Conveyance vehicle system

Abstract

To provide a conveyance vehicle system capable of causing each processing device to operate as much as possible by not setting a conveyance capability excessively and by processing a conveyance request based on the allowable value for a delay in a conveyance time.SOLUTION: A conveyance vehicle system 1 includes a conveyance vehicle controller 20 that controls unmanned conveyance vehicles 10 based on a conveyance request to convey goods from a conveyance originator place to a conveyance destination place. The conveyance vehicle controller 20 calculates, based on a buffer number n at a processing device at the conveyance destination place, the statistics of processing times at the processing device at the conveyance destination place, the conveyance time of a conveyance flow for a conveyance from the conveyance originator place to the processing device at the conveyance destination place, and a probability that represents a reliability for an un-occurrence of the delay for the conveyance of the goods, a variability allowable value for the conveyance time in the conveyance flow, and controls the unmanned conveyance vehicles 10 based on the variability allowable value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a transport vehicle system. [Background technology]

[0002] As described in Patent Document 1, a system is known in which a ground controller stores the cycle time of a processing device, and after an article is delivered to the processing device, an automated guided vehicle is assigned so that the automated guided vehicle arrives at a station when the cycle time has elapsed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-296922 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above system, the ground controller predicts the time when the article can be removed from the processing equipment and dispatches an automated guided vehicle to the processing equipment. This reduces the waiting time until the article is loaded onto the automated guided vehicle. However, the above system does not take into account the tolerance of processing time variations in the processing equipment and transport time delays. Therefore, there is a possibility that the transport capacity of the system will become excessive.

[0005] The present disclosure describes a transport vehicle system that can operate each processing device as much as possible by not setting excessive transport capacity and processing transport requests based on an allowable value for delay in transport time. [Means for solving the problem]

[0006] A transport vehicle system according to an embodiment of the present disclosure includes at least one transport vehicle for transporting an article between a plurality of processing devices, a buffer provided in each of the processing devices for temporarily holding at least one other article before processing according to the number of buffers, and a controller for controlling the transport vehicle based on at least one transport request for transporting an article from a transport source to a destination which is one of the processing devices. The controller calculates a variation allowable value for the transport time in the transport flow based on the number of buffers in the processing device at the destination, a statistical amount of the processing time in the processing device at the destination, the transport time of the transport flow corresponding to the transport request, and a probability indicating a degree of reliability that the transport of the article will not be delayed, and controls the transport vehicle based on the variation allowable value.

[0007] According to this transport vehicle system, the variation tolerance is quantitatively calculated and the transport vehicle is controlled based on the calculated variation tolerance, thereby preventing waiting times for processing equipment and enabling each processing equipment to operate as much as possible.

[0008] The controller may allocate transport requests with a higher priority to transport flows with smaller variation tolerances, which reduces the probability of transport delays occurring in transport flows with smaller variation tolerances.

[0009] The controller may allocate an available transport vehicle that is not currently executing another transport request to the processing device that is the transport source for the transport request of the transport flow with a small variation tolerance. In this case, the probability of a transport delay occurring in the transport flow with a small variation tolerance is reduced.

[0010] The controller may prioritize the transport request of the transport flow with a small variation tolerance in the route planning. In this case, the probability of transport delays occurring in the transport flow with a small variation tolerance is reduced. In this case, arrival waits at the destination of the transport flow with a small variation tolerance are prevented.

[0011] When a transfer request having a certain transfer flow is newly generated after the controller has performed allocation for the transfer request, the controller may re-allocate the transfer request with a smaller variation tolerance, thereby reducing the probability of a transfer delay occurring in the transfer flow of the newly generated transfer request. Effect of the Invention

[0012] According to the present disclosure, by quantitatively calculating the variation tolerance and controlling the transport vehicle based on the calculated variation tolerance, waiting times for processing devices can be eliminated and each processing device can be operated as much as possible. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is an overall schematic diagram of a guided vehicle system according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining the transport time from a plurality of transport sources to a certain destination. [Diagram 3] FIG. 3 is a diagram showing an example of the distribution of the time difference obtained by subtracting the time it takes for the previous item placed in the buffer to be processed by the processing device from the transport time. [Figure 4] FIG. 4 is a functional block diagram showing the functional configuration of the controller. [Diagram 5] FIG. 5 is a table showing the input values ​​for the three transport flows. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated description will be omitted.

