JP2001175330A - Automatic carrier system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect an obstacle existing in an area where an automatic carrier device passes through so that the operation efficiency of a carrier system is not impaired. SOLUTION: A state that a virtual OHT vehicle 1' having the same shape as an OHT vehicle 1 is arranged in front of the moving direction of the OHT vehicle 1 is shown. Optical reflection sensors S1 to S4 are respectively arranged on the moving direction front part 2 of the OHT vehicle 1 along respective sides S1 to S4. An irradiation area m1 is irradiated with an optical beam radiated from the sensor S1 along the side L1' of the virtual OHT vehicle 1'. Similarly respective irradiation areas m2 to m4 are irradiated with optical beams radiated from respective sensors S2 to S4 along the sides L2' to L4' of the virtual OHT vehicle 1'. Consequently a passage area surrounded by the sides L1 to L4 of the OHT vehicle 1 can be completely detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transfer device that travels unattended at an assembly site in a factory, and more particularly to a sensor technology for detecting an obstacle in the direction in which the automatic transfer device moves.

[0002]

2. Description of the Related Art In a factory or the like, an automatic transfer device (hereinafter, referred to as a vehicle) is preferably used when parts are transferred in an assembly process. In particular, in a semiconductor processing step, dust and the like are disliked, so that a semiconductor wafer is transported or assembled using a vehicle in a clean room without manual intervention. For example, when assembling semiconductor wafers and liquid crystal devices, an OHT (Overhead Hoi
st Transport) is used.

FIG. 4 is a conceptual diagram showing the operation of an OHT system used in a semiconductor wafer processing step or the like. In the figure, the right drawing part shows a side view of the OHT vehicle, and the left drawing part shows a state diagram when a front view in the traveling direction of the OHT vehicle is arranged at a predetermined position in the traveling direction. That is, in the figure, a track 21 is laid along a process line on a ceiling in a clean room (not shown), and a part of the track 21 is shown in the figure. An OHT vehicle 22 is suspended below the track 21 so as to run freely. The OHT vehicle 22 has, for example, a square frame, and is configured to hold the wafer cassette 23 in the frame and travel along the track 21.

[0004] A forward monitoring sensor 24 is attached to the front of the OHT vehicle 22 in the traveling direction. The front monitoring sensor 24 generally uses an optical reflection sensor such as an infrared ray, and is configured to detect an obstacle in the moving direction of the OHT vehicle 22 in a non-contact manner.
That is, an obstacle ahead is detected by a light beam radiated in a conical shape from the forward monitoring sensor 24. And
When the forward monitoring sensor 24 detects an obstacle ahead, OH
The T vehicle 22 automatically stops. still,
In FIG. 4, the front monitoring sensor 24 is provided on the left side of the OHT vehicle 22 assuming that the OHT vehicle 22 moves to the left in the figure. However, since the OHT vehicle 22 normally moves in both directions, It is assumed that a front monitoring sensor 24 is also provided on the right side of the OHT vehicle 22.

[0005]

However, the orbit 2
In the very vicinity of the periphery of the device 1, there may be an associated manufacturing apparatus, a door of the manufacturing apparatus may be open, or a part in process may be placed. Further, a stepladder or a workbench may be placed for maintenance or the like, or a person may be present in the passage of the OHT vehicle 22. Therefore, the OHT vehicle 22 is traveling while the front monitoring sensor 24 monitors the front so that the OHT vehicle 22 does not collide with them. However, as shown in FIG. 4, if the detection area of the light emitted from the front monitoring sensor 24 is widened as in the detection area A in order to detect an obstacle in the pass area of the OHT vehicle 22, the vehicle travels more than necessary. There is a possibility that an object around the road may be detected and the vehicle may not be able to travel.

