AUTOMATED TRANSPORT VEHICLE MANAGEMENT SYSTEM AND AUTOMATED TRANSPORT VEHICLE CONTROL METHOD

Abstract

To suppress variance of work loads for unmanned transport vehicle.SOLUTION: An unmanned transport vehicle management system that manages a plurality of unmanned transport vehicles includes a task information acquisition unit that acquires information of a scheduled transport task performed by the unmanned transport vehicle, a performance acquisition unit that acquires an accumulated transport performance representing a degree of a performance in which the unmanned transport vehicle transports transported products, and an instruction unit that determines an unmanned transport vehicle performing the transport task according to the accumulated transport performance and instruct the determined unmanned transport vehicle to perform the transport task.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an automated guided vehicle management system and a method for controlling an automated guided vehicle. [Background technology]

[0002] Regarding a system for managing multiple automated guided vehicles, Patent Document 1 discloses a technology that stores the cumulative travel distance of multiple guided vehicles and instructs a guided vehicle whose cumulative travel distance exceeds a predetermined value to move to a maintenance station. This allows a guided vehicle with a large accumulated load to be automatically moved to the maintenance station for maintenance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-233422 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned system, the load may vary from one transport vehicle to another. If the load varies from one transport vehicle to another, for example, there is a high possibility that efficient maintenance of multiple transport vehicles cannot be performed collectively, or that the timing when each transport vehicle reaches the end of its life may vary. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, an automated guided vehicle management system for managing a plurality of automated guided vehicles is provided. The automated guided vehicle management system includes a task information acquisition unit that acquires information on a transport task to be executed by the automated guided vehicle, a performance acquisition unit that acquires, for each automated guided vehicle, an accumulated transport performance indicating a track record of the automated guided vehicle transporting an object, and an instruction unit that determines the automated guided vehicle that will execute the transport task according to the accumulated transport performance and instructs the determined automated guided vehicle to execute the transport task. In this manner, the automated guided vehicle that executes the transport task can be determined based on the accumulated transport performance, so that the variation in the load for each automated guided vehicle can be suppressed. (2) In the above embodiment, the cumulative transportation performance may be represented by any one of the following in the past transportation task: (a) a cumulative amount of work representing a cumulative value of the amount of work based at least on the travel distance of the automated guided vehicle and the weight of the transported object, (b) a cumulative transport distance representing a cumulative value of the distance the automated guided vehicle transported the transported object, and (c) a cumulative number of transports representing a cumulative value of the number of times the automated guided vehicle transported the transported object. In this embodiment, an automated guided vehicle to execute a transportation task can be determined according to any one of the cumulative amount of work, the cumulative transport distance, and the cumulative number of transports. (3) In the above embodiment, the instructing unit may instruct the automated guided vehicle with the smallest accumulated transport performance to execute the transport task. In this embodiment, it is more likely that the automated guided vehicle with the smallest accumulated load can be instructed to perform the transport task. (4) In the above embodiment, the instruction unit may determine the automated guided vehicle to be instructed to execute the transport task from among the automated guided vehicles whose accumulated transport performance is equal to or lower than a predetermined level. With this embodiment, the automated guided vehicle to execute the transport task can be determined from among the automated guided vehicles with a smaller accumulated load. (5) In the above embodiment, the cumulative transportation performance is represented by the cumulative amount of work, and the information on the transportation task includes the weight of the transportation target, which is the object to be transported in the transportation task, and the position information of the transportation source and the transportation destination of the object to be transported. The system further includes a position information acquisition unit that acquires information on the current position of each of the automated guided vehicles, and a calculation unit that calculates an estimated value of the amount of work when each of the automated guided vehicles performs the transportation task based on at least the distance each of the automated guided vehicles moves from the current position to the transportation source, the distance each of the automated guided vehicles moves from the transportation source to the transportation destination, and the weight of the transportation target. The instruction unit may determine the automated guided vehicle that performs the transportation task according to the sum of the cumulative amount of work and the estimated value. In this embodiment, the automated guided vehicle that performs the transportation task can be determined by taking into account the estimated value of the amount of work when the transportation task is performed. Therefore, it is possible to suppress the variation in the load for each automated guided vehicle, and to increase the possibility of transporting the object more efficiently in the transportation task.

