WO2018110178A1

WO2018110178A1 - Travelling vehicle system

Info

Publication number: WO2018110178A1
Application number: PCT/JP2017/040742
Authority: WO
Inventors: 一見原崎
Original assignee: 村田機械株式会社
Priority date: 2016-12-14
Filing date: 2017-11-13
Publication date: 2018-06-21
Also published as: TW201826060A; JP2020024476A

Abstract

A travelling vehicle system is provided with a plurality of travelling vehicles and a controller. A first travelling vehicle sends to the controller a reverse travel permission request when trying to perform reverse travel to a destination point to the rear within a prescribed section. In this case, an interference prevention section is set that includes a section from the current position of the first traveling vehicle to the destination point, and when another traveling vehicle positioned directly to the rear within the prescribed section is stopped or planning to stop farther to the rear than the interference prevention section, reverse travel permission is sent to the first travelling vehicle, and when stopped or planning to stop inside the interference prevention section, reverse travel permission is not sent to the first travelling vehicle.

Description

Traveling vehicle system

One embodiment of the present invention relates to a traveling vehicle system.

The traveling vehicle system described in Patent Literature 1 includes a plurality of traveling vehicles that travel along a track, and a controller that communicates with each of the plurality of traveling vehicles and controls the operations of the plurality of traveling vehicles. Yes. In this traveling vehicle system, a plurality of zones are set on the track in order to realize backward traveling of traveling vehicles while preventing interference between traveling vehicles, and only one traveling vehicle exists in each of the plurality of zones. Thus, the operation of the traveling vehicle is controlled.

Japanese Patent Laid-Open No. 7-49714

In the traveling vehicle system as described above, even when the traveling vehicle is going to travel backward, the other traveling vehicles are prohibited from entering the entire zone set on the track. There is a risk that the smooth running of the vehicle may be hindered. In order to avoid such a situation, if it is attempted to set a shorter zone and a larger number of zones, it takes time to set the zone.

Therefore, according to one aspect of the present invention, an appropriate section for prohibiting the entry of another following traveling vehicle is set according to the current position of the traveling vehicle at a timing when the traveling vehicle is going to travel backward. It is an object of the present invention to provide a traveling vehicle system that can realize backward traveling of a traveling vehicle while preventing interference with the traveling vehicle.

A traveling vehicle system of one embodiment of the present invention includes a plurality of traveling vehicles that travel along a track, and a controller that communicates with each of the plurality of traveling vehicles and controls operations of the plurality of traveling vehicles, When the traveling vehicle is located in a predetermined section of the track, when the traveling vehicle tries to travel backward to a destination point behind the traveling vehicle in the predetermined section, the traveling vehicle transmits a backward traveling permission request to the controller. When a travel permission request is received from a traveling vehicle, an interference prevention section including a section from the current position of the traveling vehicle to the destination point is set, and another traveling located immediately behind the traveling vehicle in the predetermined section When the vehicle is stopped or is scheduled to stop behind the interference prevention zone, a reverse drive permission to the destination point is transmitted to the travel vehicle that transmitted the reverse travel permission request, and other travel vehicles If it is stopped or the scheduled stop in the stop section, it does not send a reverse travel permission to the destination point in the vehicle that sent the reverse travel authorization request.

In this traveling vehicle system, every time the traveling vehicle tries to travel backward, an interference prevention section including a section from the current position of the traveling vehicle to a destination point behind the traveling vehicle is set. Then, when another traveling vehicle located immediately behind the traveling vehicle is stopped or scheduled to stop behind the interference prevention section, backward traveling of the traveling vehicle is permitted. On the other hand, when another traveling vehicle located immediately behind the traveling vehicle is stopped or scheduled to stop in the interference prevention zone, the backward traveling of the traveling vehicle is not permitted. For this reason, without setting a zone in advance, it is possible to set only a section where entry of other traveling vehicles should be prohibited as an interference prevention section, and to realize backward travel of the traveling vehicle within the interference prevention section. Therefore, according to the current position of the traveling vehicle at the timing when the traveling vehicle is going to travel backward, an appropriate section for prohibiting the entry of other following traveling vehicles is set to prevent the traveling vehicles from interfering with each other. It becomes possible to realize reverse traveling of the car.

In the traveling vehicle system of one aspect of the present invention, the interference prevention section is a section from the current position of the traveling vehicle that transmitted the reverse travel permission request to the rear end of the traveling vehicle in a state where the traveling vehicle is located at the destination point. It may be. In this case, since the shortest section where entry of other traveling vehicles should be prohibited can be set as the interference prevention section, smooth traveling of the other traveling vehicles can be realized.

