WO2023199740A1

WO2023199740A1 - Conveyance system

Info

Publication number: WO2023199740A1
Application number: PCT/JP2023/012503
Authority: WO
Inventors: 亘北村
Original assignee: 村田機械株式会社
Priority date: 2022-04-15
Filing date: 2023-03-28
Publication date: 2023-10-19
Also published as: TW202348521A

Abstract

Provided is a conveyance system that can heighten conveyance efficiency, even when applied to systems having tracks with various configurations. The present invention is a conveyance system (1) for conveying articles by causing a plurality of conveyance vehicles to travel, characterized by comprising a plurality of conveyance vehicles (2) for conveying articles (M) to be conveyed, and a controller (6) that causes the plurality of conveyance vehicles (2) to travel by assigning conveyance instructions to each of the plurality of conveyance vehicles (2), and further characterized in that according to an execution situation of the conveyance instructions, the controller (6) puts a portion of the plurality of conveyance vehicles (2) in a standby state, in which conveyance instructions cannot be assigned thereto.

Description

Conveyance system

The present invention relates to a conveyance system, and particularly to a conveyance system that conveys articles by running a plurality of conveyance vehicles.

JP 2003-233422A (Patent Document 1) describes a conveyance system and its control method. This transport system includes a circular track, a plurality of transport vehicles running on the track, a station for loading/unloading goods onto the transport vehicle, and a waiting station for keeping the transport vehicles on standby. ing. The transport system also includes a transport controller, and each transport vehicle travels on the track based on commands from the transport controller.

Furthermore, a transport instruction is inputted to the transport controller from the host computer, and based on this transport instruction, a transport instruction table is created that stores the transport source station (starting point) and transport destination station (destination). . The conveyance control controller causes the conveyance vehicle to travel based on this conveyance instruction table and executes the input conveyance instruction. Further, the transport controller determines the number of transport vehicles to be operated based on the number of transport instructions. In other words, if the number of transport vehicles on the track is too large for the number of items to be transported, the transport vehicles compete with each other at branch points, junctions, stations, etc. on the track, resulting in waiting times and reducing transport efficiency. decreases. The conveyance system described in Patent Document 1 attempts to realize quick and efficient conveyance by determining the number of conveyance vehicles to be operated based on the number of conveyance instructions.

JP2003-233422A

However, the invention described in Patent Document 1 has a problem in that the transport efficiency cannot be sufficiently increased depending on the transport system to which it is applied. That is, in the invention described in Patent Document 1, the number of conveyance vehicles to be operated is determined based on the number of conveyance instructions, but the number of conveyance instructions does not necessarily reflect the load placed on the conveyance system. transport vehicle cannot be operated. In other words, even if the number of transport commands is small, if each command is a long-distance transport command or a transport command that requires a long movement, the load on the system will be large. Even if there are a large number of transport commands, if each command is a short-distance transport command or a command that takes only a short time, the load on the system will be small. For example, in the invention described in Patent Document 1, the guided vehicle is configured to run on a circular track, but depending on the configuration of the track on which the guided vehicle runs, the total number of guided vehicles, the arrangement of stations, etc. Conveyance efficiency cannot be sufficiently increased.

Therefore, an object of the present invention is to provide a conveyance system that can improve conveyance efficiency even when applied to systems with various configurations.

In order to solve the above-mentioned problems, the present invention provides a conveyance system that conveys articles by running a plurality of conveyance vehicles. The controller includes a controller that causes a plurality of guided vehicles to run by assigning a conveyance command to each vehicle, and the controller causes some of the guided vehicles to run according to the execution status of the conveyance command. , is characterized by being in a standby state where no transport command can be assigned.

In the present invention configured in this way, each transport vehicle is caused to travel by assigning a transport command to a plurality of transport vehicles for transporting the articles to be transported. Depending on the execution status of the transport command, the controller places some of the transport vehicles out of the plurality of transport vehicles in a standby state to which a transport command cannot be assigned.

According to the present invention configured in this way, the controller puts the guided vehicles in a standby state depending on the execution status of the conveyance command, so it is possible to appropriately set the number of guided vehicles to be operated. As a result, the transport efficiency of the transport system can be improved.

In the present invention, preferably, the controller moves the guided vehicle placed in a standby state to a standby area and stops it.
According to the present invention configured in this way, the guided vehicle in the standby state is moved to the waiting area, so the guided vehicle in the standby state is prevented from interfering with the operating vehicle. This allows the transport efficiency of the transport system to be improved.

In the present invention, preferably, the controller sets, as a waiting area, a track on which there is little traffic of the guided vehicle among the tracks on which the guided vehicle can travel, and moves the guided vehicle in the standby state to this waiting area.

According to the present invention configured in this way, since the waiting area is set on the track on which the guided vehicle can travel, the guided vehicle can be moved to the waiting area simply by sending a control signal from the controller, and the guided vehicle can be moved to the waiting area by simply sending a control signal from the controller. The vehicle can be easily transferred from a working state to a standby state or from a standby state to a working state.

