JPH08268552A - Control method of each layer picking device - Google Patents

Abstract

PURPOSE: To prevent overturning and crushing of picking object goods by controlling advancing speed of a carriage by a picking condition of the picking object goods. CONSTITUTION: When the fact that a pickup roller 8 installed on the tip of a carriage 6 advances up to a specific distance position from picking object goods is detected, advancing speed of the pickup roller 8 is reduced, and the picking object goods can be prevented from being damaged by collision. When the fact that one end of the picking object goods is raised by the pickup roller 8 is detected, the advancing speed of the pickup roller 8 is increased up to predetermined speed according to rotating speed of the pickup roller, and a movement of the center of gravity of the picking object goods in the pickup roller 8 direction is facilitated, and overturning of the picking object goods is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling a layer-by-layer picking apparatus, in which picked articles stacked on a warehouse shelf are taken out from the uppermost picked article in layers and transferred to a predetermined position. The present invention relates to prevention of rising and falling of picked products.

[0002]

2. Description of the Related Art A layer-by-layer picking device is one in which picked articles stacked on a distribution warehouse shelf are taken out layer by layer from the top and transferred to a predetermined place. The operation of the picking device for each layer when the picked products stacked on the distribution warehouse rack are taken out for each layer will be described below with reference to the operation process chart of FIG. 7. The layered picking device moves, for example, the carriage 6 in the direction of the picked article 3 and
The pickup roller 8 is rotated in the direction in which the picked item 3 is lifted. When the pick-up roller 8 hits the picked article 3 as shown in FIG. 7A, the picked article 3 in the front row is lifted on the pick-up roller 8 as shown in FIG. 7B by the rotation of the pick-up roller 8. To be Thereafter, as shown in FIG. 7C, the picked articles 3 are successively lifted and sent to the carriage roller 13. In this way, when the topmost picked product 3 stacked on the distribution warehouse shelf is taken out, the carriage 6 and the pickup roller 8 stop at an appropriate position and then move back to a predetermined position to pick up the picked product 3 Finish taking out. However, as shown in FIG. 7C, when the picked article 3 in the last row is lifted by the pickup roller 8, the center of gravity of the picked article 3 moves and the picked article 3 leans against the front stopper 14. When the carriage 6 starts to move backward,
As shown in (d), the inclination may become large and the vehicle may fall.

On the other hand, in the layer picking device disclosed in Japanese Unexamined Patent Publication No. 4-303330, a lower front stopper for pressing the lower side of the picked article 3 and the picked article 3 are provided.
The upper front stopper that holds down the upper side of the picked item 3 is picked up when the picked item 3 in the last row is picked up and the upper front stopper is pushed out when the picked item 3 in the last row is picked up. It reliably moves from the roller 8 to the carriage roller 13 to prevent the picked article 3 from tipping over.

Further, in the layer picking apparatus disclosed in Japanese Patent Laid-Open No. 4-303331, the forward speed of the carriage is slowed until the pickup roller collides with the end face of the picked article in the uppermost layer, and the impact caused by the collision is applied. The picking product is prevented from being damaged, and the advance speed of the carriage is increased immediately after the collision to prevent the pickup work efficiency from decreasing.

[0005]

However, the double-layer picking device described above cannot prevent the articles to be picked in the middle row from falling over during picking. The principle when the picked articles in the middle row fall down during picking will be described below with reference to FIG. For example, when the height H of the picked article 3 is low, and the width W of the picked article 3 in the pickup direction and the height H of the picked article 3 are high.
In the case of W / 2 ≦ H, the picked product 3 is likely to fall. This is because when the height H of the picked article 3 is small, the picked article 3 is less likely to be caught later, and the width W of the picked article 3 in the pickup direction and the height H of the picked article 3 are W. This is because the center of gravity G of the picked product 3 is less likely to move from the contact point B of the picked product 3 to the pickup roller 8 side when / 2≤H.

