JPH11119830A - Automatically guided vehicle system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the largest number of automatically guided vehicles to travel in a dead-end section and to improve the transportation capability by locking the areas including the destination of the vehicle against the following vehicles to secure the travelable areas for the vehicle and then canceling the lock states of the traveled areas. SOLUTION: A traveling route 2 is set inside a plant, etc., and divided into areas in every prescribed section. The automatically guided vehicles 8 of several pieces to about a hundred pieces are prepared, and plural stations 10 are set along the route 2. Then, the vehicles 8 carry the goods among the stations 10. In such a system, the areas including the destination are locked for the vehicle 8 traveling in a dead-end section 4 so that the following vehicles 8 are inhibited from entering the locked areas. Thus, the locked areas where the preceding vehicle 8 passed are canceled and the following vehicles 8 can travel on the same route when plural vehicles 8 travel in the same direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic guided vehicle system that travels on the ground or on a ceiling, and more particularly to control of a dead end section.

[0002]

2. Description of the Related Art An automatic guided vehicle system is used for transporting articles in factories and warehouses. In the automated guided vehicle system, several to several tens of automated guided vehicles are used and run along the track, or run while recognizing the current position on the track by scanning a position recognition pattern with a laser or the like. Let it.

[0003] Due to the layout of stations and the like, dead ends may occur in the traveling route. Then, the number of unmanned guided vehicles that can travel in the dead end section is limited to one to prevent collision. However, with this control, the transport capacity in a dead end section is reduced, and the dead end section may become a bottleneck in the transport capacity of the automatic guided vehicle system.

[0004]

An object of the present invention is to enable a plurality of automatic guided vehicles to travel simultaneously when traveling in the same direction even in an overlapping area in a dead end section, and to improve the transport capacity in a dead end section. Is to strengthen it. Claims 2 and 3
Another object of the invention is to prevent deadlock in a dead end section.

[0005]

According to a first aspect of the present invention, there is provided a system in which an automatic guided vehicle is caused to travel on a traveling route having a dead end section. It is characterized in that it is configured to lock the ranked vehicle so that it travels in an area where it can travel, and to unlock the area where it has traveled.

[0006] The traveling route may be tracked or trackless,
The dead end section refers to a section in which the automatic guided vehicle travels in the same section in two forward and reverse directions. An area is a unit obtained by further dividing a section, and a lock in a dead end section refers to prohibiting the traveling of an unmanned guided vehicle in a rear order. Therefore, it is possible for a plurality of automatic guided vehicles from the first to the last to lock the same area, or for a rear-order vehicle to make a lock reservation, and in this case, it is the best that can actually travel in that area. Limited to unmanned guided vehicles in the first order.
Locking may be performed when the automatic guided vehicle requests traveling in a dead end section, or locking may be permitted when traveling becomes possible. However, if the lock is granted at the time of the travel request, the lock for the unmanned guided vehicle that cannot travel is accepted, and the transport capacity is undesirably reduced.

[0007] The area which can travel in the dead end section means an area which is continuous to the current position of the automatic guided vehicle and is not locked by the preceding automatic guided vehicle. If the vehicle is not connected and cannot travel, it is not called a travelable area.

The invention according to claim 2 further detects that the destination into the dead end section is locked by another automatic guided vehicle, and prohibits entry of the automatic guided vehicle into the section or changes the destination. It is characterized by having such a configuration. This process has the problem of overlapping destinations within a section,
The processing when the destinations overlap outside the dead end section is optional. The invention according to claim 3 is further characterized in that the number of unmanned guided vehicles in the dead end section is limited.

[0009]

According to the first aspect of the present invention, the area to the destination in the section is locked for the automatic guided vehicle traveling in the dead end section, and the automatic guided vehicle in the rear rank is locked in the section where the automatic guided vehicle is locked. Prohibit entry. Then, the locked area is unlocked. For this reason, when a plurality of automatic guided vehicles run in the same direction, the lock is released from the area where the preceding automatic guided vehicle has passed, and the subsequent automatic guided vehicles can travel on the same route.

[0010] When two AGVs try to travel in the dead end section in the opposite direction, the AGV on the side locked first can travel, and the area where the AGV passes and is unlocked is in the rear rank. Is not continuous with the current position of the automatic guided vehicle on the opposite side, so that the automatic guided vehicle on the opposite side cannot travel. In this way, the two AGVs do not travel simultaneously in the same area in opposite directions, and no collision occurs. According to the first aspect of the present invention, a plurality of automatic guided vehicles are allowed to travel in the same direction, and only one vehicle is allowed to travel in the opposite direction. Therefore, it is possible to improve the transportation capacity in a dead end section while preventing a collision. .