In the present invention, preferably, the conveyance vehicle is configured to run on a mounted battery, and a plurality of charging stations are provided on a track on which the conveyance vehicle can travel, and the conveyance vehicle is stopped at these charging stations. Accordingly, the controller sets a charging station with a low operating rate among the plurality of charging stations as a standby area.

According to the present invention configured in this way, since the charging station with a low operating rate is set in the waiting area, it is possible to prevent waiting guided vehicles from interfering with operating guided vehicles. .

In the present invention, preferably, the guided vehicle is configured to run by an installed battery, and when the guided vehicle is placed in a standby state, the guided vehicle is set to a low power consumption mode.
According to the present invention configured in this way, the guided vehicle placed in a standby state is set to the low power consumption mode, so that the energy consumption of the guided vehicle while it is on standby can be suppressed.

In the present invention, preferably, the controller changes the guided vehicles placed on standby at predetermined time intervals even if the number of guided vehicles placed on standby remains unchanged.
According to the present invention configured in this way, even if there is no change in the number of guided vehicles in the standby state, the guided vehicles in the standby state are replaced every predetermined time, so that some of the guided vehicles It is possible to avoid a situation in which some of the transport vehicles continue to operate for a long period of time while some of the transport vehicles remain in a standby state for a long period of time, and it is possible to make the loads on each transport vehicle approximately equal.

In the present invention, preferably, the guided vehicle is configured to run using a mounted battery, and the controller preferentially selects a guided vehicle whose mounted battery has been charged more times and puts it in a standby state.

According to the present invention configured in this way, since the carrier vehicle whose mounted battery has been charged more times is selected preferentially and placed in a standby state, the number of times the battery mounted on each carrier vehicle is charged is equally distributed. This makes it possible to prevent battery deterioration from occurring unevenly in some transport vehicles.

In the present invention, preferably, the track on which the transport vehicle travels is formed in a grid pattern, and the transport vehicle is configured to be able to go straight, turn right, and turn left at each intersection of the grid track.

According to the present invention configured in this way, transport vehicles run on tracks formed in a lattice pattern, and even in a transport system capable of going straight, turning right, and turning left at each intersection of the tracks, an appropriate number of vehicles can be transported. Vehicles can be operated and transportation efficiency can be improved.

According to the conveyance system of the present invention, conveyance efficiency can be improved even when applied to systems having various configurations.

1 is a perspective view from above of a conveyance system according to an embodiment of the present invention. FIG. It is a perspective view showing a conveyance vehicle with which a conveyance system according to an embodiment of the present invention is equipped. FIG. 1 is a block diagram of an entire transport system according to an embodiment of the present invention. 5 is a flowchart showing processing by a controller in a conveyance system according to an embodiment of the present invention. 1 is a plan view schematically showing an example of a semiconductor manufacturing factory to which a transport system according to an embodiment of the present invention is applied. 6 is an example of a heat map showing the traffic volume of transport vehicles in the semiconductor manufacturing factory shown in FIG. 5. FIG.

Next, a conveyance system according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view of a conveyance system according to an embodiment of the present invention, viewed from above. FIG. 2 is a perspective view showing a transport vehicle included in the transport system according to the embodiment of the present invention. In this embodiment, the present invention is applied to a transport system that transports articles such as a foup containing a semiconductor wafer and a reticle pod containing a reticle in a clean room of a semiconductor manufacturing factory. Applied.

As shown in FIG. 1, a transport system 1 according to an embodiment of the present invention includes a transport vehicle 2 for transporting articles to be transported, and a plurality of rails 4 for forming a track on which the transport vehicle 2 runs. , and a controller 6 that causes the transport vehicle to travel by sending a transport command signal to the transport vehicle. Although only one conveyance vehicle 2 is shown in FIG. 1, the conveyance system 1 according to the present embodiment includes a plurality of conveyance vehicles 2, and the controller 6 controls each of the conveyance vehicles 2. By sending a command signal, a plurality of transport vehicles 2 are made to travel simultaneously.

The rail 4 is a beam-shaped member suspended from the ceiling in a building such as a clean room, and extends in a horizontal plane in a first direction D1 and a second direction perpendicular to the first direction. A large number of them are provided at equal intervals. Each transport vehicle 2 is configured to be able to travel along the rails 4 while being suspended below the rails 4 between two adjacent rails 4 . As described above, the transport system 1 of the present embodiment is a ceiling transport vehicle in which the transport vehicle 2 travels along a track formed by the rails 4 suspended from the ceiling. That is, a track extending in the first direction D1 is formed between two adjacent rails extending in the first direction D1, and a track extending in the second direction D2 is formed between two adjacent rails extending in the first direction D1. Tracks extending to 1 are formed, and each transport vehicle 2 runs along these tracks. Therefore, the multiple rails 4 extending in the first direction D1 and the second direction D2 form a grid-like track on which each transport vehicle 2 can travel.

