JPS6251505A - Control system of transferring machine - Google Patents

Abstract

PURPOSE:To improve an amount of a material passing, by a method wherein, in control of a transferring machine, e.g., a FA system robot a stock rate of a buffer between a present and a preceding process is grasped, and when the stock rate exceeds a given value, materials on a conveyor are processed in priority. CONSTITUTION:The state of a temporary stowing equipment A is decided, and when it is normal and there are materials, the temporary stowing equipment A forms a proposed place to be grasped. If materials are present on a conveyor 106 and are materials to be processed by a processor 10, materials 102 on the conveyor 106 form a proposed material to be grasped. In which case, if materials in the temporary stowing equipment A and the materials 102 on the conveyor 106 are both proposed materials to be grasped, a stock rate of a buffer 104 between processes is confirmed. If the stock rate exceeds a given value alpha%, the materials on the conveyor 106 are grasped in priority, and a transferring machine 107 is controlled. If the stock rate is below alpha%, the materials in the stowing equipment A are processed in a way that materials outgo in the order of incoming. This constitution improves an amount of the material passing.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a robot used in an FA system,
Concerning control methods for transfer equipment such as cranes.

[Background of the invention]

In order to clarify the problems with the conventional system, first an overview of the FA system to be controlled will be explained using FIG.

The area to be controlled is one of the shops (processes) such as assembly and processing, and it is area 101 in the figure.
corresponds to The material 102 is the pre-process 1 of the area 101.
It flows from 03. In addition, the pre-process 103 and area 10
An inter-process buffer 1.04 is installed between each process so that load smoothing can be performed independently of other processes.

The processing machines 105 are lined up beside the conveyor 106. It is fed from the inter-process buffer 104 and transferred to the conveyor 10.
The material 102 that has flowed over the material 102 is grabbed by a transfer machine A107 and unloaded onto a cart 108.

The cart 108 carries the material 102 and moves to the processing machine 105. The processing machine 105 transfers the material 102 to a cart 108
Process it while it is on. When the processing is completed, the trolley 10
8 moves to the transfer machine B109. Transfer machine B109
grabs the material 102 from above the cart 108 and returns it to the conveyor 106. In this way, to simplify the flow of goods (
transfer machine A107 is conveyor 10
The transfer machine B109 transfers only the material 102 from the processing machine 105 to the conveyor 106.
Only 02 movements are performed.

Various materials 102 flow on the conveyor 106 . Material 1
02, the group of processing machines 105 to be passed through differs depending on the type. Therefore, some materials 102 pass directly in front of the processing machine 105 shown in FIG. 1, while others are taken into the processing machine 105 as described above.

Now, let us consider a case where a material 102 (referred to as material M) to be taken into the processing machine 105 is flowing on the conveyor 106, and a material (referred to as material N) that passes through immediately after the material M is flowing. If the cart 108 is not empty, the material M has no destination and must wait on the conveyor 106. This waiting hinders the movement of material N. As a result, the amount of material passing through is reduced. In order to solve this problem, a temporary storage facility A110 is provided between the conveyor 106 and the trolley 108 as a place to save the material 102. In the above-mentioned situation, the material M
A transfer machine A107 transfers the data from the conveyor 106 to the temporary storage facility A107. When the trolley 108 becomes empty, the transfer machine A
107 transports the material M from the temporary storage facility A110 to the trolley 108.
Move to.

The temporary storage facility B111 is also a temporary storage facility between the trolley 108 and the conveyor 106 and has almost the same function as the temporary storage facility All0.

The materials 102 processed in this area 101 are sent to a shipping site 112 where the materials 102 are assembled by destination.

Now, the main control purposes of the FA system mentioned above are 2.
There is one. The first objective is to maximize the amount of material passing through. Specifically, the aim is to improve the operating rate of processing machines. The second objective is to reduce the time required to assemble materials destined for the same destination. In other words, in order to reduce the load on the assembly work, the materials that are sequentially introduced into the area 101 for the same destination are not dispersed. Note that the first purpose is
Since this is given priority over the purpose of the above, first-in, first-out control is carried out to prevent the dispersion of materials destined for the same destination without affecting the maximization of the amount of materials passing through.

