JPH087765B2 - Work alternative method of LAN integrated production system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a work alternative method for a LAN integrated production system, and particularly when the equipment in the system fails, the increase in the delivery delay due to the equipment failure is minimized. Work alternative method for doing.

[Conventional technology]

In the conventional production system, the host computer 1 controls the devices 2-1 to 2-n in the system as shown in FIG. Only communication between the devices 2-1 to 2-n was possible. Further, when any of the devices 2-1 to 2-n in the system fails, the host computer 1 needs to change the work plan of the entire system. The system cannot be controlled during the changing operation, and in the worst case, the system may be deadlocked. Therefore, as shown in FIG. 1, a distributed control system in which the host computer 1 and the devices 2-1 to 2-n in the system are connected by LAN4 has been devised (Proceedings of the Precision Engineering Society Autumn Conference 1987 P865). reference). In this case, the first
As shown by an arrow 3-1 in the figure, communication is performed not only between the host computer 1 and the devices 2-1 to 2-n but also between any devices 2-1 to 2-n in the system. Therefore, if the device 2-1 in the system fails,
By communicating between the device 2-1 and the normal devices 2-2 to 2-n, the failed device 2-1 substitutes its own work for another device 2-2 to 2-n. You can However, there was a problem that it was difficult to minimize the increase in delivery delay due to the change of the work plan at that time, because the work alternative method at that time was not clarified (precision in 1988. Proceedings of the Spring Meeting of the Engineering Society P459).

[Problems to be Solved by the Invention]

The work alternative method of the above-mentioned conventional LAN integrated production system is that the failed device communicates with another device,
I was able to substitute my own work for other equipment, but at that time, I did not consider the delivery time of each work, and interrupted the work to a specific equipment by the priority that was set first, so that There was a problem that the delivery delay of the work increases due to the change of the work plan.

An object of the present invention is to prevent an increased load of work due to equipment failure by minimizing the load concentrated on a specific equipment by updating the work plan in consideration of the delivery time of the work of the failed equipment. It is to provide a work alternative method that is characterized by the limitation.

[Means for solving the problem]

A work alternative method of a LAN integrated production system according to the present invention is a work plan and a failure occurrence history of a first device in which a failure has occurred in a plurality of devices specified in the work plan, and the first device. Candidate device name for substituting the above work and the first
Information of a work substitution record indicating which work is accepted as a substitute work by the second device that substitutes the work of the first device, and the first device requests another device to substitute its own work. Cases and devices other than the first device are the first device
In the work replacement method of the LAN integrated production system including the equipment having the means for performing the communication procedure in the two cases when the work replacement is requested from the equipment, the first equipment communicates with other equipment. In order to satisfy the delivery time of the own work, the work substitute means for interrupting the own work during the idle time of the work of the second equipment that has received the substitute work, and the work held by the second equipment Work plan recreating means for recreating the work plan is provided so as to minimize an increase in delivery delay of the work which may occur due to the plan change.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.
First, FIG. 1 shows an example of a production system. This production system includes a host computer 1 and devices 2-1 to 2-n.
Are connected by the LAN 4, so that the devices 2-1 to 2-n can communicate with each other via the LAN 4, as indicated by an arrow 3. FIG. 2 shows the data structure of each of the devices 2-1 to 2-n. Each device in the system 2
Each of -1 to 2-n is operated by its own control program 5.

For example, assume that the device 2-1 has failed. The device 2-1 follows the possession information 6 and the communication procedure 7 when transmitting the work alternative request,
Equipment 2-2 to 2-n to search for alternative equipment for own work
Communicate with. The devices 2-2 to 2-n follow the possession information 6 and the communication procedure 8 when the work alternative request is received, and the failed device 2-
It is checked whether the work of item 1 can be replaced, and the result is returned to the faulty device 2-1. When the failed device 2-1 receives the reply that the work cannot be replaced, another device is inquired.

Here, it is assumed that the device 2-2 replies that work replacement is possible. The device 2-1 having received it transmits its own work plan to the device 2-2. Then, the device 2-2 receives the work plan of the work to substitute from the device 2-1 and updates its own work plan.

Next, the possession information 6 of the devices 2-1 to 2-n will be described.

The item a of the possession information 6 shows the part number of the work to be worked, its working time and delivery date. Based on its own work time and delivery date, the failed device makes a substitute request for work to each device in the same delivery date, before delivery date, and after delivery date, and searches for a device that can interrupt that work. It should be noted that these pieces of information have been received from the host computer in advance and are updated every time work replacement is performed.

Item b of the possession information 6 indicates a device that can substitute the work of the device when the device fails. Note that this is received from the host computer in advance, and when a failure occurs, it is referred to and the requested substitute device for work is determined.

Item c of the possession information 6 is a classification of the time from the occurrence of a failure in the device to the recovery by failure, predicting the recovery time from the failure, and substituting for another device in the operation of the failed device. It is used to determine the requested range.

The item d of the possession information 6 is a record of from which device the substitute work is accepted. Then, when the device for which the work replacement is requested recovers from the failure earlier than the scheduled recovery, the device for which the work is requested is used to send the work back to the recovered device.

