JPH05181873A - Automatic process design system - Google Patents

Abstract

PURPOSE:To provide an automatic process design system which enables anyone to easily design optimum processes of high production efficiency in a short time. CONSTITUTION:In an automatic process design system main body 1, attribute data such as works, work priority levels, the tact time of each work, a restrictive condition, and an additional time of the restrictive condition which are inputted from an input/output part 6 are stored. A priority level setting part 4 sets priority levels based on attribute data stored in an input data storage part 2 and information in a knowledge base 5. A process design generation part 3 determines the execution order of processes based on data stored in the input data storage part 2 and priority levels set by the priority level setting part 4. The result of the process design due to the process design generation part 3 is displayed on a display part 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic process design device for automatically determining the order of work processes in assembling or processing an article.

[0002]

2. Description of the Related Art In recent years, automation of product assembly has been actively carried out in factories. In order to automate product assembly, the assembly order must first be determined.
However, this assembling order is not determined in a unified manner depending on the product, and there are many assembling orders depending on the position and shape of each component. For example, when assembling the parts A, B, C, and D, it is possible to assemble in the order of A → B → C → D.
Frequently, the situation is such that it can be assembled in the order of C → B → D.

Conventionally, when determining such an assembly sequence, for example, the following method is used. That is, the total takt time is calculated for each of the various assembling orders, and as a result, the assembling order with the shortest total takt time is selected.

[0004]

However, as the number of assembling operations increases, the kinds of assembling sequences that can be assembled explosively increase, and further, various operations such as finger replacement and jig attitude change due to assembly work surface modification are required. It is necessary to calculate including such factors. Therefore, as in the above-described conventional example, it often happens that it is almost impossible for a human to calculate the total tact time for each assembly sequence.

The present invention has been made in view of the above-mentioned conventional example, and provides an automatic process designing apparatus which enables a person other than an expert to easily perform optimum process designing with high production efficiency in a short time. The purpose is to

[0006]

In order to achieve the above object, an automatic process designing apparatus according to the present invention stores a plurality of input work processes and preceding order information and attribute information of each work process. Storage means, priority setting means for setting priority conditions based on the attribute information of each of the work processes stored in the storage means, precedence information stored in the storage means, and the priority And a process designing unit that determines an execution sequence of the work processes based on the priority condition set by the setting unit.

Further, according to another invention, the attribute information in the storage means includes a target cycle time, and the process design means is set by the precedence order and the priority order setting means stored in the storage means. The execution order of the work processes is generated based on the priority and compared with the target cycle time, and the execution order that matches the target cycle time is determined. In the present invention, the adaptation to the target cycle time refers to the order of execution of the work processes that achieves the target value or becomes the value closest to the target value.

According to another aspect of the invention, the above automatic process designing apparatus further comprises a knowledge base for storing knowledge and know-how about process designing, and the priority setting means is stored in the storage means. Priorities are set based on the attribute information of each work process and the knowledge base.

[0009]

In the above structure, when the user inputs the precedence information indicating the context of each process and the attribute information, the precedence condition and the precedence information set on the basis of the inputted attribute information are combined with each other. Based on this, the execution order of the input steps is determined.

In addition, in the structure according to another aspect of the invention, in addition to the above-described operation, the target cycle time is further input, so that the process sequence is determined by the priority condition of the lower priority until the target cycle time is satisfied. To go.

Further, in the configuration according to another invention, the priority condition is automatically set optimally based on the information stored in the knowledge base and the inputted attribute information. Then, the process order is determined based on the automatically set priority condition and the preceding order information.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the overall construction of an automatic process designing apparatus according to this embodiment. 1 is the main body of the automatic process design system. Automatic process design system body 1
Has an input data storage unit 2, a process design creation unit 3, a priority order setting unit 4, and a knowledge base 5. The input data storage unit 2 and the priority order setting unit 4 input data from the input / output unit 6. Things are possible. A display unit 7 displays processing results and the like according to the display output of the input / output unit 6. A keyboard 8 and a mouse 9 are connected as input devices to the input / output unit 6 to input various process data and build a knowledge base. The input data storage unit 2 stores the takt time of each work, the attribute data of each work, the constraint condition, the additional time of the constraint condition, and the like.