In this way, in the transport system 1 of the present embodiment, the transport vehicle 2 travels along a track configured in a grid pattern, and at each intersection of the track in the first direction D1 and the track in the second direction D2, This is a so-called "grid system" in which each carrier 2 is configured to be able to go straight, turn right, and turn left. Therefore, by traveling along the tracks, each transport vehicle 2 can move to any location within the area where the grid-like tracks are provided. In the present embodiment, the lattice-like track formed by each rail 4 is configured such that the first direction D1 and the second direction D2 intersect at right angles to each other. The angle formed by the second direction D2 does not necessarily have to be a right angle.

Next, as shown in FIG. 2, the transport vehicle 2 includes a main body 10, four running wheels 12 attached to the upper side of the main body 10, and a transfer device attached to the lower side of the main body 10. 14. The transport vehicle 2 is configured to be able to travel along a track formed by each rail 4 by rotating each running wheel 12 while being suspended between each rail 4 . Further, the transport vehicle 2 is configured to be able to suspend the article M to be transported below, and transports the article M to the destination point by traveling along the track with the article M suspended. It is configured so that it can be In this embodiment, since the transport system 1 is applied to a semiconductor manufacturing factory, the transport vehicle 2 transports a hoop, which is an article M, from a certain processing device 22a (FIG. 5) to the next process. Transfer to device 22g (FIG. 5).

The main body 10 of the transport vehicle 2 is a rectangular casing that is square in top view, and the length of one side of the square is smaller than the interval between the rails 4. Therefore, the guided vehicle 2 fits between two adjacent rails 4, and a guided vehicle 2 running on a certain track can pass another guided vehicle 2 running on the adjacent track. . Further, the main body portion 10 includes a battery 16 and a circuit board 18, as shown in FIG.

The battery 16 is configured to supply power for driving the four running wheels 12 provided on the transport vehicle 2 and power for operating the circuit board 18. Furthermore, as will be described later, the transport system 1 is equipped with a charging station 24 (FIG. 5), and is configured to be able to charge the battery 16 of each transport vehicle 2. That is, a predetermined charging position Cp (FIG. 5) is set near the charging station 24 on a track on which the guided vehicle 2 can run, and by stopping the guided vehicle 2 at the charging position for a predetermined time, the track can be moved. The battery 16 of the transport vehicle 2 located above can be charged.

The circuit board 18 is built into the main body 10 and is configured to control the operation of the transport vehicle 2. On the circuit board 18, a transmission/reception circuit (not shown) for transmitting and receiving control signals to and from the controller 6, and a drive circuit (not shown) for a motor (not shown) for driving the running wheels 12 are provided. ) etc. are provided. Specifically, these circuits include a microprocessor, an input/output interface circuit, a memory, etc. mounted on the circuit board 18, and are operated by the power of the battery 16 according to software stored in the memory. .

Next, the running wheels 12 are wheels provided at the four corners of the upper surface of the main body 10, and when these running wheels 12 engage with the respective rails 4 extending on both sides of the main body 10, the transport vehicle 2 moves. It is suspended below the rail 4. Each running wheel 12 is rotationally driven by a motor (not shown) provided in the transport vehicle 2, so that the transport vehicle 2 travels along the track while being suspended below each rail 4. .

Furthermore, each of the traveling wheels 12 is configured to be rotatable around an axis A extending in the vertical direction, so that the transport vehicle 2 can change the direction in which it travels. That is, in the state shown in FIG. 2, the transport vehicle 2 can travel on a track extending in the second direction D2, and from this state, each traveling wheel 12 can be rotated by 90 degrees around the axis A. By moving the vehicle, it becomes possible to travel on a track extending in the first direction D1. Therefore, when changing the running direction of the guided vehicle 2, the guided vehicle 2 is placed at the intersection of the trajectory in the first direction D1 and the trajectory in the second direction D2 (the point where the guided vehicle 2 is located in FIG. 1). to stop. In this state, by rotating each traveling wheel 12 by 90 degrees around the axis A, the carrier 2 can travel in different directions.

Next, the transfer device 14 is provided below the main body 10 of the carrier 2, and by operating the transfer device 14, the article M to be transferred is loaded onto the carrier 2 or It can be unloaded from the transport vehicle 2.

Specifically, in this embodiment, the transfer device 14 includes an elevating drive section 14a and an article holding section 14b provided below the elevating drive section 14a. The elevating/lowering driving section 14a is composed of a hoist (not shown), and is configured to be able to raise and lower the article holding section 14b by suspending the article holding section 14b with a wire (not shown). There is. On the other hand, the article holding section 14b includes a chuck (not shown) having a movable claw (not shown), and by gripping a part of the article M to be transported with this chuck, the article M can be transported. Can be hung.

In this embodiment, when loading the article M onto the conveyance vehicle 2, the conveyance vehicle 2 is stopped above the article M to be conveyed, and in this state, the lifting drive section 14a is operated to move the article holding section 14b. lower it. Next, with the article holding section 14b lowered to a predetermined position, a chuck (not shown) of the article holding section 14b is operated to hold the article M. After the article M is held by the article holding section 14b, the lifting drive section 14a is operated to lift the article holding section 14b together with the article M to a predetermined position, so that the article M is loaded onto the transport vehicle 2. In this state, the article M can be transported by driving the transport vehicle 2 to the destination point. Further, when the transport vehicle 2 reaches the target point, the lifting drive section 14a is activated to lower the article holding section 14b together with the article M to a predetermined position, and the holding of the article M by the chuck (not shown) is released. Thereby, the articles M loaded on the transport vehicle 2 can be unloaded.