In the traveling vehicle system according to one aspect of the present invention, the track may include a plurality of branching / merging portions that branch or join, and the predetermined section may be a section between the branching / merging portions adjacent to each other on the track. In this case, it is possible to suppress an increase in the number of other traveling vehicles that are stopped in order to realize the backward traveling of the traveling vehicle.

According to one aspect of the present invention, an appropriate section for prohibiting the entry of another following traveling vehicle is set in accordance with the current position of the traveling vehicle at a timing when the traveling vehicle is going to travel backward. It is possible to achieve reverse travel of the traveling vehicle while preventing this interference.

FIG. 1 is a plan view of a part of a traveling vehicle system according to an embodiment of the present invention. FIG. 2 is a sequence diagram for illustrating reverse travel control in the traveling vehicle system of FIG. FIG. 3 is a plan view for illustrating reverse travel control in the traveling vehicle system of FIG. 1. FIG. 4 is a plan view for explaining reverse travel control in the traveling vehicle system of FIG. 1. FIG. 5 is a plan view for explaining reverse travel control in the traveling vehicle system of FIG. 1.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or equivalent part, and the overlapping description is abbreviate | omitted.
[Configuration of traveling vehicle system]

As shown in FIG. 1, the traveling vehicle system 1 includes a track 10, a plurality of traveling vehicles 20, and a controller 50. The track 10 is laid near the ceiling of a semiconductor manufacturing factory equipped with a plurality of processing devices. The traveling vehicle 20 is an OHT (Overhead Hoist Transfer) and travels along the track 10 while being suspended on the track 10. On the track 10, the forward direction of the traveling vehicle 20 is determined. The traveling vehicle 20 normally travels in one direction (forward direction) along the track 10 (forward travel). Further, the traveling vehicle 20 travels in a direction opposite to one direction along the track 10 (reverse traveling) when the backward traveling control described in the present embodiment is performed, for example. The traveling vehicle 20 transports a FOUP (Front Opening Unified Pod) 90 containing a plurality of semiconductor wafers as a transported object to a load port provided in each processing apparatus. The controller 50 communicates with each traveling vehicle 20 and controls the operation of each traveling vehicle 20.

In the following description, “downstream” and “upstream”, “front” and “rear”, “merge” and “branch” are based on the traveling direction when the traveling vehicle 20 travels forward along the track 10. The term is used.

The track 10 has a plurality of sections. The track 10 has a branch point (a branch junction) where one section branches into a plurality of sections, and a junction (a branch junction) where a plurality of sections merge into one section. In the present embodiment, the track 10 includes a portion constituted by

sections

10a, 10b, 10c, 10d, and 10e. The section 10a and the section 10b join the section 10c at the joining point 11a. The section 10c and the section 10e join the section 10d at the joining point 11b.

In the following description, the “predetermined section” refers to a section between adjacent junctions, a section between adjacent branch points, or between adjacent junctions and branch points on the track 10. It is a section. For example, the predetermined section S in FIG. 1 is a section 10c between

adjacent junctions

11a and 11b. In addition, the structure of the track | orbit 10 shown in the figure is an example, Comprising: It is not limited to this.

In the section 10c, two processing devices 100 and a load port 101 provided in each processing device 100 are arranged. When the FOUP 90 is supplied to the load port 101 by the traveling vehicle 20, the semiconductor wafer accommodated in the FOUP 90 is taken into the processing apparatus 100. Then, the semiconductor wafer is stored in the FOUP 90 again after being subjected to a predetermined process in the processing apparatus 100. As a result, the FOUP 90 is in a state where it can be transported by the traveling vehicle 20.

More specifically, the two processing apparatuses 100 are a processing apparatus 100A and a processing apparatus 100B arranged on the downstream side of the processing apparatus 100A. A load port 101 provided in the processing apparatus 100A is a load port 101A. A load port 101 provided in the processing apparatus 100B is a load port 101B.

The traveling vehicle 20 has a transfer mechanism for transferring the FOUP 90 to the load port 101. The transfer mechanism includes, for example, a gripping part that grips the FOUP 90 and a lifting mechanism that lifts and lowers the gripping part. As a result, the traveling vehicle 20 that has stopped at the position where the FOUP 90 can be transferred to the load port 101 can transfer the FOUP 90 to the load port 101 by operating the transfer mechanism. The transfer of the FOUP 90 to the load port 101 includes a case where the FOUP 90 held (loaded) by the traveling vehicle 20 is supplied (unloaded) to the load port 101 and a case where the FOUP 90 placed on the load port 101 is transferred. And the case where the traveling vehicle 20 acquires (catch).

