JP2003081410A - Automatic conveying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic conveying system capable of properly loading and unloading a load at all times by setting a distance between movable racks and an automated forklift truck 2 to a distance suitable for loading and unloading the load. SOLUTION: This system comprises a stop means for stopping the movable racks 1 when the movable racks 1 move to the automated forklift truck 2 stopped between the movable racks 1 and the distance between the movable racks 1 and the automated forklift truck 2 reaches a pre-set stop distance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire traveling type movable rack which moves on the floor along the front-rear direction, and a movable rack which is driven along guide lines laid vertically and horizontally on the floor. The present invention relates to an unmanned transport system that automatically transports a load in combination with an unmanned forklift that loads and unloads the load.

[0002]

2. Description of the Related Art Conventionally, as an unmanned conveying system of this type, there is one that adopts a configuration as shown in FIG. 9, for example.

This unmanned transport system comprises a plurality of tire-traveling movable shelves 1 for storing loads, and an unmanned forklift 2 for transporting loads. Each moving shelf 1 has a tire 3 attached to the bottom of the shelf, and a traveling device (not shown) that drives each tire 3 is provided. The traveling device drives the tires 3 to move, so that the movable rack 1 moves on the floor along the front-rear direction.

On the other hand, the unmanned forklift 2 is of an autonomous traveling type, and a vehicle body is provided with a guide sensor (not shown) for magnetic detection. The guide sensor guides magnetic tapes laid vertically and horizontally on the floor. The vehicle runs along the guide line 4 while detecting the line 4.

In this unmanned transport system, the movable shelves 1 that do not require loading and unloading of loads are arranged close to each other, while the moving shelves 1 that require loading and unloading of loads are:
The shelf 1 is moved by a predetermined distance to form a passage through which the unmanned forklift 2 can enter. Then, when the movable rack 1 stops at a predetermined position, next, after the unmanned forklift 2 enters the passage between the movable racks 1 along the guide line 4,
Loading and unloading are performed on the frontage of the designated mobile shelf 1.

As described above, the unmanned transfer system in which the movable rack 1 and the unmanned forklift 2 are combined is used for loading and unloading a load.
Not only can the labor required for carrying out be greatly reduced, but moving shelves 1
By using, the occupying area required for the shelf installation can be greatly reduced, and conversely, if the occupying area is the same, there is an advantage that the storage amount of the load can be greatly increased as compared with the fixed shelf.

Further, when the above-mentioned tire traveling type movable rack 1 is used, since there is no step on the floor surface as compared with the rail traveling type movable rack 1, when the unmanned forklift truck 2 travels across the rails. There is an advantage that no vibration is generated and the facility cost and labor for laying the rail can be saved.

[0008]

However, when the tire traveling type movable rack 1 is used in the conventional unmanned conveying system, there is still room for improvement in the following points.

The movable rack 1 is a heavy object loaded with a load, and in the case of a tire traveling type, the braking distance changes depending on the surface condition such as the slope or unevenness of the floor surface or the condition of the brake mechanism or the like. Therefore, even when an attempt is made to stop at a regular stop position preset as an appropriate separation distance from the unmanned forklift 2, it is likely that the vehicle will be displaced from the regular stop position to the front and the rear. Hereinafter, the positional shift along the front-back movement direction of the movable rack 1 will be referred to as the front-back shift. In other words, in order to stop the moving rack, a mark indicating the stop position is attached to the floor surface, and when this mark is detected by the detector provided on the moving rack, the moving rack is stopped. Will occur.

On the other hand, the unmanned forklift 2 may be stopped optimally so that the guide line 4 and the center of the vehicle body are aligned with each other when entering between the movable shelves. You have to stop in front of you, and if you stop as it is, there will be a back-and-forth shift.

