JPH03154965A - Scheduling method for transfer device - Google Patents

Abstract

PURPOSE:To obtain an excellent transfer schedule by producing plural transfer schedules for an object to be transferred and evaluating and selecting these schedules. CONSTITUTION:A transfer schedule is required in a prescribed procedure and then another schedule better than the former one is required. In such a case, the transfer sequence of the object to be transferred via the better schedule is replace with another. Thus the possibility is increased for acquisition of the better schedule. In this respect, the upper limit number of objects to be transferred and scheduled is previously set so that the total number of transfer schedules which are obtained with replacement the transfer sequence of the object to be transferred and having the transfer schedule set at that time point is equal to the factorial of the upper limit value. Therefore a controller can evaluate and select all transfer schedules. Then an optimum transfer schedule is obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an improvement in a scheduling method for a transport device that transports a plurality of objects one by one at a plurality of service stations on a single linear or circular transport line.

[Conventional technology]

BACKGROUND ART Conventionally, there is a scheduling method for a transport device in which a transport schedule for a plurality of objects to be transported is determined according to a predetermined procedure. This procedure for determining the transport schedule for the transported object includes determining the transport schedule of the transported object by sequentially determining the transport of the transported object at the service station closest to the current position of the transport vehicle or the position at which the transport vehicle is located after the transport operation is completed. There is something called asking for. On the other hand, such a scheduling method for a transport device has a predetermined evaluation procedure and evaluation criteria, lists all the schedules that the transport vehicle can execute at the time of scheduling, and selects from among these schedules. There is a method of selecting the optimal schedule using a comprehensive method according to the evaluation procedure and evaluation criteria described above.

[Problem to be solved by the invention]

However, the conventional scheduling method of the transport device has the following problems. In the method of scheduling the transport device according to the predetermined procedure described above, the idle running time is inevitably the shortest in the first transport immediately after this scheduling. However, the total idle running time in the next conveyance or the next conveyance is not necessarily the minimum, and the idle running time that occurs during conveyance is even shorter than in the above-mentioned procedure for scheduling the conveying device. It is possible to come up with a procedure, but in any case
There is no guarantee that the schedule determined by the transport device scheduling method that follows these predetermined procedures is the optimal schedule. In addition, in the method of comprehensively evaluating all schedules that a transport vehicle can execute, the total number of schedules that must be evaluated is N, where N is the total number of objects that must be transported. It is the factorial of . For example, if there are 7 objects to be transported, the total number of schedules that must be evaluated is the factorial of 7, so a total of 5040 schedules are evaluated in order. I have to do it. When the number of objects that must be transported becomes much larger than 7, the total number of schedules that must be evaluated becomes enormous. It can be seen that there is a problem in that it is impossible to complete the scheduling process within a processing time that can be practically used as a scheduling method.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and the present invention is made in view of the above-mentioned problems in the prior art. If so, it is an object of the present invention to provide a scheduling method for a transport device that can obtain a more optimal transport schedule by determining several transport schedules and evaluating them.

[Means to solve the problem]

The present invention provides a scheduling method for a transport device that transports a plurality of transported objects one by one at a plurality of service stations on a linear or circular sheep transport route, in which the plurality of transported objects are Find a transport schedule for a predetermined number of objects to be transported, use this as the initial solution of the transport schedule, and determine whether to adopt the initial solution of the transport schedule as the determined schedule according to the predetermined evaluation procedure and evaluation criteria. If the determination is to be adopted as the determined schedule, the initial solution of the transportation schedule is set as the determined schedule, and if the determination is not to be adopted as the determined schedule, transportation is performed using the initial solution of the transportation schedule. The above objective is achieved by finding the optimal solution for the transportation schedule from among all combinations of the transportation order of the objects to be transported and using this as the determined schedule.

