JP3370147B2 - Article transfer control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article transfer control device used in, for example, an automatic warehouse. 2. Description of the Related Art Conventionally, storage shelves into which articles (work) are to be stored are selected based on empty shelf data for a large number of storage shelves provided in an article storage, and the selected storages are selected. The storage of the articles on the shelves is automatically performed by the article receiving operation by the traveling crane, and the articles to be taken out are selected based on the inventory data on the articles stored in the respective storage shelves. 2. Description of the Related Art There is known an automatic warehouse configured to automatically carry out an article from a storage shelf in which articles are stored by an article unloading operation using a traveling crane. A traveling crane used for loading and unloading articles in such an automatic warehouse is also called a stacker crane, and is configured to travel on rails laid along the article storage. The traveling crane is
A mast erected on the base and extending in the vertical direction, a lifting table supported by the mast and raised and lowered along the mast,
An article transfer means such as a running fork for transferring an article placed on the elevator to a storage shelf, and for transferring articles from the storage shelf to the elevator, traveling drive control of a traveling crane, and an elevator And a control means for performing drive control of the lifting and lowering and drive control of the article transfer means. When the traveling control of the traveling crane and the elevation control of the elevator are performed, for example, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open No. 1-156308, it is known to control the speeds of a traveling motor and a lifting motor based on an acceleration / deceleration pattern set based on a relative position from a start position and a destination position. [0005] By the way, in the loading / unloading operation using the traveling crane having the above-described configuration, the traveling crane moves in the horizontal direction and the lifting platform on which the articles are placed moves in the vertical direction. Is performed at the same time, thereby speeding up the loading and unloading work. For this reason, the elevating platform draws a moving trajectory in an oblique direction. [0006] However, some of the articles placed on the elevator are considerably heavy, and the elevator on which the articles made of the heavy articles are placed is located above the mast.
When the traveling crane is moved in the horizontal direction, there is a problem in that the mast is swayed. [0007] Therefore, in order to avoid the lateral swing of the mast, it is desirable that the traveling crane be moved horizontally in a state where the elevator is as low as possible below the mast. There is a possibility that the efficiency of the outgoing work may be reduced . [0008] In view of the above circumstances, the present invention is to provide a poise reduce the efficiency of the entry and leaving work, the article transport control device capable of reducing the deflection side of the lifting platform support member, such as a mast With the goal. According to the present invention, there is provided an article transport control device for an automatic warehouse, comprising:
And a traveling crane that moves in and out
A vertically extending machine on the base of the lane.
And the mast, which is held by the mast and
In article transport controller having a lifting platform which later, when the movement of the elevator platform and the movement of the traveling crane is performed simultaneously, as the locus drawn by the said lifting platform is convex downward, the lifting Increase the traveling crane acceleration when the platform rises
Larger than the platform, and the deceleration of the traveling crane
While making it smaller than the platform,
Reduces the acceleration of the traveling crane compared to the elevator, and
The traveling crane is provided with control means for making the deceleration larger than that of the lifting platform . [0010] The article conveyance control device according to the operation and effect of the present invention, as the locus drawn by the lifting platform is convex downward, traveling crane and vertical movement speed of the temperature <br/> Fudai because a control means for controlling the horizontal movement speed of the lifting platform is Ma
