Control system for controlling multiple autonomous vehicles

Abstract

To provide a control system that can return multiple autonomous vehicles to a predetermined position in an orderly manner.SOLUTION: A control system for controlling multiple autonomous vehicles including a first autonomous vehicle and a second autonomous vehicle comprises: a communication unit; a storage unit that stores positions of multiple nodes constituting a main line and a branch line, and a current position of a traveling vehicle obtained from the autonomous vehicle via the communication unit; and a command unit that sends a command regarding a destination to the autonomous vehicle via the communication unit. When causing the first autonomous vehicle to be directed to an entrance node constituting the branch line, the command unit refers to the storage unit to determine whether or not the second autonomous vehicle is present at the entrance node (step S1), and if it is determined that the second autonomous vehicle is present, sends, to the second autonomous vehicle, a command to set a spare node which is a node other than the entrance node constituting the branch line as a destination (step S6), and then sends, to the first autonomous vehicle, a command to set the entrance node as a destination (step S7).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a system for controlling a plurality of autonomous vehicles, and more particularly to a system for controlling autonomous vehicles traveling on a main line and a dead-end branch line connected to the main line. [Background technology]

[0002] Conventionally, control systems that control the travel of multiple autonomous vehicles within a work environment have been known. One such control system (management means C) is described in Patent Document 1. Under the control of this control system, a mobile body (e.g., mobile body A2) that is an autonomous vehicle loads a load at one station (e.g., station ST4), unloads it at another station (e.g., station ST5), and then returns to station ST1, which serves as a home position HP, and waits there (see FIG. 6). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-119043 Summary of the Invention [Problem to be solved by the invention]

[0004] In a relatively small work environment, it may not be possible to secure a home position that is large enough, or the home position may be a dead end. If multiple autonomous vehicles are returned to such a home position simultaneously, traffic congestion may occur near the entrance to the home position, or the autonomous vehicles may collide with each other.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control system that can return multiple autonomous vehicles to a predetermined position in an orderly manner. [Means for solving the problem]

[0006] In order to solve the above problem, the control system of the present invention is a control system that controls multiple autonomous vehicles, including a first autonomous vehicle and a second autonomous vehicle, traveling on a main line and a dead-end branch line connected to the main line, and is equipped with a communication unit, a memory unit that stores the positions of multiple nodes that make up the main line and the branch line, and the current positions of the autonomous vehicles obtained from the autonomous vehicles via the communication unit, and a command unit that sends commands regarding the destination to the autonomous vehicles via the communication unit.When the command unit directs the first autonomous vehicle toward an entrance node, which is a node that makes up a branch line directly connected to a node that makes up the main line, it refers to the memory unit to determine whether a second autonomous vehicle is at the entrance node, and if it determines that a second autonomous vehicle is present, it sends a command to the second autonomous vehicle to make a spare node, which is a node other than the entrance node that makes up the branch line, its destination, and then sends a command to the first autonomous vehicle to make the entrance node its destination.

[0007] A backup node in the control system is, for example, a node directly connected to an ingress node.

[0008] When there are multiple spare nodes, the command unit of the control system may determine one spare node based on the number of connected nodes and send a command to the second autonomous vehicle to make that spare node the destination, or may determine one spare node based on the distance from the entry node and send a command to the second autonomous vehicle to make that spare node the destination.

[0009] The plurality of autonomous vehicles of the control system may further include a third autonomous vehicle. In this case, the command unit may be configured to, when directing the first autonomous vehicle toward the entry node, determine by referring to the memory unit whether a second autonomous vehicle is present at the entry node, and if it determines that a second autonomous vehicle is present, determine by referring to the memory unit whether a third autonomous vehicle is present at a first spare node directly connected to the entry node, and if it determines that a third autonomous vehicle is present, send a command to the third autonomous vehicle to make a second spare node other than the first spare node its destination, then send a command to the second autonomous vehicle to make the first spare node its destination, and then send a command to the first autonomous vehicle to make the entry node its destination.