The controller 50 includes a transport controller 50A and a traveling vehicle controller 50B. The transport controller 50A is a host controller for the traveling vehicle controller 50B. The conveyance controller 50A communicates with a manufacturing controller (not shown) and the traveling vehicle controller 50B. The manufacturing controller communicates with the processing apparatus 100 and transmits a transport request for transporting the FOUP 90 to the load controller 101 provided in the processing apparatus 100 to the transport controller 50A. When the transport controller 50A grasps that there is a transport request, the traveling vehicle controller 50B sends a transport corresponding to the transport request to any traveling vehicle 20 located in a predetermined jurisdiction area on the track 10. Assign a command. The jurisdiction area of the traveling vehicle controller 50B in FIG. 1 includes

sections

10a, 10b, 10c, 10d, and 10e.

Each of the transport controller 50A, the traveling vehicle controller 50B, and the manufacturing controller is configured as a computer apparatus including, for example, a processor, a memory, a storage, and a communication device. In each controller, a processor executes predetermined software (program) read into a memory or the like, and controls reading and writing of data in the memory and storage, and communication between controllers by a communication device, thereby controlling each controller. The function is realized.

In the traveling vehicle system 1 configured as described above, the following blocking control is performed at the junction and the branch point. That is, in the blocking control, blocking areas that prohibit entry of the traveling vehicle 20 are set in advance at the junction and the branch point. When traveling vehicle 20 travels along track 10 and reaches a predetermined distance to the junction or branch point where the blocking area is set, it transmits a blocking area passage permission request to traveling vehicle controller 50B.

When the traveling vehicle controller 50B receives the passage permission request from the traveling vehicle 20 and does not permit the other traveling vehicle 20 to pass through the blocking area, the traveling vehicle controller 50B transmits the passage permission request to the traveling vehicle 20 that has transmitted the passage permission request. It is determined that the passage of the blocking area is permitted, and the passage permission of the blocking area is transmitted to the traveling vehicle 20. The said traveling vehicle 20 will pass the said blocking area, if the passage permission of the said blocking area is received from the traveling vehicle controller 50B.

On the other hand, when the traveling vehicle controller 50B receives the passage permission request from the traveling vehicle 20, the traveling vehicle controller 50B has already permitted the other traveling vehicle 20 to pass through the blocking area, and has transmitted the passage permission request. It is determined that the passage of the blocking area is not permitted to 20 and the passage permission of the blocking area is not transmitted to the traveling vehicle 20. When the traveling vehicle 20 does not receive the passage permission of the blocking area from the traveling vehicle controller 50B, the traveling vehicle 20 stops on the upstream side of the blocking area and receives the passage permission of the blocking area from the traveling vehicle controller 50B. stand by. Thereafter, when the other traveling vehicle 20 that has permitted passage through the blocking area completes passage through the blocking area, the traveling vehicle controller 50B transmits passage permission through the blocking area to the traveling vehicle 20 that has transmitted the passage permission request. To do. When the traveling vehicle 20 receives permission to pass through the blocking area from the traveling vehicle controller 50B, the traveling vehicle 20 starts traveling again along the track 10 and passes through the blocking area.
[Backward travel control in a traveling vehicle system]

In the traveling vehicle system 1, reverse traveling control described below is performed. As an example, reverse travel control performed in the following situation will be described. That is, as shown in FIG. 1, there are a first traveling vehicle 20A, a second traveling vehicle 20B, a third traveling vehicle 20C, and a fourth traveling vehicle 20D as the traveling vehicles 20 on the track 10. The first traveling vehicle 20A is located in a predetermined section S (section 10c) of the track 10. Specifically, the first traveling vehicle 20A holds the FOUP 90 and stops at a position where the FOUP 90 can be transferred to the load port 101B provided in the processing apparatus 100B. This position is the current position P of the first traveling vehicle 20A. The second traveling vehicle 20B and the third traveling vehicle 20C are traveling forward on the downstream side of the junction 11a in the predetermined section S and on the upstream side of the processing apparatus 100A. The second traveling vehicle 20B is located in front of the third traveling vehicle 20C. There is no other traveling vehicle 20 between the second traveling vehicle 20B and the first traveling vehicle 20A. In other words, the second traveling vehicle 20B is located in the immediate vicinity of the rear of the first traveling vehicle 20A in the predetermined section S. The fourth traveling vehicle 20D travels forward on the section 10a connected to the upstream side of the section 10c, which is the predetermined section S. At this time, the first traveling vehicle 20A supplies the FOUP 90 to the load port 101B provided in the processing apparatus 100B, and becomes an empty carriage. Then, when the FOUP 90 placed on the load port 101A provided in the processing apparatus 100A is in a transportable state, the traveling vehicle controller 50B assigns a transportation instruction for the FOUP 90 to the first traveling vehicle 20A.