That is, the passing area C of the OHT vehicle 22 as viewed from the front in the moving direction of the OHT vehicle 22 is indicated by a solid line on the left side of the drawing. OHT vehicle 2
A wide detection area A in which all the two pass areas C can be detected is indicated by a broken line. The wide detection area A is the conical bottom surface of the light beam emitted from the forward monitoring sensor 24 at a predetermined position.

When the passage area C of the OHT vehicle 22, that is, the front shape of the OHT vehicle 22 is different from the circular wide detection area A having a conical bottom surface, for example, when the OHT vehicle 22 is rectangular as shown in the figure, a large detection area is used. An excess detection area D is generated in a portion where A protrudes from the passage area C and is detected. When an object is placed in the excessive detection area D, the OHT vehicle 22 stops even though it does not actually obstruct the passage of the OHT vehicle 22.

On the other hand, if the detection area is narrowed like a narrow detection area B indicated by a broken line, a corner portion of the passage area C of the OHT vehicle 22 cannot be detected as a non-detection area E. In such a case, the OHT vehicle 22 may collide with the object in the non-detection region E in the corner portion due to the passage of the OHT vehicle 22.

FIG. 5 is an explanatory diagram showing an example of a forward monitoring sensor of an OHT vehicle and an obstacle. That is, as shown in the figure, when the stepladder 25 stands in the forward direction of the movement of the OHT vehicle 22 and the detection area of the front monitoring sensor 24 is wide such as the detection area A, the OHT vehicle 22 collides with the stepladder 25. In spite of this, the OHT vehicle 22 is detected as an obstacle and stops. If the detection area is as narrow as the detection area B, the stepladder 25 is used.
Is not detected, but if parts or the like are placed very close to the OHT vehicle 22, they cannot be detected, and there is a risk of collision and damage.

FIG. 6 is a conceptual diagram when an OHT vehicle is used in a semiconductor manufacturing apparatus. As shown in FIG. 1, for example, in a 300 mm wafer manufacturing apparatus, an end face of an OHT vehicle 22 that conveys a wafer is connected to a semiconductor manufacturing apparatus 26.
The distance P from the front surface is defined by standards so as to be about 30 mm. When the work is performed at such a narrow interval, if the detection area is too large, the front monitoring sensor 24 detects the door of the semiconductor manufacturing apparatus 26 and the like, and the OHT vehicle 22 hardly operates and the work cannot be performed. When the detection area is reduced, the OHT vehicle 2
The second corner or the like hits a semiconductor wafer or the like (not shown) mounted on the semiconductor manufacturing apparatus 26 or the like, and may damage these semiconductor wafers.

The present invention has been made in view of such circumstances, and an object of the present invention is to reliably remove obstacles in an area where an automatic transfer device passes so that the operation efficiency of the transfer system is not impaired. An object of the present invention is to provide an automatic transfer device provided with a sensor capable of detecting the same.

[0012]

In order to solve the above-mentioned problems, an automatic transport system according to the present invention includes forward monitoring means for monitoring an obstacle in an area through which the automatic transport device passes without contact, and comprising: An automatic transport system that transports
The forward monitoring means monitors only the area of the projection surface of the automatic transport device in the direction in which the automatic transport device passes, and when the forward monitoring device detects an obstacle in the area of the projection surface, It is characterized in that traveling is decelerated or stopped.

That is, the forward monitoring means according to the present invention comprises:
Since only the area of the actual passage area of the automatic transfer device is monitored, parts that are placed in the immediate vicinity of a position that does not interfere with running are detected and travel stops, or the automatic transfer device stops This can prevent a problem such as colliding with the like. Therefore, in an automatic transport system used in an assembly process of a semiconductor manufacturing apparatus, it is necessary to transport components and travel in an extremely narrow range. It is further improved.

Further, in the automatic transport system according to the present invention, in the above invention, the forward monitoring means is an optical reflection sensor which emits a light beam for irradiating a belt-shaped area over the entire outer periphery of the projection surface of the automatic transport apparatus. The optical reflection sensor detects an obstacle in a region of the light beam irradiated by the optical reflection sensor. That is, by irradiating the light beam only to the outer peripheral portion of the area where the automatic transport device passes and detecting the reflected light of this light beam, it is possible to easily detect only the pass area of the automatic transport device.