FIG. 3 is a diagram showing an example of the contents stored in the input data storage unit 2. The takt time is the time from the start to the end of each process. As the finger name, the type of finger corresponding to the work to be assembled in each process is registered. When the finger names are different in two consecutive processes, the finger exchange operation is performed between the processes. This finger replacement operation causes additional time. The assembling work surface indicates the direction of the work to be assembled in each process. That is, upper, left, right, front, and rear are registered for each work, and if the assembly work surface is different in two consecutive processes, the assembly work surface conversion operation is performed between the processes. This assembly work surface conversion operation causes additional time.

For work properties, "messy" is entered for low clean work such as grease coating, "clean" is entered for high clean work, and "normal" is entered for other works. Usually, it is preferable to perform "messy" work and "clean" work continuously. When the entire process is performed by a plurality of robots, it is desirable that at least the same robot perform at least the same cleanliness. The No. of the process before each process is registered as the preceding work No. The No. of the process after each process is registered as the subsequent work No.

The priority order setting unit 4 sets what is prioritized when determining the execution order of processes in process design based on the knowledge base 5 regarding knowledge, experience and know-how.
An example is shown in FIG. In FIG. 2, the smaller the number, the higher the priority. In other words, the finger replacement minimization has the highest priority, the posture change minimization due to the work surface modification then the minimization, and then the work property priority and the work assembly priority. In FIG. 2, the priority is different for all constraint conditions, but it is not always necessary to do so, and there may be a plurality of those having the same priority.

The process design creation section 3 is composed of the input data storage section 2
Based on the data stored in and the priority set by the priority setting unit 4, the execution order of the processes input to the input data storage unit 2 is determined and the process design is executed.

FIG. 4 shows a basic flowchart of process design creation according to this embodiment. The operation of the automatic process design apparatus will be described in more detail below by presenting specific examples (FIGS. 5 and 6) with reference to the figure.

(Step S101): Data input As input data, (1) assembly precedence order diagram (showing the precedence relation of the assembly order between the assembly parts), (2) each work attribute data including the work takt time, (3) Additional time,
(4) The target production tact is input using the input device of the input / output unit 6 such as the keyboard 8 and the mouse 9.

As a concrete example, the base unit shown in the assembly drawing of FIG. 6 will be described. FIG. 5 shows an assembly precedence chart of the base unit shown in FIG. 6 and work attribute data such as takt time for each process. This base unit consists of 10 assembly operations.

In FIG. 5, after the work of,
It indicates that any of the tasks in (1) can be assigned. Also, the work of, for example, indicates that the work of ,, can only be allocated after the work has already been allocated. Based on the preceding relationship between each work like this,
Allocation is performed in various orders, and the optimum process order is extracted.

Further, in FIG. 5, as work attribute data of each process, four data of (1) process name, (2) work takt time, (3) finger name, and (4) assembly work surface name are stored. Shown next to work.

Next, as additional time, (1) finger exchange time is set to 2.0 seconds, and (2) posture change time due to change of the assembly work surface is set to 1.0 second. Furthermore, the target production tact upper limit value for each robot (station) is set to 10.0 seconds. Further, the lower limit value of the target production tact indicating the allowable range of the target production tact is set to 9.0 seconds.

(Step S102): Initialization of data From the inputted assembly precedence order diagram (FIG. 5), precedence relationship data between each work is created. Further, the weight (W) of each work is set from each work attribute data and the preceding relationship data. The weight W of each work is expressed by the following formula: W = work takt time + (number of subsequent elements × 10). For example, the work weight (W ₂ ) is W ₂ = 1.0 + (1 × 10) = 11.0.

