JPH09225783A - Agv operation planning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible production system capable of performing the AGV operation plan taking into consideration the avoidance of collision in advance, and capable of continuing the production without delay even when the production line or the production schedule is changed. SOLUTION: A system A successively presents the carriage demand of a lot 2 to each working machine 1 from each working machine 1 to each AGV 3 following the schedule control object 4 in which the operation plan of all AGVs 3 is stored and the prescribed working schedule, and establishes the operation plan of each AGV 3 to the carriage demand from each working machine 1 one by one following the prescribed rule, and the operation plan stored in the schedule control object 4 is successively corrected following the established operation plan. The flexible production system can be realized thereby.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AGV operation planning system, and more specifically, it is applicable to an automatic production line.
The present invention relates to a GV operation plan planning system.

[0002]

2. Description of the Related Art In recent years, along with the ever-increasing demand for labor saving and high-mix low-volume production, factory production lines are being automated and general-purposed. In such a production line, lots are transported in parallel by a plurality of AGVs (Automated Guided Vehicles), and their operation plans are centrally managed by a central system. However, processing machines and A
When the number of GVs increases and the production line or production process becomes complicated, it becomes difficult to centrally manage the operation plan of the AGV. Also, if there is a change in the production line, such as when the AGV or processing machine fails, or when a new AGV or processing machine is introduced, or if there is a change in the production schedule due to an express lot, etc. Had to change its central control system, resulting in an inflexible production system. Therefore, an autonomous distributed flexible production system has been proposed in which each component of the production system is provided with an autonomous decision-making function and a communication function for real-time production scheduling (Moriwaki et al. Study on design and operation of distributed manufacturing system ", Japan Society of Mechanical Engineers, Volume 59, No. 568 (1993-1993)
12)).

[0003]

In the conventional AGV operation planning system in the production system as described above, each machine tool, each lot, and each AGV may sometimes make inconsistent or competing decisions, which is why separate decisions are made. It was necessary to provide an adjusting unit having the adjusting function of (1) to eliminate conflicts or conflicts. For example, when an operation plan is created such that AGVs collide with each other, the adjusting unit re-creates the operation plan of the AGV in consideration of collision avoidance. For this reason, although there is a large amount of communication between the constituent elements of the production system, if there is a contradiction or conflict in the autonomous decision making among the constituent elements, the resolution of the contradiction or conflict is eventually adjusted. Since it is left to the department, the communication between each component up to that point is wasted. In this case, it is difficult to take prompt action when the production line or production schedule is changed, and it is difficult to realize a flexible production system. The present invention has been made in view of the above circumstances, and an object of the present invention is to make an AGV operation plan in consideration of collision avoidance in advance even when a production line or a production schedule is changed, and the operation is delayed. It is to provide an AGV operation planning system capable of realizing a flexible production system capable of continuing production without any trouble.

[0004]

In order to achieve the above object, the present invention provides a plurality of processing machines with a plurality of AGVs as processing targets.
All the AGVs in the AGV operation planning system that plans the operation of each AGV for transportation by
Operation plan storage means for storing the operation plan of the above, and a transfer request presenting means for sequentially presenting a transfer request for a processing target of each processing machine to each AGV according to a predetermined processing schedule, and the above operation plan While referring to the operation plan stored in the storage means, the operation plan of each AGV in response to the transfer request from each processing machine is determined according to a predetermined rule.
It is characterized in that it comprises an operation plan making means for making a plan one by one, and an operation plan correcting means for making a sequential correction to the operation plans stored in the operation plan storing means according to the made operation plans. It is configured as an AGV operation planning system. Further, the AGV further comprises rule modifying means for modifying the above-mentioned predetermined rule.
It is an operation planning system. Furthermore, the AGV operation planning system further includes a processing schedule correction means for correcting the above-mentioned predetermined processing schedule.