[0015] First, an overview of an automated guided vehicle system 1 will be described with reference to Figs. 1 to 3. As shown in Fig. 1, the automated guided vehicle system 1 is a transport system that transports articles between a plurality of processing devices 11 to 15 arranged in a building of a factory that manufactures secondary batteries, and transports articles between the outside and inside of the building. As shown in Fig. 1, the automated guided vehicle system 1 includes a plurality of processing devices 11 to 15, a plurality of automated guided vehicles 10 that transport articles, a transport vehicle controller 20 that controls the plurality of automated guided vehicles 10, and a host controller 5 that issues a transport request to the transport vehicle controller 20. Hereinafter, the automated guided vehicle system 1 will be abbreviated as "transport vehicle system 1", and the automated guided vehicle 10 will be abbreviated as "transport vehicle 10".

[0016] FIG. 1 shows five processing devices as an example. Each of the first processing device 11, the second processing device 12, the third processing device 13, the fourth processing device 14, and the fifth processing device 15 is arranged so that an article can be transferred thereto by the transport vehicle 10 traveling along a predetermined path 2. Examples of various processing devices include a processing machine, a picking robot, an electrode manufacturing device, and a cell assembly device. The transport vehicle system 1 may include one or more automated warehouses (not shown) for storing a plurality of articles. The automated warehouse may have a storage shelf on which a plurality of articles can be placed, a stacker crane for transferring articles to the storage shelf, and a plurality of entry / exit ports to which articles can be transferred by the transport vehicle 10 (all not shown). The number and arrangement of the processing devices and the path 2 may be freely determined and are not limited to the example shown in FIG. 1.

[0017] Each of the first processing device 11, the second processing device 12, the third processing device 13, the fourth processing device 14, and the fifth processing device 15 has an receiving station 3 for receiving an article into the device, and a discharging station 4 for discharging the processed article. In each processing device, the receiving station 3 has, for example, one or more conveyors (not shown) and a buffer B (see FIG. 2) provided adjacent to the conveyor. The discharging station 4 has, for example, one or more conveyors (not shown). The buffer B in the receiving station 3 is a temporary storage area for temporarily holding the article. The number of articles that can be held in the buffer B (the number of buffers) is determined for each processing device. That is, the buffer B is provided in each of the processing devices 11 to 15, and can temporarily hold a number of articles before processing according to the number of buffers. The number of buffers may be one or more. Each processing device can detect the presence of an article in the buffer B. Each processing device can detect the number of articles held in the buffer B (the number of buffers present). Each processing device transmits the current number of occupied buffers to the transportation vehicle controller 20 by wired or wireless communication means.

[0018] The number of buffers is not limited to the number physically prepared for each processing device. For example, it may be set to a number greater than the actual number, assuming that buffer B will be empty before the next article arrives at receiving station 3. Buffer B may be provided at discharge station 4. In addition, it is not limited to the case where receiving station 3 and discharge station 4 are provided separately, and they may be integrated to form a transfer station.

[0019] A carry-in / carry-out opening 7 for carrying raw materials and / or goods into and out of the factory is provided in a part of the wall of the building. The carry-in / carry-out opening 7 has an unloading station 3A and a carry-in station 4A, each of which includes a conveyor or the like (not shown). The unloading station 3A and / or the carry-in station 4A may have a buffer B similar to that described above.

[0020] The transport vehicle 10 autonomously travels along a preset route 2. The transport vehicle 10 is, for example, an AGV (Automated Guided Vehicle). The route 2 may be, for example, a magnetic tape or a magnetic marker provided on the floor of a building to form a travel route of the transport vehicle 10. In this case, the transport vehicle 10 travels while detecting a magnetic signal or the like output from the magnetic tape or the magnetic marker. The transport vehicle 10 may travel while detecting its own position by generating light from a laser or the like and detecting the reflected light reflected by a mirror attached to the wall of the building, or may travel while detecting its own position by using information from a GPS or the like. A SLAM (Simultaneous Localization and Mapping) technique may be used as a guidance method for the transport vehicle 10. A charging point or a charging station for the transport vehicle system 1 to supply power to the transport vehicle 10 may be provided. The transport vehicle 10 may simply be called a "traveling vehicle".