In addition, priorities are set in this step. The setting of the priority order is performed based on a knowledge base that stores process design knowledge and know-how. As an example of setting the priority order, the priority order setting method in this embodiment gives priority to the finger replacement time and the attitude change time, whichever is larger. If the finger replacement time and the posture change time are the same, the larger one of the input finger type and the assembling direction is prioritized. In the present embodiment, the finger replacement time is 2.0 seconds and the posture change time is 1.0 seconds, so the finger replacement minimization is prioritized.

(Step S103): Extraction of Candidate Work A candidate work that can be allocated is extracted based on the current allocation status and the precedence relation. In the case of this embodiment, the first step is the work of. Also, next to the step of,
, Are extracted as candidate works.

(Step S104): Candidate check Adds the takt time of the candidate work to the total takt time (current takt: T) by the processes allotted up to the present, and the provisional present takt time when this candidate is allocated. Find (t).

In this case, the finger name and assembly work surface name of the final work for which allocation has been confirmed and the finger name and assembly work surface name of the candidate work are defined in the following four patterns (A) to (D). The temporary tact (t) is determined by checking.

Pattern (A): When finger name and assembling work surface name are the same, t = T + candidate work tact time Pattern (B): When finger name is the same and assembling work surface name is different, t = T + Candidate work tact + posture change time pattern (C): When the finger names are different and the assembling work surface names are the same, t = T + candidate work tact + finger replacement time pattern (D): finger name and assembling work surface name If they are different, t = T + candidate work tact + (finger replacement time or posture change time, whichever is larger). Candidate check is performed using the temporary current tact (t) determined by the above four patterns. .. The check method is
The temporary current tact (t) is compared with the target cycle time. Then, if there is any candidate work for which the provisional current tact (t) ≦ target cycle time is present, the process proceeds to step S105, and if not, the process proceeds to step S109.

(Step S105): Candidate work narrowing process based on allocation priority When there are a plurality of candidate works, the candidates are narrowed down to one according to the allocation priority as follows. This candidate narrowing process will be described with reference to the flowchart of FIG.

(Step S201): Priority check process In accordance with the priority order determined in the above step S102, the candidate work remaining after the process in step S104 is set to 1
This is a process for narrowing down to one, and (1) selects a candidate that satisfies a condition of high priority. In this embodiment, since the priority of finger replacement minimization is the highest, the candidate work having the same finger name as the currently assigned work is preferentially selected. (2) One is extracted in (1). If not possible, narrow down the candidate work by the above method of selecting a candidate that satisfies the condition with the next higher priority.

(Step S202): Weight narrowing processing If there are still a plurality of candidate works narrowed down in step S201, step S10 among those candidate works is performed.
The candidate work having the largest weight (W) set in 2 is selected. The candidate work narrowed down to one is determined by the candidate work narrowing down process as described above.

(Step S106): Allocation process of candidate work In step S105, the candidate work narrowed down to one is allocated as the next work. Then, the current tact T is updated to the temporary current tact t checked in step S104.

(Step S107): Check the number of allocated works Compare the number of works allocated so far with the total number of works,
If (number of assigned work up to now) = (total number of work),
The process proceeds to the output of result data in step S108. Otherwise, the process returns to step S103.

(Step S108): Result data output From the allocation data by the candidate allocation work in step S106 or the allocation data of each station (robot) saved by the station change processing in step S110, (1) line balance data, ( 2) Line balance histogram, (3) Process data for each station are created and output.

(Step S109): Cycle time check The current tact t is compared with the target cycle time upper limit value and lower limit value. Target cycle time upper limit value ≧ current tact t ≧
In the case of the lower limit value, the process proceeds to step S110. Otherwise, the process proceeds to step S111.

(Step S110): Station change processing When the allocation contents meet the target cycle time condition or the backtrack end processing is completed, the allocation to the next robot (station) can be performed. , Save the order of allocation work up to now and clear the allocation data. Currently tact is reset to zero.