According to the second aspect of the present invention, if the destination in the dead end section is locked by another automatic guided vehicle, entry into the section is prohibited or the destination is changed. Therefore, there is no need for two AGVs to travel to the same destination at the same time, or for a subsequent AGV to travel to the station occupied by the first AGV, and to cause deadlock in dead-end sections. Can be prevented.

According to the third aspect of the present invention, the number of unmanned guided vehicles in the dead end section is further limited, so that the unmanned guided vehicle does not enter beyond the number of stations or standby positions in the section, for example. Deadlock in a dead end section can be prevented.

[0013]

1 to 6 show an embodiment. FIG. 1 shows the traveling route 2 of the automatic guided vehicle in the embodiment. The traveling route 2 is provided on a track or a track in a factory or a warehouse, and is divided into an area (not shown) for each predetermined section. 4 and 6 are dead-end sections provided on the traveling route 2. For example, several to 100 automatic guided vehicles 8 are arranged on the traveling route 2, a plurality of stations 10 shown in FIG. 2 are arranged along the traveling route 2, and the automatic guided vehicles 8 convey articles between the stations.

FIG. 2 shows the arrangement of the dead end section 4.
This section 4 includes 12-1 including the branch from the main route.
The area is divided into eight areas of 12 to 8 and two stations 10, 10 are provided in contact with the areas 12-5, 12-8. The upper limit of the number of automatic guided vehicles 8 in the areas 12-2 to 12-8 is limited to two, and the destination in the section is limited to the areas 12-5 and 12-8.

FIG. 3 shows a control system of the automatic guided vehicle system. The system is managed by a system computer 20, and an automatic guided vehicle management unit 22 communicates with the automatic guided vehicle 8 by wire or wireless communication. Each automatic guided vehicle 8 locks the area to be driven by the automatic guided vehicle management unit 2.
2 and report the execution status of the transfer command. The automatic guided vehicle management unit 22 assigns a transfer command to each of the automatic guided vehicles 8 and recognizes a lock request from the automatic guided vehicle 8 to permit traveling. Then, the automatic guided vehicle 8 travels to the next area by being permitted to lock.

Reference numeral 24 denotes a bus in the system computer 20 which receives a transfer command from a host computer (not shown) or a control terminal or the like, and reports the transfer result to the external input / output 2.
6, an allocating unit 28 for allocating and executing a transfer instruction to the automatic guided vehicle 8 and the like are connected. The allocating unit 28 includes a route table of the traveling route 2 and stores the required traveling time between the stations along the traveling route 2 in, for example, a graph format.
Search for unmanned guided vehicles that can execute transfer commands in the shortest time,
The transfer command is assigned to an automatic guided vehicle capable of executing the transfer command in the shortest time and executed.

Reference numeral 30 denotes a dead end section control unit which receives a travel request in the dead end sections 4 and 6 from the automatic guided vehicle 8 via the automatic guided vehicle management unit 22, that is, a lock request, and
Permitted or denied, and automatic guided vehicles 8 in sections 4 and 6
Is controlled to be equal to or less than the upper limit, and a plurality of automatic guided vehicles do not try to travel to overlapping destinations in the sections 4 and 6.

FIGS. 4 to 6 show the control in the dead end section 4. As shown in FIG. 6, the AGV 8 that is going to travel in the dead end section 4 sends the information from the area next to the current position to the destination (destination) to the dead end section control unit 30 via the automatic guided vehicle management unit 22. Request lock on area. However, as a prerequisite, it is required that the number of the automatic guided vehicles in the dead end section has a margin, and that the areas 12-5 and 12-8 facing the destination station are not the destination or the current position of another automatic guided vehicle. You. When destinations overlap, there is no problem if the destination can be changed, for example. If these conditions cannot be satisfied, entry into dead end section 4 is impossible, and automatic guided vehicle 8 waits outside section 4. Note that the automatic guided vehicle attempting to escape outside section 4 does not have these restrictions, and there is no problem even if destinations overlap outside the section.

In response to a lock request for an area up to a destination, for example, a lock request from area 12-1 to area 12-5 or area 12-8, if there is an area in which the automatic guided vehicle can currently travel, the lock request is made. It is permitted and the subsequent, that is, the second-order, automatic guided vehicle is prohibited from traveling in the locked area. Here, traveling is possible when there is an area continuous with the current position without being locked by the unmanned guided vehicle of the preceding rank. Note that the areas can be locked in an overlapping manner, and even if the area is locked by itself, the area locked by the unmanned guided vehicle in the first order cannot travel. Then, the automatic guided vehicle unlocks the traveled area each time. When the automatic guided vehicle arrives at the destination in the section 4, the lock of the other area should have been released except for the lock of the current position. Then, the process shown in FIG. 6 is performed for each of the automatic guided vehicles 8 that are going to travel in the dead end sections 4 and 6.