Further, in the automatic transport system according to the present invention, in the above invention, a plurality of the optical reflection sensors are installed all around the outer peripheral end on the front surface in the traveling direction of the automatic transport device. A light beam radiated in a fan shape from the light source irradiates a band-shaped region over the entire outer periphery of the traveling direction projection plane of the automatic transport device.

That is, a plurality of optical reflection sensors are arranged over the entire periphery near the outer peripheral end on the front surface in the traveling direction of the automatic transport device. Then, the light beam emitted from each optical reflection sensor is applied to the entire outer periphery of the passing area in a band shape. As a specific method, for example,
If the front surface in the moving direction is a rectangular automatic conveyance device, a band-shaped slit is provided along each side of the rectangle, and a light beam is radiated from the inside of the slit in a fan shape. The entire side is illuminated in a band shape.
Therefore, by combining the belt-shaped irradiation areas on each side,
The entire outer periphery of the passage area can be illuminated in a band shape.

Further, in the automatic transport system according to the present invention, in the above-mentioned invention, the belt-shaped area irradiated with the light beam may include:
It is characterized in that a part of the band-shaped width protrudes from the outer peripheral end of the projection surface. That is, it is desirable that the width of the detection area has some allowance so that an obstacle is not erroneously detected due to a mechanical shift or the like during the movement of the automatic transport device or a detection omission does not occur.

Further, in the automatic transfer system according to the present invention, the automatic transfer device constituting the automatic transfer system according to each of the above-mentioned inventions is characterized in that the automatic transfer device is an OHT running on a ceiling track, an AGV running on a floor, or running on a floor track. RGV. That is, the automatic transfer system of the present invention is an automatic guide system (AGV) that automatically transfers materials, parts, products, and the like in an automation factory, in addition to the OHT used for precision work of a semiconductor manufacturing device or the like.
(ED Vehicle) and RGV (Rail Guided Vehicle).

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an automatic transport system according to the present invention will be described with reference to the drawings. In the following description, a traveling track or the like is omitted, and an OHT vehicle having a rectangular cross section on the front surface, which is a passage area, will be described as an example. FIG. 1 shows an OHT according to an embodiment of the present invention.
It is an external appearance perspective view of a vehicle. In the figure, four optical reflection sensors S1, S2, S3, S4 are installed on the front surface 2 of the OHT vehicle 1 along the sides of the front surface 2 in the moving direction as front monitoring sensors. I have.

That is, in order to secure the minimum area of the area through which the OHT vehicle 1 passes, an optical reflection sensor S1 that emits a fan-shaped light beam is arranged along the side L1, and similarly, the optical reflection sensor S2 Is along side L2,
The optical reflection sensor S3 is arranged along the side L3, and the optical reflection sensor S4 is arranged along the side L4.

Each of the optical reflection sensors S1, S2, S3, S
For example, the slit 4 is formed by forming a thin rectangular slit along the vicinity of each side L1, L2, L3, L4, and providing an infrared light source inside each slit.
Thus, a light beam from an infrared light source (not shown) is emitted from each slit. Therefore, each light beam is emitted in a fan shape from each of the optical reflection sensors S1, S2, S3, S4, and the irradiation light having a cross-sectional shape similar to the shape of each slit is formed on the projection surface at a predetermined position. Becomes

FIG. 2 is a conceptual diagram showing a state in which the OHT vehicle shown in FIG. 1 is used to monitor the front of the moving direction. The figure shows that the OHT is located in front of the OHT vehicle 1 in the moving direction.
This shows a state in which a virtual OHT vehicle 1 'having the same shape as the vehicle 1 is arranged.