[0021] The transport vehicle system 1 of this embodiment is equipped with a plurality of transport vehicles 10. Each transport vehicle 10 transports an article between at least a plurality of processing devices. Each transport vehicle 10 can transport an article from the discharge station 4 of any processing device to the receiving station 3 of any other processing device and the carry-out station 3A of the carry-in / carry-out opening 7. Also, each transport vehicle 10 can transport an article from the carry-in station 4A of the carry-in / carry-out opening 7 to the receiving station 3 of any processing device. Each transport vehicle 10 can transfer (hand over) an article between the receiving station 3, the discharge station 4, the carry-out station 3A, and the carry-in station 4A. In the following description, the receiving station 3, the discharge station 4, the carry-out station 3A, and the carry-in station 4A may be collectively referred to as "transfer stations".

[0022] When a transport command (described later) is assigned from the transport vehicle controller 20, the transport vehicle 10 executes travel control and loading / unloading control for transporting an article from the discharge station 4 or carry-in station 4A, which is the source of the transport command, to the receiving station 3 or carry-out station 3A, which is the destination of the transport command. In the travel control, for example, the various guidance methods described above can be used. In the loading / unloading control, the lifter of the transport vehicle 10 is raised and lowered to load the article from the discharge station 4 or carry-in station 4A onto the transport vehicle 10, and to unload the article from the transport vehicle 10 to the receiving station 3 or carry-out station 3A.

[0023] The transport vehicle controller 20 is a control device that manages a plurality of transport vehicles 10. The transport vehicle controller 20 is a computer having a ROM (Read Only Memory) in which programs and the like are stored, a RAM (Random Access Memory) for temporarily storing data, a storage medium such as a HDD (Hard Disk Drive), a processor such as a CPU (Central Processing Unit), and a communication circuit such as a wireless LAN. The transport vehicle controller 20 can be configured as software in which a program stored in the ROM is loaded onto the RAM and executed by the CPU. The transport vehicle controller 20 may be configured as hardware such as an electronic circuit. The transport vehicle controller 20 may be configured as one device or multiple devices. When configured as multiple devices, these devices are connected via a communication network such as the Internet or an intranet to logically construct one transport vehicle controller 20.

[0024] The transport vehicle controller 20 is connected to the transport vehicle 10 and the upper controller 5 by wire or wirelessly. The transport vehicle controller 20 receives information on the current position and current speed of the transport vehicle 10 from the transport vehicle 10. The transport vehicle controller 20 receives a transport request from the upper controller 5 to transport an article from one processing device to another processing device. The transport request is generated, for example, when an article arrives at the tip of the outgoing conveyor, or when an article arrives at the dispensing station after processing in the upstream equipment is completed. Each transport request includes a transport flow that means a job of transporting an article from a transfer station (processing device) at the transport source to a transfer station (processing device) at the transport destination. That is, one transport flow (a pair of From and To) is determined corresponding to one transport request. The transport vehicle controller 20 generates a transport command according to the received transport request and assigns the transport command to the transport vehicle 10. Each transport request may include information such as the transport flow, the time of request occurrence, the allocatable transport vehicle group number, and the load posture designation at the time of unloading.

[0025] The transport command is a control command for transporting an article from the source transfer station in the transport request to the destination transfer station by the transport vehicle 10. The transport command includes information regarding the transfer of the article at the source transfer station, travel along the route 2 from the source transfer station to the destination transfer station, and the transfer of the article at the destination transfer station.

[0026] That is, the transport vehicle controller 20 controls the transport vehicle 10 based on a transport request for transporting an article from a source to a destination which is one of the processing devices 11-15.

[0027] In the transport control by the transport vehicle controller 20 of this embodiment, the extent to which delay in transport time is tolerable is taken into consideration for the transport flow in each of the multiple transport requests. The index of "the extent to which delay in transport time is tolerable" is used in the control by the transport vehicle controller 20 as a "tolerable variation value" regarding the transport time to prevent transport delays.

[0028] With reference to Fig. 2, the idle prevention conditions in the automated guided vehicle system 1 will be described. Fig. 2 is a diagram for explaining the transport time from a plurality of source transfer stations to a destination transfer station. Articles are transported from a plurality of source transfer stations including a first unloading station 41, a second unloading station 42, and a third unloading station 43 to a destination receiving station 50. The number of buffers B in the receiving station 50, i.e., the number of buffers, is n (n is an integer equal to or greater than 1).

[0029] Delivery time to destination T a But the average μ a , variance σ a 2 The processing time at the destination is T s But the average μ s , variance σ s 2 Here, the random variable T is defined as a variable related to the time difference obtained by subtracting the time it takes for the previous item placed in buffer B to be processed by the processing device from the transportation time. Considering a transportation stationary state in which transportation from the source to the destination has been repeated sufficiently, the random variable T follows the following normal distribution (see also Figure 3) by the central limit theorem.

number

[0030] And, as a prerequisite for avoiding idle time in the production process, the next item (baggage) must arrive at the destination transfer station before the items (baggage) equivalent to the buffer number n are processed at the destination transfer station. In other words, the value of the random variable T must be less than 0 (negative value). In other words, the following formula (2) and further formula (3) obtained by modifying formula (2) must hold.

number

number

[0031] Equation (3) is σ a Solving this, we obtain the following inequality (4).