Will be moving in close proximity to the lower end of the strike, the placed article lifting platform even with heavy, it is possible to reduce the deflection side of the mast. Embodiments of the present invention will be described below with reference to the accompanying drawings. As schematically shown in FIG. 1, a traveling crane 1 is configured to travel horizontally on a rail 3 laid along an article storage 2 and is erected on a base 4. A mast 5 extending in a vertical direction, a lift 6 held by the mast 5 and moving up and down along the mast 5, and an article (hereinafter referred to as “work”) 7 placed on the lift 6 are stored in a storage 2. And a traveling motor for moving the traveling crane 1 such as a running fork or the like for transferring the workpiece 7 from the shelf of the hangar 2 to the elevating platform 6. And control means for controlling the drive of a lifting motor for raising and lowering the lift 6 and the drive of the article transfer means. Next, the drive control of the traveling motor and the lift motor will be described. FIG. 2 is a diagram showing basic speed characteristics common to the horizontal movement of the traveling crane 1 and the vertical movement of the lift 6. In the figure, V _MAX is the limit speed (maximum speed), t ₀ is the time required for movement, t ₁ is the acceleration time from zero speed to reach the limit speed V _MAX , t ₂ is the speed from the limit speed V _MAX to zero speed It is the deceleration time until. Since the moving distance D of the lift 6 is represented by the area of the trapezoid shown in FIG. 2, D = [t ₀ + (t ₀ −t ₁ −t ₂ )] V _MAX / 2. _{= (2t 0 -t 1 -t2)} V MAX / 2 (1) of the drive control of the running motor and the lifting motor by the control means, wherein, at the time of rise of the lifting table 6, extends from zero speed to the limit speed V _MAX relates acceleration time t ₁ until, shorter in the horizontal movement than in the vertical direction moving, and relates deceleration time t ₂ from the limit velocity V _MAX until zero speed, vertical movement than in the horizontal movement Is shorter. On the other hand, when the elevator 6 descends, the acceleration time t ₁ from zero speed to the limit speed V _MAX is opposite to the acceleration time t ₁ .
Shorter in the vertical direction moving than in the horizontal movement, and relates deceleration time t ₂ from the limit velocity V _MAX until zero speed, better in the horizontal movement than in the vertical direction moving it is shorter. Here, the moving distance of the traveling crane 1 in the horizontal direction: L (m) (moving by the traveling motor) The moving distance of the lifting platform 4 in the vertical direction: H (m) (moving by the lifting motor) Horizontal limit speed: V _{MAX L} Vertical limit speed: V _{MAX H} Horizontal travel time: t _L Vertical travel time: t _H When the horizontal movement and the vertical movement are simultaneously performed, assuming that the horizontal limit speed V _{MAX L} is equal to the vertical limit speed V _{MAX H} , L> L
If H, t _L > t _H , and if L <H, t _L <t _H
It becomes. Therefore, when L ≠ H, in order to set t _L = t _H = t ₀ , the one that requires more moving time is moved at the limit speed, and the other is moved at a speed lower than the limit speed. good. Therefore, the speed characteristic on the side moving at the limit speed is called the basic limit speed characteristic, and the limit speed V _{MAX L} when the horizontal moving side moves at the basic limit speed characteristic is V _MAX.
Let _L0 be the limit speed V _{MAX H} when the vertical movement side moves with the basic limit speed characteristic, V _{MAX H0} . Now, it is assumed that t _L = t _H = t ₀ and that t _a <t _b
When the times t _a and t _b having the following relationship are substituted for the acceleration time t ₁ and the deceleration time t ₂ , when the lift 6 is lifted, FIG.
4A and 4B, and when the lift 6 descends, it becomes as shown in FIGS. 4A and 4B. The above equation (1) becomes the following equation (2). D = (2t ₀ −t _a −t _b ) V _MAX / 2 (2) By controlling the driving of the traveling motor and the elevating motor in this manner, the trajectory drawn by the elevating table 6 becomes As shown by the reference numeral Q in FIG. 1, the projection becomes downward, so that the lateral run-out of the mast 5 that occurs when the heavy workpiece 7 is raised or lowered in an oblique direction can be quickly converged. (Embodiment 1) Assuming that the basic speed characteristics are t _a = 0.5 sec and t _b = 1.5 sec, the moving distance D is obtained from the equation (1) as follows: D = (2t ₀ -0.5-1) .5) V _MAX / 2 Therefore, D = (2t−2.0) V _MAX / 2 (3) In addition, the length of the hangar 2 is set to 10 m, the height is set to 13 m, and the basic limit speed V _MAX of the traveling crane 1 is set. _L0 = the basic limit speed V _{MAX H0 of the} lift 6 is 3 m / sec. (Specific Example 1) From the origin O, L = 10 m,
When storing a work in the storage shelf of H = 1m (rising): L
> H, the horizontal movement side is set to the basic limit speed characteristic (V _{MAX L0} = 3 m / sec). And D = L = 10m,
Substituting V _MAX = V _{MAX L0} = 3 m / sec into equation (3) gives
t0 = 4.333 sec. Next, the required time t0 = 4.333 sec.
