JP3098470B2 - Transfer control device for automatic guided vehicle and control method therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer control device for an automatic guided vehicle and a control method therefor, and more particularly to a transfer control device for an automatic guided vehicle that can realize efficient transfer with a minimum system configuration and a control method therefor.

[0002]

2. Description of the Related Art A general conventional transport control device includes:
In some cases, an unmanned guided vehicle is searched for in the order of the time at which a transfer request issued from a transfer source occurs, and a transfer instruction is issued to the unmanned guided vehicle. 2 (a) and 2 (b) are a block diagram showing the configuration of the conventional transport system and an explanatory diagram of its functions.

In FIG. 2A, a transport request a generated from a transport request generator 1 is notified to a transport controller 2.
The transfer control unit 2 receives the notified transfer request a,
The transfer requests a are processed in the order of the received times, and the transfer instructions b are instructed to the automatic guided vehicle 4 in the same order.

For example, it is assumed that a transfer request a generated by the transfer request generation unit 1 is as shown in FIG.
That is, the arrow is shown from the transfer source station (ST) to the transfer destination station (ST), and ST3 → ST5, ST
7 → ST2, ST4 → ST6
The transfer instruction b given by the transfer control unit 2 to the automatic guided vehicle 4 is also the same order, ST3 → ST5, ST7 → ST2, ST4 → S
This is the instruction of T6.

As another conventional example, Japanese Patent Application Laid-Open No.
No. 1313 is disclosed. This calculates the evaluation function with the workpiece stock amount of the transfer source, the distance between stations and the waiting time in the waiting area as parameters,
The automatic delivery of vehicles is performed according to the priority of the evaluation function. This is shown in the block diagram of FIG.

In this conventional example, the host computer 21
Are connected to the automatic guided vehicle 4 via signal lines 24 to the transport paths 10 to 13. The host computer 21 detects the stock amount of the unload stations 15 to 17 and uses it as a parameter D1, and from the waiting areas 18 to 20 via the load station 14 to the unload station 1.
The distance data from 5 to 17 is defined as a parameter D2, and the time during which the automatic guided vehicles 4a and 4b wait in the standby areas 18 to 20 is defined as a parameter D3. These parameters D1 to D
3 is used to calculate the evaluation function F according to the following equation (1) to prioritize the transport requests.

F = α 1 · D 1 + α 2 · D 2 + α 3 · (1 / D 3) (1) where α i is a weighting factor.

[0008]

In the above-described conventional transport system, the unload stations 15 to 17 transport the transported objects 22 and 23 by the automatic guided vehicle 4 respectively.
Is it time to arrive, i.e. waiting time of the respective conveying request of the equipment when unloading station equipment (hereinafter, referred to as cycle time) is different. This takt time corresponds to the minimum time interval at which the facility processes one conveyed object. In addition, the transport system is composed of a number of unload stations with different tact times.If the system is configured in this conventional example, the transport must be performed in accordance with the shortest tact time, so the system scale is reduced. there is a disadvantage that the size of Kunar. This is because in this conventional example , there is no variable representing the tact time of the unload station in the variable of the evaluation function F.

For example, the unloading station 15
Tact time of 10 minutes, unload station 16
When the tact time is 30 minutes, the performance of the transport system itself must be realized in time of 10 minutes, so that a large number of unmanned transport vehicles 4 are required.

An object of the present invention is to solve these problems,
An object of the present invention is to provide a transfer control device for an automatic guided vehicle that can efficiently transfer with a minimum system configuration.

[0011]

SUMMARY OF THE INVENTION According to the present invention, there is provided an automatic guided vehicle transport control apparatus for optimally controlling a plurality of automatic guided vehicles for transporting each transported object. A transfer request generation unit that generates a transfer request by specifying, and a transfer control unit that instructs the automatic guided vehicle from each of the transfer requests to a traveling route according to a predetermined priority,
This transport control unit performs the minimum transport process for each of the transported objects.
Tactable waiting time for each transport request corresponding to the time interval
A tact time database that stores time
Tact time from the tact time database of
The time from the request generation time of each transport request to the current time
An evaluation function calculator that outputs the difference as an evaluation function;
Each of the above-mentioned transports is performed in ascending order of the calculation result of the value function calculating unit.
<br/> Rukoto be possessed and prioritizing means for prioritizing transmission requests and said.

[0012]

According to another aspect of the present invention, there is provided an automatic guided vehicle transport control method for optimally controlling a plurality of automatic guided vehicles for transporting each transported object. Make a request and carry out the transport processing of each of the above-mentioned transported goods
The waiting time of each transport request corresponding to the minimum time interval is stored in advance as tact time , and these tact times are stored.
From the request occurrence time to the current time of each transport request
Are output as evaluation functions, respectively.
Each of the above transport functions is sequentially described in ascending order of the operation result of the evaluation function.
Request priority is determined .

According to the structure of the present invention, in order to execute the transfer request issued from the transfer request generation unit, the priority order setting means corresponds to each transfer request by the evaluation function calculation unit with reference to the tact time database. After calculating the evaluation functions, the transfer control unit changes the order of executing the plurality of transfer requests according to the value of each evaluation function. As a result, the priority of a transfer request having a short tact time is increased, and the transfer process is executed with priority over other transfer requests. Therefore, the priority of the transfer can be switched according to the length of the tact time of the transfer destination, and the scale of the transfer system can be reduced.

