Ceiling transport vehicle

Abstract

This overhead conveying vehicle travels along a track and conveys an article, said vehicle including: a transfer unit that transfers the article to / from a loading port of a device; a plurality of sensors that have mutually different sensing ranges and, upon transfer of the article by the transfer unit, that emit detection waves downward to sense whether there is an obstacle; and a control unit that controls the overhead conveying vehicle. The transfer unit includes: a gripping part that grips the article; a rotation part that rotates the gripping part around a rotational axis along a vertical direction; and a lifting part that lifts the gripping part. Upon transfer of the article by the transfer unit, the control unit: controls the rotation part in accordance with the direction in which the loading port is accessed so that the article is transferred in a predetermined orientation; and performs control so that detection processing of one or a plurality of sensors, from among the plurality of sensors, that have in the detection range thereof a device, is not performed, depending on a positional relationship relative to the loading port.

Description

[Technical Field]

[0001] One aspect of the present invention relates to an overhead transport vehicle. [Background technology]

[0002] As a technology relating to overhead transport vehicles, for example, Patent Document 1 describes an overhead traveling transport device equipped with a track installed on the ceiling and a hoist-equipped cart (overhead transport vehicle) that travels along the track. In the overhead traveling transport device described in Patent Document 1, the traveling hoist-equipped cart is stopped above the load port of the manufacturing equipment, and the hand hanging section is lowered to lower the hand, which holds the article. An obstacle detection sensor (sensor) is provided on the hoist-equipped cart side to optically search the lifting path between the hoist-equipped cart and the load port to detect the presence or absence of an obstacle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3371897 Summary of the Invention [Problem to be solved by the invention]

[0004] The article has a cover on one side, and the load port must receive it with the cover facing a specific direction relative to the load port. In other words, with the above-mentioned technology, the direction in which the overhead guided vehicle can access the load port may be limited in order to ensure that the orientation of the article being transferred to and from the load port is aligned with a specified orientation. Specifically, to meet the above-mentioned conditions, only a track extending to the left and right of the load port is provided. Furthermore, in this case, the orientation of the overhead guided vehicle relative to the load port is always constant, so the sensor ensuring safety around the load port only detects a specified area in one direction. For these reasons, the above-mentioned technology has limited flexibility in track layout, and the overhead guided vehicle may have to take a circuitous path to access the load port, potentially reducing transport efficiency.

[0005] Therefore, an object of one aspect of the present invention is to provide an overhead transport vehicle that can increase the degree of freedom in track layout and improve transport efficiency. [Means for solving the problem]

[0006] An overhead transport vehicle according to one aspect of the present invention is a ceiling transport vehicle that travels along a track and transports items, and is equipped with a transfer unit that transfers items between a load port of an apparatus, a plurality of sensors having different detection ranges that emit detection waves downward to detect the presence or absence of obstacles when the transfer unit transfers an item, and a control unit that controls the ceiling transport vehicle, wherein the transfer unit includes a gripping unit that grips the item, a rotating unit that rotates the gripping unit around a rotation axis along the vertical direction, and a lifting unit that raises and lowers the gripping unit, and when the transfer unit transfers an item, the control unit controls the rotating unit in accordance with the direction of access onto the load port so that the item is transferred in a specified orientation, and prevents detection processing of one or more sensors among the plurality of sensors that include the apparatus in their detection range depending on their positional relationship with the load port.

[0007] When transferring an item with this overhead transport vehicle, the item can be rotated so that it is transferred in the orientation specified for the load port. In this case, because detection processing is not performed by one or more sensors that include the device in their detection range, the device will not be mistakenly detected as an obstacle by the sensors. Therefore, regardless of the direction in which the overhead transport vehicle accesses the load port, the item can be oriented in the orientation specified for the load port while ensuring safety around the load port with sensors, and the item can be transferred between the overhead transport vehicle and the load port. For example, this eliminates the need for a track that requires the overhead transport vehicle to take a detour to access the load port, increasing the flexibility of the track layout and improving transport efficiency.