[Effect]

In the present invention, when a transport schedule is obtained according to a predetermined procedure and an attempt is made to obtain a schedule that is better than this transport schedule, the transport order of the objects to be transported according to this transport schedule is determined. This study focuses on the fact that there is a high possibility that a better transport schedule can be found by performing replacement. When performing transport scheduling according to this predetermined procedure, if the upper limit of the number of transported objects to be schedule-linked is determined in advance, the transport created by changing the transport order of the transported objects in the transport schedule obtained at this time can be set in advance. The total number of schedules is the factorial of this upper limit, so
It is possible for the control device to evaluate and select all such transport schedules. For example, if the upper limit of the number of objects to be transported is 4, the control device only needs to create, evaluate, and select 24 transport schedules, which is the factorial of 4.

[Embodiment] A transport control device that is an embodiment of the scheduling method for a control device of the present invention will be described below with reference to the drawings. In Fig. 2, the transport route 3 is the service station S.
Seven service stations from T1 to service station s'r7= are connected. The conveyance vehicle 4 loads and unloads the conveyed object C at positions on the conveyance line 3 of seven service stations from service station STI to service station s'r7t, and from service station STI to service station ST7m. At each of the three service stations, when an object C is carried in and a transport request is issued, the destination station number reader 12 disposed at the service station reads the destination station number tag attached to the object C. 6, the destination station number of this transported object is read. In FIG. 3, the transport control device 1o performs the processing of a transport request reception processing device 14, a transport schedule creation processing device 20, and a transport vehicle running control processing device 24. When a transport request is issued at each service station, the transport request reception processing device 14 inputs the transport destination station number of the transported object read by the transport destination station number reader 12, and inputs the transport destination station number of the transported object and the service station number that performed this reading. The transport destination station numbers are combined and output to the transport request queue list main memory M. When the transport request queue processing device MC0n in the transport request queue list memory M inputs the data from the transport request reception processing device 14, it transfers the data of the transport destination station number to the service station number where the transport request was made. It is stored in the corresponding transport request queue (any one of Ml to Ml). Transport vehicle 4
The current right position of the transport vehicle 4 is constantly input to the transport control device 10, and the transport vehicle running control processing device 24 stores the current position of the transport vehicle 4 in the transport vehicle position memory 26. When the predetermined conditions are satisfied and the force is applied, the conveyance schedule creation processing device 20 performs the operations shown in FIG. 1 (A> and (B)
The process of creating a transport procedure is performed according to a predetermined procedure as shown in the flowchart shown in FIG. be remembered. When the conveyance schedule creation processing device 20 completes the data setting of the conveyance schedule in the conveyance procedure memory 22, the conveyance vehicle running control processing device 24 starts the conveyance vehicle 4.
Processes the operation and travel processing of the The transport schedule creation processing device 20 in the transport control device 10 performs processing as shown in the flowcharts in FIGS. Transport request cue list memory M and transport vehicle position memory 2 according to a procedure predetermined by
One transportation schedule is created while referring to the data from step 6, and this is used as the initial transportation schedule solution. The evaluation process A32a calculates the evaluation function F of the transport schedule created in the initial group process 30 according to a predetermined evaluation procedure and calculation formula. Evaluation process B52b calculates the number of evaluations F calculated in evaluation process A32a according to predetermined evaluation criteria.
Then, it is evaluated whether the transport schedule created in the initial group processing 30 can be used as the determined schedule. If the evaluation decision made in the evaluation process B52b is to adopt the decision schedule, the decision schedule process A34 is performed in the initial group process 30.
The transportation schedule created in is adopted as the decision schedule. If the evaluation decision in the evaluation process B52b is a decision that the determined schedule is not adopted, the exhaustive process 36 performs the exhaustive process 36 to cover the objects within the range to be transported using the initial solution of the transport schedule created in the initial group process 30. We create a transportation schedule by assembling all the permutations of items to be transported.
The transport schedule with the lowest evaluation function F is determined, and this is set as the transport schedule of 5CHi. Then, in the decision schedule process B38, the transport schedule 5CHi created in the exhaustive process 36 is set as the decision schedule. The subroutine processing shown in FIG. 1(B) for the initial preprocessing is performed as follows. Initial set processing 3
In step 0a, variables i and Pi are initialized, and in C1 determination processing 30b, the transported object Ci located at the service station closest to the transport vehicle position P is determined. In the 5T-No setting process 30c, the value of the transport vehicle position P1 is set as the destination station number of the object Ci to be transported, and the value of the variable i is increased by one.In the loop end check process 30d, the value of the variable i is
The end of the loop is checked by determining whether or not the value has become larger than 4. In the transport procedure creation process 30e, a transport schedule 5CHo is determined from the four objects C obtained through a loop process including the Ci determination process 30b, the 5T-No set process 30c, and the loop end check process 30d. Hereinafter, the operation of the conveyance control device for carrying out the present invention will be explained using the drawings. In the initial state, the transport vehicle 4 is at the service station ST.
3, the transported object C1 to be transported to the service station ST2 is located at the service station ST3, the transported object C2 to be transported to the service station STI is located at the service station ST2,