When picking up the picked article 3 having a low height H or the picked article 3 having a width W and a height H of W / 2≤H, the forward speed of the carriage is constant. If the speed is slower than the above speed, the center of gravity G of the picked product 3 does not move in the direction of the pickup roller 8 because the force in the direction of arrow A does not act on the picked product 3 and eventually the picked product falls.

Further, if the advance speed of the carriage is slowed until the pick-up roller collides with the end face of the picked article in the uppermost layer, the picking work efficiency is improved when the pick-up roller and the picked article are separated from each other. It cannot avoid falling.

If the pick-up roller is made to speed up the carriage forward immediately after the pick-up roller collides with the end surface of the picked article in the uppermost layer, as in the above-mentioned separate picking apparatus.
The picked-up product may be pressed against the picked product before the picked product is lifted, and the picked product may be crushed.

The present invention has been made to solve the above disadvantages. When the picked article is taken out, the forward speed of the carriage is controlled by the picking state of the picked article to prevent the picked article from falling or crushing. The purpose is to improve picking work efficiency.

[0010]

A method for controlling a layer-by-layer picking device according to the present invention detects a pick-up roller attached to the tip of a carriage to a position at a certain distance from a picked article. The forward speed of the pickup roller is lowered to a speed at which the picked article is not damaged by the collision, and when it is detected that one end of the picked article is lifted by the pickup roller, the forward speed of the pickup roller is predetermined according to the rotation speed of the pickup roller. Up to the desired speed.

[0011]

According to the present invention, when it is detected that the pick-up roller attached to the tip of the carriage has moved to a position of a certain distance from the picked article, the forward speed of the pick-up roller is reduced to a speed at which the picked article is not damaged by collision. However, the impact at the time of collision between the pick-up roller and the picked product is reduced.

Further, when it is detected that one end of the picked product is lifted by the pickup roller, the forward speed of the pick-up roller is increased to a predetermined speed according to the rotation speed of the pick-up roller to pick up the center of gravity of the picked product. Easy to move in the roller direction.

[0013]

1 is a side view of a layer-by-layer picking device showing an embodiment adopting the control method for the layer-by-layer picking device of the present invention. As shown in the figure, the layered picking device 1
Is to transfer the picked articles 3 stacked and stored on the pallet-loaded article storage shelf 2 to the layer-unit storage shelf 4, for example, the pallet-loaded article storage shelf 2 and the layer-unit storage shelf 4
It moves up and down along the mast of the stacker crane 5 traveling along.

The layered picking device 1 has a carriage 6 and a rear stopper 7, as shown in the perspective view of FIG. The carriage 6 includes picking roller arms 6a, 6b and 6c each including a slide arm, a pickup roller 8 provided at a tip end in the direction of the pallet-loaded article storage rack 2, a load detection sensor 9, and a lift detection sensor 10. When the picked article 3 is taken out, the carriage 6 is provided with a pallet-loaded article storage shelf 2 up to the front of the picked article 3 to be taken out.
Move vertically and horizontally along. After moving the carriage 6 to the front of the picked article 3 to be taken out,
Extend the picking roller arms 6a, 6b, 6c,
The pick-up roller 8 is horizontally moved toward the pallet-loaded article storage rack 2 at a speed at which the picked article 3 can be immediately decelerated to a speed at which the picked article 3 is not damaged by the collision. The pick-up roller 8 rotates in a direction to lift the picked articles 3, and picks up the picked articles 3 stacked on the pallet loaded article storage rack 2 in layers from the uppermost layer. The pick-up roller 8 is low at the front so that the picked article 3 can be easily mounted. The load detection sensor 9 is composed of, for example, a photo sensor, is located at both front ends of the pick-up roller 8, and detects that the pick-up roller 8 has approached a fixed distance of the picked article 3. The lifting detection sensors 10 are located at both upper ends of the pickup roller 8, for example, and detect that the picked article 3 is lifted by the pickup roller 8.

