JPH05178408A - Determination of stopping position in automatic warehouse - Google Patents

Abstract

PURPOSE:To determine a travel directional stopping position of an ascending/ descending stand in response to distortion of a shelf stage. CONSTITUTION:An ascending/descending stand 2 of a stacker crane 1 travels in front of a shelf stage 5. Caps 11 are fitted in opening parts on the edges of cants 8 to load an article W. The edge surfaces of the caps 11 are the light reflecting surfaces, and reflect the light L emitted by photoelectric sensors 12 and 12. The stacker crane 1 is made to travel for testing in order to set a stopping position, and a distance from a reference position where the caps 11 are detected is stored in a control section as a data, and the stopping position when the stacker crane 1 is operated is determined by carrying out an arithmetic operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining a stop position of an automatic warehouse, which is capable of accurately positioning the stop position of a lifting platform of a stacker crane of an automatic warehouse.

[0002]

2. Description of the Related Art A stacker crane for loading and unloading work in an automated warehouse travels and moves up and down in front of the openings of a plurality of shelves arranged in a matrix of shelves. The stacker crane lift is provided with a fork for transferring articles to and from a shelf. When delivering goods, stop the elevator at an accurate position with respect to the shelf that is going to be delivered, and do not cause an accident such as an accident where the extended fork collides with the member that constitutes the shelf. You must be able to do the hand-over work. This run
For positioning control of lifting and lowering, a plurality of shielding plates are arranged on the floor and on the mast of the stacker crane, and the optical sensor provided on the stacker crane side detects the shielding plate to determine the reference position for traveling and lifting. I was trying to detect.

[0003]

According to the method of determining the traveling stop position based on the position of the shielding plate arranged on the floor surface, there is no problem when the shelves are lined up correctly, but in practice Due to the inclination of the columns, the shelves are distorted. Due to the inclination of the pillar, the positions of the front side of the lower shelf and the front side of the upper shelf are considerably displaced along the traveling direction of the stacker crane. Therefore, it is necessary to change the traveling stop position of the stacker crane between the lower shelf and the upper shelf, and when installing the automatic warehouse, stop the stacker crane at the stop position for all shelves by manual control, Initial setting work to memorize the stop position was required. This initial setting work is laborious and time-consuming, and it is very dangerous because a person climbs a high shelf to work.

Therefore, an object of the present invention is to provide a stop position determining method for an automatic warehouse which can stop a stacker crane at an accurate position in response to a distortion of a shelf without requiring a troublesome initial setting work. is there.

[0005]

In order to achieve the above object, the present invention detects the end surface of a cap put on the open end of a cantilever by means of a detecting means attached to the lifting platform of a stacker crane. The position of the lifting table which detects the end surface of the cap by means is stored as data,
The stop position determination method of the automatic warehouse is configured so as to determine the stop position of the lifting platform based on the data.

[0006]

Since the present invention has the above-mentioned structure, it has the following effects.

In the method for determining the stop position of the automatic warehouse according to the present invention, first, the stacker crane is moved and moved up and down prior to the operation of the automatic warehouse, and the open end of the cantilever is detected by the detection means attached to the lifting platform of the stacker crane. Detect the end face of the cap covered on the. The position of the lift table when the detecting means detects the end surface of the cap is stored as data. Based on this data, the stop position of the lifting platform is determined when the stacker crane is operating, and the lifting platform is stopped. The data can be updated with an appropriate deadline and can be revised each time the vehicle is driven.

[0008]

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

1 and 2 are a plan view and a front view, respectively, showing a part of an automatic warehouse to which an embodiment of a stop position determining method for an automatic warehouse according to the present invention can be applied.

In FIG. 1, the stacker crane 1 is shown in FIG.
As the vehicle runs in the left-right direction, the elevator platform 2 moves up and down along the masts 3, 3. The lifting table 2 is provided with a fork 4 for delivering articles. The shelf 5 includes a plurality of columns 6 and 7,
It is composed of a plurality of canches 8 bridged between a set of prisms 6 and 7 in the front and rear of FIG. Adjacent canches 8 and 8 form a shelf on which the article W is placed, and a space is provided between the canches 8 and 8 so that the fork 4 can scoop the article W from below.

The cantilever 8 extends in the same direction as the first square pipes 9 and 9 fixed to the opposite side faces of the front and rear prisms 6 and 7 so as to have a horizontal posture, and the front and rear prisms 6 and 7. The first square pipes 9 and 9 are composed of the second square pipes 10 and 10 which are installed at the ends of the first square pipes 9 and 9. Second corner pipe 10, 10
Extends beyond the attachment portion 2 with the first square pipe 9, 9. Since the ends of the second square pipes 10 and 10 are open, a cap 11 is fitted to each end for ensuring safety and improving aesthetics. The end surface of the cap 11 is a reflective surface that reflects light.

Reflection type photoelectric sensors 12 and 1 are mounted on the lifting table 2.
2 are attached at intervals, and each has an optical axis L
Is emitting. The distance between the two is substantially the same as the distance between the caps 11, 11. Since the optical axis L is reflected by the end surface of the cap 11, the photoelectric sensors 12 and 12 are connected to the cap 11.
Can be detected. The photoelectric sensors 12 and 12 are connected to the control device 13 of the stacker crane 1, respectively.