[0007] In addition to the form of the automated guided vehicle management system described above, the present disclosure can be realized in various forms, such as a control method for an automated guided vehicle and an automated guided vehicle system including a plurality of automated guided vehicles. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of an automated guided vehicle system according to a first embodiment. [Diagram 2] 4 is a flowchart of a transport process in the first embodiment. [Diagram 3] 10 is a flowchart of a transport process in the second embodiment. [Figure 4] FIG. 13 is a diagram showing a schematic configuration of an automated guided vehicle system according to a third embodiment. [Diagram 5] 13 is a flowchart of a transport process in the third embodiment. [Figure 6] 13 is a flowchart of a transport process in a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A. First embodiment: FIG. 1 is a diagram showing a schematic configuration of an automated guided vehicle system 100 in a first embodiment. The automated guided vehicle system 100 includes a plurality of automated guided vehicles 20 and an automated guided vehicle management system 50 that manages the plurality of automated guided vehicles 20. In this embodiment, the automated guided vehicle system 100 includes four automated guided vehicles 20. The number of automated guided vehicles 20 in the automated guided vehicle system 100 may be two or three, or may be five or more. The automated guided vehicle system 100 may include, for example, a camera for monitoring the operation of the automated guided vehicles 20.

[0010] The automated guided vehicle 20 is also called an AGV (Automatic Guided Vehicle), and transports objects such as parts by automatically traveling while supporting the objects. In this embodiment, the automated guided vehicle 20 is configured as an image recognition AGV, and travels along a predetermined route while recognizing its own current position on the route by reading markers or the like arranged on the route. In other embodiments, the automated guided vehicle 20 may be, for example, an electromagnetic induction type, a magnetic induction type, or a laser induction type AGV, or may be a non-guided traveling type AGV.

[0011] The automated guided vehicle 20 in this embodiment includes wheels 21 for traveling, a lift 23 for supporting and operating a table 22 for loading an object to be transported, and a vehicle control unit 24. The automated guided vehicle 20 operates on the power of a battery (not shown). The battery is charged, for example, by a wired or wireless charger provided at a charging station (not shown) on the route. The vehicle control unit 24 is configured by a computer including a CPU and a memory. The wheels 21 are rotated by driving a motor (not shown) that is driven under the control of the vehicle control unit 24. The lift 23 is configured by an electric ball screw or the like that is driven under the control of the vehicle control unit 24, and is configured to be able to move the table 22 up and down. In other embodiments, the automated guided vehicle 20 may include, for example, an arm that grips the object to be transported and loads or unloads it, instead of the lift 23. The automated guided vehicle 20 may also be configured to transport the object by towing it, rather than loading and transporting it.

[0012] In this embodiment, the automated guided vehicle 20 transports the dolly 120 supporting parts and the like as an article to be transported. More specifically, the automated guided vehicle 20 enters under the dolly 120, raises the table 22 by the lift 23, loads and supports the dolly 120 on the table 22, and travels to the destination while supporting the dolly 120, thereby transporting the dolly 120 as an article to be transported.

[0013] The automated guided vehicle management system 50 is configured by a computer including a control unit 60, a storage device 90, and an external interface. The automated guided vehicle management system 50 is configured to be capable of wireless communication with each automated guided vehicle 20 and an external terminal 110. In this embodiment, the external terminal 110 is configured by a tablet terminal. The external terminal 110 may be configured by, for example, a smartphone or a computer. In addition, a plurality of external terminals 110 may be configured to be capable of communicating with the automated guided vehicle management system 50.

[0014] In this embodiment, the automated guided vehicle management system 50 receives information on transport tasks, which will be described later, by communicating with the external terminal 110. In addition, the automated guided vehicle management system 50 communicates with each automated guided vehicle 20 to receive information on the current position of each automated guided vehicle 20, and also transmits information on the transport task to the automated guided vehicle 20 that executes the transport task.

[0015] The control unit 60 includes a task information acquisition unit 65, a track record acquisition unit 70, and an instruction unit 75. Furthermore, in this embodiment, the control unit 60 includes a location information acquisition unit 80. In this embodiment, the task information acquisition unit 65, the track record acquisition unit 70, the instruction unit 75, and the location information acquisition unit 80 are each a functional unit realized by the control unit 60 executing a program.

[0016] The position information acquisition unit 80 acquires information on the current position of each automated guided vehicle 20. In this embodiment, the position information acquisition unit 80 acquires the current position information received by the automated guided vehicle management system 50 from each automated guided vehicle 20.