[0008] In the overhead transport vehicle according to one aspect of the present invention, the lifting unit may raise and lower the rotating unit together with the gripping unit, and the rotating unit may rotate only the gripping unit. In this case, the rotation for changing the orientation of the article during transfer can be achieved with a small mechanism.

[0009] In an overhead transport vehicle according to one aspect of the present invention, the rotation unit may rotate the gripper so that the rotation position of the gripper about the rotation axis is switched at least between a first position, a second position that is different by +90° from the first position, and a third position that is different by −90° from the first position. In this case, a device (such as an encoder) for adjusting the angle of rotation by the rotation unit is not required.

[0010] In an overhead transport vehicle according to one aspect of the present invention, the sensors may have detection ranges in at least three directions, in front, behind, and to one side of the direction of travel of the overhead transport vehicle, in a plan view. This makes it possible to detect the presence or absence of an obstacle even when the overhead transport vehicle accesses the load port from three directions by appropriately using any of the sensors installed on the three sides depending on the access direction to the load port. Furthermore, it is possible to detect the presence or absence of an obstacle while reducing the number of sensors used.

[0011] In the overhead transport vehicle according to one aspect of the present invention, the transfer unit may include an adjustment unit that rotates the lifting unit together with the gripping unit and the rotating unit about the rotation axis and adjusts the rotation positions of the gripping unit, the rotating unit, and the lifting unit about the rotation axis. In this case, the article can be rotated in two stages by the adjustment unit and the rotating unit.

[0012] In an overhead transport vehicle according to one aspect of the present invention, the control unit may pre-store in use sensor information that associates the rotational position of the gripper about the rotation axis with one or more sensors to be used among the multiple sensors, and when the transfer unit transfers an article, the control unit may determine one or more sensors for which detection processing will not be performed based on the use sensor information and the rotational position of the gripper about the rotation axis. In this case, the pre-stored use sensor information can be used to prevent detection processing from being performed by one or more sensors whose detection range includes the device.

[0013] In an overhead transport vehicle according to one aspect of the present invention, the overhead transport vehicle travels along a track, and the track may include a passing track that passes over an apparatus and over a load port of the apparatus in the fore-and-aft direction of the load port. Since the track includes a passing track in this way, transport efficiency can be improved compared to when the track includes a track that goes around to access the load port.

[0014] In the overhead transport vehicle according to one aspect of the present invention, the control unit may control one or more sensors that include the device in their detection ranges among the multiple sensors so that they do not emit detection waves when the detection process is not being performed. This may be disabled by stopping the sensors. In this case, no extra power is used.

[0015] In an overhead transport vehicle according to one aspect of the present invention, when transferring an article from a load port to a gripper, the control unit may control the rotation unit so that the article is gripped in a specified orientation relative to the gripper. In this case, the overhead transport vehicle can always grip the article in a fixed orientation, making it easier to adjust the rotation thereafter. In addition, since the center of gravity is always constant, the load on the vehicle during travel is reduced. [Effects of the Invention]

[0016] According to one aspect of the present invention, it is possible to provide an overhead transport vehicle that can increase the degree of freedom in track layout and improve transport efficiency. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic side view showing an overhead transport vehicle according to an embodiment. [Figure 2] FIG. 2 is a plan view showing an example of a track layout. [Figure 3] FIG. 3 is a diagram showing an example of transferring an article from a load port to an overhead transport vehicle. [Figure 4] FIG. 4 is a diagram showing another example of transferring an article from a load port to an overhead transport vehicle. [Figure 5] FIG. 5 is a diagram showing yet another example of transferring an article from a load port to an overhead transport vehicle. [Figure 6] Fig. 6(a) is a diagram showing the detection range of a second sensor according to a modified example, and Fig. 6(b) is a diagram showing the detection range of a second sensor according to another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment will be described in detail below with reference to the drawings. The same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0019] 1, 2, and 3, an overhead transport vehicle 1 travels along a track 20 installed near the ceiling of a clean room where, for example, semiconductor devices are manufactured. The overhead transport vehicle 1 transports an item 100. The item 100 is, for example, a FOUP (Front Opening Unified Pod) that houses multiple semiconductor wafers. In the drawings, the X direction corresponds to one horizontal direction, the Y direction corresponds to a horizontal direction perpendicular to the X direction, and the Z direction corresponds to the vertical direction.