In such a situation, as shown in FIGS. 1 and 2, the first traveling vehicle 20 A has a destination point T (here, the first traveling vehicle 20 A is within the predetermined section S). In order to travel backward to a position where the FOUP 90 can be transferred to the load port 101A), a reverse travel permission request is transmitted to the traveling vehicle controller 50B (step S10).

Subsequently, as shown in FIGS. 2 and 3, when the traveling vehicle controller 50B receives the reverse travel permission request from the first traveling vehicle 20A, the section from the current position P to the destination point T of the first traveling vehicle 20A. Is set (step S11). Specifically, the interference prevention section R is a section from the current position P of the first traveling vehicle 20A to the rear end 21 of the first traveling vehicle 20A in a state where the first traveling vehicle 20A is located at the destination point T. Is included.

Subsequently, the traveling vehicle controller 50B performs broadcast communication on all traveling vehicles 20 in the jurisdiction area (the first traveling vehicle 20A, the second traveling vehicle 20B, the third traveling vehicle 20C, and the fourth traveling vehicle 20D). Simultaneously, the stop request for notifying the interference prevention section R and stopping behind the interference prevention section R is transmitted (step S12). In FIG. 2, an arrow regarding broadcast communication for the first traveling vehicle 20 A is omitted.

Subsequently, when the second traveling vehicle 20B, the third traveling vehicle 20C, and the fourth traveling vehicle 20D receive the stop request from the traveling vehicle controller 50B, the second traveling vehicle 20B determines whether the stop is necessary. Specifically, in determining whether or not each traveling vehicle 20 needs to be stopped, if the traveling vehicle 20 is located within the predetermined section S, it is determined that the stop is necessary (stop determination), and the predetermined section If it is not located within S, it is determined that a stop is not necessary (determination is not required). When each traveling vehicle 20 determines that a stop is necessary (stop determination), it starts a stop operation (deceleration) at an appropriate timing according to the situation.

In the present embodiment, since the second traveling vehicle 20B is located within the predetermined section S, it is determined that the stop is necessary (stop determination), and the stop operation is started (step S13). Similarly, since the third traveling vehicle 20C is located within the predetermined section S, it is determined that it is necessary to stop (stop determination), and a stop operation is started (step S14). On the other hand, since the fourth traveling vehicle 20D is not located within the predetermined section S, it is determined that it is not necessary to stop (determination is not necessary), and continues traveling forward (step S15).

Although not shown in the drawing, a section (for example, section 10c) in which another traveling vehicle 20 cannot enter the predetermined section S even if it continues traveling forward unless it orbits the track 10. The traveling vehicle 20 is located in the predetermined section S even when traveling forward in the section 10d downstream of the section 10d or the section 10e joining the section 10c at the junction 11b downstream of the section 10c. Because it is not, stop is judged unnecessary.

Subsequently, the traveling vehicle controller 50B performs polling communication on all the traveling vehicles 20 (first traveling vehicle 20A, second traveling vehicle 20B, third traveling vehicle 20C, and fourth traveling vehicle 20D) in the jurisdiction area. Sequentially, a status request for a report (status report) regarding the current running status and the like is transmitted. In FIG. 2, an arrow related to polling communication for the first traveling vehicle 20A is omitted.

Each traveling vehicle 20 that has received the state request from the traveling vehicle controller 50B transmits a state report to the traveling vehicle controller 50B. The state report of each traveling vehicle 20 includes information as to whether or not the traveling vehicle 20 can stop behind the interference prevention section R in the predetermined section S when the traveling vehicle 20 determines stop. included. Specifically, the state report includes information that the traveling vehicle 20 is scheduled to stop (can be stopped) when it is expected that the traveling vehicle 20 can stop behind the interference prevention section R in the predetermined section S. When the traveling vehicle 20 has already stopped behind the interference prevention section R in the predetermined section S, information indicating that the traveling vehicle 20 is stopped (can be stopped) is included. On the other hand, the status report includes information that the stop is unnecessary when the traveling vehicle 20 determines that the stop is unnecessary.

In the present embodiment, the second traveling vehicle 20B is located at a position sufficiently separated from the interference prevention section R and can be stopped behind the interference prevention section R. For this reason, when the second traveling vehicle 20B receives the state request from the traveling vehicle controller 50B (step S16), the second traveling vehicle 20B includes information indicating that the second traveling vehicle 20B is scheduled to stop behind the interference prevention section R in the predetermined section S. The report is transmitted to the traveling vehicle controller 50B (step S17). Similarly, the third traveling vehicle 20 C is located at a point sufficiently separated from the interference prevention section R and can be stopped behind the interference prevention section R. Therefore, when the third traveling vehicle 20C receives the state request from the traveling vehicle controller 50B (step S18), the third traveling vehicle 20C includes information indicating that it is scheduled to stop behind the interference prevention section R in the predetermined section S. The report is transmitted to the traveling vehicle controller 50B (step S19). On the other hand, the fourth traveling vehicle 20D is not located in the predetermined section S and does not need to be stopped. Therefore, when the fourth traveling vehicle 20D receives the state request from the traveling vehicle controller 50B (step S20), the fourth traveling vehicle 20D transmits a state report including information indicating that the stop is unnecessary to the traveling vehicle controller 50B (step S21). .