That is, the movable rack itself has a stop error, and the unmanned forklift 2 itself also has a stop error, which causes two types of error factors. Therefore, if such a back-and-forth shift occurs in each of the movable shelf and the unmanned forklift 2, the forks of the unmanned forklift 2 cannot be brought close to the proper rack position of the movable shelf 1,
As a result, loading and unloading may not be performed properly. In the worst case, the fork of the unmanned forklift 2 may not reach the predetermined load mounting position on the movable shelf 1 and a problem such as the inability to load and unload the load may occur.

Therefore, an object of the present invention is to eliminate one of the error factors that existed in the moving rack and the unmanned forklift, respectively, and set the distance between the moving rack and the unmanned forklift to a distance suitable for loading and unloading a load, and always to make it appropriate. It is an object of the present invention to provide an unmanned transfer system capable of loading and unloading various loads.

[0013]

In order to achieve the above-mentioned object, the present invention travels along a movable rack that moves in the front-rear direction on a floor surface and a predetermined traveling path, An unmanned transportation system including an unmanned forklift for loading and unloading a moving shelf is as follows.

That is, in the unmanned transport system according to the first aspect of the present invention, the movable rack moves toward the unmanned forklift that has entered and stopped between the movable racks, and the movable rack and the unmanned forklift are connected. It is characterized in that it is provided with a stop means for stopping the movable rack when the separation distance reaches a preset stop distance.

As a result, the stop position of the movable rack with respect to the unmanned forklift is determined, so that the stop error of the unmanned forklift is canceled. Therefore, there is only one error factor, and the accuracy of the separation distance between the movable rack and the unmanned forklift truck can be easily obtained. For this reason, loading and unloading work can be performed accurately and safely.

According to the second aspect of the present invention, the unmanned transfer system comprises a preliminary position stopping means for stopping the movable rack at a preliminary position retracted from a regular stop position preset as a distance from the unmanned forklift, and the movement. After the shelf has stopped at the preliminary position, the unmanned forklift has moved to the position corresponding to the predetermined frontage of the movable shelf along the guideway, and the unmanned forklift has advanced to the predetermined frontage position. After that, the vehicle further comprises a normal position stop means for detecting whether or not the vehicle has moved to the regular stop position by traveling the movable rack again, and stopping the movement when it is detected that the movable rack has reached the regular stop position. Is characterized by.

As a result, the movable rack does not go straight from the traveling state to the regular stop position, but temporarily stops at the preliminary position retracted from the regular stop position. Then, after the unmanned forklift enters the position corresponding to the predetermined frontage of the movable rack, the movable rack again travels and gradually approaches the unmanned forklift at a slow speed, and stops when the vehicle body is detected. For this reason, the movable rack is always stopped at the proper position without causing the front-back shift, and it is possible to appropriately load and unload the load. Moreover, in this case, on the unmanned forklift side, when the vehicle travels between the shelves, the traveling track is corrected so that the center of the vehicle body is deviated in the direction orthogonal to the traveling direction according to the amount of front-rear displacement of the moving shelves. Since it is not necessary to perform such control, the traveling control of the unmanned forklift truck becomes easy.

According to a third aspect of the present invention, in the unmanned conveyance system according to the second aspect of the invention, the preliminary position stopping means arranges the object to be detected at the preliminary position on the floor surface, A preliminary position detection sensor for detecting the presence / absence of the detected object is provided for the movable shelf, and a traveling stop means for stopping traveling in response to the detection of the detected object by the preliminary position detection sensor. It is characterized by that.

Thus, the movable rack can be stopped at the preliminary position with a simple structure in which the object to be detected provided on the floor surface and the preliminary position detection sensor provided on the movable rack are combined.

According to a fourth aspect of the present invention, in the unmanned transportation system according to any one of the first to third aspects of the invention, the stop means or the normal position stop means is attached to the movable rack. A vehicle body detection sensor for detecting a part of the vehicle body of the unmanned forklift, and traveling stopping means for stopping traveling of the movable shelf in response to detection of the vehicle body of the unmanned forklift truck by the vehicle body detection sensor. It is characterized by being.

