JPH03267206A - Automatic warehouse - Google Patents

Abstract

PURPOSE:To provide automatic measurement of a stopping position and improved accuracy in the position, in an automatic warehouse provided with a stereoscopic storage rack and a stacker crane, by reading out reference marks formed together with a bar code for rack absolute address indication in the rack on the side of the stacker crane to detect out-of-position amount and compensate a stopping position. CONSTITUTION:A member provided with a bar code 31 showing the absolute address of a rack 11 and the marks 32, 33 showing reference points is installed on the traveling passage side of the rack 11. Moreover, an optical sensor 40 provided with a bar code reading device and a primary sensor for reference mark detection is installed on the lifting body 23 of a stacker crane. A desired rack 11 is detected by reading-out through the bar code, and a mark out-of- position amount is computed by detection of the reference marks 32, 33. According to the results of the computation, the pulse number of a stopping position is compensated for stopping at a regular position. It is thus possible to improve the stopping position accuracy and provide automation.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a measuring device for a three-dimensional storage shelf in an automated warehouse or the like comprising a three-dimensional storage shelf for storing loads and a stacker crane for transporting the loads. Incidentally, the term "pillar" as used in the present invention includes the case of the end face of the load receiving seat in the traveling direction of the stacker crane. Further, the cargo receiving seat includes a pallet receiving seat. [Prior Art] An automatic warehouse will be explained with reference to FIGS. 7 to 9. The automated warehouse runs along the three-dimensional storage shelves IO in which a large number of 11lls for storing goods are arranged horizontally and vertically, and the three-dimensional storage shelves IO, and has shelves 11, an entrance 12a for storage, and an exit 1 for storage.
2b, and a central control device 30 that gives commands to the stacker crane 20 for loading and unloading loads. The running path 28 of the stacker crane 20 is between the two parallel storage shelves 1011O.
It becomes. The three-dimensional storage shelf 10 is composed of a pillar 13 installed vertically in the travel path of the stacker crane 20, and pallet seats 14 installed in multiple stages on the pillar 13. The shelf 11 is located between the left and right pillars 13.13 and the upper and lower pallet seats 14.14. A pallet 17 carrying a load 16 is cut out on the pallet seat 14. Such three-dimensional storage shelves IO are installed on both sides of the travel path of the stacker crane 20. Note that the space between the pillars 13.13 in the running direction is called a row, the space between the pallet seats 14.14 in the vertical direction is called a stage, and each three-dimensional storage shelf 1O11O is called a column. In FIG. 7, the upper three-dimensional storage shelf 10 is referred to as a first row, and the lower three-dimensional storage shelf 10 is referred to as a second row. The stacker crane 20 includes a traveling body 21 that runs on the ground,
It consists of an elevating table 23 that raises and lowers a post 22 erected on the traveling body 21, and one fork 24 that is installed on the elevating table 23 and projects toward the shelves 11 in the left and right rows. Further, a pulse encoder is disposed between the traveling body 21 and the rail 28 on the ground to detect the traveling distance of the traveling body 21 from the origin. A pulse encoder is also arranged between the lifting table 23 and the post 22 to detect the amount of elevation of the lifting table 23 from the origin. The current position, deceleration start position, and stop position of the traveling body 21 and the lifting platform 23 are determined by the detection rings of these two pulse encoders. The central control device 30 instructs the content of the next loading/unloading operation and the shelf position. The on-machine control device 25 mounted on the stacker crane 20 controls the travel of the traveling body 21 of the stacker crane 20, the elevation and descent of the lifting platform 23, and the forward and backward movement of the fork 24 in response to the above-mentioned commands. As a result, the loading and unloading of cargo is automatically performed. Such an automated warehouse is disclosed in Japanese Patent Application Laid-Open No. 63-51202,