[0010] When there are multiple second spare nodes, the command unit of the control system may determine one second spare node based on the number of connected nodes and send a command to the third autonomous vehicle to make that one second spare node the destination, or may determine one second spare node based on the distance from the first spare node and send a command to the third autonomous vehicle to make that one second spare node the destination. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a control system that is capable of returning a plurality of autonomous vehicles to a predetermined position in an orderly manner. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a work environment in a first embodiment of the present invention. [Figure 2] 1 is a diagram showing the relationship between a control system according to a first embodiment of the present invention and a plurality of autonomous vehicles under its control. [Figure 3] FIG. 2 is an operation flow diagram of the control system according to the first embodiment of the present invention. [Figure 4]1A and 1B are diagrams showing the home position situation in a first embodiment of the present invention, in which (A) shows a situation where one autonomous vehicle is waiting at the home position, (B) shows a situation where two autonomous vehicles are waiting at the home position, and (C) shows a situation where three autonomous vehicles are waiting at the home position. [Figure 5] FIG. 10 is a diagram showing a home position in a second embodiment of the present invention. [Figure 6] FIG. 1 is a diagram showing a work environment in which a conventional control system (management means) is installed. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a first embodiment and a second embodiment of a control system according to the present invention will be described with reference to the accompanying drawings.

[0014] [First Example] 1 shows a work environment in which autonomous vehicles AMR1-AMR4 controlled by a control system 10 according to a first embodiment of the present invention perform their work. As shown in the figure, the work environment includes tables T1-T13 where customers can dine, a main travel area made up of 16 nodes N1-N15, NK, and a home position HP made up of three nodes NH, NR1, NR2. If the main travel area made up of nodes N1-N15, NK is considered to be a main line, then the home position HP made up of nodes NH, NR1, NR2 can be said to be a dead-end branch line connected to the main line.

[0015] As will be explained in detail later, control system 10 is configured to wirelessly transmit destination-related commands to autonomous vehicles AMR1 to AMR4. For example, control system 10 transmits a command to autonomous vehicle AMR2, which has loaded food to be delivered to table T8 at node NK near the kitchen, to set node N9 as its destination. Upon receiving the command, autonomous vehicle AMR2 basically travels toward destination node N9 via the shortest route (i.e., NK → N1 → N7 → N8 → N9). At this time, autonomous vehicle AMR2 does not need to pass exactly through nodes N1, N7, and N8 along the way; it is sufficient for autonomous vehicle AMR2 to pass near these nodes. Furthermore, if autonomous vehicle AMR2 detects an obstacle on its route, it may make a detour that does not significantly deviate from the shortest route, or it may wait until the obstacle is gone.

[0016] As mentioned above, the home position HP is composed of three nodes NH, NR1, and NR2. Node NH is the "entrance node" directly connected to node N7 that constitutes the main line, node NR1 is the "first backup node" directly connected to the entrance node NH, and node NR2 is the "second backup node" directly connected to the first backup node NR1. Backup nodes NR1 and NR2 are not directly connected to any of the nodes that constitute the main line.

[0017] Control system 10 is installed in a location where it can communicate with autonomous vehicles AMR1 to AMR4. Control system 10 may be installed inside or outside the work environment.

[0018] 2, control system 10 according to this embodiment includes a communication unit 11, a memory unit 12, and a command unit 13. Furthermore, autonomous vehicle AMR1 controlled by control system 10 includes a communication unit 20, a position estimation unit 21, a memory unit 22, a control unit 23, a traveling device 24, and a steering device 25. Like autonomous vehicle AMR1, other autonomous vehicles AMR2 to AMR4 also include a communication unit 20 and the like.

[0019] The communication unit 11 of the control system 10 performs two-way wireless communication with the communication units 20 of the autonomous vehicles AMR1 to AMR4.