[0020] The ceiling transport vehicle 1 transfers the articles 100 between load ports 210 of a plurality of processing devices (devices) 200. The processing devices 200 are devices that perform various processes on, for example, semiconductor wafers. In the example shown in FIG. 2, the plurality of processing devices 200 are arranged in a clean room so as to be lined up in the X direction at predetermined intervals.

[0021] The track 20 is suspended from, for example, the ceiling. The track 20 is a predetermined one-way running path along which the ceiling transport vehicle 1 travels. The track 20 passes over a plurality of load ports 210. The track 20 includes a passing track 25. The passing track 25 is a track that passes over the processing equipment 200 and also passes over the load port 210 of the processing equipment 200 in the front-to-rear direction of the load port 210.

[0022] The load port 210 is a mounting table in the processing apparatus 200. One or more articles 100 are placed on the load port 210. The load port 210 is arranged on the aisle side (outer edge side) of the processing apparatus 200 in a plan view. The load port 210 has a set orientation, for example, the aisle side of the load port 210 faces the front side (front side). The article 100 is transferred to the load port 210 in a specified orientation. For example, the article 100 is placed on the load port 210 so that the front side of the article 100 (the side opposite the lid side) is aligned with the front side of the load port 210.

[0023] The load port 210 includes a first load port 201, a second load port 202, and a third load port 203. The first load port 201 is a mounting table whose front-to-rear direction intersects (is perpendicular to) the travel direction of the track 20. The second and third load ports 202, 203 are mounting tables along whose front-to-rear directions the passing track 25 passes. For the second load port 202, the direction from its front to its rear corresponds to the travel direction of the passing track 25. For the third load port 203, the direction from its rear to its front corresponds to the travel direction of the passing track 25. The second and third load ports 202, 203 are provided so as to enter the processing equipment 200 in a plan view. The second and third load ports 202, 203 are arranged in spaces open to the aisle and upper sides of the processing equipment 200.

[0024] The ceiling transport vehicle 1 comprises a frame unit 2, a running unit 3, a lateral unit 4, a theta unit (adjustment unit) 5, a lifting drive unit (lifting unit) 6, a rotation unit (rotation unit) 7, a gripping unit (gripper) 8, and a transport vehicle controller (control unit) 9.

[0025] The frame unit 2 has a center frame 15, a front frame 16, and a rear frame 17. The front frame 16 extends downward from the end of the center frame 15 on the front side (the front side in the traveling direction of the overhead transport vehicle 1). The rear frame 17 extends downward from the end of the center frame 15 on the rear side (the rear side in the traveling direction of the overhead transport vehicle 1).

[0026] The traveling unit 3 is disposed above the center frame 15. The traveling unit 3 travels along the track 20 by receiving a contactless supply of power, for example, from a high-frequency current line laid along the track 20. The lateral unit 4 is disposed below the center frame 15. The lateral unit 4 moves the theta unit 5, the lifting drive unit 6, the rotation unit 7, and the gripping unit 8 laterally (to the side in the traveling direction of the ceiling transport vehicle 1).

[0027] The theta unit 5 is disposed below the lateral unit 4. The theta unit 5 rotates the lifting drive unit 6 together with the gripping unit 8 and the rotation unit 7 around a central axis (rotation axis) along the Z direction, and adjusts the rotation positions of the gripping unit 8, the rotation unit 7, and the lifting drive unit 6 around the central axis. The lifting drive unit 6 is disposed below the theta unit 5. The lifting drive unit 6 raises and lowers the rotation unit 7 together with the gripping unit 8. The lifting drive unit 6 raises and lowers by winding or unwinding a belt B connected to the rotation unit 7.

[0028] The rotation unit 7 is suspended from the lift drive unit 6 by a plurality of belts B. The rotation unit 7 rotates only the gripping unit 8 around a central axis (rotation axis) along the Z direction. The rotation unit 7 constitutes a slip-ring type turning mechanism. For example, the rotation unit 7 includes a slip ring arranged on the central axis and a motor arranged away from the central axis and connected to the slip ring by a gear. The rotation unit 7 rotates the gripping unit 8 so that the rotation position of the gripping unit 8 around the central axis switches at least between a first position which is an initial position, a second position which is different by +90° from the first position, and a third position which is different by -90° from the first position.