As a result, it is possible to detect that the movable shelf itself has approached the unmanned forklift and stop the unmanned forklift at the proper stop position, and it is not necessary to change the structure of the unmanned forklift.

According to a fifth aspect of the present invention, in the unmanned conveyance system according to the fourth aspect of the present invention, the vehicle body detection sensor is arranged in a plurality of stages along the height direction of the movable shelf. It has a feature.

Thus, even when the movable shelf is tilted back and forth in the moving direction, the vehicle body of the unmanned forklift truck can be detected according to the height position of the shelf, so that the position at that height position becomes the normal position. It can be stopped. For this reason,
Even when the movable rack is tilted back and forth, it is possible to always load and unload properly.

According to a sixth aspect of the present invention, in the unmanned conveyance system according to any one of the first to third aspects, the stopping means or the normal position stopping means is the unmanned forklift. A distance measuring sensor for measuring the distance to the movable rack and a traveling stop signal for stopping the traveling of the movable rack when the distance measuring sensor measures that the movable rack has approached a predetermined distance. While transmitting means is provided, traveling stop means for stopping the traveling of the movable shelf in response to a traveling stop signal from the unmanned forklift truck is provided.

As a result, the relative distance to the movable rack is measured on the unmanned forklift side, and the movable rack is stopped when the predetermined relative distance is reached, so that the movable rack can be stopped at the regular stop position. . Moreover, since the relative distance is measured on the unmanned forklift side according to the height position of the moving rack, it is not necessary to dispose the vehicle body detection sensor in a plurality of stages along the height direction of the moving rack. The configuration can be simplified.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a plan view showing the overall configuration of an unmanned transfer system according to Embodiment 1 of the present invention, FIG. 2 is a block diagram of a control system of a moving shelf used in the system, and FIG. 3 is an unmanned forklift used in the system. FIG. 4 is a perspective view of a three-way stacking mechanism portion of the unmanned forklift, and FIG. 5 is a block diagram of a control system of the unmanned forklift used in the system.

The unmanned transport system according to the first embodiment is
A tire traveling type moving rack 1 and an unmanned forklift 2 for loading and unloading a load from the moving rack 1 are provided.

A guide line 4 made of magnetic tape or the like is laid on the floor where the unmanned forklift 2 travels. The guide line 4 in this case is an approach line 4a for allowing the unmanned forklift 2 to enter and travel between the movable shelves 1.
And a traveling line 4b for traveling the unmanned forklift 2 closer to a certain position on the movable rack 1, and both 4a and 4b are arranged orthogonally to each other. Therefore,
The entry line 4a extends in a direction orthogonal to the moving direction of the movable shelf 1. Then, to the left and right of the approach line 4a, magnetic rods 7 that give reference positions for stopping the unmanned forklift 2 at a position corresponding to a predetermined frontage of the movable rack 1 are provided.
Are embedded at a predetermined pitch along the longitudinal direction of the entry line 4a. Further, on the same floor surface, a reference line 8 for lateral deviation detection, which is made of magnetic tape or the like, is laid along the moving direction in the front and rear of the movable shelf 1.

Further, on the floor surface, a pair of magnetic poles 9 for stopping the preliminary position, which serve as an object to be detected for regulating the preliminary position of the movable rack 1, are embedded. Each of these magnetic poles 9 for stopping the preliminary position is based on the approach line 4a, and the approach line 4a
Is arranged at a position P1 further retracted from a regular stop position P0 (hereinafter, simply referred to as a regular position) of the movable rack 1 which is separated from the approach line 4a by a predetermined distance L1. There is. In this case, the regular position P0 of the movable rack 1 is set in advance so that it can be appropriately loaded and unloaded with the unmanned forklift 2. Further, the distance ΔL (= L1−L0) between the regular position P0 and the preliminary position P1 is set in advance so as to be somewhat larger than the maximum value of the front-rear deviation occurring on the movable rack 1.