As shown in FIG. 4, it is assumed that a plurality of automatic guided vehicles try to enter dead end section 4 toward different destinations. It is assumed that there are no other automatic guided vehicles in section 4 and the number limit is satisfied. The automatic guided vehicle (Unit 1) of the first priority is requested and locked to the areas 12-1 to 12-5. Assuming that after the first car has started traveling in the section, the second car in the rear rank requests traveling to the area 12-8. For example, in the areas 12-1 and 12-2, the first car has been driven and has been unlocked. The No. 2 car can also run, and is recognized by requesting a lock request for the areas 12-1 to 12-4 and the areas 12-6 to 12-8. Unit 2 also starts traveling in section 4, and after passing through area 12-4, unit 1 passes there and arrives at station 12-8. At this time, the number of the automatic guided vehicles in the section 4 is two, and no more automatic guided vehicles can enter. In addition, the two stations are both occupied by automatic guided vehicles, and from this point, the entry of other automatic guided vehicles becomes impossible. When the vehicle travels in the section 4 in the same direction as described above, a plurality of automatic guided vehicles can travel at the same time, and the transport capacity of the dead end sections 4 and 6 is enhanced.

FIG. 5 shows a process when two automatic guided vehicles try to travel simultaneously in the section 4 in the reverse direction. For example, suppose that the first car in the first order tries to get out of section 4, and then the other car in the second order requests entry into section 4. When the first car requests the escape, the areas 12-1 and 12-5 are collectively locked, and the areas 12-4 and 12-5 in which the first car has been driven and unlocked are connected to the current position of the other car. No other aircraft can run. Therefore, other units cannot lock the area in section 4. Suppose that the third automatic guided vehicle attempts to travel in the same direction as the first vehicle after the other vehicle requests entry into section 4. The unlocked areas 12-4 and 12-3 can travel, the third automatic guided vehicle can also lock up to the area 12-1, and the areas 12-1 and 12-2 are double locked. . After the third automatic guided vehicle has passed through the branch area 12-1, the automatic guided vehicle waiting outside the section 4 can enter the section. For this reason, the automatic guided vehicle that follows in the same direction is given priority over the automatic guided vehicle that is going to travel in the opposite direction to the first vehicle, and the transport capacity in the dead end section 4 is increased.

Although specific examples have been described in the embodiments, the present invention is not limited to these. In particular, each element of the present invention is effective, and specific means are arbitrary as long as substantially similar means are used. For example, dead end sections 4, 6
It is optional whether the dead end section control unit 30 performs the intensive control as in the embodiment or allows the autonomous control by the communication between the automatic guided vehicles.

[Brief description of the drawings]

FIG. 1 is a diagram showing a traveling route of an automatic guided vehicle system according to an embodiment.

FIG. 2 is a diagram showing a dead end section in the automatic guided vehicle system of the embodiment.

FIG. 3 is a diagram illustrating a control system of the automatic guided vehicle system according to the embodiment;

FIG. 4 is a diagram showing control when two automatic guided vehicles enter a dead end section in the embodiment.

FIG. 5 is a diagram showing control when two unmanned guided vehicles try to travel in opposite directions in a dead end section in the embodiment.

FIG. 6 is a flowchart showing a control algorithm in the embodiment.

[Explanation of symbols]

 2 Travel route 4,6 Dead end section 8 Automatic guided vehicle 10 Station 12-1 to -8 Area 20 System computer 22 Automatic guided vehicle management section 24 Bus 26 External input / output 28 Assignment section 30 Dead end section control section

Claims (3)

[Claims] 1. A system in which an unmanned guided vehicle travels on a traveling route having a dead end section, wherein an area up to a destination in the section is locked for an unmanned guided vehicle traveling in the section relative to a rear-ranking vehicle. An automatic guided vehicle system characterized in that the automatic guided vehicle system is configured to travel in a travelable area and to unlock a traveled area. 2. An automatic guided vehicle configured to detect that a destination into a dead end section is locked by another automatic guided vehicle and to prohibit entry of the automatic guided vehicle into the section or change the destination. The automatic guided vehicle system according to claim 1, wherein: 3. The automatic guided vehicle system according to claim 1, wherein the number of unmanned guided vehicles in the dead end section is limited.