[0017] The task information acquisition unit 65 acquires information on the transport task to be executed by the automated guided vehicle 20. In this embodiment, the information on the transport task includes the weight of the transport target and the location information of the transport source and destination of the transport target. The transport target refers to the transport object to be transported by the automated guided vehicle 20 in the transport task. In this embodiment, the task information acquisition unit 65 acquires information on the transport task received by the automated guided vehicle management system 50 from the external terminal 110. In another embodiment, the task information acquisition unit 65 may acquire, for example, an identifier of the transport task transmitted from the external terminal 110, and acquire the weight of the transport target and the location information of the transport source and destination from the storage device 90 by referring to the information stored in the storage device 90 based on the identifier. In this case, the storage device 90 may store the identifier of the transport task, the weight of the transport object to be transported by the transport task, and the location information of the transport source and destination in advance in association with each other. In addition, for example, when the transport source and the transport destination are predetermined for each transport object, the identifier of the transport object may be used as the identifier of the transport task.

[0018] The transport task is executed by the automated guided vehicle 20 instructed by the instruction unit 75 described later. In the transport task, the automated guided vehicle 20 first travels along a route to move from the current position to the transport origin. Next, the automated guided vehicle 20 loads the transport object at the transport origin. The automated guided vehicle 20 travels along a route while supporting the loaded transport object, and moves from the transport origin to the transport destination. Then, the automated guided vehicle 20 unloads the transport object at the transport destination. In this embodiment, the automated guided vehicle 20 that has transported the transport object to the transport destination waits there until it is instructed to execute a new transport task, unless it moves to a charging location or to secure a route for another automated guided vehicle 20. In other embodiments, loading of the transport object onto the automated guided vehicle 20 and unloading of the transport object from the automated guided vehicle 20 may be performed, for example, by a robot or manually.

[0019] The result acquisition unit 70 acquires the accumulated transport result for each automated guided vehicle 20. In this embodiment, the result acquisition unit 70 acquires the accumulated transport result stored in the storage device 90 for each automated guided vehicle 20 from the storage device 90. The accumulated transport result indicates the extent to which the automated guided vehicle 20 has transported an object. In this embodiment, the accumulated transport result is represented by an accumulated workload indicating an accumulated value of the workload in past transport tasks of the automated guided vehicle 20. The workload in a transport task of a certain automated guided vehicle 20 is calculated based on at least the distance traveled by the automated guided vehicle 20 in the transport task and the weight of the object transported by the automated guided vehicle 20 in the transport task.

[0020] In this embodiment, the cumulative work amount is calculated as a cumulative work amount representing a cumulative value of work done in past transport tasks by the automated guided vehicle 20. The cumulative work amount of a certain automated guided vehicle 20 includes a cumulative value of a first work representing work done when the automated guided vehicle 20 travels toward the transport source without supporting an object to be transported, a cumulative value of a second work representing work done when the automated guided vehicle 20 loads an object to be transported, a cumulative value of a third work representing work done when the automated guided vehicle 20 travels toward the transport destination while supporting the object to be transported, and a cumulative value of a fourth work representing work done when the automated guided vehicle 20 unloads the object to be transported.

[0021] In this embodiment, the first work and the third work are calculated based on the rolling resistance, acceleration resistance, and travel distance when the automated guided vehicle 20 travels toward the origin or destination. The rolling resistance and acceleration resistance are calculated based on the weight of the automated guided vehicle 20. When the automated guided vehicle 20 travels toward the destination while supporting an object, the weight of the object is added to the body of the automated guided vehicle 20, so that the third work is usually larger than the first work. In other embodiments, the first work and the third work may be calculated by taking into account, for example, air resistance and gradient resistance when the automated guided vehicle 20 travels. The second work and the fourth work are calculated based on the change in potential energy due to the up and down movement of the object. In other words, the second work amount and the fourth work amount are calculated based on the weight of the object.

[0022] The control unit 60 may, for example, determine the maintenance time of the automated guided vehicle 20 according to the accumulated transport performance, and perform the maintenance of the automated guided vehicle 20. For example, in this embodiment, the control unit 60 may move the automated guided vehicle 20 to a maintenance location (not shown) where maintenance is performed, each time the accumulated work volume is added by a predetermined value. At the maintenance location, for example, the wheels 21 and the lift 23 of the automated guided vehicle 20 may be repaired or replaced, or other members may be repaired or replaced. The more the accumulated work volume of the automated guided vehicle 20 is, the more likely it is that the wheels 21 and the lift 23 are subjected to a large load due to transport. Therefore, by determining the maintenance time of the automated guided vehicle 20 according to the accumulated work volume, the automated guided vehicle 20 can be maintained more effectively. In addition, when the automated guided vehicle 20 reaches the maintenance time, the automated guided vehicle management system 50 may, for example, notify the user that the automated guided vehicle 20 has reached the maintenance time by an annunciation unit such as a monitor or a speaker, or by transmitting a signal to the external terminal 110.