The rear stopper 7 is mounted on the carriage 6 and has a rear pressing arm 11 and a regulating arm 12. The rear pressing arm 11 has multi-stage slide arms 11a, 11b, 11c that can move along the carriage 6 as shown in the perspective view of FIG. To expand and contract. Regulation arm 12
Is provided at the tip of the rear pressing arm 11 at almost the same height as the surface of the carriage 6, and when the picked article 3 is picked up, the movement of the picked article 3 in the traveling direction of the carriage 6 is opposite to the traveling direction of the carriage 6. Regulate from the direction. Since the rear stopper 7 includes the regulation arm 12 provided at substantially the same height as the surface of the carriage 6, the picked article 3 regulates the movement of the carriage 6 in the traveling direction.
Regulated by. Since the picked article 3 is prevented from moving in the direction opposite to the traveling direction of the carriage 6, the force with which the carriage 6 presses the picked article 3 becomes large. Eventually, the frictional resistance between the carriage 6 and the picked article 3 becomes sufficiently large, and the carriage 6 can take out the picked article 3. In addition, the regulation arm 12
Restricts the movement of the picked articles 3 below the picked articles 3, so that the picked articles 3 in the last row are prevented from leaning against the regulation arm 12 even if the picked articles 3 in the last row are tilted.
The picked article 3 is prevented from tipping over when retreating. The regulating arm 12 is formed of a roller or the like to reduce the frictional resistance between the picked article 3 and the picked article 3 in the last row, and the rear portion of the picked article 3 moves downward due to the frictional resistance. You may make it prevent from being pulled.

Next, the layered picking apparatus 1 having the above-mentioned structure
Will be described with reference to the flowchart of FIG. 4 and the operation process diagram of FIG. 5 when the picked articles 3 stacked and stored on the pallet loaded article storage shelf 2 are taken out.

When the stacker crane 5 travels along the pallet-loaded article storage rack 2 and advances to the pallet-loaded article storage rack 2 in which the picked articles 3 to be taken out are stored and then stopped, as shown in FIG. 5 (a). Stratified picking device 1
Aligns with the upper side of the shelf 2 in which the picked article 3 from which the rear stopper 7 is to be taken out is raised or lowered to be taken out (step S1). Then, the layered picking device 1
As shown in FIG. 4B, the rear surface pressing arms 11a, 11b, 11c of the rear surface stopper 7 are extended until the regulating arm 12 is located behind the picked article 3. Thereafter, the layered picking device 1 descends, and as shown in FIG. 5C, from the designated height of the load of the uppermost layer of the picked article 3 from which the regulating arm 12 is to be taken out, for example, from below the load of the uppermost layer. Three
Lower to a height of about 0 mm (step S2).

The picking apparatus 1 for each layer moves the carriage 6 horizontally toward the picked article 3 while rotating the pickup roller 8. Here, if the forward movement speed of the carriage 6 is too fast, it is not possible to immediately reduce the speed to such a degree that the picked article 3 is not damaged by the collision. On the other hand, if the advance speed of the carriage 6 is too slow, the picking efficiency becomes poor. Therefore, as shown in FIG. 6, the carriage 6 advances at a speed V ₀ that can be immediately reduced to a speed that does not damage the picked article 3 due to a collision. (Step S3).

Pickup roller 8 is picked product 3
When a certain distance is approached to, the load detection sensor 9 blocks the light, so that the picked article 3 is detected as shown in the waveform diagram of FIG. 6 (step S4). When the load detection sensor 9 detects the picked product 3, the layered picking device 1 reduces the forward speed of the carriage 6 to a speed Vl at which the picked product 3 is not damaged by a collision (step S5).