JP-A-63-123703, JP-A-63-147
This is shown in Publication No. 710, etc. Now, when the stacker crane 20 is moved toward the target shelf 11 for loading and unloading and stopped, there are variations in the running stop position of the traveling body 21 of the stacker crane 20 and the lifting stop position of the lifting platform 23. arise. On the other hand, when a three-dimensional storage shelf is constructed, the spacing between the columns 13, the vertical spacing of the pallet seats 14, the inclination of the columns 13, the bending of the center of the columns 13 as shown by the broken line in FIG. 8, and the movement of the stacker crane 20. This causes errors in the vertical level of the rail 28, etc. There are also errors such as bending of the post 22 of the stacker crane 20. The size of the shelf 11 is determined taking these into account. However, increasing the tolerance for these errors reduces the number of machines for a given volume. Set these tolerance values somewhat strictly. In this way, when the stacker crane 20 is stopped at the position of the target shelf 11, the stopping position of the stacker crane 20 may not be a normal position with respect to the shelf 11. That is,
The center position of the fork 24 with respect to the center of the shelf 11 in the traveling direction of the stacker crane 20 may be outside the permissible value. Further, the vertical position of the fork 24 with respect to the pallet seat 14 may also be outside the allowable value. In this case, loading and unloading cannot be carried out normally. Therefore, once the three-dimensional storage shelf 10.10 is constructed, the stacker crane 20 is run to measure the shelf position, and based on this, the shelf position (corresponding to the count value of the pulse encoder) is determined. There is. This work will be explained below. First, the shelf positions (referred to as reference values), which are determined based on the design values of the spacing between the pillars 13 and the vertical spacing of the pallet seats 14, are input to the on-machine control device 25 of the stacker crane 20. The reference value in the running direction is the distance from the origin on one end side of the running path to each row, and the reference value in the vertical direction is the distance from the origin on the lower end side to each step. Next, the stacker crane 20 is stopped at the first row on one end side (origin side) of the travel path. Further, the fork 24 is stopped at the first shelf from the bottom. This stop is automatically performed using the reference value. Here, the measuring person gets on the fork 24 and
The stopping position of the stacker crane 20 in the traveling direction with respect to the shelf of each stage is measured. That is, the distance from the end face of the pillar 13 or the pallet seat 14 to the reference position of the fork 24 is measured. With this, it is possible to calculate in which direction and by how much the stop position of the stacker crane 20 in the traveling direction is shifted. In addition, the measuring tool is the upper surface of the fork 24 and the pallet receiver 14.
Measure the distance between the top surface of the With this, it is possible to calculate in which direction and by how much the stop position of the fork 24 in the vertical direction is shifted. In this way, two positions, that is, positions in two directions, are measured for one shelf. Since the three-dimensional storage shelves 10 are located on both sides of the travel path, there are two shelves at one stop position, so measurements are taken at two locations for each shelf. This measurement is performed using a measuring tool such as a tape measure or a ruler. Record this measurement value on recording paper. If the first shelf 11 in the first row is measured, the fork 2
The measuring tool mounted on 4 instructs the operator mounted on the driver's cab 26 of the stacker crane 20 to run. The operator is
Operate the on-board control device 25 to travel toward the second row of shelves. No command is given to change the height position of the fork 24; in other words, the command is given as the target shelf as the first shelf on the second row. The stacker crane 20 travels toward the first shelf in the second row and stops. In this case, the on-board control device 25 uses the theoretical second row shelf position (reference value) that has been input in advance.