[0023] The instruction unit 75 determines an automated guided vehicle 20 that will execute a transport task according to the accumulated transport performance, and instructs the determined automated guided vehicle 20 to execute the transport task. In this embodiment, the instruction unit 75 determines an automated guided vehicle 20 that will execute a transport task according to the accumulated work volume so that the load on each automated guided vehicle 20 is leveled.

[0024] FIG. 2 is a flowchart of the transport process in this embodiment. The transport process refers to a process in the automated guided vehicle system 100 in which the automated guided vehicle 20 executes a transport task to transport an object from a source to a destination. The flowchart in FIG. 2 can also be said to represent a method of controlling a plurality of automated guided vehicles 20. The transport process in FIG. 2 is executed by the control unit 60 when the automated guided vehicle management system 50 accepts a transport task. In this embodiment, the automated guided vehicle management system 50 accepts the transport task by receiving information on the transport task from the external terminal 110.

[0025] In step S105, the control unit 60 functioning as the task information acquisition unit 65 acquires information on the transportation task to be executed. In step S110, the control unit 60 functioning as the position information acquisition unit 80 acquires current position information of each automated guided vehicle 20. In step S115, the control unit 60 functioning as the performance acquisition unit 70 acquires the accumulated work amount of each automated guided vehicle 20.

[0026] In step S120, the control unit 60 functioning as the instructing unit 75 refers to the accumulated work amount acquired in step S115, determines the AGV 20 with the smallest accumulated work amount as the AGV 20 that will execute the transport task, and instructs the AGV 20 to execute the transport task. In this embodiment, the control unit 60 instructs the determined AGV 20 to execute the transport task by transmitting an execution command for the transport task and position information of the transport origin and the transport destination.

[0027] The automated guided vehicle 20 that has been instructed to execute the transportation task in step S120 executes the transportation task based on the received location information of the transportation source and the transportation destination. After that, the automated guided vehicle 20 transmits a completion signal indicating that the transportation task has been completed to the automated guided vehicle management system 50.

[0028] In step S125, the control unit 60 updates the accumulated work amount of the automated guided vehicle 20 that performed the transport task. In this embodiment, the control unit 60 executes step S125 when the automated guided vehicle management system 50 receives a completion signal from the automated guided vehicle 20. In step S125, the control unit 60 updates the accumulated work amount by adding the work amount due to the transport task to the accumulated work amount before the automated guided vehicle 20 that performed the transport task. In this embodiment, the control unit 60 calculates the work amount due to the transport task as the sum of the first job, the second job, the third job, and the fourth job in the transport task.

[0029] According to the automated guided vehicle management system 50 in this embodiment described above, the instructing unit 75 determines the automated guided vehicle 20 that will execute the transport task according to the accumulated transport performance, and instructs the determined automated guided vehicle 20 to execute the transport task. This makes it possible to determine the automated guided vehicle 20 that will execute the transport task according to the accumulated transport performance, thereby suppressing the variation in the load for each automated guided vehicle 20.

[0030] In the present embodiment, the instructing unit 75 instructs the automated guided vehicle 20 with the smallest accumulated transport performance to execute the transport task. This increases the possibility of instructing the automated guided vehicle 20 with the smallest accumulated load to execute the transport task.

[0031] In other embodiments, the cumulative transport performance may be expressed, for example, by the cumulative transport distance or the cumulative transport count, instead of the cumulative workload. The cumulative transport distance of a certain automated guided vehicle 20 refers to the cumulative value of the distance traveled by the automated guided vehicle 20 while supporting the transported object. The cumulative transport count of a certain automated guided vehicle 20 refers to the cumulative value of the number of times the automated guided vehicle 20 transports the transported object. Since the cumulative transport count and the cumulative transport performance are correlated with the load of the wheels 21 and the lift 23, as with the cumulative workload, even in this case, the transport task can be executed while suppressing the variation in the load for each automated guided vehicle 20 by executing the transport process. For example, when the cumulative transport performance is expressed by the cumulative transport distance, the control unit 60 acquires the cumulative transport distance of each automated guided vehicle 20 in a process corresponding to step S115 of the transport process shown in FIG. 2. Then, in a process corresponding to step S120, the control unit 60 determines the AGV 20 with the shortest accumulated transport distance as the AGV 20 that will execute the transport task, and instructs the determined AGV 20 to execute the transport task. After that, in a process corresponding to step S125, the control unit 60 updates the accumulated transport distance. Even when the accumulated transport performance is represented by the accumulated number of transports, the control unit 60 can execute the transport process in the same manner as described above.