The movable rack 1 has tires 3 mounted on the bottom thereof, a traveling device 10 for driving these tires 3, a lateral shift detection sensor 12 for detecting a lateral shift amount in a direction orthogonal to the moving direction of the movable rack 1, A preliminary position detecting sensor 15 for detecting the magnetic rods 9 for stopping the preliminary positions and a vehicle body detecting sensor 16 for detecting the presence or absence of the vehicle body of the unmanned forklift 2 are provided. Furthermore, the traveling device 1 is based on the detection outputs of the sensors 12, 15, and 16.
A controller 17 including a microcomputer for controlling 0 is provided. The controller 17 has a memory 17a that stores various data and an arithmetic control unit 17b that controls each unit including the traveling device 10 and the like. The controller 17 corresponds to the traveling stop means of the movable rack in the claims.

The lateral deviation detection sensor 12 is, for example, a magnetic sensor in which a plurality of Hall elements are arranged in an array along the longitudinal direction of the movable shelf 1, and has a different voltage value depending on the position where the reference line 8 is crossed. By outputting the signal, the lateral shift amount of the movable shelf 1 is detected. Further, each preliminary position detection sensor 15 is composed of a magnetic sensor such as a Hall element. Further, the vehicle body detection sensor 16 is configured, for example, by arranging the light emitting element 16a and the light receiving element 16b opposite to each other on the arm portion protruding from the lower portion of the column located at both ends of the movable shelf 1 in the longitudinal direction. There is.

Reference numerals 21 and 22 denote optical communication devices arranged on the floor, which are connected to a controller 17 provided on the movable shelf 1 via a transmission cable 20.
Data communication is performed between the movable rack 1 and the unmanned forklift 2 via 1 and 22.

On the other hand, the unmanned forklift 2 has a vehicle body 23.
Traveling wheels 24 are provided on the front side of the vehicle and driving steered wheels 25 are provided on the rear side thereof.
And a three-way stacking mechanism 27 is provided along the mast 26 so that the three-way stacking mechanism 27 can be moved up and down by a lift mechanism (not shown).

As shown in FIG. 4, the three-way stacking mechanism 27 is provided so that the shift carriage 32 can slide along the pair of upper and lower shift rails 31 formed on the lift bracket 30 toward the left and right of the vehicle body 23. A finger bar 33 is rotatably provided on the shift carriage 32, and a fork 34 is fixed to the finger bar 33. Therefore, the fork 34
Can be shifted in the left-right direction of the vehicle body 23 by a predetermined length,
In addition, it can be turned in the front direction and each of the left and right directions, and is further moved up and down along the mast 26 by the lift mechanism. A light blocking plate 35 for blocking the light from the vehicle body detection sensor 16 provided on the movable rack 1 is fixed to each of the left and right ends of the lift bracket 30.

A guide sensor 36 for detecting the guide line 4 is provided in front of and behind the bottom of the vehicle body 23 of the unmanned forklift 2.
However, a pair of count sensors 37 for detecting the above-mentioned magnetic rods 7 are attached to the left and right positions close to the traveling wheels 24, respectively. Each guide sensor 36 is a magnetic sensor having the same configuration as the lateral deviation detection sensor 12 provided on the movable shelf 1, and each count sensor 3 is also provided.
Reference numeral 7 is composed of a magnetic sensor such as a Hall element.

Further, the vehicle body 23 includes a traveling device 40 for driving and driving the driving steered wheels 25, a steering device 41 for steering, a traveling encoder 42 for measuring a traveling distance, and optical communication devices 21, 22. An optical transmission unit 43 and an optical reception unit 44 that perform optical communication between them are provided, and a controller 45 including a microcomputer or the like is provided. The controller 45 has a memory 45a that stores various data and an arithmetic control unit 45b that controls each unit including the three-way stacking mechanism 27, the traveling device 40, the steering device 41, and the like. The light transmitting unit 43 and the light receiving unit 44 are arranged, for example, on the front side of the vehicle body 1 and on the side surface of the vehicle body so that the light transmitting and receiving of the light beam does not interfere. They are installed at appropriate places.

