JPH06271008A - Stop controller for mover in automatic warehouse - Google Patents

Abstract

PURPOSE:To stop a mover accurately in a specified position by detecting a mark for discrimination of stop position at deceleration of a mover, and operating the number of pulses at stop position, based on the number of counter pulses at this times, so as to control the mover to be stopped. CONSTITUTION:When a mover shifts along a guide course, each of encoders 19 and 21 generates pulses, and each of counters 30 and 31 counts these pulses so that they may be added or subtracted at advance or retreat. Moreover, sensors 20 (a and b) and 22 (a and b) loaded on the mover read the marks for discrimination of stop position arranged on a guide course. Furthermore, a storage means 28 stores the numbers A and B of pulses corresponding to a set distance from the reference position to the mark and a set distance from the mark to the stop position, respectively. And, the mark is detected at deceleration of the mover, and at this time the number of pulses, substituting the number A of pulses for it, while the number of pulses at stop position is calculated by adding the number B of pulses to the number A of pulses, whereby the mover is controlled by a control means 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movement stop control device for a moving body such as a stacker crane in an automatic warehouse provided in a factory or the like.

[0002]

2. Description of the Related Art As a control method for stopping a stacker crane used in an automatic warehouse at a predetermined position, for example, Japanese Patent Publication No. 60-44203 discloses a conventional method.
The crane main body is equipped with a rotary encoder that rotates without contacting the fixed side without causing slippage, and corresponds to the distance traveled by the crane from the home position for every load-carrying unit on the rack with the load-carrying unit in a matrix. There is disclosed a method of presetting (setting and storing) the number of pulses to be performed in advance and stopping the crane when the number of pulses from the rotary encoder reaches a preset value corresponding to the set destination.

[0003]

In the above method, the rotary encoder must be rotated so as not to relatively cause slippage, so that means such as a rack and a pinion are required. Also, since the counting error in the counter that counts the number of pulses from the rotary encoder that allows the occurrence of some relative slippage is not accumulated, the counter value is reset to zero (counting) when the crane returns to the home position. Is set to 0) to make a correction.

By the way, since the actual stop accuracy of the crane itself is not ± 0, an error is generated at the stop position where the crane returns to the home position. In the publication, in order to solve the drawback, a stop position correction detecting means (mark) capable of detecting an error between the movement start reference point and the actual stop position of the transporting movable body at the home position.
Is provided to correct the pulse set value corresponding to the set destination.

However, in any of the above-mentioned conventional techniques, no measure is taken for the counting error of the counter due to the slip of the rotary encoder during the process (the going process, the returning process) in the middle of not returning to the home position. When stopping at a predetermined destination,
Even if the crane is stopped when the counter value matches the set value, there is a problem that the transporting mobile body cannot be accurately stopped at a predetermined location.

An object of the present invention is to solve this problem and to provide a stop control device for a moving body in an automatic warehouse, which can accurately stop the moving body for transportation at a predetermined position. .

[0007]

In order to achieve the above object, a stop control device for a moving body in an automatic warehouse according to the present invention includes an encoder that works together when a moving body for transportation moves along a guide route, and the encoder. A counter for adding the pulse from the forward direction and subtracting the pulse for the backward direction, a stop position determination mark provided on the guide path, a sensor mounted on a moving body for conveyance to read the stop position determination mark, and a reference position. To a stop position determination mark, and a storage unit that stores the number of section setting pulses corresponding to the setting distance from the mark and the stop setting pulse number corresponding to the setting distance from the mark to the stop position, respectively When in the moving range, the sensor detects a stop position determination mark, and the pulse number of the counter at that time is replaced with the section setting pulse number and stored. On the other hand, a control means is provided for adding the stop setting pulse number to the replaced section setting pulse number to calculate the stop position pulse number, and controlling to stop the transporting movable body at the stop position pulse number. It is characterized by that.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described. FIG. 1 is an automatic warehouse in which a stacker device 2 running along the front surface of a pair of left and right shelves 1, 1 can be used for cargo delivery. FIG. 2 shows a partially cutaway front view. Figure 1
As shown in FIG. 3, the shelf 1 includes a plurality of base members 4 laid on the floor surface 3 at regular intervals so as to intersect the stacker device 2 at a right angle, and a plurality of base members 4. It consists of upright columns 5 and shelf plates 6 provided on each column 5 at regular intervals in the vertical direction, whereby the load receiving spaces 7 are formed in a matrix shape in the vertical and horizontal directions. The left and right sides of the lower surface of the luggage W are placed on 6, 6 respectively.