Next, FIG. 3 shows a communication procedure 7 at the time of transmitting the work alternative request held by the devices 2-2 to 2-n.

The faulty device refers to the above-mentioned possession information and makes substitution requests in the order of high priority under the same conditions (steps 11, 14, 1).
7). The conditions take into account the delivery time of the work for which the substitute request is made, and the alternative device that can finish the work according to the original delivery date (step 11) and the alternative device that can finish the work before the original delivery date (step 14). , And the order of alternative devices (step 17) that can finish the work after the initial delivery date.

When the device that received the work replacement request replies that work replacement is not possible (NO in steps 12, 15, and 18), the presence or absence of another replacement candidate device under the same conditions is referred to. If they do not exist under the same conditions (NO in steps 13 and 16), the substitute request is made under the following conditions. If there is no alternative candidate device (N in step 19)
O), end without doing anything. If there are alternative candidate devices (YES in steps 13, 16, and 19), the alternative request is made to the device (steps 11, 14, and 17). If the device that requested the replacement is permitted to interrupt the work (YES in steps 12, 15, and 18), refer to the failure history and refer to the work plan data in the range until the failure is considered to be recovered. Is transmitted to the alternative device (step 20).

Next, FIG. 4 shows a communication procedure 8 held by the devices 2-1 to 2-n when transmitting a work alternative request in the form of a flowchart.

When a work replacement request is received from a device that has malfunctioned (step 31), it confirms whether work replacement is possible by referring to its own status (step 32). If work replacement cannot be performed (NO in step 33), a response indicating that substitution is not possible is made (step 34), and the process ends. If work replacement is possible (YES in step 33), a work replacement possible response is sent (step 35). Then, the work plan of the substitute request device is received,
Update your work plan (step 36).

Next, FIG. 7 shows a conventional work substitution result in which the work delivery date is not considered, and FIG. 5 shows a work substitution result in consideration of the work delivery date in the present invention in the form of a Gantt chart.

This is based on the assumption that the device A breaks down while the devices A, B, and C are working, and the work of A2 to A4 is replaced by another device.

The left part of FIGS. 7 and 5 shows the load condition of each device before the device A fails, and the right part of FIGS. 7 and 5 changes the work plan after the device A fails. The load status of each device is shown. In FIG. 7, the work A _{2 to} A ₄ of the broken device A is replaced by the work of the device B without considering the delivery date of the work.
Since the work is interrupted between B ₁ and B ₂ , the substitute work is concentrated on a certain specific device (device B), and the delivery of the work B ₂ is delayed. However, in FIG. 5, in consideration of the delivery time of the work, the work A _{2 to} A ₄ of the defective device A is interrupted in the idle time of the work of the devices B and C, so that the delivery time of the work is not delayed. It shows the state.

In this way, when a device in the system breaks down and the work plan is changed, it is possible to minimize the increase in the work due to the delivery delay due to the change of the work plan.

In addition, when changing the work plan, the load on the host computer can be reduced.

〔The invention's effect〕

As described above, according to the present invention, by providing each device in the system with the information and communication procedure necessary for performing work substitution, when some device in the system fails, a failure occurs. When the generated equipment communicates with other equipment and can substitute its own work for other equipment in consideration of the delivery date of the work, and when the equipment in the system breaks down and the work plan is changed, the work This has the effect of minimizing the increase in late delivery work due to plan changes.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
FIG. 3 is an explanatory view showing a data structure held by each device of one embodiment of the present invention, FIG. 3 is a flowchart of a communication procedure at the time of transmitting the work alternative request of FIG. 2, and FIG. 4 is at the time of receiving the work request of FIG. FIG. 5 is a flow chart of the communication procedure, FIG. 5 is a Gantt chart showing the result of the work substitution of the embodiment of FIG. 1, and FIG.
FIG. 7 is a Gantt chart showing the result of work substitution of the work substitution method of the conventional LAN integrated production system of FIG. 6 in the block diagram of the work substitution method of the LAN integrated production system. 1 ... Host computer, 2-1 to 2-n ... Equipment,
3 ... Arrow, 4 ... LAN, 5 ... Control program, 6 ...
… Holding information, 7 …… Communication procedure when sending work replacement request, 8
...... Communication procedure when receiving work replacement request, 9-1 to 9-n ...
… Arrow.

Claims (1)

[Claims] 1. A work plan and a failure occurrence history of a first device in which a failure has occurred among a plurality of devices specified in the work plan, and alternative candidate devices for substituting the work of the first device. Name and a work substitution record indicating which work is accepted as a substitute work by the second device which substitutes the work of the first device, and the first device substitutes its own work. Integrated production equipped with a device that has a means for performing a communication procedure in two cases when requesting a device other than the first device and when a device other than the first device is requested to substitute the work by the first device In the work replacement method of the system, the second device has received the replacement work so that the first device can satisfy the delivery date of its own work by communicating with other devices.
Alternative means for interrupting own work in the idle time of the work of the second device, and the increase of the delivery delay of the work which may be caused by the change of the work plan held by the second device is minimized. Thus, there is provided a work plan recreating means for recreating the work plan, as described above, a work alternative method for a LAN integrated production system.