area. If there are multiple no-go areas on the shortest route, a route that bypasses all of the no-go areas is selected. The following steps 1307 to 1310 are performed for each no-go area on the route.

First, in step 1307, the movement path calculation function 208 identifies all moving objects whose movement paths include the NG area found in step 1303. This is done by referring to the movement paths and speeds 706 in the moving object status table 204.

In step 1308, the movement path calculation function 208 calculates the entry and exit times of the NG area for all moving bodies identified in step 1307. This is done by referring to the position coordinates 703 and the movement path and speed 706 in the moving body status table 204. The movement path and speed 706 represent the entire movement path of the moving body 101. The position coordinates 703 represent the current position, and therefore represent a point along the entire movement path.

The movement route calculation function 208 calculates the movement time for the remaining movement route from the current position to the destination point. The entry time into the no-go area can be calculated by adding this movement time to the current time. If another no-go area is passed before arriving at the no-go area, the waiting time at that time is also added. The exit time can be calculated by calculating the length of the no-go area in the direction of travel of the moving object, and calculating the time required to pass through assuming that the moving object is moving at its maximum speed, and adding this to the entry time.

In step 1309, the movement path calculation function 208 checks whether the entry time of each moving body 101 into the NG area calculated in step 1308 is later than the exit time of all moving bodies that previously entered the NG area. If YES, proceed to step 1304; if NO, proceed to step 1310.

In step 1310, the movement path calculation function 208 calculates the movement exclusive control waiting time. The moving body control function 201 performs movement exclusive control so that multiple moving bodies do not enter a certain NG area at the same time. In other words, the movement speed of the following moving body is adjusted to delay the entry time so that the following moving body does not enter the NG area until the exit time of the moving body that entered the NG area first has passed. The delayed time at this time is the movement exclusive control waiting time. By reducing this movement exclusive control waiting time, the efficiency of transporting goods by the moving body 101 can be improved. Details of this will be explained in FIG. 18.

In step 1304, the movement path calculation function 208 calculates the movement time for each calculated movement path. At this time, if there is a waiting time due to the movement exclusive control calculated in step 1310, this is added. If the moving body 101 passes through multiple NG areas, the waiting times of all the NG areas are added.

Finally, in step 1305, the movement route calculation function 208 selects the movement route with the shortest movement time and the movement speed at that time as the result of the movement route calculation function. If it is determined in step 1303 that no NG area is included (1303: NO), the shortest distance is selected.

If it is determined in step 1303 that an NG area is included (1303: YES), the route with the shorter travel time is selected from the detour route and the shortest route. In other words, if the calculated amount of time delay (latency) is greater than the travel time delay calculated assuming that the area with deteriorated communication quality is detouring, the detour route is selected with priority.

In one example, if a predetermined time has passed since a certain NG area was determined to be an NG area, the movement route calculation function 208 preferentially selects a route that includes the NG area as the result of the movement route calculation, even if the movement time is not the shortest. By intentionally making the mobile unit 101 pass through the NG area, it becomes possible to measure and update the communication quality of the NG area. This makes it possible to periodically determine whether the communication quality has returned to normal and to suppress the implementation of unnecessary exclusive control.

Figure 14 is a flowchart of the state management function 301 of the mobile unit 101. This flowchart is executed periodically. First, in step 1401, the state management function 301 acquires position coordinate information from the position coordinate acquisition function 306. Next, in step 1402, the state management function 301 acquires a communication quality measurement value from the communication quality measurement function 305.

Furthermore, in step 1403, the status management function 301 obtains the current speed from the driving function 307. In step 1404, a position and speed information notification message is created that includes these three pieces of information, and is sent for movement. Finally, in step 1405, an operation status notification message that includes the contents of the operation status table 304 is created and sent.

Figure 15 is a conceptual diagram of a movement route calculation. Let us assume that a moving object 101 located at the position in the figure moves to a destination represented by a black circle. A movement route P1 with the shortest distance is calculated, but an NG area 106 exists on the route. Therefore, a detour route P2 with the second shortest distance is also calculated.

Figure 16 is a diagram showing a case where the movement exclusion control of Figure 13 is required. In the diagram, the movement paths of moving body 101A and moving body 101B intersect, with NG area 106A at the intersection. If things continue as they are, moving body 101B will enter NG area 106A while moving body 101A is staying in NG area 106A. Due to communication difficulties, they will hide behind a shelf and will not be able to recognize each other until the last moment, and it is predicted that they will collide. To avoid this, moving body 101A is made to pass NG area 106A first, and moving body 101B is made to pass NG area 106A afterwards. Note that moving body 101B can enter NG area 106A after moving body 101A has entered NG area 106B.

Figure 17 is a diagram showing another example where the movement exclusion control of Figure 13 is necessary. There are NG areas 106A and 106B in the part where the movement paths of moving body 101A and moving body 101B overlap. The exclusion control makes moving body 101A pass through NG area 106A first, and then makes moving body 101B pass through NG area 106A. Also, makes moving body 101A pass through NG area 106B first, and then makes moving body 101B pass through NG area 106B. Immediately after moving body 101A passes through NG area 106A or NG area 106B, moving body 101B enters NG area 106A or NG area 106B.