Optical reflection sensors S1, S2, S3, S4 are arranged on the front surface 2 in the moving direction of the OHT vehicle 1 along the sides L1, L2, L3, L4. The light beam emitted from the optical reflection sensor S1 irradiates the irradiation area m1 along the side L1 'of the virtual OHT vehicle 1'. Also, the optical reflection sensor S
The light beam emitted from 2 is a virtual OHT vehicle 1 '
The irradiation area m2 is irradiated along the side L2 'of FIG. Further, the light beam emitted from the optical reflection sensor S3 is
Irradiation area m along side L3 'of virtual OHT vehicle 1'
3 has been irradiated. Then, the light beam emitted from the optical reflection sensor S4 is the side L of the virtual OHT vehicle 1 ′.
The irradiation area m4 is irradiated along 4 '.

Further, these irradiation areas m1, m2, m
The reflected light of the light radiated to 3, m4 is detected by the optical reflection sensors S1, S2, S3, S4, respectively. That is, each of the optical reflection sensors S1, S2, S3,
Band-shaped irradiation area m of the beam light spreading in a fan shape from S4
1, m2, m3, and m4 are areas for detecting an obstacle.

Thus, an obstacle can be detected in a region surrounded by the side L1 ', the side L2', the side L3 ', and the side L4' of the virtual OHT vehicle 1 '. That is, OH
Sides L1, L2, L of front part 2 in the moving direction of T vehicle 1
3. Passage areas surrounded by L4 are detected without any omission. In addition, the detection area is the area itself of the front part 2 in the moving direction of the OHT vehicle 1, and the OHT system can detect the obstacle of the OHT system extremely efficiently without a detection omission part or an excessive detection part.

In actual obstacle detection, OH
The setting of the emission direction of the light beam emitted from each of the optical reflection sensors S1, S2, S3, S4 is devised so as to irradiate an area slightly wider than the area through which the T vehicle 1 passes. As a result, the surrounding manufacturing apparatus is not detected and O
It is desirable to prevent unnecessary detection or detection omission due to mechanical displacement due to vibration or the like when the HT vehicle 1 moves.

As a specific method of setting a light beam, for example, each of the optical reflection sensors S1, S2, S3, S3 shown in FIG.
4 is provided with a light guiding cylinder for regulating the direction in which light is emitted.
Then, the direction of the light beam emitted from each light guide cylinder is adjusted so as to be slightly outward from the outer periphery of the virtual OHT vehicle 1 '. That is, the irradiation areas m1, m2, and m in FIG.
3 and m4 are sides L1 'and L of virtual OHT vehicle 1'
If it protrudes slightly outside of 2 ′, L3 ′, and L4 ′, it is possible to detect an area slightly wider than the passage area of the OHT vehicle 1. As described above, if the optical reflection sensors that radiate a light beam in a fan shape are arranged around the front surface in the moving direction of the OHT vehicle 1 so as to efficiently detect only the passage area of the OHT vehicle 1, Unnecessary stopping of the vehicle 1 and unexpected collision with parts and the like can be avoided, and the OHT system can be operated efficiently.

In this embodiment, the OHT vehicle 1 having a rectangular cross section in the moving direction has been described. However, the present invention can be applied to any shape of the cross section in the moving direction. . For example, if the cross section of the OHT vehicle in the moving direction is a polygon, a band-shaped light beam may be applied so as to connect each side according to the polygon, and if the cross section in the moving direction is an ellipse, The elliptical outer periphery may be irradiated in a band shape over the entire periphery.

Next, an example of the actual use of the OHT vehicle provided with the above-described forward monitoring sensor will be described.
FIG. 3 is a perspective view showing an example of a semiconductor manufacturing apparatus using the OHT vehicle of the present invention. When a semiconductor device is manufactured by a semiconductor manufacturing apparatus as shown in FIG. 3, the above-mentioned OHT vehicle is used to automatically transfer a semiconductor wafer between various apparatuses. That is, in general, a semiconductor device is such that a semiconductor wafer such as silicon is transported by an OHT vehicle coming and going between various semiconductor manufacturing apparatuses (for example, a wafer processing apparatus, a storage apparatus, a work table, and a buffer apparatus). It is manufactured through a number of processing steps.