Thereafter, the pickup roller 8 is moved to the position shown in FIG.
As shown in (d), when the picked article 3 hits the lower front portion of the picked article 3, the picked article 3 is pressed against the pickup roller 8 since the movement of the carriage 6 in the traveling direction is restricted by the restriction arm 12 of the rear stopper 7. To be

The picked article 3 is a pickup roller 8
Lifted upward due to frictional resistance between and. When the tip of the picked item 3 is lifted, the lifting detection sensor 10 detects light picked up by the picked item 3 and the picked item 3 is lifted as shown in the waveform diagram of FIG. 6 (step S6). . When the lifting detection sensor 10 detects that the tip of the picked article 3 is lifted,
As shown in the waveform diagram of FIG. 6, the pickup roller 8 increases the forward speed to a speed Vh which is predetermined according to the rotation speed of the pickup roller 8 (step S7).

Now, the relationship between the rotation speed of the pickup roller and the speed Vh predetermined according to the rotation speed will be described. As already described with reference to FIG. 8, the picked product 3 having a low height H or the picked product 3 having a relationship in which the width W and the height H in the pickup direction are W / 2 ≦ H.
When the carriage 6 is picked up, if the forward speed of the carriage 6 is slower than a certain speed, the force in the direction of arrow A does not act on the picked item 3 and the center of gravity G of the picked item 3 does not move in the pickup roller 8 direction. Eventually, the picked item 3 will fall. Therefore, in order to prevent the picked item 3 from falling, the picked item 3 is indicated by the arrow A.
The power of should work. For that purpose, the upper end of the rear end of the picked article 3 is always in contact with the subsequent picked article 3 until the picked article 3 moves onto the pickup roller 8. As shown in the figure, if the rotation speed of the pickup roller 8 is v and the radius of the pickup roller 8 is h, the horizontal distance L between the central axis of the pickup roller 8 and the lower rear end of the picked article 3 is L = K · √
((W-vt) ^2- (2h) ² ). However, K is a coefficient related to friction and slippage. Therefore, the horizontal distance L between the central axis of the pickup roller 8 and the lower rear end of the picked article 3 is dL / dt = -v. (W-vt).
/ K · √ ((W-vt) ² − (2h) ² ) It is considered that this is the speed at which the picked item 3 picked up moves away from the picked item 3 later. Therefore, the forward speed Vh of the pickup roller 8 is v ·
If it is faster than (W−vt) / K · √ ((W−vt) ² − (2h) ² ), the picked item 3 is the later picked item 3
Will be in contact with. Therefore, from the time when the picked article 3 is lifted by the pickup roller 8 to the time when the center of gravity is moved onto the pickup roller 8, for example, the rotation speed v of the pickup roller 8 and Vh ≧ v · (W−vt) /
The pickup roller 8 is advanced at a speed Vh having a relationship of K · √ ((W-vt) ^2- (2h) ² ). In the experiment, if the pickup roller 8 is moved forward with Vh> 0.4 · v, no fall occurs. Here, since the friction and slip between the picked article 3 and the pallet are not taken into consideration in the above empirical formula, a coefficient K is generally applied and Vh> K.
・ 0.4 ・ v.

When the pickup roller 8 is advanced at the above-described forward speed, the center of gravity G of the picked article 3 moves in the direction of the pickup roller 8 and the picked article 3 rides on the pickup roller 8. When the picked article 3 gets on the pickup roller 8, the load detection sensor 9 does not detect the picked article 3 until the picked article 3 approaches the next picked article 3 as shown in FIG. 6 (step S8). When the load detection sensor 9 stops detecting the picked product 3, the pickup roller 8 returns the forward speed to the speed V _{0 at} which the picked product 3 can be immediately decelerated to the extent that the picked product 3 is not damaged by the collision (step S9).

Thereafter, similarly, the carriage 6 advances, and as shown in FIG. 4 (f), when all the picked articles 3 of the uppermost layer are placed on the carriage 6 (step S10), the carriage 6 and the rear surface stopper 7 retreat. Then, the picked item 3 is completely taken out. In this way, when it is detected that one end of the picked item 3 is lifted by the pickup roller 8, the forward speed of the carriage 6 is increased to a speed having a predetermined relationship with the rotation speed of the pickup roller 8, and the picked item 3 is picked up. Center of gravity pickup roller 8
Since it is easy to move in the direction, the picking work 3 of the picked product 3 in a layer unit can be reliably performed, and the picked work 3 is prevented from being damaged by being overturned or crushed.