[0020] The memory unit 12 of the control system 10 stores map information (which includes the positions (relative positions with respect to any point in the work environment) of all nodes N1 to N15, NK, NH, NR1, and NR2 that make up the main line and branch line, and the connections between them), as well as the current vehicle positions (relative positions with respect to any point in the work environment) periodically acquired from each of the autonomous vehicles AMR1 to AMR4. The current vehicle positions stored in the memory unit 12 are updated each time a new current vehicle position is acquired from each of the autonomous vehicles AMR1 to AMR4. The current vehicle positions are acquired via the communication unit 11.

[0021] A command unit 13 of the control system 10 transmits a command related to the destination to the autonomous vehicles AMR1 to AMR4. This transmission is performed via the communication unit 11.

[0022] For example, when the food to be delivered to table T8 is ready, command unit 13 sends a command to any one of the autonomous vehicles that is not currently delivering food (e.g., autonomous vehicle AMR2) to set node NK as its destination. Furthermore, command unit 13 sends a command to autonomous vehicle AMR2 that has loaded the food to be delivered to table T8 at node NK to set node N9, which is near table T8, as its destination. Furthermore, command unit 13 sends a command to autonomous vehicle AMR2 that has finished delivering the food to the customer at table T8 at node N9 to set entrance node NH, which constitutes home position HP, as its destination.

[0023] The communication unit 20 of each of the autonomous vehicles AMR1 to AMR4 performs two-way wireless communication with the communication unit 11 of the control system 10.

[0024] Storage unit 22 of autonomous vehicles AMR1 to AMR4 stores map information (which includes the positions of all nodes N1 to N15, NK, NH, NR1, and NR2 that make up the main line and branch lines, and the connections between these).

[0025] Position estimation unit 21 of autonomous vehicles AMR1 to AMR4 estimates the position of the vehicle within the work environment (hereinafter referred to as "current vehicle position") based on information obtained by analyzing images captured by cameras or information obtained from various sensors. Position estimation unit 21 periodically transmits the estimated current vehicle position of the vehicle to control system 10. This transmission is performed via communication unit 20.

[0026] The travel device 24 and steering device 25 of the autonomous vehicles AMR1 to AMR4 are composed of a pair of left and right drive wheels. When the left and right drive wheels rotate in the same direction at the same speed, the autonomous vehicle AMR1 moves forward or backward. When the left and right drive wheels rotate in the same direction at different speeds, the autonomous vehicle AMR1 turns in either the left or right direction while moving forward or backward. Furthermore, when the left and right drive wheels rotate in different directions at the same speed, the autonomous vehicle AMR1 turns on the spot.

[0027] When the control unit 23 of the autonomous vehicles AMR1 to AMR4 receives a command regarding the destination via the communication unit 20, it rotates the left and right drive wheels, which also serve as the running device 24 and steering device 25, so that the current position of the vehicle estimated by the position estimation unit 21 matches the position of the node that is the destination stored in the memory unit 22.

[0028] The control unit 23 may transmit a report on the operating state of the vehicle to the control system 10 at the same time that the position estimation unit 21 transmits the current position of the traveling vehicle, or at a different time. This transmission is also performed via the communication unit 20.

[0029] Next, the operation flow of the control system 10 according to this embodiment will be described with particular reference to FIGS.

[0030] When moving (returning) an autonomous vehicle (e.g., autonomous vehicle AMR1) that has finished transporting food to an entrance node NH at home position HP, command unit 13 of control system 10 determines whether entrance node NH can be used (step S1). Specifically, command unit 13 compares the position of entrance node NH stored in memory unit 12 with the current vehicle positions of other autonomous vehicles AMR2 to AMR4, and determines whether other autonomous vehicles AMR2 to AMR4 are present at entrance node NH. If another autonomous vehicle (e.g., autonomous vehicle AMR2) is present at entrance node NH, command unit 13 determines that entrance node NH cannot be used, and if no other autonomous vehicles AMR2 to AMR4 are present at entrance node NH, command unit 13 determines that entrance node NH can be used.

[0031] After determining in step S1 that entry node NH is available, command unit 13 transmits a command to autonomous vehicle AMR1 to set entry node NH as the destination (step S7).