Figure 18 is a conceptual diagram of mobile exclusion control. It is a schematic time series diagram of the residence time 1801 of a mobile object 101 in a certain prohibited area. The residence time 1801 represents the time from when the mobile object 101 enters the prohibited area to when it leaves. In other words, one mobile object occupies the prohibited area during the residence time.

To achieve this, when the stay time of a certain moving object overlaps with the entry time of another moving object into the relevant prohibited area, the entry time of the subsequent moving object into the relevant prohibited area is delayed until after the end of the stay time. This delay time is the movement exclusive control waiting time 1802. In order to delay the entry time of the subsequent moving object, the subsequent moving object may stop temporarily just before the relevant prohibited area or may slow down its movement speed.

Some of the functions of the mobile body control device 102 and the management information for implementing the functions may be omitted. For example, the mobile body control device 102 may execute exclusive control of the mobile body 101 in the NG area based on the current position of the mobile body 101 without determining the route of the mobile body.

The present invention is not limited to the above-described embodiments, but includes various modified examples. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. It is also possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

Furthermore, each of the above configurations, functions, processing units, etc. may be realized in hardware, for example by designing some or all of them as an integrated circuit. Furthermore, each of the above configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. Information such as the programs, tables, files, etc. that realize each function can be stored in a memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card or SD card.

In addition, the control lines and information lines shown are those considered necessary for the explanation, and not all control lines and information lines on the product are necessarily shown. In reality, it can be assumed that almost all components are interconnected.

101 Mobile unit 102 Mobile unit control device (WCS)
106 Communication difficult area (NG area)
201 Mobile object control function 206 Warehouse MAP information table 208 Movement route calculation function 301 Status management function 401 Position and speed information notification 402 Transportation information, movement route notification 501 Operation status notification 1801 Time required for a mobile object to pass through the relevant NG area 1802 Exclusive control waiting time

Claims (6)

A mobile object control device that controls the movement of a plurality of mobile objects within a mobile object control area using wireless communication,
one or more computing devices;
one or more storage devices;
the one or more storage devices store management information indicating a current position of each of the plurality of moving objects;
The one or more computing devices,
identifying an exclusive control area based on a measurement result of wireless communication quality within the mobile object control area received from the plurality of mobile objects ;
controlling the movement of the plurality of moving objects based on the management information so that the number of moving objects simultaneously present within the exclusive control area is equal to or less than a prescribed number ;
the shortest route from the current location of the first moving object to the destination passes through the exclusive control area;
The one or more computing devices,
Estimating a travel time of the shortest route, including a waiting time for the first moving object to pass through the exclusive control area;
estimating a travel time of a detour route of the first moving object that detours around the exclusive control area;
If the travel time of the detour route is shorter than the travel time of the shortest route, the detour route is prioritized over the shortest route;
When a specified time has elapsed since the exclusive control area was identified, the one or more computing devices prioritize the shortest route over the detour route . The mobile object control device according to claim 1,
A mobile control device, wherein the specified number is 1. The mobile object control device according to claim 1,
The mobile object control area is divided into a plurality of partial areas in advance,
The one or more calculation devices determine the exclusive control area for each of the plurality of partial areas. The mobile object control device according to claim 3,
A mobile object control device, wherein each partial area of the plurality of partial areas has a size that enables each mobile object of the plurality of mobile objects to automatically avoid collision with other mobile objects. A method for controlling movement of a plurality of moving objects within a moving object control area by a moving object control device using wireless communication, comprising:
the mobile object control device holds management information indicating a current position of each of the plurality of mobile objects;
The method further comprises the steps of:
receiving measurement results of wireless communication quality within the mobile control area from the plurality of mobile objects;
Identifying an exclusive control area based on the measurement result;
controlling the movement of the plurality of moving objects based on the management information so that the number of moving objects simultaneously present within the exclusive control area is equal to or less than a specified number;
the shortest route from the current location of the first moving object to the destination passes through the exclusive control area;
The method further comprises the steps of:
Estimating a travel time of the shortest route, including a waiting time for the first moving object to pass through the exclusive control area;
estimating a travel time of a detour route of the first moving object that detours around the exclusive control area;
If the travel time of the detour route is shorter than the travel time of the shortest route, the detour route is prioritized over the shortest route;
the shortest route is prioritized over the detour route if a prescribed time has elapsed since the exclusive control area was identified. 1. A mobile system comprising:
A plurality of moving bodies;
a mobile object control device that controls the movement of the plurality of mobile objects within a mobile object control area using wireless communication;
The mobile object control device includes:
identifying an exclusive control area based on a measurement result of wireless communication quality within the mobile object control area received from the plurality of mobile objects;
controlling the movements of the plurality of moving objects based on current positions of the plurality of moving objects so that the number of moving objects simultaneously present within the exclusive control area is equal to or less than a specified number;
the shortest route from the current location of the first moving object to the destination passes through the exclusive control area;
The mobile object control device includes:
Estimating a travel time of the shortest route, including a waiting time for the first moving object to pass through the exclusive control area;
estimating a travel time of a detour route of the first moving object that detours around the exclusive control area;
If the travel time of the detour route is shorter than the travel time of the shortest route, the detour route is prioritized over the shortest route;
A mobile system that prioritizes the shortest route over the detour route if a specified time has elapsed since the exclusive control area was identified.

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