Next, the configuration and operation of the controller 6 will be explained with reference to FIGS. 3 to 5.
FIG. 3 is a block diagram of the entire transport system 1 according to the embodiment of the present invention, including the controller 6. As shown in FIG. FIG. 4 is a flowchart showing the processing in the controller 6. FIG. 5 is a plan view schematically showing an example of a semiconductor manufacturing factory to which the transport system 1 according to the embodiment of the present invention is applied.

As shown in FIG. 3, the controller 6 includes a request signal input section 6a, an operation rate calculation section 6b that calculates the operation rate of the guided vehicle 2 according to the execution status of the conveyance command, and a It has a transport vehicle determining unit 6c that determines a transport vehicle, and a command signal transmitting unit 6d that transmits a command signal to the determined transport vehicle. Specifically, the controller 6 includes a microprocessor, a memory, an interface circuit, a transceiver, software for operating these, and the like (not shown).

The request signal input unit 6a is configured to input a transport request signal sent from the upper controller 20. In this embodiment, the higher-level controller 20 is a controller that oversees the entire semiconductor manufacturing process, and sends transport instructions for articles M such as reticle pods and hoops that need to be transported in the semiconductor manufacturing process as transport request signals. Output to controller 6.

Here, the transport request signal is a signal that instructs which point on the track on which the transport vehicle 2 can travel and to which point the article M is to be transported. For example, the transfer request signal may be used to transfer a hoop containing semiconductor wafers that have been processed in the first processing device 22a (FIG. 5) from the load port of the first processing device 22a to a second processing device that will perform the next process. This is a signal for instructing transport to the load port of the processing device 22g (FIG. 5). Note that in this embodiment, the host controller 20 and the controller 6 are configured separately, but they may be configured integrally.

Next, calculation of the operation rate by the operation rate calculation unit 6b in FIG. 3 will be explained with reference to FIG. 5. FIG. 5 is a plan view schematically showing an example of a semiconductor manufacturing factory to which the transport system 1 is applied, and the parallel lines in the vertical and horizontal directions drawn in a lattice shape are the tracks along which the transport vehicle 2 can travel. represents. Furthermore, in FIG. 5, rectangles drawn with imaginary lines represent each of the processing devices 22a to 22g installed on the floor of a semiconductor manufacturing factory. Furthermore, in FIG. 5, a rectangle drawn with a broken line represents a charging station 24 installed on the floor, and charging positions Cp1 to Cp3 indicated by ◎ are provided on the orbit near this charging station 24. ing. By stopping the carrier 2 at any of these charging positions, the battery 16 mounted on the carrier 2 can be charged in a non-contact manner via a coupler (not shown). Further, in the example shown in FIG. 5, a waiting area S is set in the lower left part. In addition, in FIG. 5, in order to distinguish between a plurality of transport vehicles, each transport vehicle is labeled with numerals 2a to 2d.

The operating rate calculation unit 6b (FIG. 3) is configured to calculate the percentage of the transport vehicles 2 that are operating to execute the transport request signal. For example, in FIG. 5, the transport vehicle 2a moves the article M located at a point P1 near the processing device 22a in the semiconductor manufacturing factory along the trajectory indicated by the arrow in accordance with the transport request signal, and moves the article M to the vicinity of the processing device 22g. The vehicle is being transported to point P2. Further, in accordance with another transport request signal, the transport vehicle 2b transports the article M located at a point P3 near the processing device 22d to a point P4 near the processing device 22e by traveling along the trajectory indicated by the arrow. There is. On the other hand, the transport vehicle 2d is stopped in the standby area S and is in a standby state. On the other hand, although the transport vehicle 2c is not in a standby state, the transport command signal is not assigned to it, and it is stopped.

As described above, in the present embodiment, the guided vehicle is classified into a guided vehicle in a standby state (transfer vehicle 2d) and a guided vehicle in a non-standby state (transfer

vehicles

2a, 2b, and 2c). Transport vehicles in a non-standby state are classified into transport vehicles to which a transport command signal has been assigned and which are actually carrying out transport (

transport vehicles

2a, 2b), and transport vehicles to which a transport command signal has not been assigned (transport vehicle 2c). be done. In this embodiment, the operation rate is calculated by dividing the number of guided vehicles actually carrying out transportation by the number of guided vehicles in a non-standby state, and the operating rate calculation unit 6b calculates the operating rate. It is configured. Further, although the operating rate changes from moment to moment according to the execution status of transportation in each transport vehicle 2, the operating rate calculation unit 6b is configured to calculate the average operating rate for a predetermined period of time. .