Then, a vertical moving speed characteristic is created so that D = H = 1 m. That is, from the equation (3), the vertical limit speed V _{MAX H is} 0.3 m / sec. Accordingly, the horizontal speed characteristics and the vertical speed characteristics are as shown in FIGS. 5A and 5B, respectively, and the movement trajectory Q of the lift 6 is as shown in FIG. 5C. Become. (Specific Example 2) From the origin O, L = 10 m,
When a work is stored in a storage shelf of H = 10 m (rise):
Since L = H, it moves at V _{MAX L0} = V _{MAX H0} = 3 m / sec, and from equation (3), t ₀ = 4.333 s
ec. The horizontal speed characteristic in this case is shown in FIG.
In addition, the vertical velocity characteristics are as shown in FIG. 6B, and the movement trajectory Q of the lift 6 is as shown in FIG. 6C. (Specific Example 3) From the origin O, L = 3 m, H
= Work is stored in a storage shelf of 8 m (rise): L <
Since it is H, the vertical movement side is set to the basic limit speed characteristic (V _{MAX H0} = 3 m / sec). Then, D = H = 8m, V
_By substituting _MAX = V _{MAX H0} = 3 m / sec into equation (3), t
₀ = 3.667 sec, V _{MAX L} = 1.129 m / sec
Therefore, the horizontal speed characteristics are as shown in FIG. 7A, the vertical speed characteristics are as shown in FIG. 7B, and the movement trajectory Q of the lift 6 is as shown in FIG. 7C. . (Specific Example 4) When the work is taken out from the storage shelf with L = 10 m and H = 2 m (down): Since L> H, the horizontal movement side is set to the basic limit speed characteristic (V _{MAX L0).}
= 3 m / sec). From equation (3), t ₀ = 4.333 sec,
Since V _{MAX H} = 0.6 m / sec, the horizontal speed characteristics are as shown in FIG. 8A, and the vertical speed characteristics are as shown in FIG. 8B. (Specific Example 5) When a work is taken out from a storage shelf with L = 8 m and H = 12 m (down): Since L <H, the vertical movement side is set to the basic limit speed characteristic (V _{MAX H0).}
= 3 m / sec). From equation (3), t ₀ = 5.0 sec, V _{MAX
Since L} = 2 m / sec, the horizontal speed characteristic is shown in FIG.
FIG. 9A shows the vertical velocity characteristics shown in FIG. 9B. (Embodiment 2) In this embodiment, the basic speed characteristics and the method of obtaining the moving distance D are the same as those in Embodiment 1, but the basic limit speed of the traveling crane 1 and the basic limit speed of the lift 6 are different. This is the case when they are different from each other. That is, V _{MAX L0} = 2 m / sec, V _{MAX H0} = 3 m
/ Sec. (Specific Example) From the origin O, L = 9 m, H = 1
When storing a work in a 2m storage shelf (elevated):
It is determined in the following manner which of the horizontal movement side and the vertical movement side has the basic limit speed characteristic. For the horizontal movement side, L = 9 m, V _MAX
The _L0 = 2m / sec (3) are substituted into equation and determine the travel time t _L, a t _L = 5.5sec. On the vertical movement side, H = 12 m and V _{MAX H0} = 3 m / sec are substituted into the equation (3) to determine the movement time tH. As a result, t _H = 5.0 sec.
It becomes. That is, since t _L > t _H , the horizontal movement side is set to the basic limit speed characteristic (V _{MAX L0} = 2 m / se).
c). Therefore, t ₀ = t _L = 5.5 sec, and the limit speed V _{MAX H} on the vertical movement side is 2.667 m / sec. The horizontal speed characteristics in this case are shown in FIG.