The stacker device 2 has a traveling base 9 which can travel along a lower guide rail 8 which is laid between the upper surfaces of the base members 4 laid in parallel, and a vertically long corner which is erected on the traveling base 9. The column 10 includes a cylindrical column 10 and a vertically movable rail (not shown) provided at a corner portion of the outer peripheral surface of the column 10, and a vertically movable elevator base 11 that is vertically movable.
Although not described in detail, a loading unit 12 such as a fork section that moves back and forth toward each loading space 7 in the shelves 1, 1 is provided, and the loading unit 12 loads and unloads the load W into and from the shelves 6, 6. To do.

The traveling base 9 is provided with traveling wheels 13, 13 which are placed on the lower guide rail 8 and roll, and the upper end of the column 10 is suspended by a connecting member 14 connecting the upper ends of the shelves 1, 1. It has guide wheels 16, 16 which are inserted into an upper guide rail 15 having a downwardly-facing U-shape that supports and rolls. The stacker device 2 is equipped with a drive motor 17 for traveling and a drive motor 18 for raising and lowering the elevator 11; however, these drive motors are not mounted on the stacker device but are arranged at a fixed position, and a pulling wire or the like is installed. You may make it run and raise / lower through it. The traveling platform 9 includes a traveling unit encoder 19 such as a rotary encoder for measuring a traveling distance of the traveling platform 9, and a non-contact traveling unit sensor 20 for detecting a mark on the base member 4 or the like. It is provided. Further, the lifting platform 11 includes a lifting unit encoder 21 such as a rotary encoder for measuring the vertical movement distance of the lifting platform 11, and the shelf 1.
And a non-contact lift sensor 22 for detecting the position of the cargo receiving space 7 arranged in the vertical direction.

As shown in FIG. 4, the traveling section sensor 20 is composed of a pair of a forward movement sensor 20a and a backward movement sensor 20b, and an elevating section sensor 22 as shown in FIG. And a descending sensor 22b, and the sensor of each portion is a light reflection type including a light emitting portion and a light receiving portion. Then, in the traveling section sensor 20, when the traveling platform 9 advances in the direction of arrow A, the position of the one end 4a of the base member 4 having the width dimension E1 which is the traveling stop position determination mark in the traveling direction is set as the forward movement sensor 20a. Then, it advances to the position of the chain double-dashed line in FIG. 4 (distance E1) and stops. When the traveling platform 9 retreats in the direction of arrow B, the position of the other end 4b of the base member 4 is detected by the forward movement sensor 20b, and the vehicle advances to the position of the alternate long and two short dashes line in FIG. 4 (distance E1) and stops (FIG. 4).

On the other hand, the elevating section sensor 22 corresponds to the interval of the load receiving space 7 in the vertical direction, and the front end in the traveling direction with respect to the elevating stop position determining mark 23 of the length E2 attached to the side surface of the column 10. The position of the lift sensor 22a can be detected when the lift table 11 moves up in the U direction.
The position of the lower end 23a of the mark 23 is detected at, and the position is advanced to the position of the alternate long and two short dashes line in FIG. When the lift table 11 descends in the D direction, the lowering sensor 22b detects the position of the lower end 23b of the mark 23, advances to the position of the chain double-dashed line in FIG. 5 (distance E2), and stops (FIG. 5). reference).

It should be noted that whether or not each of the columns 5 of the shelf body 1 is tilted or bent in the direction of arrow A or B of FIG. A teaching sensor 24 for detecting is provided. A computer installed in the stacker device 2 for the traveling / stop control of the traveling platform 9 and the elevating / stopping control of the elevating platform 11 in the stacker device 2 or on an operation panel in an automatic warehouse or another central command device. A read-only memory (ROM) 27 that is executed by a central processing unit (CPU) 26 in the control means 25 such as the above, and these central processing units 26 store the programs of the respective controls.
Randomly readable and writable memory (R
AM) 28, input / output interface 29, counter 3
0 and 31 are connected, and the input / output interface 29 is connected to the drive motors 17 and 18 and the sensors 20a and 20.
b, 22a, 22b, 24 and encoders 19, 21 are connected (see FIG. 6). By inputting the data of the coordinate position of the cargo receiving space 7 to be loaded and unloaded to the operation panel or the central command device, the lifting platform 11 can be positioned at the designated position of the cargo receiving space 7 arranged in a matrix,
A command signal for moving the stacker device 2 in the A or B direction and a command signal for moving the lift table 11 in the U or D direction are sent to the central processing unit 26 mounted on the stacker device 2 by optical communication.