[0029] The gripping unit 8 is disposed below the rotation unit 7. The gripping unit 8 grips (holds) the item 100 in a specified orientation. The gripping unit 8 has a pair of grippers 12, 12. The pair of grippers 12, 12 are opened and closed, for example, by a drive motor and a link mechanism. The rotation unit 7 and gripping unit 8 are raised and lowered by the lifting drive unit 6 winding or unwinding the belt B. The lateral unit 4, theta unit 5, lifting drive unit 6, rotation unit 7, and gripping unit 8 constitute a transfer section that transfers the item 100 between the load port 210. Hereinafter, the lateral unit 4, theta unit 5, lifting drive unit 6, rotation unit 7, and gripping unit 8 will also be referred to simply as the "transfer section."

[0030] The transport vehicle controller 9 is disposed, for example, in the frame unit 2. The transport vehicle controller 9 is an electronic control unit configured with a CPU (Central Processing Unit), a ROM (Read only memory), a RAM (Random access memory), etc. The transport vehicle controller 9 controls each part of the overhead transport vehicle 1.

[0031] Here, the ceiling transport vehicle 1 of this embodiment is equipped with a plurality of sensors S. The sensors S emit directional detection waves downward to detect the presence or absence of an obstacle when the transfer unit (lateral unit 4, theta unit 5, lifting drive unit 6, rotation unit 7, and gripping unit 8) transfers the article 100. The sensors S are so-called look-down sensors. The sensors S are not particularly limited, but for example, laser range finders are used. The sensors S may also be configured to emit other detection waves, such as ultrasonic waves.

[0032] For example, the sensor S emits a laser beam toward the vicinity of the destination of the gripping unit 8 and receives the reflected light. The sensor S detects whether or not an obstacle is present around the load port 210 based on the reflected light of the received laser beam. For example, the sensor S detects whether or not an obstacle such as a worker is present in front of the load port 210 (the aisle side). The sensor S is connected to the transport vehicle controller 9. The multiple sensors S include a first sensor S1, a second sensor S2, and a third sensor S3.

[0033] The first sensor S1 is installed on one side of the ceiling transport vehicle 1 in the traveling direction in a plan view. The first sensor S1 is provided at the bottom of the lifting drive unit 14. The first sensor S1 detects the presence or absence of an obstacle within a detection range R1. The detection range R1 is a range that starts from the first sensor S1 and extends two-dimensionally downward along the XZ plane. The detection range R1 is a range in which the detection result of the first sensor S1 is valid. The range of the detection range R1 needs to be along the XZ plane, and may be inclined with respect to the XZ plane.

[0034] The second sensor S2 is installed at the rear of the ceiling transport vehicle 1 in the traveling direction in a plan view. The second sensor S2 is provided at the bottom of the rear frame 17. The detection range R2 is a range that starts from the second sensor S2 and extends two-dimensionally downward along the YZ plane. The detection range R2 is a range in which the detection result of the second sensor S2 is valid. The range of the detection range R2 needs only to be along the YZ plane, and may be inclined with respect to the YZ plane.

[0035] The third sensor S3 is installed at the front of the ceiling transport vehicle 1 in the direction of travel in a plan view. The third sensor S3 is provided at the bottom of the front frame 16. The detection range R3 is a range that starts from the third sensor S3 and extends two-dimensionally downward along the YZ plane. The detection range R3 is a range in which the detection result of the third sensor S3 is valid. The range of the detection range R3 needs only to be along the YZ plane, and may be inclined with respect to the YZ plane.

[0036] The transport vehicle controller 9 stores map data relating to the positions, orientations, etc. of the multiple load ports 210 in advance. For example, when the transport vehicle controller 9 receives a transport command to transport an article 100 from a higher-level controller, it acquires port information relating to the positions and specified orientations of the source and destination load ports 210 from the map data. The transport vehicle controller 9 controls the traveling unit 3 based on the port information, and causes the overhead transport vehicle 1 to travel to a position corresponding to the load port 210. The transport vehicle controller 9 then controls the transfer unit to transfer the article 100 between the load ports 210.