Object C3 to be transported to service station ST5
is located at the service station ST4, the transported object C4 to be transported to the service station ST3 is located at the service station ST5, and the transported object C5 to be transported to the service station ST6 is located at the service station ST7. A transport request for the object to be transported has already been issued. The fact that the current position of the transport vehicle 4 is the position of the service station ST3 is stored in the transport vehicle position memory 26 by the transport vehicle running control processing device 24. Further, the service station numbers to which the objects C1, C2, C3, and C1 2 4 are carried in and the respective destination station numbers are determined by the transport request reception processing device 1.
4 is stored in the corresponding station queue (any one of M1 to M1) in the transport request queue list memory M. In such an initial state, the transport schedule creation processing device 20 performs the processing shown in the flowcharts of FIGS. 1(A) and 1(B), and schedules the transport schedule as follows. In the initial state, the transport vehicle 4 is at the service station ST3.
Therefore, the initial pre-processing 30 is carried out at the service station ST3 as the transported object constituting the transport schedule.
The conveyed object C1 at the position is determined. Since this first conveyed object C1 is to be conveyed to the service station ST2, the position of the next conveyance vehicle 4 becomes the position of the service station ST2. The initial preprocessing 30 determines the object C2 located at the service station ST2 as the object constituting the second transport schedule. Since this object C2 is to be transported to the service station STI, the next position of the transport vehicle 4 will be the position of the service station STI. The initial preprocessing 30 determines the object C3 located at the service station ST4 closest to the current transport vehicle position as the object constituting the third transport schedule. Since this object C3 is to be transported to the service station ST5, the next position of the transport vehicle 4 will be the service station ST5. The initial preprocessing 30 determines the object C4 located at the service station ST5, which is the current position of the transport vehicle, as the object constituting the fourth transport schedule. Since this conveyed object C4 is to be conveyed to the service station ST3, the next position of the conveyance vehicle 4 is the service station ST3.
becomes. In this way, the initial pre-processing 30 is performed in the order of C1 and C2 for the four objects to be transported before the initial stage of the transport schedule.
, C3, and C4 are obtained. Note that here, since the upper limit of the number of transported objects constituting the transport schedule is 4, the transported object C5 is not included in the transport schedule. Next, the evaluation process A32a obtains an evaluation function of the transport schedule for the objects C1, C2, C3, and C4 obtained in this way, but this evaluation function F is generated when the transport schedule is actually executed. This is the total free running distance. The movement of the conveyance vehicle 4 when the initial solution of this conveyance schedule is executed is as shown in the trajectory diagram of the movement of the conveyance vehicle 4 in the center of FIG. , the total of the idle running process when represented by the dotted line in FIG. 2 is 3°C. That is, the evaluation function F(SC
The value of Ho) is 3J2. Evaluation process B521] performs this evaluation by determining whether the value of the evaluation function F (SCFo) of the initial solution of the transport schedule is smaller than a predetermined evaluation standard (=2J2). As mentioned above, the number of evaluation intervals F for the initial solution of this transport schedule
The value of (SCHo) is 3℃, which is the evaluation standard 2
Therefore, the evaluation process B52b determines that the initial solution of the transportation schedule is not adopted as the determined schedule. Due to such evaluation and determination, the flow of processing in the flowchart of FIG. 1(A) then becomes exhaustive processing 36. The exhaustive process 36 creates a transport schedule by listing all permutations of the transported objects CI, C2, C3, and C4 selected in the initial preprocessing 30, and selects the transport schedule from which the evaluation function F is the smallest. Find the schedule and check this on 5CH
i, the best transport schedule determined by this method is for the four objects 03, C4, and C.
They are arranged in the order of I and C2, as shown in the locus diagram of the movement of the transport vehicle 4 on the right side of FIG. The total empty running distance of the transport vehicle 4, which is represented by a dotted line in FIG. 2, is IJ2 in the procedure determined by the comprehensive processing 36. As a result, the value of the evaluation function F in the transport schedule obtained through exhaustive processing is 1°C, and this value is higher than the value 3 of the evaluation function F of the initial solution of the transport schedule. It is small and smaller than 2° C., which is the evaluation standard used in the evaluation process B52b. Determination schedule processing 838 converts the transportation schedule obtained in this exhaustive processing 36 into determination schedule S CH
t and is stored in the transport procedure memory 22. As described above, the transport control device in this embodiment schedules the transport schedule, and the transport vehicle running control processing device 24 controls the movement and running of the transport vehicle 4 based on the determined schedule obtained thereby. . By performing the above-described transportation device scheduling method, it is possible to obtain multiple transportation schedules in a relatively short processing time and to determine the best operation procedure that results in the smallest evaluation function value among them. The exhaustive processing 36 in this embodiment is 2, which is the factorial of 4.
It is possible to create four transport schedules and evaluate and select them in order.6 However, instead of using this method, we created and evaluated all possible transport schedules for all transport requests from service stations. In this method, if transport requests were received from all seven service stations, it would be necessary to create and evaluate 5040 transport schedules, which is the factorial of 7. The method in the example can be said to be quite superior in terms of processing speed. Effects of the Invention As described above, according to the present invention, a plurality of transport schedules for target objects to be transported are created and evaluated and selected within the control device processing time allowed as a scheduling method for the transport device. This has made it possible to obtain better transport schedules. The ability to improve the quality of the scheduling process and shorten the processing time in the scheduling method for the transport device in this way has great industrial significance.