With the above objectives in mind, the conventional method and its problems will be explained. The items to be determined for the control of the transfer machine are transfer machine A,
For each of B, the gripping position and unloading position of the material are determined.

First, the determination of the gripping position of the material with respect to the transfer machine A will be described. The problem here is the conveyor 106 and the temporary storage facility A.
This is a case where there is a material 102 to be grasped on both sides.

In the conventional method, the first purpose is considered to be the same no matter which one is grabbed, and priority is given to the temporary storage facility A110 from the second purpose. However, since the material 102 passing through the processing machine 105 also flows on the conveyor 106, the material 102 on the conveyor 106
If 02 is processed later, the flow of material on the conveyor 106 will be poor during the time period when a large amount of material flows on this conveyor 106, and as a result, the inter-process buffer 104 will become full, causing a queue of work stoppages in the previous process 103. cause a negative situation.

Next, the determination of the unloading position of the material with respect to the transfer machine A will be described. If it can be unloaded from purpose 1 to cart 108, it will be unloaded. Trolley 108
If it cannot be unloaded, it is unloaded to temporary storage facility A110, but this is a problem. This problem is caused by the fact that even if the cart 108 becomes empty during unloading to the temporary storage facility A110, the material 102 will be unloaded to the temporary storage facility A110, so one cart 108 will be idle, and as a result, the operation of the processing machine 105 will be interrupted. This means that the rate will decrease.

Regarding the determination of the position where transfer machine B grabs the material, from objective 1, if it can be grabbed from the trolley '08, it will be grabbed. If it cannot be grabbed from the trolley 108 but can be grabbed from the temporary storage facility B111, it can be grabbed from there. From objectives 1 and 2, there is no problem with this method.

Regarding the determination of the unloading position of material by transfer machine B, please refer to conveyor 1.
If there is no material 102 at 06 (the part where the material 102 is delivered to and from the transfer machine B111), the material 102 is transferred there. conveyor 106
If there is material on top, it is unloaded to temporary storage facility B111, but this is a problem. This problem is that even if the conveyor 106 is empty during unloading to the temporary storage facility @8111, the material l○2 will be unloaded to the temporary storage facility B111, resulting in unnecessary cargo handling, which causes the material to pass through. reduce the amount.

Next, the problems with the method of instructing the transfer machine to perform work will be explained with reference to FIG.

The processing machines 201 are arranged next to the conveyor 1020. The material 1030 flowing on the conveyor 1020 is grabbed by a transfer machine (A) 1040. The grabbed material 1030 is unloaded onto a cart 1050. The cart 1050 carries the material 1030 and moves to the processing machine 1010. The processing machine 1010 processes the material 1030 while it is placed on the cart 105 (+). When the processing is completed, the cart 1050 moves to the transfer device (B) 1060. Transfer device (B) 1
060 grabs the material 1030 from above the cart 1050 and returns it onto the conveyor 1020. In this way, in order to simplify the flow of goods (to make it unidirectional), transfer machine (A) 1
The transfer machine (B) 1060 only moves the material 1030 from the processing machine 1010 to the conveyor 102.

Various materials 103o flow on the conveyor 1020.

The material 1030 is processed by the processing machine 101 depending on its type.
Group 0 is different. Therefore, the processing machine 101 shown in the figure
There are materials 1030 that pass directly in front of the processing machine 1010, and there are materials 1030 that are taken into the processing machine 1010 as described above.

Now, a material 203 (referred to as material M) to be taken into the processing machine 1010 flows on the conveyor 202, and the material 1030
Let us consider the case where a passing material (referred to as material N) flows immediately after. If the cart 1050 is not empty, the material M has no destination and must wait on the conveyor 1020. This waiting hinders the movement of material N. As a result, the amount of material passing through is reduced.