The vehicle is caused to travel towards the target, and the reference value is compared with the amount of movement (number of pulses) detected by the pulse encoder to determine the deceleration start position and stop position, and the vehicle is brought to a stop. The measuring tool measures four locations in the same manner as above. Note that while the stacker crane 20 is traveling, the measuring tool and the operator remain on board. Thereafter, measurements are taken in the same manner by stopping on the first shelf of the third row. In this way, it is stopped at the first stage of each row from one end to the other, and measurements are taken. After measuring to the other end row, next measure the upper shelf in the same way as above. For example, the height of the three-dimensional storage shelf 10 is 1
If it is 0, then the fifth shelf in the middle is measured. Then, the fork 24 is raised to the fifth stage and stopped. This compares the amount of movement (number of pulses) detected by the pulse encoder for elevation with the reference value of the fifth stage, determines the deceleration start position and stop position, and then stops. With the position of the fork 24 fixed at the fifth stage, the reference value and the number of pulses of the pulse encoder are compared with each other in the same manner as described above, and the fork 24 is stopped at each row. Then, measure in the same manner as above. For example, measurements are performed sequentially from the first row to the other end row. After measuring the shelves in each row of the 5th tier, the fork 24 is raised to the 10th tier, which is the highest tier. This stopping is performed by comparing the reference value and the number of pulses. Then, with the fork 24 fixed at the 10th stage, it is stopped at each row and measured in the same manner as described above. In addition, if the acquisition entrance is outside the three-dimensional storage shelf 10, the stacker crane 20 is also stopped at that entrance.
Measure in the same way. Next, based on the recorded measurement values, the correct position of each shelf is determined by calculation, and this is determined by the on-board control device 2.
Enter 5. The position of the shelf is indicated by the distance from the origin to the row of the shelf, and the distance from the origin to the step of the shelf. The distance corresponds to the number of pulses of each pulse encoder. To explain how to calculate the stop position (number of pulses) for each row, in one row, the measured values in the running direction of the 1st, 5th, and top rows are averaged, and the amount of positional deviation (direction) for that row is calculated. ), and then converts this into the number of pulses of the pulse encoder to find the number of pulses that is the correct stopping position for that row. In this case, since the three-dimensional storage shelf 10 has two columns, the stopping position (number of pulses) of one row is determined by averaging the measured values at six locations for one row. Do this for each row. On the other hand, to explain the calculation of the stopping position W1 (number of pulses) of each stage, the measured values in the vertical direction from the first row to the last row for one stage are averaged, and the positional deviation amount (including direction) of that row is calculated. This is then converted into the number of pulses of the pulse encoder to find the number of pulses at the correct position of that stage. In this case, since there are two rows of the three-dimensional storage shelf lO, the stopping position (number of pulses) of one stage is determined by averaging the measured values of the two rows for one stage. Do this for each stage. Non-measurement stage (2nd to 4th stage, 6th stage)
9th to 9th tier) are determined by analogy from the measured tier values. The above-mentioned averaging means finding a position where the fork 24 is located within a predetermined range of the shelf even if the fork 24 is protruded in any direction at one stop position. In addition, the stopping position in the running direction is not determined for each stage, but is determined for each row (and there is one for every two rows), and the stopping position in the vertical direction is not determined for each row, but for each stage. The unit is defined as (one unit per two rows).
This is due to the relationship with the storage capacity of the on-board control device 25, etc. The above-mentioned work of determining the stop position for each column is called the adjustment work of shelf arrangement. [Problem to be Solved by the Invention 1] The above-mentioned conventional adjustment work for the arrangement of shelves has the following problems. l) In addition to the measurer, a manual operator of the stacker crane is always required. 2) The person taking the measurement is placed on the lifting platform 24 and is performing the measurement in a high place and in a cramped working environment, which poses safety issues.
Also, the reliability and accuracy of measurement decreases. 3) As the scale of the warehouse increases and the number of machines increases, the measurement time and adjustment work time become longer, leading to an increase in costs (personnel expenses). SUMMARY OF THE INVENTION In order to solve these problems, it is an object of the present invention to automatically and accurately measure the relationship between shelves in an automated warehouse and the stop positions of a stacker crane.

[Means for Solving the Problems] The present invention includes installing a member consisting of a barcode indicating the absolute address of each column and a mark indicating a reference point on a shelf of a three-dimensional shelf facing the travel path. The stacker crane includes a reader that reads the barcode, and a one-dimensional sensor that reads the position of the mark. and a control circuit that corrects the number of pulses at the stop position based on the amount of deviation read by the one-dimensional sensor;
[Function 1] A barcode reader reads the unique position (absolute address) of the shelf, and a one-dimensional sensor reads and corrects the deviation amount of the stop pulse. [Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. First, the preconditions will be explained. In FIG. 7, there are two rows of three-dimensional storage shelves lO. The inlet 12a of one column and the outlet 12b of the other column are in the same row,
are at the same height. For this reason, the stacker crane 20 that has delivered the cargo to the delivery port 12b does not move when the stacker crane 20 leaves the storage port 12b.