(Step S111): Backtrack check In the current allocation status, the allocation status is returned to the previous status. At this time, the current tact of the current allocation status and the allocation sequence data are saved.

If the status immediately before the allocation status is the first process of each station (robot), the process proceeds to step S113. Otherwise, the process proceeds to step S112.

(Step S112): Backtrack process In the current allocation status, the allocation status is returned to the previous allocation status, and candidate works other than the current final process are extracted. Then, the process proceeds to step S104.

(Step S113): Backtrack end processing When the backtrack destination is returned to the first process of each station (robot) by the backtrack check, the data saved in the backtrack check of step S111 is used as the current tact time. Select the largest data and delete other data.

The process design is executed according to the flowchart described above. 8 and 9 show the design results by the automatic process designing apparatus when the finger replacement minimization is prioritized in the preceding order diagram and the work attribute data of FIG.

As described above, according to the present embodiment, by building the knowledge and know-how of process design, which was conventionally performed by experts such as system designers, as a knowledge base, even non-experts can optimize it. Can output various process design results.

Further, by giving a target cycle time, the number of stations (robots) required to achieve the target cycle time is automatically set as shown in FIGS. The line balance data and so on are also output, which significantly improves the efficiency of process design.

In the above embodiment, the upper limit value and the lower limit value of the target cycle time are given and the process design is executed so as to achieve these, but the present invention is not limited to this.
For example, only the upper limit value may be given to satisfy this.

Further, the attribute data of each work is not limited to the finger type and the assembling work surface, and various data can be used as the attribute data according to various products and facilities. Further, in the present embodiment, the order of the work process by the robot is determined, but the present invention is not limited to this, and it is also possible to design the process order when a human performs the work.

The present invention may be applied to either a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a system or apparatus with a program for executing the processing defined by the present invention.

[0048]

As described above, according to the automatic process designing apparatus of the present invention, optimum process designing can be performed in a short time. Further, by constructing the knowledge and know-how of process design as a knowledge base, even a person other than an expert can easily perform an optimum process design with high production efficiency in a short time.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an automatic process designing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing constraint conditions in which priorities are set.

FIG. 3 is a diagram showing an example of each work takt time and attribute data registered in an input data storage unit 2.

FIG. 4 is a basic flowchart of an automatic process designing apparatus according to an embodiment of the present invention.

FIG. 5 is a diagram showing an assembly precedence order diagram and work attribute data of a specific example of process design in the present embodiment.

FIG. 6 is an assembly drawing of base unit parts which is a specific example of the process design in the present embodiment.

FIG. 7 is a flowchart of candidate narrowing processing of the automatic process designing apparatus according to the embodiment of the present invention.

FIG. 8 is a diagram showing an example of a process design result by an automatic process designing apparatus that is an embodiment of the present invention.

FIG. 9 is a diagram showing an example of a process design result by an automatic process designing apparatus that is an embodiment of the present invention.

[Explanation of symbols]

 1 Automatic process design system main body 2 Input data storage unit 3 Process design creation unit 4 Priority setting unit 5 Knowledge base 6 Input / output unit 7 Display unit 8 Keyboard 9 Mouse

Claims (3)

[Claims] 1. A storage unit for storing a plurality of input work steps and preceding order information and attribute information of each of the work steps, and a priority order condition based on the attribute information stored in the storage section. Priority setting means for setting, and a process design means for determining the execution order of the work processes based on the precedence information stored in the storage means and the priority condition set by the priority setting means. An automatic process design device comprising: 2. The attribute information in the storage means includes a target cycle time, and the process design means is based on the precedence order stored in the storage means and the priority order set by the priority order setting means. 2. The automatic process designing apparatus according to claim 1, wherein an execution order of the work processes is generated and compared with the target cycle time to determine an execution order that matches the target cycle time. 3. A knowledge base for storing knowledge and know-how about process design is further provided, wherein the priority order setting means sets the priority order based on the attribute information and the knowledge base stored in the storage means. The automatic process design apparatus according to claim 1 or 2, characterized in that.