[0037] The transport vehicle controller 9 controls the rotation unit 7 so that the article 100 is transferred in a specified orientation when the transfer unit transfers the article 100. Specifically, when the transfer unit transfers the article 100, the transport vehicle controller 9 controls the rotation unit 7 based on the port information, and rotates the gripping unit 8 around the central axis so that the specified orientation specified for the load port 210 matches the orientation of the article 100 gripped by the gripping unit 8.

[0038] When the transfer unit transfers the article 100, the transport vehicle controller 9 disables one or more sensors S among the multiple sensors S that include the processing device 200 in their detection range. Specifically, the transport vehicle controller 9 pre-stores sensor usage information that associates the rotational position of the gripping unit 8 around its central axis with one or more sensors S to be used among the multiple sensors S. While traveling, detection processing for all sensors S is not performed, but when the transfer unit transfers the article 100, the transport vehicle controller 9 executes detection processing for the sensor S to be used based on the sensor usage information and the rotational position of the gripping unit 8 around its central axis. Executing the detection processing specifically means emitting laser light toward the vicinity of the destination of the gripping unit 8 and receiving the reflected light. As described above, during transfer, one or more sensors S that include the processing device 200 in their detection range do not execute detection processing.

[0039] The sensor usage information here includes a first position, a second position, and a third position as rotational positions of the grip unit 8, and each of these rotational positions is associated with one of the first to third sensors S1 to S3, which are the sensors S to be used. For example, in the sensor usage information, the first sensor S1 is associated as the sensor S to be used with the first position, where the grip unit 8 is the initial position, the second sensor S2 is associated as the sensor S to be used with the second position, where the grip unit 8 is +90° from the first position, and the third sensor S3 is associated as the sensor S to be used with the third position, where the grip unit 8 is -90° from the first position.

[0040] The ceiling transport vehicle 1 configured as above operates, for example, as follows.

[0041] [Transfer between the first load port 201 and the overhead transport vehicle 1] For example, as shown in FIG. 3, when transferring an article 100 from a first load port 201 to an overhead transport vehicle 1, the overhead transport vehicle 1, which is not holding the article 100, first acquires port information relating to the position and orientation of the first load port 201 from map data. The overhead transport vehicle 1 travels based on the port information, traveling along the track 20 to a position corresponding to the first load port 201 and stopping there. At the same time, the overhead transport vehicle 1 rotates the rotation unit 7 and adjusts the direction of the gripping unit 8 based on the port information so that the orientation of the article 100 to be transferred matches the specified orientation. Note that when transferring to the first load port 201, the rotation unit 7 is not rotated on the overhead transport vehicle 1 because the rotation position of the gripping unit 8 about the central axis of the initial position, the first position, can remain the initial position for transfer. However, at this time, if the position of the gripping unit 8 to be lowered is deviated from the first load port 201, the ceiling transport vehicle 1 adjusts the horizontal position and horizontal angle of the rotation unit 7 and the gripping unit 8 by driving the lateral unit 4 and the theta unit 5.

[0042] In the ceiling transport vehicle 1 of this embodiment, when transferring an article 100, detection processing is not performed for one or more of the multiple sensors S whose detection range includes the processing device 200. Specifically, the ceiling transport vehicle 1 references the sensor usage information and determines to use the first sensor S1 and not to perform detection processing for the second and third sensors S2, S3 based on the fact that the rotation position of the gripping unit 8 about the central axis is the first position, which is the initial position. Then, the ceiling transport vehicle 1 detects the presence or absence of an obstacle around (in front of) the first load port 201 using only the first sensor S1. Next, the ceiling transport vehicle 1 lowers the rotation unit 7 and the gripping unit 8 using the lifting drive unit 6, and the gripping unit 8 grips the flange of the article 100 placed on the first load port 201. Thereafter, the ceiling transport vehicle 1 raises the rotation unit 7 and the gripping unit 8 to their highest positions using the lifting drive unit 6, and then becomes able to travel.