A can receive cargo. Measurements for determining the shelf position shall be made for all shelves.
Then, the position of the shelf (indicated by the number of pulses in the traveling direction and the number of pulses in the lifting direction) is determined for each column based on the above-mentioned actual measurement values, and this is set as the stopping position during actual work on the machine of the stacker crane 20. Input to control device. That is, in the conventional example, the number of pulses in the running direction is determined for each row based on the measured value at each row in one row, and the number of pulses in the vertical direction is determined by the measured value at each row in one row. It is decided on a stage-by-stage basis based on. Moreover, in this embodiment, where a common number of pulses is set for two rows of shelves, such settings are not made for each row or column in principle. That is the meaning. However, since the storage entrance 12a and the storage exit 12b are located in opposite positions, and after leaving the warehouse, warehousing work is very often performed without running the stacker crane 20. The position is determined by averaging the positions. In FIGS. 1 and 2, a measuring member 30 is provided on the surface of the pallet receiving seat 14 constituting the shelf 11 facing the running path 28.
is attached. Pallet catch 14 to which this member is attached
The surface is the position that most protrudes toward the traveling path 28 side. The member 30 has a bar code 31 indicating the position (absolute address) of the shelf 11 to which the member 30 is attached, a mark 32 indicating a reference point in the traveling direction, and a mark 33 indicating the reference point in the ascending and descending direction. Consisting of In FIGS. 3 and 4, an optical sensor 40 is mounted on the elevating body 23 of the stacker crane 20 to read this member 30.
is installed. This sensor includes a barcode reader ta41 for reading the barcode 31 and a mark 32.3.
It consists of two one-dimensional sensors 42 and 43 installed in the horizontal direction and vertical direction, respectively, to read the position of 3. 50 is a known control device, which is installed in the stacker crane 20. The control device 50 moves the stacker crane 20 to a target position in response to a cargo handling command, and drives the fork device 24 and the like to load and unload the cargo.The current position is determined by a pulse encoder 51. 52 pulses are integrated and recognized. The control device stores the number of pulses as the stop position for each column, and stops the stacker crane 20 at the position corresponding to this number of pulses. A control device 45 drives the sensor 40, reads data from the sensor, and updates the position (number of pulses) of the shelf 11. 49 is a terminal for outputting the measurement results to the outside. The control device 45 can store measurement results and calculation results. Next, the measurement, calculation, and update procedures will be explained with reference to FIGS. 5 and 6. Before starting the measurement work, the following must be done. As in the conventional case, the stop position in each column (consisting of the number of pulses in the travel direction and the number of pulses in the up/down direction) is input into the on-board control device 25 based on the design values. Note that the number of pulses is a count of the number of pulses of a pulse encoder for detecting the distance from the origin. As is well known, there are two types of pulse encoders: one for traveling and one for lifting.
It is set to 0. First, the stacker crane 20 is stopped at a shelf other than the one on which the measurement is to be started. In this state, the controller 45 is commanded to start measurement work. The worker then leaves the stacker crane 20 to a safe position. When a predetermined period of time has elapsed since the command to start measurement, the control device 45 transmits to the on-board control device 50 an address and a movement command to the shelf where the measurement is to be started. The first predetermined time is the time required for the worker to escape from the stacker crane 20 to a safe area. Measurements are performed under dark conditions so that no external light enters the sensor. Next, in FIG. 5, when the shelf is stopped at the target shelf position, the control device 50 outputs a stop signal indicating that traveling and lifting are stopped, and the number of pulses in the traveling direction and the number of pulses in the lifting direction are output. It is output to the control device 45. Control device 45
enter and store these. The number of pulses in the traveling direction and the number of pulses in the vertical direction are determined by the traveling pulse encoder 51.