With reference to FIG. 3, a description will be given of the processing steps in which the OHT vehicle transports the semiconductor wafer. An OHT vehicle 12 hung on a track 11 laid on a ceiling of a clean room (not shown) freely travels, and a wafer carrier 14 containing a semiconductor wafer 13 is moved between each semiconductor manufacturing apparatus 15 or between the semiconductor manufacturing apparatus 15 and a stocker. 16 and various process processes are performed.

The OHT vehicle 12 shown in FIG.
1 and a traveling portion 12a
And a hand 12c suspended vertically by the hand suspension unit 12b. Then, the wafer carrier 14 placed on the load port 15a of the semiconductor manufacturing apparatus 15 is gripped by the hand 12c, and the hand suspension unit 12b raises the hand 12c, and then travels along the track 11 by the traveling unit 12a. It has become. In manufacturing a semiconductor device, a plurality of OHTs are used.
The vehicle 12 moves between the plurality of semiconductor manufacturing apparatuses 15 arranged side by side along the track 11, holds the wafer carrier 14 from above the load port 15 a of each semiconductor manufacturing apparatus 15, and It is designed to be transported to the load port 15a.

That is, when transporting the wafer carrier 14, first, the OHT vehicle 1 is moved along the track 11.
Wafer carrier 1 that travels and transports from now on
4 is stopped above the load port 15a. Then, the hand suspension unit 12b is lowered to remove the hand 12c.
Is lowered, and the wafer carrier 14 is held by the hand 12c. Then, the hand suspension unit 12b is wound up to load the wafer carrier 14 into the load port 15a.
And rolled it up to the highest height, then again, OH
The T vehicle 12 is run.

Then, it stops above the other semiconductor manufacturing apparatus 15 for performing the next process or the load port 15a of the stocker 16, and lowers the hand suspending portion 12b to remove the hand 12.
c is lowered, and the wafer carrier 14 is placed on the load port 15a. Thereafter, the hand 12c releases the wafer carrier 14, raises the hand 12c together with the winding of the hand suspension unit 12b, and moves on to the next transport operation.

Incidentally, these transport operations are performed in an extremely narrow range, so that they do not come into contact with doors of various devices or adjacent parts in the moving direction of the OHT vehicle 12 and do not hinder the movement. A forward monitoring sensor (not shown) for detecting a minimum range in which the OHT vehicle 12 does not hinder the movement of the OHT vehicle 12 is provided so as to prevent the OHT vehicle 12 from being stopped regardless of these detections. The OHT system of the semiconductor manufacturing apparatus can efficiently process the semiconductor wafer by monitoring the front monitoring sensor (not shown). Thereby, the production efficiency of semiconductor devices and the like can be further improved.

The embodiment described above is an example for explaining the present invention, and the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the invention. is there. That is, the above embodiment has described the case where the forward monitoring sensor is installed on the OHT vehicle traveling on the overhead track, but the present invention is not limited to this. For example, an AGV (Automatic Guide Vehicl) running on the floor
e) RGV (Rail Guide Vehicle) running on orbit
For example, the forward monitoring sensor of the present invention can be installed. AGVs and RGVs are used in process lines for transporting materials and moving finished products unattended in automation factories and the like. However, by providing the forward monitoring sensor of the present invention, AGVs and RGVs are unnecessary. There is no danger of the RGV stopping or colliding with other parts and damaging them.

[0036]

As described above, according to the automatic transport system of the present invention, the vehicle travels while monitoring only the substantial moving area of the automatic transport device, so that only obstacles can be reliably detected. In other words, there is no possibility that a surrounding object or a person that does not actually interfere with the traveling is detected, or an obstacle that cannot be detected is not detected, resulting in unnecessary stoppage or damage to equipment. Therefore, the automatic transport device can be safely and efficiently run, and thus a safer and more efficient automatic production system can be constructed.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an OHT vehicle according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a state in which the OHT vehicle of FIG. 1 is used to monitor the front in the moving direction.