[0032] B. Second embodiment: 3 is a flowchart of the transport process executed by the control unit 60 in the second embodiment. In this embodiment, unlike the first embodiment, the control unit 60 of the automated guided vehicle management system 50 determines an automated guided vehicle 20 to be instructed to execute a transport task from among the automated guided vehicles 20 whose accumulated transport performance is equal to or less than a predetermined level. The configuration of the automated guided vehicle system 100 in the second embodiment is the same as that in the first embodiment unless otherwise specified.

[0033] Steps S205 to S215 are similar to steps S105 to S115 in FIG. 2, respectively, and therefore will not be described.

[0034] In step S220, the control unit 60 executes an extraction process. The extraction process refers to a process of extracting an automated guided vehicle 20 whose accumulated transport performance is equal to or less than a predetermined level. In this embodiment, the control unit 60 extracts an automated guided vehicle 20 whose accumulated workload is equal to or less than a predetermined threshold in the extraction process. In this embodiment, the threshold in the extraction process is set to a value obtained by multiplying the maximum value of the accumulated workload acquired in step S215 by a predetermined coefficient that is greater than 0 and less than 1. In other embodiments, the threshold may be set to, for example, the average value or the median value of the accumulated workload acquired in step S215.

[0035] In step S225, the control unit 60 determines whether or not an automated guided vehicle 20 has been extracted by the extraction process executed in step S220. If it is determined that an automated guided vehicle 20 has been extracted by the extraction process, in step S230, the control unit 60 determines an automated guided vehicle 20 to be instructed to perform a transport task from among the automated guided vehicles 20 extracted by the extraction process, and instructs the automated guided vehicle 20 to perform the transport task.

[0036] In this embodiment, the control unit 60 instructs the automatic guided vehicle 20 closest to the transport target, among the automatic guided vehicles 20 extracted by the extraction process, to execute the transport task in step S230. In the extraction process in this embodiment, the smaller the threshold value, the more likely it is that an automatic guided vehicle 20 with a smaller cumulative work amount will be extracted. Therefore, by reducing the threshold value, the more likely it is that the variation in the load for each automatic guided vehicle 20 can be suppressed. On the other hand, the larger the above-mentioned threshold value, the more likely it is that more automatic guided vehicles 20 will be extracted in the extraction process. Therefore, in this embodiment, by increasing the threshold value, the more likely it is possible to instruct the automatic guided vehicle 20 that is closer to the transported object to execute the transport task in step S230. Therefore, by appropriately determining the threshold value, the transported object can be efficiently transported by the automatic guided vehicle 20 while suppressing the variation in the load for each automatic guided vehicle 20. In this embodiment, when the threshold value is increased, the value of the above-mentioned coefficient is increased, and when the threshold value is decreased, the value of the coefficient is decreased.

[0037] If it is determined that no AGV 20 has been extracted by the extraction process in step S225, in step S235, the control unit 60 determines an AGV 20 to be instructed to execute the transport task from among all AGVs 20, and instructs the AGV 20 to execute the transport task. In this case, since the difference in the cumulative work amount for each AGV 20 is smaller than when it is determined that an AGV 20 has been extracted in step S225, no matter which AGV 20 executes the transport task, the difference in the load variation for each AGV 20 is unlikely to occur. In this embodiment, in step S235, the control unit 60 instructs the AGV 20 that is closest to the transport target, among all AGVs 20, to execute the transport task.

[0038] Step S240 is the same as step S125 in Fig. 2. For example, when the threshold value in the extraction process is set to the average or median of the cumulative amount of work acquired in step S210, step S225 and step S235 may be omitted.

[0039] According to the automated guided vehicle management system 50 in the second embodiment described above, the instructing unit 75 determines an automated guided vehicle 20 to be instructed to execute a transport task from among the automated guided vehicles 20 whose accumulated transport performance is equal to or less than a predetermined level. This makes it possible to determine an automated guided vehicle 20 to execute a transport task from among the automated guided vehicles 20 whose accumulated load is smaller. In particular, in this embodiment, among the automated guided vehicles 20 whose accumulated transport performance is equal to or less than a predetermined threshold, the automated guided vehicle 20 that is closest to the transport target is instructed to execute the transport task. Therefore, the load variation for each automated guided vehicle 20 can be suppressed, and the transported object can be transported efficiently by the automated guided vehicles 20.

[0040] In another embodiment, the control unit 60 may not instruct the automatic guided vehicle 20 closest to the transport target to execute the transport task in step S230 or step S235 in Fig. 3. For example, the control unit 60 may instruct the automatic guided vehicle 20 having the highest remaining battery power to execute the transport task in step S230 or step S235. Furthermore, when executing the transport process in Fig. 3, the control unit 60 may use the accumulated transport distance or the accumulated transport count, instead of the accumulated work amount, as the accumulated transport performance, as in the first embodiment.