In addition, the transport vehicle 2 that is actually carrying out the transport is the transport vehicle 2 that is heading toward the product M to load the product M to be transported, and the transport vehicle 2 that is traveling toward the transport destination with the product M loaded thereon. The transport vehicle 2 can be classified into the transport vehicle 2 that is currently in use, and the transport vehicle 2 that is traveling to a position where it is easy to carry out the next transport after transporting the article M to the transport destination. In this embodiment, the operating rate is calculated for all of these transport vehicles 2 as transport vehicles 2 that are currently performing transport. In addition, as a modified example, among the above-mentioned transport vehicles 2, the transport vehicle 2 loaded with the article M is traveling toward the transport destination, and after transporting the article M to the transport destination, the next transport is carried out. It is also possible to calculate the operating rate by assuming that only the transport vehicle 2 that is traveling to a position where it is easy to carry out the transport is considered to be the transport vehicle 2 that is currently performing transport.

Next, the guided vehicle determining unit 6c determines how many of the guided vehicles 2 that can be controlled by the controller 6, based on the average operating rate in a predetermined time calculated by the operating rate calculating unit 6b. It is determined how many vehicles 2 are placed in an operating state (non-standby state) to which a transport command can be assigned, and how many vehicles are placed in a standby state (non-operational state) to which a transport command cannot be assigned. That is, if the number of transport vehicles 2 that are actually in operation is too large relative to the amount of transport commands, congestion of transport vehicles 2 may occur on the track, which may actually reduce transport efficiency. Furthermore, if there are many transport vehicles 2 that are in operation but are not actually transporting, power will be wasted. As an example, the number of guided vehicles 2 to be in operation is determined so that the operating rate, which is the execution status of the transportation command, is 70% to 80%, and the remaining guided vehicles 2 are in a standby state (non-operational state). shall be.

Furthermore, the conveyance vehicle determining unit 6c is configured to determine which of all the conveyance vehicles 2 is to be in the operating state and which is to be in the standby state. That is, if only some of the transport vehicles 2 are always in operation, the transport vehicles 2 will be severely worn out, and the service life of the transport system 1 as a whole will be shortened. Furthermore, the transport vehicle 2 may become malfunctioning if it remains in a standby state for a long period of time. For this reason, in the present embodiment, even if the number of guided vehicles 2 to be in the operating state has not changed, the guided vehicles to be in the standby state are replaced at predetermined time intervals. This prevents only some of the transport vehicles 2 from always being in an operating state or always being in a standby state, and prevents the load from being biased only to some of the transport vehicles 2.

Further, the guided vehicle determining unit 6c preferentially selects the guided vehicle 2 whose mounted battery 16 has been charged more times and puts it into a standby state. That is, since the transport vehicle 2 runs on the power of the battery 16, the battery 16 of the transport vehicle 2 that has carried out many transports is charged many times. By preferentially setting the guided vehicle 2 that has been charged a large number of times into a standby state, the guided vehicle 2 that has been charged a small number of times and has a small amount of transportation can be put into an operating state, and the degree of deterioration of the battery 16 of all the guided vehicles 2 can be reduced. can be approximated evenly.

Next, the command signal transmitting unit 6d is configured to transmit a command signal to each guided vehicle 2 and cause each guided vehicle 2 to travel as necessary. That is, the command signal transmitter 6d sends a transport command signal to the transport vehicle 2 set in the operating state by the transport vehicle determination unit 6c, and causes the transport vehicle 2 to execute transport based on the transport request signal input from the host controller 20. Further, the command signal transmitting unit 6d issues a command to the guided vehicle 2 set in the standby state by the guided vehicle determination unit 6c to move to the waiting area S, and moves the guided vehicle 2 to the waiting area S (FIG. 5). After moving, stop. Note that in this embodiment, the waiting area S is not a fixed dedicated area, but is set on a part of the track on which the transport vehicle 2 can run, and is changed as appropriate depending on the operating status of the transport system 1. .

Note that the guided vehicle 2 in the standby state that has been moved to the standby area S and stopped is set to a low power consumption mode, and consumption of the power charged in the battery 16 is suppressed. That is, although the guided vehicle 2 set to the low power consumption mode can be restarted in response to a signal transmitted from the command signal transmitter 6d of the controller 6, it is in a sleep state and the circuit board 18, etc. The power consumption is suppressed. Therefore, the conveyance vehicle 2 in the standby state takes a predetermined time to actually become capable of conveyance in response to the command signal from the command signal transmitter 6d, and the conveyance vehicle 2 that is in the standby state takes a predetermined time to actually become capable of conveyance. The condition is different from car 2.

Next, the operation of the controller 6 will be explained with reference to FIG.
Note that the process according to the flowchart shown in FIG. 4 is repeatedly executed by the controller 6 while the transport system 1 of this embodiment is in operation.
First, in step S1 in FIG. 4, a transport request signal is input from the host controller 20 to the request signal input section 6a of the controller 6. Further, in step S1, the execution status of the transport command is also input to the controller 6.