FIG. 3 is a perspective view showing an example of a semiconductor manufacturing apparatus using the OHT vehicle of the present invention.

FIG. 4 is an operation conceptual diagram of an OHT system used in a semiconductor wafer processing step or the like.

FIG. 5 is an explanatory diagram showing an example of a front monitoring sensor of an OHT vehicle and an obstacle.

FIG. 6 is a conceptual diagram when an OHT vehicle is used in a semiconductor manufacturing apparatus.

[Explanation of symbols]

1, 12, 22 OHT vehicle 1 'Virtual OHT vehicle 2 Movement front surface S1, S2, S3, S4 Optical reflection sensor L1, L2, L3, L4, L1', L2 ', L3', L
4 'side m1, m2, m3, m4 Irradiation area 11, 21 Track 12a Running part 12b Hand hanging part 12c Hand 13 Semiconductor wafer 14 Wafer carrier 15, 26 Semiconductor manufacturing equipment 15a Load port 16 Stocker 23 Wafer cassette 24 Forward monitoring sensor 25 Stepladder A Wide detection area B Narrow detection area C Vehicle passing area D Excess detection area E Non-detection area

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[Procedure amendment]

[Submission date] October 24, 2000 (2000.10.
24)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 2

[Correction method] Change

[Correction contents]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

[0012]

In order to solve the above-mentioned problems, an automatic transport system according to the present invention includes forward monitoring means for monitoring an obstacle in an area through which the automatic transport device passes without contact, and comprising: An automatic transport system that transports
Forward monitoring means, in the direction of the automatic transporting device passes, to monitor the area A of the projection plane of the automatic conveying device, when the forward monitoring device detects the obstacle in the area of the projection surface, automated transporter It is characterized in that traveling is decelerated or stopped.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

[0014] The automatic conveyor system of the present invention, in the above invention, the forward monitoring unit, with optical sensors that emit light beam illuminating Wataru Ru realm to entire periphery of the projection plane of the automated transporter The optical reflection sensor detects an obstacle in a region of the light beam irradiated by the optical reflection sensor. That is, by irradiating the light beam only to the outer peripheral portion of the area where the automatic transport device passes and detecting the reflected light of this light beam, it is possible to easily detect only the pass area of the automatic transport device.

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Claims (5)

[Claims] 1. An automatic transport system for transporting an article, comprising: a forward monitoring means for monitoring an obstacle in an area through which the automatic transport device passes without contact; And monitoring only the area of the projection surface of the automatic transport device in the direction in which the automatic transport device moves, and when the forward monitoring unit detects an obstacle in the area of the projection surface, decelerates or stops the travel of the automatic transport device. Automatic transfer system characterized by the following. 2. An optical reflection sensor which emits a light beam for irradiating a belt-shaped area over the entire outer periphery of a projection surface of the automatic transport device, wherein the forward reflection monitoring means comprises: The automatic transport system according to claim 1, wherein an obstacle is detected in a region of the light beam. 3. A plurality of the optical reflection sensors are installed around the entire periphery near the outer peripheral end on the front surface in the traveling direction of the automatic transport device, and light beams radiated from each of the optical reflection sensors in a fan shape are: 3. The automatic transport system according to claim 2, wherein a belt-shaped region extending over the entire outer periphery of the traveling direction projection plane of the automatic transport device is irradiated. 4. The automatic transport system according to claim 3, wherein the belt-shaped region irradiated with the light beam has a part of a band-like width protruding from an outer peripheral end of the projection plane. . 5. The automatic transport device according to claim 4, wherein the automatic transport device is one of an OHT running on a ceiling track, an AGV running on a floor, and an RGV running on a floor track. Automatic transfer system.