The magnetic rod 9 for stopping the preliminary position described above,
The preliminary position detecting sensor 15 and the controller 17 of the movable rack 1 constitute preliminary position stopping means in the claims. In addition, the controller 1 of the mobile shelf 1
7 and the one optical communication device 22 constitute an entrance permission unit. Further, the vehicle body detection sensor 16 and the controller 17 of the movable shelf 1 constitute a normal position stopping means.

Next, the operation of loading and unloading the load in the unmanned transportation system having the above-mentioned structure will be described.
This will be described with reference to FIGS. 1, 6 and 7.

As shown in FIG. 1, for example, when the moving rack 1 is present at the position P2 away from the entry line 4a and loading / unloading of the moving rack 1 is required, The controller 17 controls the traveling device 10 to start moving toward the predetermined approach line 4a. At that time, the unmanned forklift 2 is stopped at a predetermined standby position on the travel line 4b. Further, when the movable rack 1 moves, the lateral deviation detection sensor 12 detects the lateral deviation amount from the reference line 8, and accordingly, the controller 17 controls the traveling device 10 according to the detected amount and moves. Correction is performed so that the attitude of the shelf 1 and the lateral shift are reduced.

When the preliminary position detecting sensor 15 detects the preliminary position stopping magnetic rod 9 as the movable shelf 1 moves, the controller 17 accordingly causes the traveling device 10 to move.
To stop driving. Therefore, as shown in FIG. 6, the movable rack 1 is temporarily stopped at the preliminary position P1 which is further retracted from the regular position P0 by a distance ΔL.

At this time, depending on the condition of the floor surface, the movable rack 1
However, since the distance ΔL between the regular position P0 and the preliminary position P1 is set in anticipation of the maximum value of the front-back displacement that occurs on the movable rack 1, the unmanned forklift 2 enters. There is no hindrance when traveling along the line 4a.

In this way, once the movable rack 1 stops at the preliminary position P1, the controller 17 outputs a permission signal for starting the entry between the movable racks 1 to the unmanned forklift 2 via the optical communication device 22. When the permission signal is received by the light receiving unit 44, the controller 45 of the unmanned forklift 2 drives the traveling device 40 and the steering device 41 based on the detection output of the guide sensor 36 and starts autonomous traveling. Then, after changing the direction from the traveling line 4b to the approach line 4a, the vehicle enters between the movable shelves 1 along the approach line 4a.

Then, the controller 45 of the unmanned forklift 2 includes a count sensor 37 and a traveling encoder 42.
It is determined whether or not the vehicle body 23 has reached the position corresponding to the predetermined frontage of the movable shelf 1 based on the detection output of 1., and when it is determined that the vehicle body 23 has reached the predetermined position, the traveling by the traveling device 40 is stopped. Then, the optical communication device 21 is transmitted through the optical transmitter 43.
Sends an entry completion signal to the.

When this approach completion signal is received by the optical communication device 21, this approach completion signal is sent to the controller 1 of the mobile shelf 1.
7, so the controller 1
7 starts the traveling device 10 to start traveling the movable rack 1 again. In this case, the controller 17 controls the traveling device 10 so that the traveling device 10 travels at a speed sufficiently slower than the traveling speed at which the vehicle travels from the position P2 to the preliminary position P1.

The mobile shelf 1 is an unmanned forklift 2
The light-emitting element 1 of the vehicle body detection sensor 16
The light beam emitted from 6a is blocked by the light blocking plate 35 attached to the unmanned forklift 2, and the light receiving element 16b
Since no light is received by the controller 17, the controller 17 stops the traveling device 10 accordingly.