[0015]

Embodiments of the present invention will now be described with reference to the drawings. FIGS. 1A and 1B are a block diagram for explaining an embodiment of the present invention and a functional explanatory diagram of a priority assigning unit thereof. In FIG. 1A, the transport control unit 2
The conveying request generating unit 1 from the received transport instruction conveying source, recognizing the transport destination and the transport request generation time Tn. The transport control unit 2 includes a priority ordering unit 5, and the priority ordering unit 5 predicts a tact time tn for each transport request.
Tact time database 3 to be stored and prioritized
An evaluation function calculation unit 6 that calculates an evaluation function of the user is included.
The automatic guided vehicle 4 is instructed from the output of the prioritizing section 5.
It is.

The prioritizing unit 5 calculates each evaluation function Hn using a predefined time as a variable by the following equation (2). Here, the current time is set to To, and Hn = tn- (To-Tn) (2). The priority assigning means 5 determines the priority order for executing the transfer request based on the value Hn of the evaluation function calculated for each of the plurality of transfer requests a.
Gives a transfer instruction to the automatic guided vehicle 4 in accordance with the priority order.

As an operation of the present embodiment, first, a transfer request a issued from the transfer request generation unit 1 is transmitted to the transfer control unit 2. The transfer control unit 2 requests the priority ordering unit 5 to calculate an evaluation function corresponding to the transfer request a for the plurality of transfer requests a from the transfer request generation unit 1. The priority assigning unit 5 refers to the tact time database 3 to extract the tact time for the transfer request, and the evaluation function calculation unit 6 calculates the evaluation function Hn corresponding to the transfer request.

For example, as shown in the transfer request a of FIG. 1B, the transfer request 1 = ST3 → ST5, the transfer request 2 = ST7.
Assuming the order of → ST2, transfer request 3 = ST4 → ST6, the transfer control unit 2 determines that these three transfer requests a
And the request time Tn are transmitted to the priority ordering unit 5. The priority ordering unit 5 determines the tact time t1... For each transport request a from the tact time database 3 in FIG. t2 and t3 are obtained, and H1, H2, and H3 are calculated from the previously defined equation (2) of the evaluation function Hn.

The priority assigning unit 5 compares the values H1, H2, and H3 of the evaluation functions corresponding to the respective transport requests, and replaces the transport requests in the order of the values to notify the transport controller 2. The transfer control unit 2 changes the transfer instruction b to the automatic guided vehicle 4 in the order of the smaller evaluation function Hn as shown in FIG. 1B regardless of the order of the transfer requests a issued from the transfer request generator 1. Process.

For example, when the transport controller 2 receives the transport request a from the transport request generator 1 in the order of transport request 1, transport request 2, and transport request 3 in the above-described order, the evaluation function H Assuming that the magnitude relationship is H2 <H3 <H1, the transfer instruction b for the automatic guided vehicle 4 is ST7 → ST
2, ST4 → ST6, ST3 → ST5.

In the conventional transfer control device, the transfer system is configured according to the shortest tact time of a plurality of transfer destinations. However, in this embodiment, just-in-time (JI
T) According to the tact time of the destination by control,
Since the priority of the transfer request can be switched, the number of the automatic guided vehicle 4 can be reduced according to the transfer request, and the scale of the transfer system can be reduced.

[0022]

As described above, according to the present invention, in contrast to the conventional large-scale system which requires only an unmanned guided vehicle as long as a transfer request is made, the number of the unmanned guided vehicle is reduced according to the priority of the transfer request of the unmanned guided vehicle. And the size of the transport system can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a transport system for explaining an embodiment of the present invention and a functional explanatory diagram thereof.

FIG. 2 is a block diagram of a transport system for explaining a conventional transport control device and an explanatory diagram of its functions.

FIG. 3 is a functional block diagram of a transport system for explaining another transport controller of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transport request generation part 2 Transport control part 3 Tact time database 4, 4a, 4b Automatic guided vehicle 5 Priority ordering part 6 Evaluation function calculation part 10-13 Transport path 14 Load station 15-17 Unload station 18-20 Standby area 21 Host computer 22, 23 Conveyed object 24 Signal line

Continuation of the front page (56) References JP-A-62-85305 (JP, A) JP-A-3-51300 (JP, A) JP-A-63-128404 (JP, A) JP-A-63-225005 (JP) JP-A-63-116215 (JP, A) JP-A-63-120061 (JP, A) JP-A-2-12501 (JP, A) JP-A-5-94212 (JP, A) 10-214115 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G05D 1/02

Claims (3)

(57) [Claims] 1. A transfer control device for an automatic guided vehicle that optimally controls a plurality of automatic guided vehicles for transporting each of the transferred items, wherein the transfer request is generated by designating a source and a destination of the transferred item. A generating unit, and a transport control unit that instructs the automatic guided vehicle to a traveling route from the transport request in accordance with a predetermined priority order .
Of each transport request corresponding to the minimum time interval for
Tact tie that stores wait time as tact time
Time database and this takt time database
From the tact time of the
Evaluation that outputs the difference from the time up to the time as an evaluation function
A function calculator and a smaller calculation result of the evaluation function calculator.
Priority to determine the priority of each transport request in order from
The transfer control device of the automatic guided vehicle, characterized in Rukoto which have a and ranking means. 2. Each evaluation function Hn is defined by each tact time t.
n, the current time To, the transport request generation time Tn and the time Hn = tn- (To-Tn) automated guided vehicle conveyance control apparatus according to claim 1, wherein. 3. A conveyance control method of the automatic guided vehicle to optimally control a plurality of AGV for transporting the conveyed object, issue the transfer request with the transport origin and the transport destination of the transported object, wherein each Equivalent to the minimum time interval for transporting conveyed objects
Pre waiting time of the respective transport request to the tact time
These tact times and the transport
Evaluate the difference between the request generation time and the current time
Output as functions, and the operation results of these evaluation functions
A transfer control method for an automatic guided vehicle , wherein the priorities of the transfer requests are determined in ascending order .