Next, as an example of the transporting movable body, the traveling stop control of the traveling platform 9 will be described. As shown in FIG. 2, the forward movement sensor 20a is attached to the other end 4b of the base member 4 at a designated destination among the base members 4 arranged at a constant interval (appropriate interval) in the right direction from the reference position O.
When the two match, the traveling of the traveling platform 9 is stopped.

First, first, a set distance X ₁ from the reference position (origin, movement start point) O to the starting end 4a of each base member 4 as a stop position discrimination mark arranged along the frontage direction of the shelf _{1. , X 2, X 3, X} 4, ‥‥ X n interval setting pulse number corresponding to _{P 1, P 2, P 3} , P 4, for storing the ‥‥ P _n in RAM 28, the running board at manual operation The position of each of the starting ends 4a is detected by the forward movement sensor 20a while moving 9 along the guide rail 8 which is a guide path (teaching traveling). At this time, the encoder 19 generates a pulse number according to the moving distance from the reference position O, and the pulse number is counted and stored in the RAM 28. The number of pulses e1 corresponding to the distance E1 from the one end 4a to the other end 4b of the base member 4 is also counted and stored.

The elevating table 11 is held at an appropriate height, and the teaching sensor 24 detects the traveling distance of the side edges of the columns 5 in the direction A, and the starting ends 4a of the base members 4 are detected.
Calculate the deviation amount from the mileage up to. By performing this measurement while changing the holding height of the lifting table 11, it is possible to detect the degree of inclination or bending in the A direction at the mid-height position of each of the columns 5.

Next, a flow chart shown in FIG. 7 for an embodiment of stop control in the case where the stacker device 2 is caused to travel during the actual unloading work and stopped at four n-th base members counting from the reference position O to the right. The stacker device 2 is stopped so that the forward movement sensor 20a coincides with the reference position O. Following the start, the counter 30 is reset to zero by initialization and the count value is returned to 0 (step S1).

Then, traveling in the direction of arrow A is started, the traveling section encoder 19 is operated, and counting by the counter 30 is started (step S2). This running unit encoder 19
The number of pulses generated in step 3 is counted by the counter 30,
It is added when moving forward (moving in the direction of arrow A in FIG. 2) and subtracted when moving backward (moving in the direction of arrow B in FIG. 2). The traveling speed of the stacker device 2 is, as shown in FIG.
It has an acceleration range, a constant speed range, and a deceleration range, and the constant speed range is set to change according to the distance to the specified destination. Therefore, if the destination is specified, the acceleration end point and deceleration are set. The starting point is automatically calculated, and predetermined acceleration, deceleration and steady speed are also designated and executed.

As shown in step S3, when the vehicle reaches the deceleration start point after accelerating to constant speed traveling (step S3).
4), deceleration running is executed (step S5). During this deceleration traveling, when the forward movement sensor 20a detects the position of the one end 4a of the n-th base member 4 (step S6), the counter value C by the counter 30 at this time is read (step S7). Running encoder 1
In consideration of the occurrence of slippage error and the like of the rotating portion of No. 9, the number of section setting pulses P _n corresponding to the selected distance X _n from the reference point O to the one end 4a of the n-th base member 4 is set to the RAM 28.
And the counter value C in the counter 30
Is replaced with P _n and reset (step S8). In addition, the reset counter value C (= P _n ) is stored in the RAM.
While the data is stored in another storage area of 28 (step S
9), the stop setting pulse number e1 corresponding to the set distance E1 from the one end 4a to the other end 4b of the base member 4 stored in the RAM 28 is called, and the stop position calculation of Co = C + e1 is executed (step S10). When the counter value reaches Co, the traveling platform 9 is stopped.

In this way, the stop position discriminating mark is attached to the set distance shorter than the moving distance from the reference position to the stop position at the designated destination, and the stop position discriminating mark is detected by the sensor, Since the interval setting pulse number is replaced so as to eliminate the error in the counter value, the measurement error by the encoder can be corrected (corrected) before the actual stop. In other words, every time you specify the destination of the transport vehicle and move toward it, the measurement error by the encoder can be corrected (corrected) before the stop position at that destination, so you can return to the home position as before. It is possible to reduce the error of the stop position after the moving body for transportation is moved, as compared with the case of correcting the measurement error by the encoder after that.