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[0032] Here, γ p is a constant that depends on the value of probability p and can be read from the standard normal distribution table. For example, If the probability p is 90.0%, then γ p is 1.29, If the probability p is 95.0%, then γ p is 1.65, If the probability p is 97.5%, then γ p is 1.96, If the probability p is 99.0%, then γ p is 2.33.

[0033] Next, the calculation of the "variation tolerance" in the transport vehicle controller 20 will be described. As shown in Fig. 4, the transport vehicle controller 20 has a transport request receiving unit 21, an information acquiring unit 23, a tolerance calculating unit 24, an allocation determining unit 25, and a storage unit 27. The transport request receiving unit 21 receives a transport request from the upper controller 5, and generates a transport command in response to the received transport request.

[0034] The information acquisition unit 23 acquires device information received from each of the processing devices 11-15. For each transport request, the information acquisition unit 23 acquires the following information: the number of buffers n in the destination processing device, statistics of the processing time in the destination processing device, the transport time of the transport flow corresponding to the transport request, and a probability indicating the degree to which it is reliable that no delay will occur in the transport of the item. The statistics of the processing time in the destination processing device are, for example, the average and variance of the processing time in the processing device. The average and variance are calculated by dividing the above average μ s and σ s These averages and variations may be values ​​based on actual values ​​stored in the storage unit 27, or may be values ​​that reflect the current operating conditions. The transport time of the transport flow is, for example, an average of the transport times, and is a time that can be calculated from the transport distance and the average transport speed. The average transport time is calculated by multiplying the average μ a As the transport time of the transport flow, a performance value in the same transport path may be used.

[0035] The probability that indicates the degree to which it can be trusted that there will be no delay in transporting an item is also called the reliability, and is given by the user of the transport vehicle system 1. This probability is, for example, the probability that it is guaranteed that there will be no delay in transporting an item. In this specification, "delay" means "occurrence of idle time in a processing device." The following are some of the factors that cause such a delay: The transportation vehicle 10 to which the transportation request is assigned starts moving toward the transportation source late. (In this case, it takes time for the transportation vehicle 10 to process the tasks it already has.) The delay in the arrival of the transport vehicle 10 at the transport source after it starts moving toward the transport source (In this case, the route to the transport source is congested with other transport vehicles 10, etc.) The transportation vehicle 10 is slow to arrive at the destination from the source. (In this case, the transport route is also congested with other transport vehicles 10, etc.)

[0036] The tolerance calculation unit 24 calculates a tolerance for variation in the transport time in the transport flow corresponding to each transport request based on the various information acquired by the information acquisition unit 23. In detail, the tolerance calculation unit 24 calculates, for example, a value σ a However, the tolerance calculation unit 24 outputs the value σ a When calculating, the root is positive and nμ s -μ a If the condition that is positive is not met, an input value error is output.

number

[0037] The variation tolerance is a concept related to time. The unit of the variation tolerance may be time or the square of time. The variation tolerance calculated by the tolerance calculation unit 24 is not limited to the above formula (5). For example, the tolerance calculation unit 24 may output the variation tolerance using a calculation formula for t value. In this case, instead of considering the steady state of transportation, it is considered that the transportation time Ta and the processing time Ts at the transportation destination are each multiplied by the number of samples m. a ,m s It is assumed that the data is collected as follows. The tolerance calculation unit 24 outputs t value shown in the following formula (6) as the variation tolerance.

number

[0038] Here, the transport time to the destination T a Variance of σ a , and the processing time at the destination Ts Variance of σ s is defined as the unbiased variance. From the distribution table of t-values, the sample size m a ,m s , and find the t value corresponding to the probability p, and from the above equation (6), find the variance σ a The variation tolerance is a different concept from the "time margin" that is used in a transport request to determine whether an article needs to be transported immediately.

[0039] The allocation determination unit 25 prioritizes allocation of transport requests of transport flows with smaller variation tolerances calculated by the tolerance calculation unit 24. In other words, the smaller the variation tolerance of a transport flow, the more priority the allocation determination unit 25 places on processing the transport request. The allocation determination unit 25 allocates an empty transport vehicle (empty unmanned transport vehicle) that is a transport vehicle 10 that is not currently executing another transport request, to the transport request.