Next, in step S2, the operating rate of the transport vehicle 2 is calculated by the operating rate calculation unit 6b based on the execution status of the transport command input in step S1. In this embodiment, a conveyance vehicle 2 is heading toward the article M to load the article M to be transported, a conveyance vehicle 2 is traveling toward the destination with the article M loaded thereon, and the conveyor vehicle 2 is conveying the article M. A conveyance vehicle 2 that is moving to a position where it is easy to carry out the next conveyance after being transported ahead is defined as a conveyance vehicle 2 that is currently performing transport, and the total number of these conveyance vehicles 2 that are in a non-standby state is calculated as follows: The operating rate is calculated by dividing by the number of transport vehicles 2. Furthermore, the average value of a plurality of operating rates calculated at predetermined time intervals in the recent past is calculated as the hourly operating rate.

Furthermore, in step S3, the number of guided vehicles 2 to be in an operating state (non-standby state) among all guided vehicles 2 is determined according to the operating rate per hour calculated in step S2. As described above, in this embodiment, the operating rate is 70 to 80%, that is, on average, about 70 to 80% of the transport vehicles 2 that are in operation are actually carrying goods. The number of transport vehicles 2 to be put into operation is determined so that the transport vehicles 2 are loaded with M and are running. This makes it possible to quickly respond to short-term increases in workload, and improves transport efficiency while suppressing power consumption.

Next, in step S4, it is determined whether the number of operating vehicles 2 determined in step S3 has increased compared to the current number of operating vehicles. If the number of operating units has increased, the process in the flowchart proceeds to step S5, and if it has not increased, the process proceeds to step S7.
In step S5, the guided vehicle determining unit 6c selects the increased number of guided vehicles 2 to be newly put into operation from the guided vehicles 2 in the standby state. In the present embodiment, the guided vehicle determining unit 6c selects the guided vehicles 2 from among the guided vehicles 2 in the standby state in order of the number of times the mounted battery 16 has been charged in the past, and puts them into operation.

Next, in step S6, the command signal transmitter 6d sends a start command signal to the guided vehicle 2 newly set to the operating state, and returns it from the low power consumption mode to the start state. In the example shown in FIG. 5, a start command signal is transmitted from the command signal transmitter 6d of the controller 6 to the guided vehicle 2d, which is in a standby state and stopped in the standby area S, to return it to the operating state. ing. Further, in step S1, if a new transport request signal has been input, a transport command signal is transmitted to the transport vehicle 2 set in the operating state in order to execute this signal. For example, in the example shown in FIG. 5, a transport command signal is transmitted to the transport vehicle 2c which is stopped in an operating state, and transport corresponding to the new transport request signal is executed. In addition, when all of the transport vehicles 2 in the operating state are transporting articles M loaded thereon, a transport command signal is transmitted to the transport vehicle that has newly returned to the operating state.

On the other hand, if it is determined in step S4 that the number of operating vehicles 2 determined in step S3 has not increased compared to the current number of operating vehicles, the process in the flowchart proceeds to step S7. In step S7, it is determined whether the number of operating vehicles 2 has decreased, and if the number of operating vehicles 2 determined in step S3 has decreased compared to the current number of operating vehicles, The process in the flowchart proceeds to step S8. In step S8, the guided vehicle determining unit 6c selects the guided vehicle 2 to be changed from the operating state to the standby state. In this embodiment, among the guided vehicles 2 in the operating state, the guided vehicles 2 are selected in order of the number of times the installed battery 16 has been charged, and these are placed in a standby state. Thereby, the operating conditions of each transport vehicle 2 can be made nearly uniform.

Next, in step S6, the command signal transmitter 6d sends a command signal to the guided vehicle 2 newly selected for the standby state, moves it to the waiting area S, and moves the guided vehicle 2 moved to the waiting area S. After stopping, set to low power consumption mode. Note that if the conveyance vehicle 2 newly selected to be in the standby state is currently conveying the article M, it is moved to the standby area S after the conveyance is completed. In the example shown in FIG. 5, a waiting area S is set as an area where the amount of traffic of the guided vehicle 2 is small among the tracks on which the guided vehicle 2 can travel.

Note that in this embodiment, the waiting area S is not set in a special track area that is not used for transporting the article M by the transport vehicle 2, but is set in a special track area that is not used for transporting the article M by the transport vehicle 2. It is set as part of the available area. Therefore, the position and size of the waiting area S are changed as appropriate depending on the operating status of the transport system 1. Thereby, a certain area is not always occupied to provide the standby area S, and the area in which the transport vehicle 2 can travel can be effectively utilized. For example, if there is a processing device 22 in a semiconductor manufacturing factory that is out of operation due to maintenance or the like, a standby area S can be set in the orbit near the processing device 22.

Next, with new reference to FIG. 6, the setting of the standby area S in this embodiment will be explained.
FIG. 6 is an example of a heat map showing the amount of traffic of transport vehicles 2 in the semiconductor manufacturing factory shown in FIG. The heat map shown in FIG. 6 is a map that shows the frequency with which the guided vehicle 2 traveled on the track within a predetermined period by color shading, and the trajectory where the guided vehicle 2 frequently traveled is shown in a dark color. , less frequent trajectories are shown in lighter colors.