[0041] C. Third embodiment: 4 is a diagram showing a schematic configuration of an automated guided vehicle system 100b in the third embodiment. In this embodiment, unlike the first embodiment, the control unit 60b of the automated guided vehicle management system 50b includes a calculation unit 85 that calculates an estimated value of the amount of work when each automated guided vehicle 20 executes a transport task. In addition, the control unit 60b functioning as the instruction unit 75 determines the automated guided vehicle 20 that executes the transport task according to the sum of the accumulated amount of work and the calculated estimated value of the amount of work. The configuration of the automated guided vehicle system 100b in this embodiment is the same as that in the first embodiment unless otherwise described.

[0042] The calculation unit 85 in this embodiment is a functional unit that is realized by the control unit 60b executing a program. More specifically, the calculation unit 85, the control unit 60b, calculates a task estimation value that represents an estimated value of the amount of work when each automated guided vehicle 20 executes the transportation task, based on at least the distance that the automated guided vehicle 20 moves from the current position to the transportation origin when the transportation task is executed, the distance that the automated guided vehicle 20 moves from the transportation origin to the transportation destination, and the weight of the transportation target. In this embodiment, the control unit 60b calculates the task estimation value as the work when the automated guided vehicle 20 executes the transportation task, based on the current position information of the automated guided vehicle 20, the position information of the transportation origin and the transportation destination, and the weight of the transportation target, in the same way as calculating the amount of work in the transportation task in the first embodiment.

[0043] Fig. 5 is a flowchart of the transport process in the third embodiment. Steps S305 to S315 are similar to steps S105 to S115 in Fig. 1, respectively, and therefore the description thereof will be omitted.

[0044] In step S320, the control unit 60b functioning as the calculation unit 85 calculates the above-mentioned task estimated value. In this embodiment, in step S320, the control unit 60b calculates an estimated value of the first job, an estimated value of the second job, an estimated value of the third job, and an estimated value of the fourth job when each automated guided vehicle 20 executes the transportation task, and calculates the sum of these estimated values ​​as the task estimated value.

[0045] In this embodiment, in step S320, the control unit 60b calculates the estimated value of the second work, the estimated value of the third work, and the estimated value of the fourth work as values ​​common to each automated guided vehicle 20. On the other hand, the estimated value of the first work is estimated as a different value for each automated guided vehicle 20 when the travel distance from the current position to the destination differs for each automated guided vehicle 20. In other embodiments, the control unit 60b may calculate the estimated value of the second work, the estimated value of the third work, and the estimated value of the fourth work for each automated guided vehicle 20 in step S320, for example, depending on the specifications of each automated guided vehicle 20 and deterioration of the wheels 21, the lift 23, and the like due to aging.

[0046] In step S325, the control unit 60b functioning as the calculation unit 85 calculates the sum of the accumulated workload acquired in step S315 and the task estimated value calculated in step S320 for each automated guided vehicle 20. The sum of the accumulated workload and the task estimated value for each automated guided vehicle 20 may also be referred to as an estimated accumulated value.

[0047] In step S330, the control unit 60b functioning as the instruction unit 75 determines the AGV 20 with the smallest estimated cumulative value as the AGV 20 to execute the transport task, and instructs the AGV 20 to execute the transport task. As a result, for example, even if the cumulative work volume of a certain AGV 20 is the smallest, if the estimated cumulative value is not the smallest, the AGV 20 is not instructed to execute the transport task, and another AGV 20 is instructed to execute the transport task. In this case, the task estimated value of the AGV 20 instructed to execute the transport task is smaller than the task estimated value of the AGV 20 with the smallest cumulative work volume. That is, in this embodiment, the current position of the AGV 20 instructed to execute the transport task in this case is closer to the transport origin than the current position of the AGV 20 with the smallest cumulative work volume. Therefore, there is a high possibility that the transport target will be transported more efficiently in the transport task to be executed. Step S335 is the same as step S125 in FIG. 2.

[0048] According to the automated guided vehicle management system 50b in the third embodiment described above, the instruction unit 75 determines the automated guided vehicle 20 that will execute the transport task according to the cumulative workload and the estimated workload calculated based on the current position information and transport task information. This allows the automated guided vehicle 20 that will execute the transport task to be determined taking into account the estimated workload when the transport task is executed. This makes it possible to suppress the variation in the load for each automated guided vehicle 20, and increases the possibility of transporting the transported object more efficiently in the transport task.