[0040] Several examples of prioritizing the processing of transport requests are given below. As a first example, when multiple transport requests occur in the same time period, the allocation determination unit 25 prioritizes the transport request of the transport flow with a smaller variation tolerance value and performs allocation.

[0041] As a second example, after the allocation determination unit 25 has performed allocation for a transport request having a certain transport flow (after provisional allocation), if another transport request having a different transport flow is newly generated, the allocation determination unit 25 performs allocation again by prioritizing the transport request having a smaller variation tolerance. In other words, if a transport request that should be given higher priority is generated after provisional allocation, the allocation determination unit 25 changes the allocation.

[0042] As a third example, the allocation determination unit 25 allocates an available transport vehicle that is not currently executing another transport request to the processing device at the transport source for a transport request of a transport flow with a small variation tolerance. That is, the allocation determination unit 25 preliminarily allocates an available transport vehicle to the transfer station at the transport source for a transport flow that should be particularly prioritized.

[0043] As a fourth example, the allocation determination unit 25 prioritizes a transportation request of a transportation flow with a smaller variation tolerance in the route planning. The route planning may be an offline plan implemented in advance, or an online plan implemented while carrying out the transportation control. The allocation determination unit 25 implements a prioritized route planning, thereby securing a route. As an example of the route planning, a shortcut route is applied to a transportation flow with a smaller variation tolerance. Instead of the route planning, an exclusive control may be performed.

[0044] According to the various priority processing examples described above, the variation tolerance value is quantitatively calculated and the transport vehicle is controlled based on that, thereby eliminating waiting times for the processing devices and allowing each processing device to operate as much as possible.

[0045] With reference to FIG. 5, an example of transport control for three transport flows in the first example will be described. Transport flow A is a transport flow for transporting an article from the discharge station 4 of the fourth processing device 14 to the discharge station 3A at the carry-in / carry-out opening 7. Transport flow B is a transport flow for transporting an article from the discharge station 4 of the second processing device 12 and the third processing device 13 to the receiving station 3 of the fourth processing device 14. Transport flow C is a transport flow for transporting an article from the discharge station 4 of the first processing device 11 to the receiving station 3 of the fifth processing device 15. The transport distance and the average processing time μ s and variance σ s , and the number of buffers n are as shown in the table in FIG. 5. When the average speed of the automated guided vehicle 10 is 0.3 m / sec, the average transport time μ a are 200, 150, and 100 seconds. For example, to ensure that delivery is on time with a 99% probability (confidence), γ p is 2.33.

[0046] Based on the above values, the tolerance calculation unit 24 outputs variation tolerances of 33 seconds, 83 seconds, and 79 seconds for the transport flows A, B, and C, respectively. Therefore, the allocation determination unit 25 prioritizes processing in the order of transport flow A, transport flow C, and transport flow B. Here, according to the third example, since the transport flow A is determined to be a transport flow that should be given particular priority, an empty cart may be placed in advance at the discharge station 4 of the fourth processing device 14.

[0047] According to this embodiment, the transportation vehicle controller 20 prioritizes allocation of transportation requests of transportation flows with small variation tolerances, so the probability of transportation delays occurring in transportation flows with small variation tolerances is low.

[0048] When a transport request with a certain transport flow is newly generated after the transport vehicle controller 20 has performed allocation for the transport request, the transport request with the smaller variation allowance is given priority for re-allocation (second example above). This reduces the probability of transport delays occurring in the transport flow of the newly generated transport request.

[0049] In response to a transport request for a transport flow with a small variation tolerance, the transport vehicle controller 20 allocates an available transport vehicle that is not currently executing another transport request to the processing device from which the transport is originated (third example above). This reduces the probability of transport delays occurring in a transport flow with a small variation tolerance.

[0050] The transport vehicle controller 20 prioritizes transport requests of transport flows with small variation tolerances in the route planning (the fourth example above). This reduces the probability of transport delays occurring in transport flows with small variation tolerances. In this case, arrival waits at the destination of a transport flow with small variation tolerances are prevented.