As shown in FIG. 6, the tracks near the center of the semiconductor manufacturing factory and the tracks adjacent to the frequently used processing equipment 22 are shown in dark colors because the transport vehicles 2 travel frequently. On the other hand, the corners of the semiconductor manufacturing factory and the tracks where the processing equipment 22 is not installed are less frequently traveled by the transport vehicle 2 and are shown in a lighter color. Therefore, for a trajectory on which the guided vehicle 2 travels less frequently, the proportion of time that the trajectory is occupied by the guided vehicle 2 is reduced. In this way, even if the guided vehicle 2 in the standby state is stopped in a part of the track where the proportion of occupied time is small, it will not interfere with the traveling of the guided vehicle 2 in the operating state, and the conveyance system 1 will be able to No reduction in efficiency. Therefore, in the example shown in FIG. 6, the waiting area S is set in a region of the trajectory where the proportion of time occupied by the transport vehicle 2 is small and is shown in a light color on the heat map.

Alternatively, as shown in FIG. 5, charging positions Cp1 to Cp3 are provided near the charging station 24 in the semiconductor manufacturing factory, but among these charging positions, a charging position with a low operating rate is placed in the standby area S. It can also be set. In the example shown in FIG. 6, among the three charging positions, the operation rate of charging position Cp1 is low, and the proportion of the occupied time at charging position Cp1 is small. By setting such a charging position with a low operating rate in the standby area S, the guided vehicle 2 can be placed on standby without interfering with the traveling of the guided vehicle 2, and the guided vehicle 2 in the standby state can be charged. You can also do

In addition, in this embodiment, a waiting area is set in an area on the track that the transport vehicle can also use to transport goods, but depending on the configuration of the transport system, the transport vehicle may The present invention can also be configured so that a dedicated area where the vehicle does not run is used as a waiting area. Furthermore, if there is a low possibility that the vehicle will be in operation for a long period of time, some or all of the vehicles set to standby will be evacuated outside the track where the vehicle can travel. The present invention can also be configured.

On the other hand, in step S7 of FIG. 4, if the number of operating vehicles 2 determined in step S3 has not decreased from the current number of operating vehicles (if the number of operating vehicles 2 has not changed), In this case, the process in the flowchart proceeds to step S9. In step S9, the guided vehicle determination unit 6c determines whether it is necessary to replace the guided vehicle 2 in the standby state. If it is necessary to replace the guided vehicle 2 in the standby state, the process in the flowchart proceeds to step S10, and if there is no need to replace it, the process proceeds to step S6.

That is, if the number of operating vehicles 2 determined in step S3 is the same as the current number of operating vehicles, the guided vehicle 2 in the standby state is put into operation, or the guided vehicle 2 in the operating state is put on standby. The operation of the transport system 1 can be continued without changing the state. However, if the number of operating vehicles remains unchanged for a long period of time and only some of the guided vehicles 2 continue to operate, the load will be concentrated on those guided vehicles 2, causing deterioration of the guided vehicles 2. It's too early. Therefore, in the transport system 1 of the present embodiment, the controller 6 controls the controller 6 even when there is no change in the number of transport vehicles 2 in the operating state (therefore, there is no change in the number of transport vehicles 2 in the standby state). , the conveyance vehicle that is in a standby state is changed at predetermined time intervals. In this embodiment, if the number of guided vehicles 2 in the standby state remains constant for a predetermined period of time or more, it is determined that the guided vehicles 2 in the standby state need to be replaced.

If it is determined that it is necessary to replace the guided vehicle 2 that is placed in the standby state, the process proceeds to step S10, where the guided vehicle determination unit 6c replaces the guided vehicle 2 that is placed in the standby state. In this embodiment, the transport vehicle 2 is replaced by a toggle method. For example, No. 1~No. There are 12 transport vehicles 2, of which No. If the four machines No. 1 to No. 4 remain in standby mode for a predetermined period of time, No. 1 to 4 are put into operation, and No. The transport vehicles 2 from 5 to 8 are put on standby. Furthermore, No. When transport vehicles 2 No. 5 to No. 8 remain in the standby state for a predetermined period of time, the No. Transport vehicles 2 9 to 12 are placed in a standby state. In this way, even if there is no change in the number of guided vehicles 2 to be in the standby state, the guided vehicle determining unit 6c changes the guided vehicles 2 to be in the standby state every predetermined time, and assigns each guided vehicle 2 to This ensures that the load is evenly distributed.

According to the transport system 1 of the embodiment of the present invention, the controller 6 puts the transport vehicle 2 in a standby state depending on the execution status of the transport command, so the number of transport vehicles to be operated can be appropriately set. . Thereby, the transport efficiency by the transport system 1 can be sufficiently improved.

Furthermore, according to the transport system 1 of the present embodiment, the transport vehicle 2 in the standby state is moved to the standby area S (FIG. 5), so that the transport vehicle 2 in the standby state is moved to the transport system in operation. It is possible to avoid getting in the way of the vehicle 2, and it is possible to improve the transport efficiency of the transport system 1.