The vertical speed characteristics are as shown in FIG. As is apparent from the above description, in the present embodiment, when the elevator 6 rises, the acceleration time required for the traveling crane 1 to reach the limit speed V _{MAX L} from the zero speed is determined by the speed of the elevator 6 being zero. From the acceleration speed until reaching the limit speed V _{MAX H} and the traveling crane 1
The deceleration time from _{MAX L} to zero speed is determined by the elevator 6
Is longer than the deceleration time from the limit speed V _{MAX H} to the speed zero (the reverse when the lift 6 is lowered), the movement locus of the lift 6 becomes convex downward, and the traveling crane Therefore, it is possible to reduce the lateral deflection of the mast 5 during the traveling of the vehicle 1. Next, an example of a program executed by the control means of the traveling crane 1 at the time of loading and unloading of the work will be described with reference to the flowcharts of FIGS. In the following description, S represents a step. First, initialization is performed in step S1 of FIG. 11, and it is determined in step S2 whether the workpiece has been entered or left. If it is a warehouse, the traveling crane 1 is moved to the loading tray in S3, the work 7 is transferred from the loading tray to the lifting platform 6 in S4, and the traveling crane 1 is moved to the work storage position in S5. The work is transferred from the lifting table 6 to the storage shelf. On the other hand, in the case of unloading, the traveling crane 1 is moved to the work take-out position in S7, the work 7 is transferred from the storage shelf to the lift 6 in S8, and the traveling crane 1 is moved in S9.
Is moved to the delivery table, and the work is transferred from the lifting table 6 to the delivery table in S10. FIG. 12 shows a routine executed between each step of S3, S5, S7 and S9 of FIG. 11 and the next step after each step. In this routine, as described in the first and second embodiments, the moving distances L and H in the horizontal direction and the vertical direction are determined in S11, and
In 12, the basic limit speed characteristic is determined to be L side or H side, and S 1
At 3, the time t ₀ required for the movement is calculated, and at S14, the basic speed characteristics are determined. Then, based on this basic speed characteristic, a speed command signal is output to the L-side and H-side drive motors (servo motors) in S15, and it is determined whether or not the target position has been moved in S16. S while NO
15, when the determination in S16 becomes YES, the process proceeds to the next step in FIG.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an article transfer control device according to the present invention. FIG. 2 shows basic speed characteristics common to a horizontal movement of a traveling crane and a vertical movement of an elevator. FIG. 3 is a diagram showing speed characteristics when the elevator is raised. FIG. 4 is a diagram showing speed characteristics when the elevator is lowered. FIG. 5 is a specific speed characteristic when the elevator is raised. FIG. 6 is a diagram showing specific speed characteristics when the elevator is raised and a diagram showing the movement trajectory of the elevator. FIG. 7 is a diagram showing specific movement when the elevator is raised. FIG. 8 is a diagram showing a speed characteristic and a movement locus of the elevator. FIG. 8 is a diagram showing specific speed characteristics when the elevator is lowered. FIG. 9 is a line showing specific speed characteristics when the elevator is lowered. FIG. 10 is a diagram showing specific speed characteristics when the elevator is raised. 11] control means of the traveling crane is a flowchart showing an example of a program to be executed during the work entry and leaving 12] Description of Flowcharts [code indicating the speed characterization routine] 1 traveling crane 2 of the article hangar 3 rail 4 traveling crane mast 6 the lifting platform 7 work of the base 5 traveling crane (goods)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-276705 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65G 1/04 G05B 19/18 G05D 3 / 12 G05D 13/62

Claims (1)

(57) [Claims] [Claim 1] Water along an article storage shelf in an automatic warehouse
A loading and unloading traveling crane that travels in a horizontal direction, and a vertical extension on the base of the traveling crane.
The mast provided , and a lift held by the mast,
In the article transport control device having a platform, when the movement of the platform and the movement of the traveling crane are performed simultaneously, the locus of the platform is convex downward , so that the The acceleration of the traveling crane when climbing
Larger than the elevator, and the deceleration of the traveling crane is
Make it smaller than the platform and lower the platform
In order to reduce the acceleration of the traveling crane
An article transport control device comprising a control means for setting a deceleration of the traveling crane larger than that of a lifting platform .