[0043] On the other hand, when transferring an article 100 from the ceiling transport vehicle 1 to the first load port 201, the ceiling transport vehicle 1 holding the article 100 first acquires port information regarding the position and orientation of the first load port 201 from map data. The ceiling transport vehicle 1 travels based on the port information, traveling along the track 20 to a position corresponding to the first load port 201 and stopping there. At the same time, the ceiling transport vehicle 1 rotates the rotation unit 7 and adjusts the direction of the gripping unit 8 based on the port information so that the orientation of the article 100 to be transferred matches the specified orientation. In this case, the ceiling transport vehicle 1 does not rotate the rotation unit because the rotation position of the gripping unit 8 about its central axis can remain in the first position for transfer. However, at this time, if the position of the gripping unit 8 to be lowered is deviated from the first load port 201, the ceiling transport vehicle 1 adjusts the horizontal position and horizontal angle of the rotation unit 7 and the gripping unit 8 by driving the lateral unit 4 and theta unit 5.

[0044] In the ceiling transport vehicle 1 of this embodiment, when transferring an article 100, detection processing is not performed for one or more sensors S that include the processing device 200 within their detection range among the multiple sensors S. Specifically, the ceiling transport vehicle 1 references the sensor usage information and, based on the fact that the rotation position of the gripping unit 8 about its central axis is the first position, determines to use the first sensor S1 and not to perform detection processing for the second and third sensors S2, S3. The ceiling transport vehicle 1 then uses only the first sensor S1 to detect the presence or absence of an obstacle around (in front of) the first load port 201. Next, the ceiling transport vehicle 1 lowers the rotation unit 7 and the gripping unit 8 using the lifting drive unit 6, places the article 100 on the first load port 201, and releases the gripping unit 8 from gripping the flange. Thereafter, the ceiling transport vehicle 1 raises the rotation unit 7 and the gripping unit 8 to their highest positions using the lifting drive unit 6, and becomes ready to travel.

[0045] [Transfer between the second load port 202 and the overhead transport vehicle 1] For example, as shown in FIG. 4, when transferring an article 100 from the second load port 202 to the ceiling transport vehicle 1, the ceiling transport vehicle 1, which is not holding the article 100, first obtains port information regarding the position and orientation of the second load port 202 from map data. The ceiling transport vehicle 1 travels based on the port information, traveling along the track 20 to a position corresponding to the second load port 202 and stopping there. At the same time, the ceiling transport vehicle 1 rotates the rotation unit 7 and adjusts the direction of the gripping unit 8 based on the port information so that the orientation of the article 100 to be transferred matches the specified orientation. Here, the ceiling transport vehicle 1 controls the rotation unit 7 to set the rotation position of the gripping unit 8 about its central axis to a second position that is +90° different from the first position, so that the article 100 is gripped by the gripping unit 8 in the specified orientation. At this time, if the position of the gripping unit 8 to be lowered is deviated from the second load port 202, the ceiling transport vehicle 1 adjusts the horizontal position and horizontal angle of the rotation unit 7 and the gripping unit 8 by driving the lateral unit 4 and the theta unit 5.

[0046] In the ceiling transport vehicle 1 of this embodiment, when transferring an article 100, detection processing is not performed for one or more sensors S that include the processing device 200 within their detection range among the multiple sensors S. Specifically, the ceiling transport vehicle 1 references the sensor usage information and, based on the fact that the rotation position of the gripping unit 8 around the central axis is the second position, determines to use the second sensor S2 and not to perform detection processing for the first and third sensors S1, S3. Then, the ceiling transport vehicle 1 detects the presence or absence of an obstacle around (in front of) the second load port 202 using only the second sensor S2, and stops output of detection waves from the first and third sensors S1, S3. Next, the ceiling transport vehicle 1 lowers the rotation unit 7 and the gripping unit 8 using the lift drive unit 6, and the gripping unit 8 grips the flange of the article 100 placed on the second load port 202. Thereafter, the ceiling transport vehicle 1 raises the rotation unit 7 and the gripping unit 8 to the highest position by the lifting drive unit 6, and then rotates the rotation unit 7 so that the rotation position of the gripping unit 8 returns to the first position, which is the initial position. After the rotation position of the gripping unit 8 returns to the initial position, the ceiling transport vehicle 1 becomes able to travel.