FIG. 3 shows a control structure of the stacker crane 1. In addition to the photoelectric sensors 12 and 12, pulse encoders 14 and 15 are also connected to the control device 13, and detect the travel distance of the stacker crane 1 and the lift distance of the lift table 2, respectively. Further, a RAM 16 is connected to the control device 13, and the values of the pulse encoders 14 and 15 can be stored as data. The control device 13 controls the traveling motor 17 and the elevating motor 18 to cause the stacker crane 1 to travel and the elevating table 2 to elevate.

According to such a configuration, each photoelectric sensor 1
When 2 and 12 detect the caps 11 and 11 at the same time, the fork 4 is located between the canches 8 and 8 and is arranged at a position where the articles W can be delivered, so that the lift table 2 is stopped in the horizontal direction. Can be detected. That is, after the automatic warehouse is installed and prior to the start of operation, the stacker crane 1 is run, the lifting platform 2 is raised and lowered, and the reference of the pulse encoders 14 and 15 when the cap 11 put on each cantilever 8 is detected. The value from the position is stored in the RAM 16 for each cap 11. As the reference position, the position of the adjacent cap 11 is suitable because the error is minimized. For example, assuming that the stacker crane 1 travels from the left to the right when stopping the lifting platform 2 at the stop position shown in FIG. 1, the photoelectric sensor 12
Moves while sequentially detecting the caps 11 arranged at the same height from the left side. The distance between the caps 11 is stored in the RAM 16 as the value of the pulse encoder 14. Therefore, in this case, after the photoelectric sensor 12 on the right side in FIG. 1 of the lift 2 detects the second cap 11 from the left in FIG. 1, the second and third caps 11 from the left are detected by the pulse encoder 14. When the distance between is detected,
If the lifting platform 2 is stopped, it can be stopped at the position shown in FIG.

Further, the article transfer position of the lifting table 2 is
The position is not limited to the position where the photoelectric sensor 12 detects the cap 11. As shown in FIG. 4, the length D1 between the two photoelectric sensors 12a and 12b may be shorter than the length D2 between the caps 11b and 11c. In order to move the fork 4 to the center between the caps 11b and 11c, if the elevator base 2 moves forward from the left, the photoelectric sensor 12a detects the cap 11b (D2-
D1) / 2 Go left further and stop.

Further, it is possible to determine whether the article W can be stored in the shelf. Whether or not a certain article can be stored is determined by the width D3 of the frontage defined by the prisms 7, 7. It goes without saying that articles larger than the width D3 of the frontage cannot be stored. The width D3 of the frontage is a cantilever 8a.
D4 between the caps 11a and 11b and the cantilever 8b
It can be calculated from the distance D5 between the caps 11c and 11d. That is, if the thickness of the prism 7 is a, then D3
Is calculated by ((D4 + D5) / 2) -a + D2.
In this case, the lifting table 2 must be stopped so that the fork 4 is located at the center of D3.

More simply, a reflector 19 is provided on the side surface of the prism 7.
It is possible to detect D3 by affixing it and detecting it with the photoelectric sensor 12.

As described above, according to the method of this embodiment, the stop position of the lift 2 is determined by detecting the caps 11 and 11 and storing the data before the operation of the automatic warehouse is started. Even if the shelf 5 is distorted due to the inclination of 7 or the like, the lifting platform 2 can be stopped at the correct delivery position with respect to the cantilevers 8.

By calculating the width D3 of the frontage, it is possible to check whether or not a particular article can be stored in the shelf.

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.

For example, in the illustrated embodiment, the photoelectric sensor 12
Although two are provided at intervals, it is possible to perform positioning with only one. Further, the photoelectric sensor 12 was used as the detection means provided on the side of the lift table 2 and the end surface of the cap 11 was used as a reflection surface. The detection means may be provided and the detection means may be a reader.

[0022]

As described above, according to the automatic warehouse stop position determining method of the present invention, the cap fitted into the opening end of the cantilever is detected prior to the operation, and the data is stored,
Since the stacker crane is operated based on the data, the fork position is properly determined by adapting to the distortion of the shelves to prevent accidents where the forks collide with the members forming the shelves,
The delivery operation can be reliably performed. Therefore, it is possible to save labor and time without requiring a troublesome initial setting.

[Brief description of drawings]

FIG. 1 is a plan view showing a part of an automatic warehouse to which an embodiment of a method for determining a stop position of an automatic warehouse according to the present invention is applied.

FIG. 2 is a front view showing the automated warehouse shown in FIG.

3 is a block diagram showing a control structure of the embodiment of FIG.

FIG. 4 is a diagram for explaining an operation state in the embodiment of FIG.

[Explanation of symbols]

 1 Stacker Crane 2 Lifting Table 4 Fork 5 Shelf 6, 7 Each Column 8 Cantilever 11 Cap 12, 12 Photoelectric Sensor W Article L Optical Axis

Claims (1)

[Claims] 1. A detection means attached to an elevator board of a stacker crane detects an end surface of a cap covered by an open end of a canch, and the position of the elevator board which detects the end surface of the cap by the detector means is used as data. A method for determining a stop position of an automatic warehouse, which is stored and a stop position of an elevator is determined based on the data.