, is the number of pulses determined by the lifting pulse encoder 52,
This is the number of pulses at the time the stop signal is output. Therefore,
This number of pulses indicates the current stop position. (Step S1.
S3) The vehicle travels and ascends and descends at low speed. Next, the control gIJ calculation device 45 performs measurement and calculation using the sensor 40 (Step S5), details of which are shown in FIG. When the work in step S5 is completed, it is checked whether or not the measurement of all the target shelves has been completed. If not, the address of the next shelf and a movement command are transmitted to the control device 50. Hereinafter, the process is repeated from step S1. (Step S
7.59) On the other hand, if the measurements of all the shelves have been completed, a command is given to move them to the return position input in advance. This return position is preferably a position where it is easy to get on and off the driver's cab and to inspect and recover the measuring device on the fork 24, such as the first stage position (usually called the home position) at the end of the travel path. Step S11.313) The contents of step S5 will be explained in detail with reference to FIG. First, the barcode reader 41 is used to read and store the address (absolute address) of the current target shelf (step S31). Next, the one-dimensional sensor 32 is used to read the mark 32 in the running direction.
Next, the amount of deviation (direction) of the center position of the mark from the reference position of the one-dimensional sensor 42 is calculated and stored. (Step 533) Since the distance from the center position of the fork device 24 of the stacker crane 20 to the reference position of the one-dimensional sensor 42, the distance from the pulse encoder 51 to the reference position, etc. are known, the distance of the shelf 11 is determined from the amount of deviation. Fork device 2 in the center position
The optimum number of pulses of the pulse encoder 51 for stopping the center of the pulse encoder 51 is calculated. The calculated value is stored in correspondence with the address. (Step 535) Next, using the -dimensional sensor 43 and mark 33, the amount of deviation in the vertical direction and the optimum number of pulses are calculated as described above. When all the shelves have been measured and the stacker crane 20 returns to its predetermined position, the operator commands it. The number of pulses for stopping the shelf of the control device 50 is updated by the optimum number of pulses. Note that an image processing device can be used as the sensor 40. [Effects of the Invention] According to the present invention, it is possible to easily and accurately measure a column.

[Brief explanation of drawings]

FIG. 1 is a front view of a shelf according to an embodiment of the present invention, FIG. 2 is a front view of a mark according to an embodiment of the present invention, and FIG. 3 is a front view of a lifting platform of a stacker crane according to an embodiment of the present invention. 4 is a block diagram of a control device according to an embodiment of the present invention, FIG. 5 is an overall flowchart for measurement, and FIG. 6 is a flowchart for calculating the optimum number of pulses. FIG. 7 is a plan view of the three-dimensional storage shelf, FIG. 8 is an enlarged front view of the three-dimensional storage shelf, and FIG. 9 is a front view of the stacker crane. 10------One three-dimensional storage column, 11---One shelf, 1
2a----One person exit, 12b---One exit, 2
0---111 stacker crane, 23---1 lifting platform, 31---bar code, 32.33---
--One reference point mark, 40------sensor, 41-
------ Barcode reader, 42.43----
One-dimensional sensor, 45.50----One control device, 51.
52-----Pulse En□// ¥2 Figure J/ ------t%-Board 12.33-44 points? -7 (3)

Claims (1)

[Claims] 1. Consisting of a three-dimensional shelf consisting of a large number of shelves, and a stacker crane that runs along the three-dimensional shelf and transports loads between the shelf and the loading/unloading entrance, the stacker crane runs In an automated warehouse equipped with a control device that performs a stop operation by integrating the number of pulses generated by The stacker crane is installed facing the running route, and includes a reader that reads the bar code, a one-dimensional sensor that reads the position of the mark, and a number of pulses at the stop position based on the amount of deviation read by the one-dimensional sensor. An automatic warehouse characterized by comprising a control circuit for correction.