[0047] On the other hand, when transferring an article 100 from the ceiling transport vehicle 1 to the second load port 202, the ceiling transport vehicle 1 holding the article 100 first acquires port information regarding the position and orientation of the second load port 202 from map data. The ceiling transport vehicle 1 travels based on the port information, traveling along the track 20 to a position corresponding to the second load port 202 and stopping there. At the same time, the ceiling transport vehicle 1 rotates the rotation unit 7 based on the port information so that the orientation of the article 100 to be transferred matches the specified orientation. Here, the ceiling transport vehicle 1 controls the rotation unit 7 to set the rotation position of the gripping unit 8 about the central axis to the second position, so that the article 100 is placed on the second load port 202 in the specified orientation. At this time, if the position of the gripping unit 8 to be lowered is deviated from the second load port 202, the ceiling transport vehicle 1 adjusts the horizontal position and horizontal angle of the rotation unit 7 and the gripping unit 8 by driving the lateral unit 4 and the theta unit 5.

[0048] In the ceiling transport vehicle 1 of this embodiment, when transferring the article 100, the detection process of one or more of the multiple sensors S that include the processing device 200 in their detection range is not performed. Specifically, the ceiling transport vehicle 1 references the sensor usage information and, based on the fact that the rotation position of the gripping unit 8 about the central axis is the second position, determines to use the second sensor S2 and not to perform the detection process of the first and third sensors S1, S3. Then, the ceiling transport vehicle 1 uses only the second sensor S2 to detect the presence or absence of an obstacle around (in front of) the second load port 202. Next, the ceiling transport vehicle 1 lowers the rotation unit 7 and the gripping unit 8 using the lift drive unit 6, places the article 100 on the second load port 202, and releases the gripping unit 8 from gripping the flange. Thereafter, the ceiling transport vehicle 1 raises the rotation unit 7 and the gripping unit 8 to the highest position by the lifting drive unit 6, and then rotates the rotation unit 7 so that the rotation position of the gripping unit 8 returns to the first position, which is the initial position. After the rotation position of the gripping unit 8 returns to the initial position, the ceiling transport vehicle 1 becomes able to travel.

[0049] [Transfer between the 3rd load port 203 and the overhead transport vehicle 1] For example, as shown in FIG. 5, when transferring an article 100 from a third load port 203 to an overhead transport vehicle 1, the overhead transport vehicle 1, which is not holding the article 100, first acquires port information regarding the position and orientation of the third load port 203 from map data. The overhead transport vehicle 1 travels based on the port information, traveling along the track 20 to a position corresponding to the third load port 203 and stopping there. At the same time, the overhead transport vehicle 1 rotates the rotation unit 7 and adjusts the direction of the gripping unit 8 based on the port information so that the orientation of the article 100 to be transferred matches the specified orientation. Here, the overhead transport vehicle 1 controls the rotation unit 7 to set the rotation position of the gripping unit 8 about its central axis to a third position that is −90° different from the first position, so that the article 100 is gripped by the gripping unit 8 in the specified orientation. At this time, if the position of the gripping unit 8 to be lowered is deviated from the third load port 203, the ceiling transport vehicle 1 adjusts the horizontal position and horizontal angle of the rotation unit 7 and the gripping unit 8 by driving the lateral unit 4 and the theta unit 5.

[0050] In the ceiling transport vehicle 1 of this embodiment, when transferring an article 100, the detection process of one or more sensors S that include the processing device 200 within their detection range is not performed. Specifically, the ceiling transport vehicle 1 references the sensor usage information and, based on the fact that the rotation position of the gripping unit 8 around its central axis is the third position, determines to use the third sensor S3 and not to perform the detection process of the first and second sensors S1, S2. The ceiling transport vehicle 1 then uses only the third sensor S3 to detect the presence or absence of an obstacle around (in front of) the third load port 203. Next, the ceiling transport vehicle 1 lowers the rotation unit 7 and the gripping unit 8 using the lifting drive unit 6, and the gripping unit 8 grips the flange of the article 100 placed on the third load port 203. Thereafter, the ceiling transport vehicle 1 raises the rotation unit 7 and the gripping unit 8 to their highest positions using the lifting drive unit 6, and then rotates the rotation unit 7 so that the rotation position of the gripping unit 8 returns to the first position, which is its initial position. After the rotational position of the gripping unit 8 returns to the initial position, the ceiling transport vehicle 1 becomes able to travel.