Here, since the traveling distance is short and the vehicle travels at a low speed until the movable rack 1 is stopped, no back and forth displacement occurs when the movable rack 1 is stopped. Therefore, FIG.
As shown in, the movable rack 1 is always stopped at the regular position P0 maintaining the appropriate relative distance L0 with respect to the unmanned forklift 2. After that, on the unmanned forklift 2 side, a lift mechanism (not shown) is operated to operate the fork 34.
Is moved up and down to the specified height where loading and unloading is required.

As described above, in this embodiment, the movable rack 1 does not go straight to the regular position P0 from the traveling state, but temporarily stops at the preliminary position P1 retracted from the regular position P0. Then, when the unmanned forklift 2 enters the position corresponding to the predetermined frontage of the movable shelf 1 and the movable shelf 1 travels again and gradually approaches the unmanned forklift 2 at a low speed, and detects the vehicle body 23 thereof. Stop at. Therefore, the movable rack 1 is always stopped at the regular position P0 without causing a front-back shift, so that it is possible to always load and unload properly.

In addition, when the movable rack 1 is stopped at the regular position P0, when the unmanned forklift 2 moves between the racks, the movable rack 1 is moved in the direction orthogonal to the approach traveling direction depending on the amount of front-rear displacement of the movable rack 1. It is not necessary to perform control such that the traveling trajectory is corrected so that the center of the vehicle body deviates from the approach line 4a. Further, even if the unmanned forklift is stopped in an emergency during traveling, it is not necessary to re-execute the correction control of the traveling track from the beginning. Therefore, the traveling control of the unmanned forklift truck becomes easy.

In the above embodiment, the pair of the light emitting element 16a and the light receiving element 1 which compose the vehicle body detection sensor 16 are provided.
6b and 6b are arranged opposite to the lower ends of the columns of the movable shelf 1, but the vehicle body detection sensor 16 is arranged in a plurality of stages along the height direction of the movable shelf 1 as shown in FIG. You can also In this case, in order to avoid mutual interference of the light beams of the vehicle body detection sensors 16 with each other, the light emitting element 16a
It is preferable that the mounting positions of the light receiving element 16b and the light receiving element 16b are different from each other.

In this way, if the vehicle body detection sensor 16 is arranged in a plurality of steps along the height direction of the movable rack 1, the movable rack 1 is moved in the moving direction because the floor surface is inclined, for example. If you are leaning forward or backward,
Since the vehicle body of the unmanned forklift truck 2 can be detected in accordance with each height position of the movable rack 1, it is possible to more reliably stop the position at that height at the regular position P0, and always load and unload properly. It will be possible to do.

Further, in this embodiment, the movable rack 1 is provided with the vehicle body detection sensor 16 to stop the movable rack 1 at the regular position P0. However, instead of this, for example, the unmanned forklift 2 may be used. A distance measuring sensor 46 may be attached to the tip of the fork 34, and the distance measuring sensor 46 may measure the distance to the horizontal rail of the moving shelf 1 to stop the moving shelf 1 at the regular position P0. Is.

That is, the distance measuring sensor 46 provided on the unmanned forklift 2 measures the distance between the movable rack 1 and the horizontal rail, and when the distance measuring sensor 46 detects that the movable rack 1 has approached a predetermined distance. The controller 45 transmits a traveling stop signal of the movable shelf 1 to the optical communication device 21 via the optical transmission unit 44. Then, when the traveling stop signal is received by the controller 17 of the movable rack 1 from the optical communication device 21, the controller 17 stops traveling in response thereto.

Therefore, also in this case, the movable rack 1 can be reliably stopped at the regular position P0. Moreover, since the relative distance between the unmanned forklift 2 and the height position of the movable rack 1 can be measured, the vehicle body detection sensor 16 can be moved along the height direction of the movable rack 1 as shown in FIG. The arrangement can be simplified because there is no need to arrange in multiple stages.

The present invention is not limited to the other configurations described in the above embodiment, either.
It goes without saying that the present invention can be appropriately modified and implemented without departing from the spirit of the present invention.