[0049] D. Fourth embodiment: 6 is a flowchart of the transport process executed by the control unit 60b in the fourth embodiment. In the third embodiment, the control unit 60b determines the automated guided vehicle 20 with the smallest estimated cumulative value as the automated guided vehicle 20 that executes the transport task, but in this embodiment, the control unit 60b determines the automated guided vehicle 20 that executes the transport task from among the automated guided vehicles 20 with estimated cumulative values ​​equal to or less than a threshold value. The configuration of the automated guided vehicle system 100b in this embodiment is the same as that in the third embodiment unless otherwise described.

[0050] Steps S405 to S425 in Fig. 6 are respectively similar to steps S305 to S325 in Fig. 5. In step S430 in Fig. 6, the control unit 60b extracts an automated guided vehicle 20 whose estimated cumulative value is equal to or less than a threshold value, in the same way as the automated guided vehicle 20 whose cumulative work amount is equal to or less than a threshold value is extracted in step S220 in Fig. 3. In step S435, the control unit 60b determines whether or not an automated guided vehicle 20 has been extracted in step S430. Steps S440 to S450 are respectively similar to steps S230 to S240 in Fig. 3.

[0051] The automated guided vehicle management system 50b in the fourth embodiment described above can determine the automated guided vehicle 20 that executes the transport task by taking into account the estimated amount of work required to execute the transport task, as in the third embodiment. This can reduce the variation in the load on each automated guided vehicle 20, and can increase the possibility of more efficiently transporting the transported object in the transport task.

[0052] E. Other embodiments: (E1) In the above embodiment, the result acquiring unit 70 acquires the accumulated transport result from the storage device 90 in the transport process. In contrast, the result acquiring unit 70 does not have to acquire the accumulated transport result from the storage device 90. For example, the storage unit of the vehicle control unit 24 of each automated guided vehicle 20 may store the accumulated transport result, and the result acquiring unit 70 may acquire the accumulated transport result transmitted from each automated guided vehicle 20 in the transport process. In this case, for example, when the automated guided vehicle 20 executes a transport task, the automated guided vehicle 20 may update the accumulated transport result by itself based on the weight of the transport target and the position information of the transport origin and the transport destination.

[0053] (E2) In the above embodiment, the workload in the past transport task and the workload as the task estimate are calculated as work to be done by the automated guided vehicle 20. In contrast, the workload does not have to be calculated as work to be done by the automated guided vehicle 20. For example, the workload may be expressed as the sum of a value obtained by multiplying the distance traveled by the automated guided vehicle 20 in a transport task when it is not supporting a transport object by the weight of the automated guided vehicle 20 in a state where it is not supporting a transport object, and a value obtained by multiplying a transport distance, which represents a distance traveled by the automated guided vehicle 20 in a state where it is supporting a transport object, by the weight of the automated guided vehicle 20 in a state where it is supporting the transport object. In addition, the workload may be expressed, for example, by a value obtained by multiplying the transport distance by the weight of the transport object, or by the sum of values ​​calculated by multiplying the transport distance and the weight of the transport object by different coefficients, respectively.

[0054] (E3) In the above embodiment, the cumulative transport performance is represented by any one of the cumulative work amount, the cumulative transport distance, or the cumulative number of transports. In contrast, the cumulative transport performance does not have to be represented by the cumulative work amount, the cumulative transport distance, or the cumulative number of transports, and may be represented by, for example, the cumulative value of the weight of the transported object transported by the automated guided vehicle 20.

[0055] (E4) In the above embodiment, the information on the transport task includes the weight of the transport target and the location information of the transport source and the transport destination. In contrast, the information on the transport task may not include the weight of the transport target, the location information of the transport source, or the location information of the transport destination. For example, when the cumulative transport performance is represented by the cumulative transport distance or the cumulative number of transports, the information on the transport task may not include the weight of the transport target. In addition, the information on the transport task may be composed of, for example, only the identifier of the transport task. In this case, the automated guided vehicle 20 that executes the transport task may obtain the location information of the transport source and the transport destination from another computer or the like based on the identifier of the transport task transmitted from the automated guided vehicle management system 50.

[0056] (E5) In the above embodiment, the control unit 60 functioning as the position information acquisition unit 80 acquires current position information of each automated guided vehicle 20 in the transfer process. In contrast, for example, when the cumulative transfer performance is represented by the cumulative number of transfers or when the cumulative transfer performance is updated by each automated guided vehicle 20, the control unit 60 does not need to acquire current position information of the automated guided vehicle 20 in the transfer process. In this case, the automated guided vehicle management system 50 does not need to be equipped with the position information acquisition unit 80.