Subsequently, the traveling vehicle controller 50B sends the first traveling vehicle 20A to the destination point T based on the status reports received from the second traveling vehicle 20B, the third traveling vehicle 20C, and the fourth traveling vehicle 20D. It is determined whether to allow reverse travel. Specifically, the traveling vehicle controller 50B receives status reports from all the traveling vehicles 20 except the first traveling vehicle 20A among the traveling vehicles 20 that have transmitted the status request, and stops at all of the status reports. When either information indicating that it is possible (during stoppage, scheduled stoppage) or information indicating that stoppage is not necessary is included, it is determined that reverse travel is permitted for the first traveling vehicle 20A (step S22). In this case, the traveling vehicle controller 50B transmits a reverse traveling permission to the destination point T to the first traveling vehicle 20A (step S23).

Here, the traveling vehicle controller 50B performs the following control in the blocking control. That is, when the traveling vehicle controller 50B transmits the backward traveling permission to the destination point T to the first traveling vehicle 20A, another traveling is performed until the first traveling vehicle 20A completes the backward traveling to the destination point T. The vehicle 20 is not permitted to pass through the blocking area set at the junction point 11a that is the nearest junction point or branch point upstream of the destination point T. As a result, another traveling vehicle 20 (for example, the fourth traveling vehicle 20D) located upstream from the junction 11a receives the passage permission of the blocking area set at the junction 11a from the traveling vehicle controller 50B. I can't. For this reason, only the traveling vehicle 20 (second traveling vehicle 20B and third traveling vehicle 20C) existing in the predetermined section S including the interference prevention section R is stopped or can be stopped behind the interference prevention section R. If it is confirmed, it is possible to suppress the interference between the first traveling vehicle 20A and the other traveling vehicle 20 even if the first traveling vehicle 20A is allowed to travel backward.

In step S22, the traveling vehicle controller 50B does not receive a state report from at least one traveling vehicle 20 other than the first traveling vehicle 20A among the traveling vehicles 20 that transmitted the state request, or the received state report. When the information indicating that the vehicle can be stopped (during stoppage, scheduled to stop) and the information that the vehicle does not need to be stopped are not included in at least one status report, the vehicle travels backward with respect to the first traveling vehicle 20A. Judge not to allow. In this case, the traveling vehicle controller 50B does not transmit the backward traveling permission to the destination point T to the first traveling vehicle 20A.

In step S22, the traveling vehicle controller 50B determines that any traveling vehicle 20 other than the first traveling vehicle 20A among the traveling vehicles 20 in the predetermined section S is stopped or scheduled to stop in the interference prevention section R. In addition, it is determined that the backward traveling to the destination point T is not permitted for the first traveling vehicle 20A, and the backward traveling permission to the destination point T is not transmitted to the first traveling vehicle 20A.

Subsequently, when the first traveling vehicle 20A receives the permission to travel backward from the traveling vehicle controller 50B, the first traveling vehicle 20A travels backward to the destination point T as shown in FIGS. 2 and 4 (step S24). On the other hand, the first traveling vehicle 20A does not travel backward to the destination point T but travels forward, for example, when the backward traveling permission is not received from the traveling vehicle controller 50B. Thus, the reverse travel control in the traveling vehicle system 1 is completed.

By the way, as described above, when the traveling vehicle controller 50B transmits the backward traveling permission to the destination point T to the first traveling vehicle 20A in the blocking control, the first traveling vehicle 20A travels backward to the destination point T. Until the completion, the other traveling vehicle 20 is not permitted to pass through the blocking area set at the junction point 11a that is the nearest junction point or branch point upstream of the destination point T. However, when the traveling vehicle controller 50B transmits the passage permission of the blocking area set at the junction 11a to the other traveling vehicle 20, and then transmits the backward traveling permission to the destination point T to the first traveling vehicle 20A. In the state where the first traveling vehicle 20A is permitted to travel backward, the other traveling vehicle 20 enters the predetermined section S through the junction 11a. Even in such a situation, in order to prevent the traveling vehicles 20 from interfering with each other more reliably, in the backward traveling control in the traveling vehicle system 1, the following control may be performed following step S24.