[0032] After determining in step S1 that the ingress node NH cannot be used, the command unit 13 searches for a backup node connected to the ingress node NH (step S2). Specifically, the command unit 13 refers to the map information stored in the storage unit 12 to search for a backup node connected to the ingress node NH. As shown in Fig. 1, in this embodiment, a first backup node NR1 is connected to the ingress node NH. Therefore, in this embodiment, the command unit 13 determines that there is a backup node connected to the ingress node NH.

[0033] After determining in step S2 that a spare node is present, command unit 13 determines whether or not that spare node (i.e., first spare node NR1) can be used (step S3). Specifically, command unit 13 compares the position of first spare node NR1 stored in memory unit 12 with the current vehicle positions of the other autonomous vehicles AMR3 and AMR4, and determines whether or not the other autonomous vehicles AMR3 and AMR4 are present at first spare node NR1. If another autonomous vehicle (e.g., autonomous vehicle AMR3) is present at first spare node NR1, command unit 13 determines that the first spare node NR1 cannot be used, and if other autonomous vehicles AMR3 and AMR4 are not present at first spare node NR1, command unit 13 determines that the first spare node NR1 can be used.

[0034] After determining in step S3 that the first spare node NR1 cannot be used, the command unit 13 searches for another spare node connected to the discovered spare node (i.e., the first spare node NR1) (step S4). Specifically, the command unit 13 refers to the map information stored in the storage unit 12 and searches for another spare node connected to the first spare node NR1. As shown in FIG. 1, in this embodiment, the second spare node NR2 is connected to the first spare node NR1. Therefore, in this embodiment, the command unit 13 determines that there is another spare node connected to the first spare node NR1.

[0035] After determining in step S4 that there is another spare node, command unit 13 determines whether or not that spare node (i.e., second spare node NR2) can be used (step S5). Specifically, command unit 13 references the position of second spare node NR2 and the current vehicle position of another autonomous vehicle AMR4, both of which are stored in memory unit 12, and determines whether or not another autonomous vehicle AMR4 is present at second spare node NR2. If another autonomous vehicle AMR4 is present at second spare node NR2, command unit 13 determines that second spare node NR2 cannot be used, and if no other autonomous vehicle AMR4 is present at second spare node NR2, command unit 13 determines that second spare node NR2 can be used.

[0036] After determining in step S5 that the second spare node NR2 cannot be used, the command unit 13 searches for another spare node connected to the discovered spare node (i.e., the second spare node NR2) (second step S4). As is clear from FIG. 1, in this embodiment, there is no such node. Therefore, in this embodiment, the command unit 13 determines in the second step S4 that there is no other spare node.

[0037] After determining in step S3 that a backup node (first backup node NR1) can be used, and after determining in step S5 that another backup node (second backup node NR2) can be used, the command unit 13 sends an evacuation command via the communication unit 11 (step S6).

[0038] Specifically, if it is determined in step S3 that first backup node NR1 can be used, command unit 13 transmits a command to autonomous vehicle AMR2 at entry node NH to set first backup node NR1 as its destination (step S6). After that, command unit 13 transmits a command to autonomous vehicle AMR1 to set entry node NH, which has become available due to the evacuation of autonomous vehicle AMR2, as its destination (step S7).

[0039] On the other hand, if command unit 13 determines in step S5 that second spare node NR2 can be used, it transmits a command to autonomous vehicle AMR3 located at first spare node NR1 to set second spare node NR2 as its destination, and transmits a command to autonomous vehicle AMR2 located at entry node NH to set first spare node NR1 as its destination (step S6). After that, command unit 13 transmits a command to autonomous vehicle AMR1 to set entry node NH, which has become available due to the evacuation of autonomous vehicle AMR2, as its destination (step S7).

[0040] After determining in step S2 that there is no spare node, and after determining in step S4 that there is no other spare node, command unit 13 decides to stop the movement of autonomous vehicle AMR1 to entry node NH (step S8) because entry node NH cannot be made free.