[0057] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention column can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0058] 20...automated guided vehicle, 21...wheel, 22...table, 23...lift, 24...vehicle control unit, 50, 50b...automated guided vehicle management system, 60, 60b...control unit, 65...task information acquisition unit, 70...performance acquisition unit, 75...instruction unit, 80...position information acquisition unit, 85...calculation unit, 90...storage device, 100, 100b...automated guided vehicle system, 110...external terminal, 120...cart

Claims

1. An automated guided vehicle management system for managing a plurality of automated guided vehicles, a task information acquisition unit that acquires information on a transportation task to be executed by the automated guided vehicle; a performance acquisition unit that acquires, for each of the automated guided vehicles, a cumulative transport performance indicating a degree of performance of the automated guided vehicles in transporting the transported object; an instruction unit that determines the automated guided vehicle that will execute the transportation task according to the accumulated transportation performance, and instructs the determined automated guided vehicle to execute the transportation task; A determination unit that determines a maintenance timing of the automated guided vehicle according to the accumulated transport performance, The cumulative transportation performance is represented by (a) a cumulative amount of work representing a cumulative value of an amount of work based at least on a travel distance of the automated guided vehicle and a weight of a transported object in a past transportation task; The information on the transport task includes a weight of a transport target that is an object to be transported in the transport task, and position information of a source and a destination of the transport target, The automated guided vehicle management system includes: a position information acquisition unit that acquires information on a current position of each of the automated guided vehicles; a calculation unit that calculates an estimated value of a work amount when each of the automated guided vehicles executes the transportation task based on at least a distance that each of the automated guided vehicles moves from the current position to the transportation origin, a distance that each of the automated guided vehicles moves from the transportation origin to the transportation destination, and a weight of the transportation target; the cumulative amount of work includes a first cumulative value of work representing work done by the automated guided vehicle when traveling toward the source side without supporting the transported object, a second cumulative value of work representing work done by the automated guided vehicle when loading the transported object, a third cumulative value of work representing work done by the automated guided vehicle when traveling toward the destination side while supporting the transported object, and a fourth cumulative value of work representing work done by the automated guided vehicle when unloading the transported object, the estimates include an estimate of the first work, an estimate of the second work, an estimate of the third work, and an estimate of the fourth work; the first job and the third job are calculated based on a rolling resistance, an acceleration resistance, and a moving distance of the automatic guided vehicle; the second work and the fourth work are calculated based on a change in potential energy due to vertical movement of the transported object, The instruction unit determines the automated guided vehicle that will execute the transportation task in accordance with the sum of the accumulated work amount and the estimated value.

2. A method for controlling a plurality of automated guided vehicles, comprising: acquiring information on a transportation task to be executed by the automated guided vehicle; acquiring, for each of the automated guided vehicles, a cumulative transport performance indicating a degree of transport performance of the automated guided vehicles in transporting the transported object; An instruction process of determining the automated guided vehicle that will execute the transport task according to the accumulated transport performance, and instructing the determined automated guided vehicle to execute the transport task, and determining a maintenance timing for the automated guided vehicle according to the accumulated transport performance, The cumulative transportation performance is represented by (a) a cumulative amount of work representing a cumulative value of an amount of work based at least on a travel distance of the automated guided vehicle and a weight of a transported object in a past transportation task; The information on the transport task includes a weight of a transport target that is an object to be transported in the transport task, and position information of a source and a destination of the transport target, The control method includes: acquiring information on a current position of each of the automated guided vehicles; and calculating an estimated value of an amount of work to be performed by each of the automated guided vehicles when the automated guided vehicles execute the transportation task, based on at least a distance traveled by each of the automated guided vehicles from the current position to the transportation origin, a distance traveled by each of the automated guided vehicles from the transportation origin to the transportation destination, and a weight of the transportation target; the cumulative amount of work includes a first cumulative value of work representing work done by the automated guided vehicle when traveling toward the source side without supporting the transported object, a second cumulative value of work representing work done by the automated guided vehicle when loading the transported object, a third cumulative value of work representing work done by the automated guided vehicle when traveling toward the destination side while supporting the transported object, and a fourth cumulative value of work representing work done by the automated guided vehicle when unloading the transported object, the estimates include an estimate of the first work, an estimate of the second work, an estimate of the third work, and an estimate of the fourth work; the first job and the third job are calculated based on a rolling resistance, an acceleration resistance, and a moving distance of the automatic guided vehicle; the second work and the fourth work are calculated based on a change in potential energy due to vertical movement of the transported object, The control method includes determining the automated guided vehicle that will execute the transportation task in accordance with a sum of the accumulated work amount and the estimated value in the instructing step.

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