[0055]

According to the present invention, the following effects can be obtained. (1) In the unmanned transport system according to the invention of claim 1, the movable rack moves toward the unmanned forklift in a stopped state, and the distance between the movable rack and the unmanned forklift becomes a preset stopping distance. The stopping means stops the movement when the moving rack stops, so that the stop position of the movable rack is determined for the unmanned forklift. Therefore, the stop error of the unmanned forklift is canceled. That is, conventionally, there were two error factors, that is, a moving rack stop error and an unmanned forklift stop error.
The error factor is one of the stop errors of the moving rack, which facilitates the accuracy of the distance between the moving rack and the unmanned forklift.
For this reason, loading and unloading work can be performed accurately and safely.

Moreover, according to the present invention, the moving rack is brought closer to the stopped unmanned forklift, so that the following points are compared with the case where the unmanned forklift is brought closer to the stopped moving shelf. Has an advantage in.

That is, when the unmanned forklift is brought closer to the movable shelf, the traveling track is corrected so that the vehicle center of the unmanned forklift is laterally displaced from the guide line in the direction orthogonal to the traveling direction. Therefore, the traveling control is difficult and the control becomes complicated.
On the other hand, when the movable rack is brought closer to the unmanned forklift, the control is performed along the traveling direction of the movable rack, so that relatively simple traveling control is sufficient.

When an unmanned forklift is brought closer to the moving rack, a method of repeating the reciprocating motion of the unmanned forklift along the guide line in order to offset the amount of front-rear displacement of the moving rack can be considered. With this method, it takes time to stop at an appropriate position, and the efficiency of the cargo handling work is reduced. On the other hand, when the movable rack is brought closer to the unmanned forklift, it is only necessary to move the movable rack straight without the need for such reciprocating reciprocating motion.

Further, when the unmanned forklift is brought closer to the moving rack, all the wheels of the unmanned forklift are turned at right angles in order to cancel the amount of the front-rear displacement of the moving rack.
Although it is possible to move the unmanned forklift truck in a direction perpendicular to the traveling direction of the unmanned forklift truck, this complicates the device and increases the vehicle cost. On the other hand, when the movable rack is brought closer to the unmanned forklift, it is possible to cope with the movable rack itself without changing the conventional structure for traveling.

(2) In the unmanned transport system according to the invention described in claim 2, the movable rack does not go straight from the traveling state to the regular position, but temporarily stops at the preliminary position retracted from the regular position,
After the unmanned forklift enters the position corresponding to the predetermined frontage of the movable rack, the movable rack again travels to gradually approach the unmanned forklift at a low speed, and stops when the vehicle body is detected. Therefore, the movable rack surely stops at the regular position without causing a front-back shift, so that it is possible to always load and unload appropriately.

Further, in this case, on the unmanned forklift side, when the vehicle travels between the shelves, the traveling track is so displaced that the center of the vehicle body deviates in the direction orthogonal to the traveling direction of the traveling shelves according to the amount of front-rear displacement of the movable shelves. Since it is not necessary to perform control such as correction, the traveling control of the unmanned forklift truck becomes easy.

(3) In addition to the effects of the invention of claim 2, the unmanned transport system according to the invention of claim 3 has an object to be detected provided on the floor and a preliminary position detection sensor provided on the movable shelf. The movable rack can be stopped at the preliminary position with a simple configuration in which the above are combined.

(4) In addition to the effects of the invention of any one of claims 1 to 3, the unmanned transfer system according to the invention of claim 4 is characterized in that the movable shelf itself approaches an unmanned forklift. Since it can be detected and stopped at the regular position, it is not necessary to change the configuration of the unmanned forklift.

(5) In addition to the effect of the invention of claim 4, the unmanned transport system according to the invention of claim 5 has the vehicle body detection sensor arranged in a plurality of stages along the height direction of the movable shelf. Therefore, even when the moving shelf is tilted forward and backward in the moving direction, it is possible to detect the vehicle body of the unmanned forklift according to the height position of the shelf and stop it at the normal position. Therefore, it is possible to always load and unload properly.