[0005]

DETAILED DESCRIPTION OF THE INVENTION AND

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and examples of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following embodiments and examples are examples of embodying the present invention and are not of the nature to limit the technical scope of the present invention. 1 is a schematic diagram showing a schematic configuration of a production line to which the AGV operation planning system according to the embodiments and examples of the present invention can be applied, and FIG. 2 is a flow chart showing an algorithm of an AGV operation plan. FIG. 3 is an explanatory diagram showing a method for realizing collision avoidance of AGV. As shown in FIG. 1, an AGV operation planning system A according to an embodiment and an example of the present invention includes a plurality of AGVs for transporting a lot 2 corresponding to a processing target to a plurality of processing machines 1 by a plurality of AGVs 3, respectively. It is the same as the conventional example in that it creates an operation plan.
However, in this system A, a schedule management object 4 including an operation plan storage unit that stores the operation plans of all AGVs, and a transfer request for the lot 2 to each processing machine 1 are sent to each processing machine 1 according to a predetermined processing schedule. The operation plan of each AGV3 in response to the transfer request from each processing machine 1 is followed according to a predetermined rule with reference to the transfer request presenting means for sequentially presenting each of the AGVs 1 to 1 and the operation plan stored in the schedule management object 4. , The conventional example in that it includes an operation plan formulation means for sequentially planning one by one, and an operation plan modification means for sequentially modifying the operation plan stored in the schedule management object 4 according to the planned operation plan. different. Further, a rule correction means for correcting the predetermined rule and a processing schedule correction means for correcting the predetermined processing schedule may be provided, which is also different from the conventional example. In addition, the transfer request presenting means of the system A, a part of the operation plan making means, a part of the rule correcting means, the machining schedule correcting means is a processing machine 1, a part of the operation plan making means
A part of the rule correction means is embodied in the AGV 3, and the operation plan correction means is embodied by a program in an execution format, which is built in the schedule management object 4, respectively.
The production line to which the system A can be applied is, for example, as shown in FIG. 1, a one-dimensional basic line, ten processing machines 1 orthogonal to the one-dimensional basic line, and a retreat line for avoiding a collision, Lot 2 is transported by four AGV3s. Further, a schedule management object 4 having a function of grasping the schedule of the entire AGV 3 is arranged. Each of these constituent elements has a communication function and can exchange messages with each other.

The operation of this system A will be described below with reference to FIG.
Steps S1, S2, ...
In FIG. 2, first, the transfer request presenting means of the processing machine 1 presents a request to transfer the lot 2 to the AGV 3 according to a predetermined lot processing schedule (S1). At this time, the information given to the AGV 3 by the processing machine 1 is the lot number, the desired arrival time, and the destination position. In other words, indicate which lot is to be delivered and when. The operation planning means of each AGV3 receives the message and makes its own operation plan for the transfer work. At this time, in order to prevent the AGVs 3 from colliding with each other on the transportation line, the operation route of the entire AGV 3 grasped by the operation plan storage means of the schedule management object 4 is referred to (S2), and the operation route is changed. Plan (S3). Here, the schedule management object 4 is represented by the graph A as shown in FIG.
Know the operation plan of GV3. The vertical axis of the figure represents time, and the horizontal axis corresponds to the horizontal position of the production line in FIG. For example, referring to this graph, it can be seen that the AGV moves from point A to point B from time t1 to time t2. Now, suppose that the processing machine at the point B requests the AGV at the symbol arrival time t3. At that time, the AGV makes its own operation plan toward the destination from the E point to the D point and from the D point to the C point (a to b in FIG. 3A). Next, an operation plan is made from the C point to the B point, but the AGV is from b to c.
It can be seen that the vehicle collides with the AGV at d at the time of operation as shown in. Therefore, the AGV is retreated on the retreat line at the point C as indicated by b to e, and after the AGV does not exist between B and C, it is moved from the point C to the point B as indicated by e to f. Make an operation plan according to such rules (corresponding to some of the predetermined rules). In this way, each AGV 3 can formulate its own operation plan considering collision avoidance while referring to the operation plan table of the schedule management object 4.

When the operation plan to the destination is completed,
The AGV 3 transmits the outline of the operation plan to the requested processing machine 1 (S4). The contents to be conveyed are the four items of one's own AGV number, departure time, arrival time, and traveled distance, and the details of the operation plan other than that are only temporarily held by the AGV itself. This is the AGV3 that is most suitable for the processing machine 1.
This is because the communication amount and communication time are reduced by exchanging only the minimum information required when selecting. When all the operation plans are transmitted from all the AGVs 3 (S5), the operation planning means of the processing machine 1 selects the optimum AGV 3 (S6). Here, for example, the following is used as the selection criterion (corresponding to a part of the predetermined rule). (1) Select an AGV that meets the desired arrival time. If all AGVs are not in time, A with less delay
Select GV. (2) If it is not decided in the above (1), select an AGV with a shorter moving distance. (3) If not decided in (2) above, select an AGV with a later departure time.