First, the operations of the second traveling vehicle 20B, the third traveling vehicle 20C, and the fourth traveling vehicle 20D while the first traveling vehicle 20A travels backward in step S24 will be described. The second traveling vehicle 20B and the third traveling vehicle 20C that have been determined to stop in steps S13 and S14 are traveling while decelerating within the predetermined section S to stop behind the interference prevention section R during step S24. . On the other hand, the fourth traveling vehicle 20D that has made the determination that the stop is unnecessary in step S15 and has received permission to pass through the blocking area set at the junction 11a continues to travel forward without deceleration during step S24. is doing. As a result, the fourth traveling vehicle 20D enters the predetermined section S through the junction 11a.

After the above operation is performed during step S24, the traveling vehicle controller 50B, like step S12, sets all traveling vehicles 20 in the jurisdiction area (first traveling vehicle 20A, second traveling vehicle 20B, third traveling). The vehicle 20C and the fourth traveling vehicle 20D) are simultaneously notified by broadcast communication of the interference prevention section R and a stop request for stopping behind the interference prevention section R is transmitted (step S25). Here, the interference prevention section R notified to each traveling vehicle 20 is the same section as the interference prevention section R notified in step S12. For example, the traveling newly entered into the jurisdiction area of the traveling vehicle controller 50B. Each traveling vehicle 20 is notified again for the case where the vehicle 20 exists. In FIG. 2, an arrow regarding broadcast communication for the first traveling vehicle 20 A is omitted.

Subsequently, when the fourth traveling vehicle 20D receives the stop request from the traveling vehicle controller 50B, the fourth traveling vehicle 20D determines again whether or not the stop is necessary. Since the fourth traveling vehicle 20D has entered the predetermined section S as a result of continuing the forward traveling, it is determined that it is necessary to stop (stop determination) and starts the stop operation (step S26).

Subsequently, as shown in FIGS. 2 and 5, the second traveling vehicle 20B and the third traveling vehicle 20C stop behind the interference prevention section R in the predetermined section S (steps S27 and S28). Thereafter, the fourth traveling vehicle 20D stops behind the interference prevention section R in the predetermined section S (step S29).

Subsequently, the traveling vehicle controller 50B performs polling communication on all the traveling vehicles 20 (first traveling vehicle 20A, second traveling vehicle 20B, third traveling vehicle 20C, and fourth traveling vehicle 20D) in the jurisdiction area. Sequentially, a status request for a status report is transmitted. In FIG. 2, an arrow related to polling communication for the first traveling vehicle 20A is omitted.

In the present embodiment, the second traveling vehicle 20B has already stopped behind the interference prevention section R in the predetermined section S. Therefore, when the second traveling vehicle 20B receives the state request from the traveling vehicle controller 50B (step S30), the second traveling vehicle 20B transmits a state report including information indicating that the vehicle is stopped to the traveling vehicle controller 50B (step S31). . The traveling vehicle controller 50B confirms the stop of the second traveling vehicle 20B by receiving this state report from the second traveling vehicle 20B (step S32). Similarly, the third traveling vehicle 20 C has already stopped behind the interference prevention section R in the predetermined section S. Therefore, when the third traveling vehicle 20C receives the state request from the traveling vehicle controller 50B (step S33), the third traveling vehicle 20C transmits a state report including information indicating that the vehicle is stopped to the traveling vehicle controller 50B (step S34). . The traveling vehicle controller 50B receives this state report from the third traveling vehicle 20C, thereby confirming the stop of the third traveling vehicle 20C (step S35). Similarly, the fourth traveling vehicle 20D has already stopped behind the interference prevention section R in the predetermined section S. Therefore, when the fourth traveling vehicle 20D receives a state request from the traveling vehicle controller 50B (step S36), the fourth traveling vehicle 20D transmits a state report including information indicating that the vehicle is stopped to the traveling vehicle controller 50B (step S37). . The traveling vehicle controller 50B receives this state report from the fourth traveling vehicle 20D, thereby confirming the stop of the fourth traveling vehicle 20D (step S38).

Thereafter, the first traveling vehicle 20A transmits an interference prevention section release request for releasing the setting of the interference prevention section R to the traveling vehicle controller 50B. When the traveling vehicle controller 50B receives the interference prevention section release request from the first traveling vehicle 20A, the traveling vehicle controller 50B cancels the setting of the interference prevention section R and broadcasts all the traveling vehicles 20 in the jurisdiction area simultaneously by broadcast communication. Notify that the setting of the interference prevention section R has been canceled.