(6) In addition to the effects of the invention of any one of claims 1 to 3, the unmanned transport system according to the invention of claim 6 provides the relative distance between the movable shelf and the unmanned forklift. Since the movable rack is stopped after the measurement and when the predetermined relative distance is reached, the movable rack can be stopped at the regular position. Moreover, since the relative distance is measured on the unmanned forklift side according to the height position of the moving rack, it is not necessary to dispose the vehicle body detection sensor in a plurality of stages along the height direction of the moving rack. The configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a plan view showing an overall configuration of an unmanned transport system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control system of a mobile shelf in the system.

FIG. 3 is a side view of an unmanned forklift in the system.

FIG. 4 is a perspective view of a three-way stacking mechanism portion of the unmanned forklift.

FIG. 5 is a block diagram of a control system of the unmanned forklift in the system.

FIG. 6 is an explanatory diagram of a control operation in the system.

FIG. 7 is an explanatory diagram of a control operation in the system.

FIG. 8 is a perspective view showing a modified example of the movable rack in the unmanned transport system according to the embodiment of the present invention.

FIG. 9 is a perspective view showing the overall configuration of a conventional unmanned transport system.

[Explanation of symbols]

1 mobile shelf 2 unmanned forklift 4 induction lines 9 Magnetic rod for stopping the preliminary position (object to be detected) 15 Preliminary position detection sensor 16 Body detection sensor 17 Mobile shelf controller 21,22 Optical communication device 45 Unmanned forklift controller 46 range sensor

Claims (6)

[Claims] 1. A mobile shelf that moves along a front-rear direction on a floor surface, and an unmanned forklift that travels along a predetermined travel path to load and unload loads from the mobile shelf. In the unmanned transfer system, the movable rack moves toward the unmanned forklift that has entered and stopped between the movable shelves, and the separation distance between the movable rack and the unmanned forklift is a preset stop distance. An unmanned transfer system comprising stop means for stopping the movable shelf when the mobile shelf is turned off. 2. A mobile shelf that moves along the front-rear direction on the floor surface, and an unmanned forklift that travels along a predetermined travel path to load and unload loads from the mobile shelf. In the unmanned transfer system, a preliminary position stopping means for stopping the movable rack at a preliminary position retracted from a regular stop position preset as a separation distance from the unmanned forklift, and after the movable rack stops at the preliminary position Entry permitting means for allowing the unmanned forklift to enter a position corresponding to a predetermined frontage of the movable rack along the guide line, and re-traveling the movable rack after the unmanned forklift enters the predetermined frontage position. To stop the movement when it is detected that it has moved to the regular stop position. An unmanned transportation system comprising: 3. The preliminary position stopping means disposes a detected object at the preliminary position on the floor surface, and a preliminary position detection sensor for detecting the presence or absence of the detected object with respect to the movable shelf, The unmanned transport system according to claim 2, further comprising: travel stopping means for stopping travel according to detection of the detected object by the preliminary position detection sensor. 4. The stop means or the normal position stop means detects a part of the vehicle body of the unmanned forklift truck with respect to the movable rack, and the vehicle body detection sensor detects the vehicle body of the unmanned forklift truck. The unmanned transfer system according to any one of claims 1 to 3, further comprising: travel stop means for stopping the travel of the movable shelf in accordance with the above. 5. The unmanned transfer system according to claim 4, wherein the vehicle body detection sensors are arranged in a plurality of stages along the height direction of the movable shelf. 6. The distance measuring sensor for measuring the distance between the unmanned forklift and the movable rack, and the distance measuring sensor measures that the movable rack approaches a predetermined distance. And a means for transmitting a traveling stop signal to the traveling rack to stop traveling of the movable shelf when the traveling rack stops, traveling to the traveling shelf in response to a traveling stop signal from the unmanned forklift truck. The unmanned transfer system according to any one of claims 1 to 3, wherein the automatic transfer system is provided with a stop means.