Furthermore, according to the transport system 1 of the present embodiment, the waiting area S is set on a track on which the transport vehicle 2 can travel, so the transport vehicle 2 can be easily operated by simply sending a control signal from the controller 6. It is possible to transition from a standby state to a standby state or from a standby state to an active state. Furthermore, based on the heat map, a trajectory with a small occupied time ratio is set as the standby area S (FIG. 6), so the standby area S can be set according to the operating state of the transport system 1. As a result, there is no need to always prepare a fixed area exclusively for the waiting area, and space can be used effectively.

Furthermore, according to the transport system 1 of the present embodiment, since the charging position Cp corresponding to the charging station 24 with a low operating rate is set in the standby area S, the transport vehicle 2 on standby is replaced by the transport vehicle 2 in operation. can be prevented from getting in the way. In addition, by setting the charging position Cp to the standby area S, it is possible to charge the waiting guided vehicle 2, reduce the number of times the operating guided vehicle 2 needs to be charged, and improve conveyance efficiency. can be improved.

Furthermore, according to the transport system 1 of the present embodiment, the transport vehicle 2 in the standby state is set to the low power consumption mode, so that the energy consumption of the transport vehicle 2 in standby can be suppressed, and the transport The energy efficiency of the system 1 can be improved.

Further, according to the transport system 1 of the present embodiment, even if there is no change in the number of transport vehicles 2 to be in the standby state, the transport vehicles to be in the standby state are replaced at predetermined time intervals (steps in FIG. 4). S10), it is possible to avoid a situation in which some of the guided vehicles 2 remain in a standby state for a long period of time while some of the guided vehicles 2 continue to operate for a long period of time, and the load on each guided vehicle 2 is evenly distributed. You can get close.

Furthermore, according to the transport system 1 of the present embodiment, the transport vehicle 2 whose mounted battery 16 has been charged more times is preferentially selected and put into a standby state (step S8 in FIG. 4), so that each transport vehicle 2 The number of charging cycles of the batteries 16 mounted on the transport vehicles 2 can be made uniform, and deterioration of the batteries 16 can be prevented from occurring unevenly in some transport vehicles 2.

Although the embodiments of the present invention have been described above, various changes can be made to the embodiments described above. In particular, in the embodiments described above, the present invention is applied to a grid system in which the tracks of the guided vehicles are formed in a grid pattern, but the present invention is applied to a conveyed system in which each guided vehicle runs along a fixed track. The invention can also be applied. In addition, in the embodiments described above, the transport system was configured by an overhead hoist transport in which the transport vehicle traveled along a track provided on the ceiling, but the transport system The present invention can be applied to various conveyance systems, such as automatic guided vehicles (AGV) that travel on the ground, and conveyance systems that use tracked automatic guided vehicles (RGV). In addition, in the embodiment described above, the track on which each guided vehicle travels is composed of rails, but the track on which each guided vehicle travels is not composed of physical members such as "rails". You don't have to.

1 Transport system 2 Transport vehicle 4 Rail 6 Controller 6a Request signal input section 6b Operation rate calculation section 6c Transport vehicle determination section 6d Command signal transmission section 10 Main body section 12 Traveling wheels 14 Transfer device 14a Lifting drive section 14b Article holding section 16 Battery 18 Circuit board 20 Upper controller 22 Processing device 24 Charging station

Claims

A conveyance system that conveys articles by running a plurality of conveyance vehicles,
a plurality of transport vehicles for transporting goods to be transported;
a controller that causes the plurality of transport vehicles to travel by assigning a transport command to each of the plurality of transport vehicles;
The conveyance system is characterized in that the controller places some of the plurality of conveyance vehicles in a standby state to which the conveyance command cannot be assigned, depending on the execution status of the conveyance command.
The conveyance system according to claim 1, wherein the controller moves the conveyance vehicle in a standby state to a standby area and stops it.
3. The controller sets, as a waiting area, a track on which there are few passages of guided vehicles among the tracks on which the guided vehicle can run, and moves the guided vehicle in a standby state to this waiting area. Conveyance system.
The carrier vehicle is configured to run on a battery mounted thereon, and a plurality of charging stations are provided on the track on which the carrier vehicle can run, and by stopping at these charging stations, the battery can be recharged. 3. The transport system according to claim 2, wherein the controller sets a charging station with a low operating rate among the plurality of charging stations in the standby area.
The conveyance vehicle according to any one of claims 1 to 4, wherein the conveyance vehicle is configured to run by a battery mounted thereon, and when the conveyance vehicle is placed in a standby state, the conveyance vehicle is set to a low power consumption mode. system.
The conveyance system according to any one of claims 1 to 4, wherein the controller changes the conveyance vehicle to be placed in a standby state at predetermined time intervals even if there is no change in the number of conveyance vehicles to be placed in a standby state. .
Any one of claims 1 to 4, wherein the guided vehicle is configured to run using a battery mounted thereon, and the controller preferentially selects a guided vehicle whose mounted battery has been charged more times and puts it in a standby state. The conveyance system according to item 1.
5. A track on which the guided vehicle travels is formed in a lattice pattern, and the guided vehicle is configured to be able to go straight, turn right, and turn left at each intersection of the lattice-shaped trajectory. Conveyance system described in.