When each traveling vehicle 20 is notified from the traveling vehicle controller 50B that the setting of the interference prevention section R has been released, the traveling vehicle 20 responds to the situation of each traveling vehicle 20 at an appropriate timing according to the situation of each traveling vehicle 20. Perform the operation. For example, the first traveling vehicle 20A may start conveying the FOUP 90 placed on the load port 101A, and the second traveling vehicle 20B, the third traveling vehicle 20C, and the fourth traveling vehicle 20D make a stop request. Accordingly, the forward traveling stopped may be resumed.

As described above, when the above-described control is performed by the reverse travel control in the traveling vehicle system 1, the traveling vehicle 20 is not located in the predetermined section S, and therefore, when the traveling unnecessary travel is determined and the forward traveling is continued. Also, after entering the predetermined section S, it is possible to stop by making a stop determination. For this reason, it becomes possible to prevent interference between the traveling vehicles 20 more reliably.
[Action and effect]

As described above, in the traveling vehicle system 1, when the first traveling vehicle 20A tries to travel backward, the destination point T (that is, the rearward position of the first traveling vehicle 20A from the current position P of the first traveling vehicle 20A (that is, An interference prevention section R including a section up to a position where the FOUP 90 can be transferred to the load port 101A) is set. Then, the traveling vehicle controller 50B determines whether the traveling vehicle 20 in the predetermined section S except for the first traveling vehicle 20A is stopped or scheduled to stop behind the interference prevention section R. The reverse travel permission to the destination point T is transmitted to the one traveling vehicle 20A. On the other hand, the traveling vehicle controller 50B is the first when the traveling vehicle 20 in the predetermined section S other than the first traveling vehicle 20A is stopped or scheduled to stop in the interference prevention section R. The backward traveling permission to the destination point T is not transmitted to the traveling vehicle 20A. For this reason, without setting the zone in advance, only the section where entry of the other traveling vehicle 20 should be prohibited is set as the interference prevention section R, and the first traveling vehicle 20A travels backward in the interference prevention section R. Can be realized. Therefore, according to the current position P of the first traveling vehicle 20A at the timing when the first traveling vehicle 20A is going to travel backward, an interference prevention section R that prohibits the entry of another traveling vehicle 20 that follows is set. It is possible to achieve reverse travel of the first traveling vehicle 20A while preventing interference between the two vehicles.

In the traveling vehicle system 1, the interference prevention section R includes the first traveling vehicle 20 A in a state where the first traveling vehicle 20 A is located at the destination point T from the current position P of the first traveling vehicle 20 A that transmitted the reverse travel permission request. This is a section up to the rear end 21. For this reason, since the shortest section which should prohibit entry of other traveling vehicles 20 can be set as interference prevention section R, smooth traveling of other traveling vehicles 20 is realizable.

In the traveling vehicle system 1, the track 10 has a plurality of merge points and branch points including the merge points 11 a and 11 b, and the predetermined section S is a section between the merge points 11 a and 11 b adjacent to each other on the track 10. . For this reason, it is possible to suppress an increase in the number of other traveling vehicles 20 that are stopped to realize the backward traveling of the first traveling vehicle 20A.
[Modification]

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment.

For example, in the above-described embodiment, in steps S22 and S23, the traveling vehicle controller 50B receives the state reports from all the traveling vehicles 20 except the first traveling vehicle 20A among the traveling vehicles 20 that transmitted the state request, and When all of these status reports include either information indicating that the vehicle can be stopped (stopped, scheduled to stop) or information indicating that it is not necessary to stop, the first traveling vehicle 20A moves backward to the destination point T. A travel permit is being sent. However, when the traveling vehicle controller 50B includes information indicating that the state report received from at least the second traveling vehicle 20B can stop behind the interference prevention section R (during stoppage, stoppage is planned), The reverse travel permission to the destination point T may be transmitted to the single traveling vehicle 20A. In other words, the traveling vehicle controller 50B can stop the second traveling vehicle 20B located immediately behind the first traveling vehicle 20A in the predetermined section S behind the interference prevention section R (during and scheduled to stop). In this case, the reverse travel permission to the destination point T may be transmitted to the first traveling vehicle 20A that transmitted the reverse travel permission request.

In the above embodiment, in steps S22 and S23, the traveling vehicle controller 50B does not receive a status report from at least one traveling vehicle 20 other than the first traveling vehicle 20A among the traveling vehicles 20 that transmitted the state request, or In the case where at least one of the received status reports does not include information indicating that the vehicle can be stopped (during or scheduled to stop) and information indicating that the vehicle does not need to be stopped, The reverse travel permission to the destination point T is not transmitted. However, the traveling vehicle controller 50B includes information that the second traveling vehicle 20B is not able to stop behind the interference prevention section R (during or is scheduled to stop) in the state report received from the second traveling vehicle 20B. In this case, the reverse travel permission to the destination point T may not be transmitted to the first traveling vehicle 20A. In other words, the traveling vehicle controller 50B can stop the second traveling vehicle 20B located immediately behind the first traveling vehicle 20A in the predetermined section S behind the interference prevention section R (during and scheduled to stop). Otherwise, the reverse travel permission to the destination point T may not be transmitted to the first traveling vehicle 20A that transmitted the reverse travel permission request.