In order to solve this problem, temporary storage equipment (A) 1 is installed between the conveyor 102 and the trolley 1050 as an evacuation place for the materials 1030.
070 is provided. In the above-mentioned situation, the transfer machine (A) 104 transfers the material M from the conveyor 1020 to the temporary storage facility [(A) 1070. When the trolley 105 becomes vacant, the transfer machine (A) 1040 transfers the material M to the temporary storage facility (A).
) Transfer from 1070 to trolley 1050.

Temporary storage facility (B) 1080 is also temporary storage facility (A)
This is a buffer between the trolley 1050 and the conveyor 1020, which has almost the same function as the conveyor 1070, so its explanation will be omitted.

Now, the purpose of the control of the FA system described above is to maximize the amount of material passing through. For this purpose, there are problems with the conventional method of giving work instructions to the transfer machine.

This will be explained below.

There are no documents describing the conventional method for transfer machines, but from the perspective of transporting objects, the same applies to transport vehicles.
The conventional method will be described based on the document ``Trends in unmanned transportation systems'' (Management Engineering Symposium...P28).

Allocating work to transport vehicles is a matter of how to deal with transport demands for transporting cargo from one point to another. Therefore, before loading something, it is important to know where it comes from.

This means instructing the trolley ``where'' to transport it. If it is rewritten as a transfer machine, at the same time that the transfer machine decides ``where to pick up the material,'' it simultaneously decides ``where to unload the material.'' The problem with this conventional method is that when the cart shown in Figure 2 is working and the temporary storage facility is empty, a work instruction is given to transport the material on the conveyor to the temporary storage facility, but the material is not placed in the temporary storage facility. This is the case when the trolley becomes empty by the time the product is unloaded. In this case, even though the trolley is empty, the materials are unloaded to the temporary storage facility and then transported from the temporary storage facility to the trolley. As a result, the above-mentioned purpose cannot be realized.

[Object of the Invention] The purpose of the present invention is to maximize the amount of material passing through an FA system, and to reduce the time required to assemble materials destined for the same destination to the ground within a range that does not affect this purpose. The object of the present invention is to provide a control method for a loading machine, and a method for giving work instructions to a transfer machine that improves the amount of material passing through.

[Summary of the invention]

The problems with the conventional method are the three points mentioned in the background of the invention. The first point concerns the determination of the gripping position of the transfer machine A. Focusing on the fact that the signs of a decrease in the amount of material passing through the area 101 can be determined by the inventory rate of materials in the inter-process buffer 104, the inventory rate is determined. % or more, it is important for the above purpose to leave as much space on the conveyor 106 as possible.
Grab it with priority over the material above 10.

The second point is determining the unloading position of transfer machine A.
When the material 102 cannot be unloaded to the temporary storage facility A110, in order to solve the problems of the conventional method, the conveyor 10
If there is no next material to grab on 6, there is no need to rush to unload the material, so it will be on standby. Only when the next material to be grabbed has arrived, the material is unloaded to the temporary storage facility A110.

The third point is determining the unloading position of the transfer machine B109. If the material cannot be unloaded onto the conveyor 106 but can be unloaded onto the temporary storage facility B111, if the next material to be grabbed is not being carried by the trolley 108. There is no need to rush to unload the materials, so we will be on standby. If the next material has already been transported by the cart 108, it is unloaded to the temporary storage facility B111.

As described above, efficient distribution control is achieved by looking at the situation of other equipment and secondary material conditions, instead of considering only the wholesale destination and the destination as in the past.

Furthermore, the processing time in processing machines often varies even for the same material. Moreover, it is often difficult to estimate the processing time.In order to solve the problems of the conventional method of giving work instructions in such an environment, it is necessary to separate the determination of the gripping position of the material and the determination of the unloading position. It is to be. first,
Determine the gripping position of the material and transmit it to the transfer machine. The transfer machine grabs the material and determines the unloading position of the material when it passes or stops at a certain point. What is a certain point?