[0041] If the home position HP is in the state shown in Figure 4(A) when the autonomous vehicle AMR1 is to be returned to the home position HP, the command unit 13 will first evacuate the autonomous vehicle AMR2 from the entrance node NH to the first backup node NR1 (step S6), and then direct the autonomous vehicle AMR1 toward the entrance node HN (step S7).

[0042] If the home position HP is in the state shown in Figure 4(B) when the autonomous vehicle AMR1 is to be returned to the home position HP, the command unit 13 will cause the autonomous vehicle AMR3 to retreat from the first backup node NR1 to the second backup node NR2 (step S6), then cause the autonomous vehicle AMR2 to retreat from the entrance node NH to the first backup node NR1 (step S6), and then cause the autonomous vehicle AMR1 to head toward the entrance node HN (step S7).

[0043] Furthermore, if the home position HP is in the state shown in Figure 4(C) when the autonomous vehicle AMR1 is to be returned to the home position HP, the command unit 13 will stop directing the autonomous vehicle AMR1 toward the home position HP (step S8).

[0044] In this way, the control system 10 according to this embodiment can return a plurality of autonomous vehicles to the home position HP in an orderly manner.

[0045] [Second Example] FIG. 5 shows a home position HP' in a second embodiment of the present invention. As shown in the figure, the home position HP' is composed of seven nodes NH, NR1 to NR6. Node NH is an "entrance node" directly connected to node N7 (see FIG. 1) constituting the main line, nodes NR1 and NR2 are "first reserve nodes" directly connected to the entrance node NH, node NR3 is a "second reserve node" directly connected to the first reserve node NR1, nodes NR4 and NR5 are "third reserve nodes" directly connected to the second reserve node NR3, and node NR6 is a "fourth reserve node" directly connected to the third reserve node NR4. The reserve nodes NR1 to NR6 are not directly connected to any of the nodes constituting the main line. This home position HP' can also be said to be a dead-end branch line connected to the main line.

[0046] The command unit 13 of this embodiment is obtained by adding a first additional function and a second additional function to the command unit 13 of the first embodiment. The first additional function is a function of determining one node to be the evacuation destination from among multiple backup nodes connected to the ingress node. The second additional function is a function of determining one node to be the evacuation destination from among multiple other backup nodes connected to a discovered backup node.

[0047] First, the first additional function will be described in more detail. When autonomous vehicle AMR1 is returning to home position HP' and another autonomous vehicle AMR2 is at entry node NH (destination), command unit 13 searches for spare nodes connected to entry node NH (step S2), and determines whether each of the two first spare nodes NR1 and NR2 found is usable (step S3).

[0048] If one is available but the other is not, command unit 13 causes autonomous vehicle AMR2 to retreat to the available first spare node (step S6). If both are available, command unit 13 causes autonomous vehicle AMR2 to retreat to the first spare node that is closer to entry node NH (step S6). Alternatively, command unit 13 may cause autonomous vehicle AMR2 to retreat to first spare node NR1 based on the fact that other spare nodes NR3, NR4, and NR5 are directly or indirectly connected to first spare node NR1, but that no other spare nodes are connected to first spare node NR2 (step S6). If neither is available, command unit 13 performs the search of step S4.

[0049] Next, the second additional function will be described in more detail. If it is determined in step S5 that another backup node (second backup node NR3) is unavailable, command unit 13 searches for another backup node connected to the discovered backup node (i.e., second backup node NR3) (second step S4), and determines whether each of the two discovered third backup nodes NR4 and NR5 is available (second step S5).

[0050] If one is available but the other is not, the command unit 13 evacuates the autonomous vehicle located at the second spare node NR3 to the available third spare node (step S6). If both are available, the command unit 13 evacuates the autonomous vehicle located at the second spare node NR3 to the third spare node that is closer to the second spare node NR3 (step S6). Alternatively, the command unit 13 may evacuate the autonomous vehicle located at the second spare node NR3 to the third spare node NR4 based on the fact that another spare node NR6 is connected to the third spare node NR4 but no other spare node is connected to the third spare node NR5 (step S6). If neither is available, the command unit 13 performs the search of step S4.