In the said embodiment, the case where there exists the 2nd traveling vehicle 20B and the 3rd traveling vehicle 20C which are moving forward downstream from the confluence | merging point 11a in the predetermined area S and upstream from the processing apparatus 100A exists. did. However, even when the second traveling vehicle 20B and the third traveling vehicle 20C do not exist, the above-described blocking control and reverse traveling control in the traveling vehicle system 1 can be performed.

In the above embodiment, the predetermined section may not be a section between junctions or branch points adjacent to each other on the track 10 (that is, all of one section), for example, a part of one section It may be.

In the above embodiment, the current position P of the first traveling vehicle 20A is a position where the FOUP 90 can be transferred to the load port 101B provided in the processing apparatus 100B in the predetermined section S. However, the current position P is It is not limited to such a position. For example, the current position P may be a parking point for the first traveling vehicle 20 A to stand by on the track 10.

In the above embodiment, the traveling vehicle controller 50B may have some or all of the functions of the transport controller 50A, and the transport controller 50A may have some or all of the functions of the traveling vehicle controller 50B. Also good. Alternatively, one controller may have the functions of the transport controller 50A and the traveling vehicle controller 50B.

In the above-described embodiment, each traveling vehicle 20 includes, for example, a distance measuring unit that measures a distance (an inter-vehicle distance) to another traveling vehicle 20 positioned in front of the own vehicle using an optical sensor or the like, and the distance measuring unit. And a braking unit that stops the traveling vehicle 20 when the measured inter-vehicle distance is equal to or less than a predetermined value. In this case, interference between the traveling vehicles 20 can be more reliably prevented.

In the above embodiment, the object to be conveyed that is transported by the traveling vehicle system 1 of one aspect of the present invention is not limited to the FOUP 90 in which a plurality of semiconductor wafers are accommodated, but other containers in which glass wafers, reticles, and the like are accommodated. There may be. In addition, the traveling vehicle system 1 of one embodiment of the present invention is not limited to a semiconductor manufacturing factory, and can be applied to other facilities.

In the above embodiment, the OHT is exemplified as the traveling vehicle 20. However, the traveling vehicle 20 is not limited to the OHT and may be any device that can travel along the track 10.

In accordance with the current position of the traveling vehicle at the timing when the traveling vehicle is going to travel backward, an appropriate section for prohibiting the entry of other following traveling vehicles is set to prevent the traveling vehicles from interfering with each other. It is possible to provide a traveling vehicle system that can realize reverse traveling.

DESCRIPTION OF SYMBOLS 1 ... Traveling vehicle system, 10 ... Track, 11a, 11b ... Junction (branch junction part), 20 ... Traveling vehicle, 20A ... 1st traveling vehicle, 20B ... 2nd traveling vehicle, 20C ... 3rd traveling vehicle, 20D ... 4th traveling vehicle, 21 ... rear end, 50 ... controller, 50A ... transport controller, 50B ... traveling vehicle controller, P ... current position, R ... interference prevention section, S ... predetermined section, T ... destination point.

Claims

A plurality of vehicles traveling along a track,
A controller that communicates with each of the plurality of traveling vehicles and controls the operation of each of the plurality of traveling vehicles;
When the traveling vehicle is located in a predetermined section of the track, and when trying to travel backward to a destination point behind the traveling vehicle in the predetermined section, a reverse travel permission request is transmitted to the controller,
The controller is
When the reverse travel permission request is received from the traveling vehicle, an interference prevention section including a section from the current position of the traveling vehicle to the destination point is set,
The travel that has transmitted the reverse travel permission request when the other travel vehicle positioned immediately behind the travel vehicle in the predetermined section is stopped or scheduled to stop behind the interference prevention section Send the vehicle permission to travel to the destination,
A traveling vehicle system that does not transmit a backward travel permission to the destination to the traveling vehicle that has transmitted the reverse travel permission request when another traveling vehicle is stopped or scheduled to stop within the interference prevention section .
The interference prevention section is a section from the current position of the traveling vehicle that has transmitted the reverse travel permission request to a rear end of the traveling vehicle in a state where the traveling vehicle is located at the destination point. The traveling vehicle system described in 1.
The track has a plurality of branching / merging portions that branch or merge,
The traveling vehicle system according to claim 1, wherein the predetermined section is a section between the branching and joining portions adjacent to each other on the track.