This refers to the point where materials can be immediately unloaded to both the temporary storage facility and the trolley. If you use this method, you can grab the material.

Even if the cart becomes empty during movement to a certain point, the material will not be unloaded to the temporary storage facility, but will be unloaded onto the cart, and as a result, the amount of material passing through will be improved.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2 to 6. FIG. 2 shows a flow for determining the gripping position of the transfer machine A. Check whether temporary storage facility A is normal and has one material (20
1) If it is normal and there is material, grab the temporary storage facility A and make it a candidate (202).

Next, it is checked whether there is material on the conveyor and whether the material is to be processed by the corresponding processing machine (203).

If so, grab the material on the conveyor and use it as a candidate (
204).

If temporary storage facility A is a candidate for grab ((205)).

If the conveyor is also not a candidate for grasping (206), the transfer machine is placed on standby (207). If only the conveyor is a candidate for grasping (205, 206), the material on the conveyor is set as a candidate for grasping (208). If both the temporary storage equipment and the conveyor are candidates for grasping (205, 209), and the inventory rate of the inter-process buffer is α% or more (210), in order to maximize the amount of materials passing through, ignoring first-in, first-out , and places the conveyor in the gripping position (208). If the inventory rate is less than α% (210),
There is no need to grab the materials on the conveyor in a hurry, and in order to protect the first-in, first-out system, the temporary storage facility A is used as the gripping position (211).

In addition, setting temporary storage equipment A as a gripping position (211) means that only that equipment is a gripping candidate (205, 209).
).

FIG. 3 shows the flow for determining the unloading position of the transfer machine A. Check whether the cart is normal and has no wood (301).

If so, select the trolley as a candidate for wholesale (302)
.

Next, check whether temporary storage facility A is normal and has no materials (3
03). If so, temporary storage facility A is selected as a candidate for wholesale (304). If the trolley is a wholesaler candidate (305
), the cart is brought to the unloading position (306). If there is only temporary storage facility A (305, 307) as a wholesaler candidate, select 2.
That's the correct conclusion. First, if the material to be processed by the corresponding processing machine has already arrived on the conveyor (308), the most important objective is to maximize the amount of material passing through, so even if the first-in, first-out system is Set storage facility A as the unloading position (309)
. The other case is when the next material to be grabbed has not arrived on the conveyor (308).

In this case, there is no need to rush to unload the materials, but wait (3
10). Of course, if neither the trolley nor the temporary storage facility A are wholesale candidates (305, 307), they will be put on standby (310).
.

FIG. 4 shows the grip position determination flow of the transfer machine B. Although this flow is the same as the conventional method, it will be explained in order to clarify the overall control. It is checked whether the cart is normal and whether there is processed material on it (401). If so, the cart is grabbed and set as a candidate (402). Next, it is checked whether the temporary storage facility B is normal and whether there is any material on it (403).

If so, grab temporary storage facility B and make it a candidate (4
04). If the cart is a gripping candidate (405), the cart is set as a gripping position (406).

If there is only temporary storage facility B as a grab candidate (405
, 407), temporary storage facility B is set as the gripping position (408
). If there are no grab candidates (405).

407), and is placed on standby (409).

FIG. 5 shows the flow of determining the unloading position of the transfer machine B. There is no material on the conveyor, and it is checked whether the material can be unloaded (501).

If so, consider the conveyor as a wholesaler candidate (50
2). Next, it is checked whether temporary storage facility B is normal and has no material (503). If so, temporary storage facility B is selected as a candidate for wholesale (504). If the conveyor is a wholesaler candidate (505).