[Brief explanation of the drawing]

Figures 1 (A) and (B) are flowcharts showing the transport schedule creation process of the transport control device for implementing the present invention, and Figure 2 shows the positions of the transport vehicle and the service station, and the movement trajectory of the transport vehicle. FIG. 3 is a block diagram showing the above-mentioned conveyance control device. 32a...Evaluation process A, 32b...Evaluation process B,
34... Determination schedule processing A, 36..., 11i! 38... Determination schedule processing B, STI~ST7... Service station, C1~C
5... Object to be transported, M... Transport request queue list memory, M con.
...Transportation request queue processing device, M1 to M7...Transportation request queue 3...Transportation route, 4...Transportation vehicle, 10...
-Transportation control device, 20...Transportation schedule creation processing device, 22...
Transport procedure memory, 26... Transport vehicle position memory, 30... Initial waste processing, 30a... Initial set processing, 30b... Ci determination processing, 30G... 5T-No set processing, 30d...・Loop end check processing, 30e...Transportation procedure creation processing,

Claims (1)

[Claims] (1) In a scheduling method for a transport device that transports multiple objects one by one at multiple service stations on a single linear or circular transport line, the multiple objects are transported one by one according to a predetermined procedure. A transport schedule for a predetermined number of objects to be transported is obtained, this is used as an initial solution of the transport schedule, and it is determined whether the initial solution of the transport schedule is adopted as the determined schedule according to a predetermined evaluation procedure and evaluation criteria. If the determination is to be adopted as the determined schedule, the initial solution of the transportation schedule is determined to be the determined schedule, and if the determination is not to be adopted as the determined schedule, the target to be transported by the initial solution of the transportation schedule is determined. A method for scheduling a transport device, characterized in that an optimal solution for a transport schedule is found from among all combinations of transport orders of objects to be transported, and this is used as a determined schedule.