When the optimum AGV3 is determined, the processing machine 1 presents the AGV number selected by itself to the AGV3. The selected AGV 3 officially adopts the operation plan drafted by itself as the operation plan (S7), and carries out the lot transfer work according to the plan (S8). Further, the selected AGV 3 transmits the operation plan to the schedule management object 4 (S9). Then, the operation plan correction means of the schedule management object 4 newly adds the operation plan to the entire operation plan table of the operation plan storage means of its own and updates it (S10). Also,
The AGV 3 not selected in step S7 erases the operation plan of its own which is temporarily held, and prepares for a new transfer work request from the processing machine 1 (S11). The above steps S1 to S11 are sequentially repeated. In this way, the processing machine 1 makes a request to the AGV 3 according to the processing schedule of a predetermined lot, and in response to this, each AGV 3 makes an operation plan and proposes it to the processing machine 1,
By adopting the optimal operation plan, it is possible to make an operation plan without delay even when the number of AGVs 3 changes.

Further, when a limited express lot is generated, the processing schedule correction means of the processing machine 1 is used to reset the limited express lot to a priority processing schedule, and the processing machine for processing the limited express lot is preferentially conveyed. By presenting the request to the AGV, it is possible to make an operation plan for the AGV that gives priority to the express lot. Further, the rules for avoiding the collision between the AGVs and the criteria for selecting the optimum AGV can be corrected by using the AGV3 and the rule correction means of the processing machine 1, respectively. As described above, in this system A, even if the production line or production schedule is changed or the number of AGVs is changed, the AGV operation plan can be performed without delay.
It is possible to build a more flexible production system than the conventional centralized control type automatic production system or autonomous distributed type automatic production system. In addition, since the AGV transfer work is planned by referring to the operation plan table of the schedule management object while avoiding collisions between AGVs in advance, each component makes a decision once, and then A
There is no need to plan again to avoid the conflict of GV conflicts. As a result, communication between the respective constituent elements is not wasted, and the amount of communication can be reduced.

[0010]

Since the AGV operation planning system according to the present invention is configured as described above, when the production line or the production schedule is changed, or the AGV operation plan system is changed.
Even if there is a change in the number of vehicles, AGV operation plans can be performed without delay, and a more flexible production system than the conventional centralized control type automatic production system or autonomous decentralized automatic production system. Can be built. In addition, by referring to the operation plan stored in the operation plan storage means, the AGV is considered in advance to avoid collision between AGVs.
Since the transfer work of V is planned, it is not necessary to make a plan again after each component once makes a decision to avoid the conflict of AGV collision. As a result, communication between the respective constituent elements is not wasted, and the amount of communication can be reduced.

[Brief description of drawings]

FIG. 1 is an AGV according to an embodiment and an example of the present invention.
The schematic diagram which shows the schematic structure of the production line which can apply operation planning system A.

FIG. 2 is a flowchart showing an algorithm of an AGV operation plan.

FIG. 3 is an explanatory diagram showing a method of realizing collision avoidance of an AGV.

[Explanation of symbols]

A ... AGV operation planning system 1 ... Processing machine (conveyance request presenting means, part of operation planning means, part of rule correction means, processing schedule correction means) 2 ... Lot (corresponding to processing target) 3 ... AGV (Equipped with a part of operation plan planning means and a part of rule correction means) 4 ... Schedule management object (includes operation plan storage means and operation plan correction means)

Claims (3)

[Claims] 1. A plurality of machining targets are processed by a plurality of AGs.
In the AGV operation planning system that formulates an operation plan for each AGV to be transported by V, all AGs
An operation plan storage unit that stores the operation plan of V, a transfer request presenting unit that sequentially presents a transfer request for a processing target of each processing machine to each AGV in accordance with a predetermined processing schedule, and the operation described above. With reference to the operation plan stored in the plan storage means, an operation plan formulation means for sequentially formulating one operation plan for each AGV in response to a transfer request from each processing machine according to a predetermined rule, and the above-mentioned plan An AGV operation plan system comprising: an operation plan correction means for sequentially correcting the operation plan stored in the operation plan storage means according to the operation plan. 2. The AGV operation planning system according to claim 1, further comprising rule modifying means for modifying the predetermined rule. 3. The AGV operation planning system according to claim 1, further comprising a processing schedule correction means for correcting the predetermined processing schedule.