In order to maximize the amount of material passing through, the conveyor is set to the unloading position (506). There are only wholesale candidates in temporary storage facility B (5
05,506), there are two conclusions. 1
First, if there is a material to be grabbed next on the cart (507)
, in order to maximize the amount of material passing, even if the first-in, first-out system is broken,
The temporary storage facility B is set as the unloading position (508). and 1
Make it possible to immediately move on to the work of grabbing the next material. The other option is that if there is no material to be picked up next on the cart (507), the conveyor may become vacant in the near future, so the conveyor will be on standby (50
9). Of course, if there are no wholesale candidates (505,506
), it is placed on standby (509).

FIG. 6 shows the control block of the present invention. block 60
1 takes in the signal from the equipment. The signals are signals for carrying in and out of materials to each piece of equipment (conveyor, trolley, temporary storage equipment, buffer between processes), and normal and abnormal signals for each piece of equipment. Based on these signals, block 602 tracks equipment status. The tracking information includes whether each piece of equipment has material or not, whether each piece of equipment is normal or abnormal, and the inventory rate on the inter-process buffer. The inventory rate is calculated from the current inventory amount of the inter-process buffer and the maximum allowable inventory amount. In block 603, the position where the transfer machine picks up the material and the position where it is unloaded are determined based on the tracking information. The flow for this determination is as shown in FIGS. 2 to 5. Block 604 converts the transport instruction determined in block 603 into a specific control signal and transmits it to the transfer machine.

Next, an example of work instructions will be explained with reference to FIGS. 7 and 8.

FIG. 7 shows a flowchart 1- for determining the material grasping position and unloading position 1 by the transfer machine. First, it is checked whether the transfer machine has arrived and completed mote 1 (710). Completion of grasping mode 1 means that the arm of the transfer machine that has grasped the material has passed a certain point or stopped. A point means a location where materials can be immediately unloaded to both the temporary storage facility and the trolley. When this mode is completed, the unloading position of the material is determined.

If the top of the trolley is empty (702) at the time of completion of gripping code 1 (701), the unloading position of the material is set to that trolley (703).
). If the table top is not empty (702) and the temporary storage facility is empty (704).

The unloading position is set as a temporary storage facility (705). if.

If the temporary storage facility is not empty, it will be put on standby (706)
.

If the transfer machine has not completed grasping mode 1 (701).

Check whether work has been assigned to the transfer machine (707
). If the work has not been assigned and there is material on the temporary storage facility (708), the gripping position is set to the temporary storage facility 8 (709). If there is no material on the temporary storage facility and there is no material on the conveyor (710).

The gripping position is set to the conveyor (711). if.

If there is no wood on the conveyor (710), it will be on standby (7
06). If the work has been assigned to the transfer machine (70
7) Don't give any instructions.

FIG. 8 shows one control block of the present invention6 First, to explain roughly, block 801 takes in equipment signals.

Based on the input data, block 802 tracks the current state of the equipment. Block 803 determines the gripping position and unloading position of the material by the transfer machine based on the tracking information.

The flow for this determination is as described above.

Note that, as will be described later, the tracking information may be rewritten based on this determination result. Block 804 is block 8
The transport instruction determined in step 03 is converted into a specific control signal and sent to the equipment.

Next, a description will be given of how the current state of equipment (tracking information) used in the flow shown in FIG. 7 is grasped. Detectors such as limit switches are installed in each piece of equipment to determine whether there is material on the trolley, temporary storage facility, or conveyor, and the detector turns on when material is brought in and turns off when it is taken out. Block 801 in FIG. 8 monitors that this happens. Block that change 8
When 01 notifies block 802, block 802 rewrites the equipment status (tracking information).

Regarding transfer machine grasping mode 1 completion (tracking information), the transfer machine is grasping the material (detector in the arm of the transfer machine is on), and when the arm passes a certain point or stops (this signal also through the detector), grasping mode 1 completed 73
The bit is turned on.

On the other hand, the bit is turned off in block 803 when the unloading position is determined. Transfer machine work assigned bit (
tracking information) at block 80 when determining the gripping position.
3. Block 802 turns off the bit when the transfer machine unloads the material.