[0051] Although the embodiment of the present disclosure has been described above, the present invention is not limited to the above embodiment. For example, the transport vehicle controller 20 may determine that the capacity of the transport vehicle 10, such as the maximum speed, is excessive based on the variation tolerance. The transport vehicle controller 20 may determine the transport request (transport flow) to be prioritized not only based on the magnitude of the variation tolerance but also by adding another index to the variation tolerance. For example, the transport vehicle controller 20 may determine the transport request to be prioritized based on the "arrival deadline". The arrival deadline is an index related to time obtained by adding the "transport time" and the "variation tolerance" to the "transport request occurrence time". Alternatively, the transport vehicle controller 20 may determine the transport request to be prioritized based on the "allowable transport lead time". The allowable transport lead time is an index related to time obtained by adding the "variation tolerance" to the "transport time". The transport vehicle controller 20 may thus determine the transport request to be prioritized based on a time index including the variation tolerance. The transport vehicle controller 20 may determine the transport request to be prioritized based on, for example, the magnitude of the time index including the variation tolerance. The transportation vehicle controller 20, for example, prioritizes the transportation request of a transportation flow having a small time index including a variation tolerance value when allocating the transportation request.

[0052] The transport vehicle 10 is not particularly limited to an AGV, and may be, for example, an overhead traveling vehicle, a tracked vehicle, etc. The transport vehicle 10 may be a moving body having a lifting function and a three-dimensional space as a moving area, a drone that can freely move in a three-dimensional space, etc.

[0053] The constituent features of one aspect of the present disclosure are described as follows. [1] At least one transport vehicle that transports articles between a plurality of processing devices; a buffer provided in each of the processing devices, capable of temporarily holding at least one other item before processing, according to the number of buffers; a controller that controls the transport vehicle based on at least one transport request for transporting the article from a transport source to a destination that is one of the processing devices; The controller, with respect to the transport request, the number of buffers in the processing device at the destination; Statistics of processing time in the processing device at the transfer destination; A transport time of the transport flow corresponding to the transport request; A probability that represents the degree to which it is possible to trust that the delivery of the goods will not be delayed; and and controls the transport vehicle based on the variation allowable value of the transport time in the transport flow. [2] The transport vehicle system according to [1], wherein the controller prioritizes allocation of transport requests of transport flows having smaller variation tolerances. [3] The transport vehicle system according to [1] or [2], wherein the controller, in response to a transport request for a transport flow having a small variation tolerance, places an available transport vehicle that is not currently executing another transport request at the source processing device. [4] The transport vehicle system according to any one of [1] to [3], wherein the controller prioritizes a transport request of a transport flow having a smaller variation tolerance in a route plan. [5] The transport vehicle system according to any one of [1] to [3], wherein when a transport request having a different transport flow is newly generated after the controller has assigned a transport request, the controller reassigns the transport request having a smaller variation tolerance by giving priority to the transport request. [Explanation of symbols]

[0054] 1...transport vehicle system (automated transport vehicle system), 2...route, 3...receiving station, 4...discharge station, 10...automated transport vehicle (transport vehicle), 11...first processing device, 12...second processing device, 13...third processing device, 14...fourth processing device, 15...fifth processing device, 20...transport vehicle controller (controller), 21...transport request receiving unit, 23...information acquisition unit, 24...tolerance calculation unit, 25...allocation determination unit, 27...memory unit, B...buffer.

Claims

1. at least one transport vehicle that transports articles between a plurality of processing devices; a buffer provided in each of the processing devices, capable of temporarily holding at least one other item before processing, the buffer corresponding to the number of buffers; a controller that controls the transport vehicle based on at least one transport request for transporting the article from a transport source to a destination that is one of the processing devices; The controller, with respect to the transport request, the number of buffers in the processing device at the destination; Statistics of processing time in the processing device at the transfer destination; A transport time of the transport flow corresponding to the transport request; A probability that represents the degree to which it is possible to trust that the delivery of the goods will not be delayed; and and controls the transport vehicle based on the variation allowable value of the transport time in the transport flow.

2. The transport vehicle system according to claim 1 , wherein the controller allocates transport requests of transport flows with smaller variation tolerances with higher priority.

3. 3. The transport vehicle system according to claim 1, wherein the controller allocates an available transport vehicle that is not currently executing another transport request to the source processing device in response to a transport request for a transport flow in which the variation tolerance is small.

4. The transport vehicle system according to claim 1 or 2, wherein the controller prioritizes a transport request of a transport flow having a smaller variation tolerance in a route plan.

5. 3. The transport vehicle system according to claim 1, wherein when a transport request having a different transport flow is newly generated after the controller has performed allocation for the transport request having a certain transport flow, the controller re-allocates the transport request having a smaller variation tolerance value.

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