JPH05170317A - Stacker crane control method - Google Patents

Abstract

PURPOSE:To perform work in a short time without causing load shifting of articles. CONSTITUTION:A stacker crane controlling device 15 controls a motor 10a for traveling and motor 11 for lifting based on the values sent by an encoders 13 and 14 and drives a fork driving motor 16 to perform carrying and loading work. Movements such as traveling, lifting, and shifting and loading are determined by reading the bar codes 18 on articles by means of a bar code reader 17 to obtain information such as being liable to crumble so that shifting and loading work may be done in short time not causing load shifting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stacker crane for an automatic warehouse, and more particularly to a control method for a stacker crane that can realize efficient loading and unloading while preventing accidents such as load collapse.

[0002]

2. Description of the Related Art In factories and warehouses, automated warehouses are used to temporarily store products and semi-processed products. Figure 3
Indicates part of an automated warehouse. In the figure, the automatic warehouse is equipped with a stacker crane 1. The stacker crane 1 travels along the rails 3 and 4 on the front surface of the shelf 2, and raises and lowers the lifting platform 5 along the mast 6. By moving the traveling carriage 7 and raising and lowering the lifting platform 5,
The article W is delivered to and from the cantilever 8 attached to a. The delivery is performed by operating a fork 9 provided on the lifting table 5.

The traveling platform 7 travels by driving the wheels 10 by the traveling motor 10a, and the elevating platform 5 drives the chain 12 by the elevating motor 11 to move up and down. The encoders 13 and 14 detect the traveling and ascending / descending distances, respectively, and the stacker crane control device 15 determines the position of the elevator table 5 to transfer the articles to and from the cantilever 8 based on the values of the encoders 13 and 14. This is done by controlling the running and lifting. When the lifting table 5 is positioned, the drive device (not shown) for the fork 9 and the lifting motor 11 built in the lifting table 5 are controlled to perform the article transfer control.

[0004]

FIG. 2 is a diagram showing a common speed-time relationship in the operations of traveling the stacker crane 1, elevating the elevating table 5, and transferring the forks 9.
As indicated by the operation a in the solid line, each device accelerates at a constant acceleration va, which is the maximum speed, at a constant acceleration, operates at a constant speed va for a while, decelerates to a low speed vb, and stops.

The time spent for traveling, lifting and transferring,
It depends on the maximum speed va and the acceleration during deceleration. If the maximum speed va is the same, if the vehicle is suddenly started and stopped at the time of starting and stopping, the time that the vehicle can travel at the maximum speed va becomes longer and the cycle time can be shortened. On the other hand, when abrupt acceleration / deceleration is performed, the lifting table 5 and the forks 9 may shake or tilt, and an article W placed on the forks 9 may collapse or fall. .. Therefore, the acceleration during acceleration / deceleration may be maximized as long as an accident does not occur. However, there are various kinds of goods stored in the automated warehouse, and their packing styles are also various. Goods that are packed or heavy are likely to collapse, and items that are extremely vulnerable to shock, such as cracks, are also handled. Therefore, the operation of each device must be determined in accordance with the article in which the accident is most likely to occur, and even a durable article that is hard to collapse is subjected to uniform gradual acceleration / deceleration as shown by the operation b, for example. Since it is handled in motion, the cycle time could not be reduced except for increasing the maximum speed va.

Therefore, it is an object of the present invention to change the operation of each device depending on the article and reduce the cycle time.

[0007]

In order to achieve the above-mentioned object, the present invention travels on the front surface of a shelf and elevates and lowers a lift table,
A stacker crane control method for transferring an article to and from a shelf by a transfer device provided in an elevator, wherein a barcode reader provided in the elevator reads a barcode attached to the article, The control method of the stacker crane is configured so that the traveling / elevating of the stacker crane and the operation of the transfer device are determined by the information written in the bar code.

[0008]

Since the present invention has the above-mentioned structure, the following operational effects are obtained.

According to the stacker crane control method of the present invention, when the elevator of the stacker crane is about to transfer an article, the barcode reader provided on the elevator allows the barcode attached to the article to be read. read. The information written in the bar code allows the operation of the stacker crane to move, move up and down, and the transfer device to be determined, so that the operation of each device can be changed for each article.

Therefore, according to the control method of the stacker crane of the present invention, by performing an appropriate operation for each article, an accident such as a load collapse of the article does not occur and the transportation time can be minimized. The transport efficiency of the stacker crane can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below.