〔Effect of the invention〕

According to the present invention, it is possible to judge whether or not material on the conveyor should be processed urgently based on the stock rate in the inter-process buffer, and the situation of the material to be processed next is also taken into account, so that the transfer machine can It is possible to reduce wasteful loading and unloading to the temporary storage facility by determining whether to unload the material to the temporary storage facility or to a trolley or conveyor, and also to implement first-in, first-out control to the extent that it does not inhibit the maximization of the amount of material passing through. This has the effect of maximizing the amount of material passing through the system and, to the extent that this is not affected, reducing the work involved in assembling materials to different destinations.

In addition, it becomes possible to determine the light position for unloading materials immediately before unloading work, and as a result, changes in the status of the unloading equipment can be fully taken into account, reducing unnecessary loading and unloading to temporary storage equipment, and FA
This has the effect of increasing the throughput of material through the system.

[Brief explanation of the drawing]

1(A) and (B) are bird's-eye views of the FA system to be controlled; FIG. 2 is a flowchart for determining the gripping position of the material for the transfer machine that conveys the material to the processing machine according to the present invention; 3
The figure is a flowchart for determining the unloading position of the material for the transfer machine that carries the material into the processing machine according to the present invention, and FIG. , FIG. 5 is according to the present invention,
Flowchart 1-1 for determining the unloading position of the material with respect to the transfer machine that carries out the material from the processing machine. Fig. 6 is a control block diagram of the present invention, and Fig. 7 shows the grasping position and unloading of the material by the transfer machine of the present invention. Position Determination Flowchart FIG. 8 shows a control block diagram of an embodiment of the present invention.

Claims (1)

[Claims] 1. A conveyor, several processing devices installed aside along the conveyor, a first transfer machine that picks up the material from the conveyor and unloads it onto a trolley, and a conveyor for when the material cannot be unloaded onto the trolley. a first temporary storage facility that serves as an evacuation site for the processing; a trolley that transports the materials to the processing equipment and transports the processed materials; and a second vehicle that grabs the processed materials from the trolley and returns them to the conveyor. A transfer machine,
A second evacuation area in case it is not possible to unload to the conveyor.
In a factory automation system that includes a process consisting of a temporary storage facility, signs of a decrease in the amount of material passing through can be ascertained by checking the inventory rate of the interprocess buffer between the aforementioned process and its previous process, and If the rate is above a certain value,
Materials on the conveyor are grabbed by the first transfer machine with priority over materials on the first temporary storage equipment, and if the inventory rate is less than a certain value, the materials on the first temporary storage equipment are grabbed by the first transfer machine. A control system for a transfer machine that is characterized by giving priority to grasping. 2. If the material cannot be unloaded onto the trolley and can be unloaded to the first temporary storage facility, if the next material to be processed has not arrived on the conveyor, the first transfer machine will be placed on standby and the next material will be unloaded. 2. The control system for a transfer machine according to claim 1, wherein if the second transfer machine has arrived, the material held by the second transfer machine is unloaded to the first temporary storage facility. 3. If the processed materials cannot be returned to the conveyor and can be unloaded to the second temporary storage facility, if the next material to be picked up has not yet been processed, the second transfer machine will be placed on standby and the next The method for controlling a transfer machine according to item 1, characterized in that if the material to be grasped has been processed, the material being grasped by the second transfer machine is unloaded to the second temporary storage facility. . 4. Among discrete factory automation systems such as machining and machine assembly, in a system in which one of several locations is selected for the material to be unloaded, first, the location for grasping the material is determined, and then Instructions are given to the transfer machine, and according to the instructions, the transfer machine picks up the material, passes a certain point, or when it stops, determines one destination based on the status of multiple destinations, and transfers the material. A control method for a transfer machine characterized in that the transfer instruction is given to the machine by separating the determination of the material gripping position and the determination of the unloading position.