The stop setting pulse number is further calculated based on the corrected counter value to measure the stop position. Therefore, the counter value simply measured by the encoder during actual traveling and the specified stop position are associated with each other. Compared with stopping the transporting moving body (traveling platform 9) when the number of stop position setting pulses is equal to the above, it is possible to obtain an effect that an error is extremely small at the stop position of the transporting moving body.

Since the stop position determination mark is detected by the sensor when the transporting moving body is decelerating and traveling, an accident such as a detection omission (missing) is eliminated.
The detection accuracy is also improved. For the stop control when the elevator 11 moves up and down, the elevator encoder 21, the elevator sensor 22, and the counter 31 for the elevator may be used, and the same control as the above-described traveling stop control may be performed. Since it is sufficient, detailed description will be omitted. Also, the counters 30, 3
Instead of 1, a partial area of the readable / writable memory (RAM) 28 may be used as a counter memory area at any time.

Further, the sensor may be a laser beam reflection reading device, and a post mark or the like may be added as a stop position determining mark on the side surface of the base member 4, the column 10 or the like.

[0024]

As described above, according to the present invention, an encoder that interlocks when a moving body for conveyance moves along a guide path and a pulse from the encoder are added when moving forward and subtracted when moving backward. Counter, a stop position determination mark provided on the guide route, a sensor mounted on a moving body for reading the stop position determination mark, and a set distance from the reference position to the stop position determination mark Storage section for storing the number of section set pulses and the number of set stop pulses corresponding to the set distance from the mark to the stop position respectively, and when the transporting vehicle is in the deceleration movement range, the stop position is detected by the sensor. The discrimination mark is detected and the pulse number of the counter at that time is replaced with the section setting pulse number and stored, while the stop setting pattern is set to the replaced section setting pulse number. The number of stop position pulses is added to calculate the number of stop position pulses, and the control means is controlled to stop the transfer moving body at the stop position pulse number, so the destination of the transfer moving body is specified. Each time you move toward it, you can correct (correct) the measurement error by the encoder before the stop position of the destination, so you can correct the measurement error by the encoder after returning to the home position as in the past. In comparison, it is possible to reduce the error in the stop position after the moving body for transportation is moved.

The stop setting pulse number is further calculated based on the corrected counter value to measure the stop position, so that the counter value obtained by simply measuring the encoder during actual traveling corresponds to the specified stop position. As compared with stopping the transporting mobile object when the number of stop position setting pulses is the same, it is possible to obtain an effect that an error is extremely reduced at the stop position of the transporting mobile object.

Further, the stop position determination mark is detected by the sensor because the transporting moving body is decelerating and traveling, so that accidents such as detection omission (missing) are eliminated.
There is an effect that the detection accuracy is also improved.

[Brief description of drawings]

FIG. 1 is a side view of an automated warehouse.

FIG. 2 is a partially cutaway front view of the same.

FIG. 3 is a partial perspective view of a shelf body.

FIG. 4 is a diagram illustrating a relationship between a traveling unit sensor and a stop position determination mark.

FIG. 5 is a diagram showing a relationship between a lift sensor and a stop position determination mark.

FIG. 6 is a functional block diagram of control means.

FIG. 7 is a control flowchart.

FIG. 8 is a traveling speed diagram.

[Explanation of symbols]

 1 Shelf 2 Stacker device 4 Base member 9 Traveling platform 11 Lifting platform 17 Traveling drive motor 18 Lifting drive motor 19 Traveling section encoder 20 Traveling section sensor 21 Lifting section encoder 22 Lifting section sensor 23 Mark

Claims (1)

[Claims] 1. An encoder that interlocks when a moving body for transportation moves along a guide path, and a counter that adds a pulse from the encoder when moving forward and subtracts a pulse when moving backward.
A stop position determination mark provided on the guide path, a sensor mounted on a transporting movable body to read the stop position determination mark, and a section setting pulse corresponding to a set distance from the reference position to the stop position determination mark And a storage means for storing the number of stop setting pulses corresponding to the set distance from the mark to the stop position, respectively, and when the transporting movable body is in the deceleration movement range, the stop position determining mark is displayed by the sensor. The detected pulse number of the counter at that time is replaced with the section setting pulse number and stored, while the stop setting pulse number is added to the replaced section setting pulse number to calculate the stop position pulse number. A stop control device for a moving body in an automated warehouse, comprising control means for controlling the moving body for transportation to stop at the number of stop position pulses.