[0051] The control system 10 according to this embodiment is common to the control system 10 according to the first embodiment except that the command unit 13 has the first additional function and the second additional device.

[0052] [Variations] Although the first and second embodiments of the control system according to the present invention have been described above, the configuration of the present invention is not limited to these.

[0053] For example, the control target of the control system according to the present invention is not limited to an autonomous vehicle that returns to a home position after delivering food to customers in a restaurant. In other words, the control system according to the present invention can be used to control any number of autonomous vehicles traveling on a main line and a dead-end branch line connected to the main line. The home position is merely one example of a dead-end branch line. [Explanation of symbols]

[0054] 10. Control System 11. Communication section (of control system) 12 Memory (of the control system) 13 Command center (of a control system) 20. Communications unit (for autonomous vehicles) 21 Position estimation unit (for autonomous vehicles) 22 (Autonomous Vehicle) Memory Unit 23 (Autonomous vehicle) control unit 24 (Autonomous Vehicle) Driving Device 25 Steering system (for autonomous vehicles) AMR1, AMR2, AMR, AMR4 autonomous vehicles HP,HP' Home position NH entry node NR1, NR2, NR3, NR4, NR5, NR6 spare nodes

Claims

1. A control system for controlling a plurality of autonomous vehicles including a first autonomous vehicle and a second autonomous vehicle traveling on a main line and a dead-end branch line connected to the main line, the control system comprising: The Communications Department and a storage unit that stores the positions of a plurality of nodes that constitute the main line and the branch line, and a current vehicle position acquired from the autonomous vehicle via the communication unit; a command unit that sends a command regarding a destination to the autonomous vehicle via the communication unit; Equipped with When directing the first autonomous vehicle toward an entrance node that is a node constituting the branch line directly connected to a node constituting the main line, the command unit refers to the storage unit to determine whether the second autonomous vehicle is at the entrance node, and if it determines that the second autonomous vehicle is present, sends a command to the second autonomous vehicle to make a spare node that is a node other than the entrance node constituting the branch line its destination, and then sends a command to the first autonomous vehicle to make the entrance node its destination. A control system comprising:

2. The backup node is a node directly connected to the ingress node.

2. The control system of claim 1.

3. If there are multiple spare nodes, the command unit determines one spare node based on the number of connected nodes, and sends a command to the second autonomous vehicle to designate the selected spare node as its destination.

3. The control system according to claim 1 or 2, wherein:

4. If there are multiple spare nodes, the command unit determines one spare node based on the distance from the entry node, and sends a command to the second autonomous vehicle to set the selected spare node as its destination.

3. The control system according to claim 1 or 2, wherein:

5. the plurality of autonomous vehicles further includes a third autonomous vehicle; When directing the first autonomous vehicle toward the entry node, the command unit refers to the storage unit to determine whether the second autonomous vehicle is present at the entry node, and if it determines that the second autonomous vehicle is present, refers to the storage unit to determine whether the third autonomous vehicle is present at a first spare node directly connected to the entry node, and if it determines that the third autonomous vehicle is present, sends a command to the third autonomous vehicle to make a second spare node that is a spare node other than the first spare node its destination, then sends a command to the second autonomous vehicle to make the first spare node its destination, and then sends a command to the first autonomous vehicle to make the entry node its destination.

3. The control system according to claim 1 or 2.

6. If there are multiple second spare nodes, the command unit determines one second spare node based on the number of connected nodes, and sends a command to the third autonomous vehicle to designate the selected second spare node as its destination.

6. The control system according to claim 5, wherein:

7. If there are multiple second spare nodes, the command unit determines one second spare node based on the distance from the first spare node, and sends a command to the third autonomous vehicle to set the one second spare node as its destination.

6. The control system according to claim 5, wherein:

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