Further, when it is detected that the pickup roller 8 at the tip of the carriage 6 has advanced to a position of a certain distance from the picked article 3, the advance speed of the pickup roller 8 is slowed down to a predetermined speed so that the pickup roller 8 is Since the impact of the picked article 3 at the time of collision is reduced, the picked article 3 can be prevented from being damaged.

In the above embodiment, both the load detection sensor 9 and the lifting detection sensor 10 are provided. However, the load detection sensor 9 detects the picked product 3 and the picked product 3 is lifted. You may do it.

Further, without using the load detection sensor 9 and the lifting detection sensor 10, the picked article 3 is detected using the position data of the picked article 3 which is input in advance.
The lift of the picked product 3 may be detected by the time after the pickup roller 8 reaches the end surface of the picked product 3. Here, the lifting time T of the picked product 3 is T = h /, where h is the height of the picking roller 8 with respect to the lower end of the picked product 3.
It becomes v + α. α indicates an increase in the lifting time of the picked item 3 due to a slip between the pickup roller 8 and the picked item 3.

In the above embodiment, photo sensors are used as the load detection sensor 9 and the lifting detection sensor 10, but
A pressure sensor or the like may be used to simultaneously measure the pressure applied to the picked article 3.

Further, in the above embodiment, as shown in FIG. 6, the forward speed of the pickup roller 8 is controlled in three stages, but the forward speed of the pickup roller 8 is adjusted by adjusting the rotational speed of the pickup roller 8. Is Vh which is a speed having a predetermined relationship with the rotation speed of the pickup roller 8.
Therefore, it is possible to immediately lower the speed Vl to the extent that the picked article 3 is not damaged by the collision,
The forward speed of the pickup roller 8 may be controlled in two stages.

[0030]

As described above, according to the present invention, when it is detected that the pickup roller at the tip of the carriage has reached a position of a certain distance to the picked product, the forward movement speed of the pickup roller does not collide with the picked product. Since the speed is slowed down and the impact at the time of collision between the pickup roller and the picked product is reduced, the picked product can be safely picked up.

Further, when it is detected that one end of the picked product is lifted by the pickup roller, the forward speed of the carriage is increased to a predetermined speed in accordance with the rotation speed of the pick-up roller to pick up the pick-up roller of the center of gravity of the picked product. Since it is easy to move in the direction, it is possible to prevent the picked article from falling and crushing.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a perspective view of a layered picking device.

FIG. 3 is a perspective view of a back pressing arm.

FIG. 4 is a flowchart illustrating an operation of the stratified picking device.

FIG. 5 is an operation process diagram showing a picking operation of a picked product.

FIG. 6 is a waveform diagram showing a signal for controlling the forward speed of the pickup roller.

FIG. 7 is an operation process chart showing an operation of a conventional stratified picking device.

FIG. 8 is an explanatory diagram showing a falling principle of a picked product.

[Explanation of symbols]

 1 Picking device for each layer 2 Pallet loaded item storage shelf 3 Stored picked item 4 Layer unit storage shelf 6 Carriage 7 Rear stopper 8 Pickup roller 9 Load detection sensor 10 Lift detection sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Ikusawa, 1-2, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor, Shinichiro Eto 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Tube Co., Ltd.

Claims (1)

[Claims] 1. A control of a layer-by-layer picking device for picking up an uppermost picked article on a carriage by a pickup roller attached to a tip of a carriage that moves in parallel toward stacked picked articles and rotating at a constant speed. In the method, when it is detected that the pickup roller attached to the end of the carriage has advanced to a position at a certain distance from the picked product, the forward speed of the pickup roller is reduced to a speed at which the picked product is not damaged by a collision. A method for controlling a layered picking device, comprising detecting that one end of the pickup roller is lifted by a pickup roller and increasing a forward speed of the pickup roller to a predetermined speed according to a rotation speed of the pickup roller.