FIG. 1 is a block diagram showing the outline of a control mechanism to which an embodiment of a stacker crane control method according to the present invention is applied, and FIG. 2 shows the speed and time of equipment controlled by the same embodiment. FIG. 3 is a view showing a common relationship, and FIG. 3 is a front view showing a part of an automated warehouse to which the same embodiment is applied.

The stacker crane control device 15 controls the stacker crane 1 by driving the traveling motor 10a and the elevating motor 11 based on the values of the encoders 13 and 14 for detecting the traveling / elevating distance, and is also built in the elevating table 5. The fork drive motor 16 is driven to operate the fork 9.

As shown in FIG. 3, a bar code reader 17 is attached to the lifting table 5 so that the bar code 18 attached to the article W can be read. Information about the attached article W is written in the barcode 18. The information about the article W is, for example, the ease with which a load collapses, the fragility, and the like. The bar code 18 is printed by a bar code printer (not shown) and attached in advance for each article.

Next, the operation of this embodiment will be described. The stacker crane 1 to which this embodiment is applied reads the information written in the barcode 18 by the barcode reader 17, and the read information is sent to the stacker crane controller 15. Based on this information, the stacker crane control device 15 performs a calculation to determine the operation of each device.

FIG. 2 is a diagram showing a common speed-time relationship in the operation of each device, that is, the traveling of the stacker crane 1, the elevating / lowering of the elevator platform 5, and the extension / shortening of the fork 9. In FIG. 2, two operations a and b are shown. Action a
Has a larger acceleration during acceleration / deceleration compared to the operation b, and thus completes the movement of the distance that is the time ta. The motion b takes a long time to move due to the small acceleration, and the motion ends at the time tb.

In the work with the stacker crane 1,
When handling a sturdy article that is hard to collapse, a bar code 18 is attached to the article in which information indicating that the article is hard to collapse and is strong is written. The stacker crane controller 15 reads this information and determines to select the operation a. In other work, when an article that easily collapses or is fragile is handled, the information to that effect is written in the bar code 18 attached to the article, and the stacker crane control device 15 operates b. Select. The operation a requires only a short working time, but since the shock during acceleration / deceleration is large, it is suitable for a durable article that does not easily collapse. On the contrary, in the operation b, since the acceleration and deceleration are gentle and the load collapse is unlikely to occur, the work time is long, but
Accidents can be prevented even for articles that easily collapse. The outline of each operation is commonly applied to the fork drive motor 16 for driving the fork 9 on which the article is placed, the traveling motor 10a for traveling the stacker crane 1, and the lifting motor 11 for lifting the lifting platform 5.

As described above, according to the present embodiment, by changing the operation of each device for each article, it is possible to finish the work in the shortest possible time without causing an accident such as a load collapse. Therefore, the transfer efficiency can be improved.

The information written on the bar code 18 is, in addition to the easiness of collapse of the load and the fragility thereof, for example, that it is a deleterious substance / dangerous substance, that it has odor, that it is water, etc. Can be written. Further, in FIG. 2, only two types of operations are selectively shown, but it is possible to select in multiple stages,
It is also possible to calculate the operation steplessly by calculation.

The embodiment of the present invention has been described above.
It is needless to say that the present invention is not limited to the above-mentioned embodiments and can be appropriately modified within the scope of the gist of the present invention.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control structure of a stacker crane to which a stacker crane control method according to the present invention is applied.

FIG. 2 is a diagram showing the relationship between the speed and time of each operation of traveling / elevating and transferring of the stacker crane controlled by the embodiment of FIG.

FIG. 3 is a front view showing a part of an automated warehouse including a stacker crane to which the embodiment of FIG. 1 is applied.

[Explanation of symbols]

 10a Traveling motor 11 Lifting motor 13, 14 Encoder 15 Stacker crane control device 16 Fork drive motor 17 Bar code reader 18 Bar code

Claims (1)

[Claims] 1. A control method for a stacker crane, which travels in front of a shelf, raises and lowers an elevator, and transfers an article to and from the shelf by a transfer device provided on the elevator.
It is characterized in that the bar code reader provided on the lifting table reads the bar code attached to the article, and the traveling / up / down of the stacker crane and the operation of the transfer device are determined by the information written in the bar code. Stacker crane control method.