[0051] On the other hand, when transferring an article 100 from the ceiling transport vehicle 1 to the third load port 203, the ceiling transport vehicle 1 holding the article 100 first acquires port information regarding the position and orientation of the third load port 203 from map data. The ceiling transport vehicle 1 travels based on the port information, traveling along the track 20 to a position corresponding to the third load port 203 and stopping there. At the same time, the ceiling transport vehicle 1 rotates the rotation unit 7 and adjusts the direction of the gripping unit 8 based on the port information so that the orientation of the article 100 to be transferred matches the specified orientation. Here, the ceiling transport vehicle 1 controls the rotation unit 7 to set the rotation position of the gripping unit 8 about the central axis to the third position so that the article 100 is placed on the third load port 203 in the specified orientation. At this time, if the position of the gripping unit 8 to be lowered is deviated from the third load port 203, the ceiling transport vehicle 1 adjusts the horizontal position and horizontal angle of the rotation unit 7 and the gripping unit 8 by driving the lateral unit 4 and the theta unit 5.

[0052] In particular, in the ceiling transport vehicle 1 of this embodiment, when transferring the article 100, the detection process of one or more of the multiple sensors S that include the processing device 200 in their detection range is not performed. Specifically, the ceiling transport vehicle 1 references the sensor usage information and, based on the fact that the rotation position of the gripping unit 8 about the central axis is the third position, determines to use the third sensor S3 and not to perform the detection process of the first and second sensors S1, S2. Then, the ceiling transport vehicle 1 uses only the third sensor S3 to detect the presence or absence of an obstacle around (in front of) the third load port 203. Next, the ceiling transport vehicle 1 lowers the rotation unit 7 and the gripping unit 8 using the lift drive unit 6, places the article 100 on the third load port 203, and releases the grip of the flange by the gripping unit 8. Thereafter, the ceiling transport vehicle 1 raises the rotation unit 7 and the gripping unit 8 to the highest position by the lifting drive unit 6, and then rotates the rotation unit 7 so that the rotation position of the gripping unit 8 returns to the first position, which is the initial position. After the rotation position of the gripping unit 8 returns to the initial position, the ceiling transport vehicle 1 becomes able to travel.

[0053] As described above, when transferring the article 100, the ceiling transport vehicle 1 can rotate the article 100 so that the article 100 is transferred in a specified orientation. At this time, since the detection process of one or more sensors S that include the processing equipment 200 in their detection range is not performed, the processing equipment 200 will not be erroneously detected as an obstacle by the sensors S. Therefore, regardless of the direction in which the ceiling transport vehicle 1 accesses the load port 210, the orientation of the article 100 can be adjusted to a specified orientation while ensuring safety around the load port 210 with the sensors S, and the article 100 can be transferred between the ceiling transport vehicle 1 and the load port 210.

[0054] Therefore, for example, when detecting the presence or absence of an obstacle using a sensor S with a detection range in one direction, depending on the direction in which the overhead transport vehicle 1 accesses the load port 210, the detection range of the sensor S may include the processing device 200, resulting in a false detection of an obstacle; however, the overhead transport vehicle 1 can avoid such false detection and there are no restrictions on the layout of the track 20. Also, for example, when transferring an article 100, the direction in which the overhead transport vehicle 1 accesses the load port 210 may be determined in order to align the orientation of the article 100 to a specified orientation; however, the overhead transport vehicle 1 does not have such restrictions on the layout of the track 20. Therefore, with the overhead transport vehicle 1, there is no need for a track 20 that requires the overhead transport vehicle 1 to make a detour to access the load port 210, for example, which increases the flexibility in the layout of the track 20 and makes it possible to improve transport efficiency.

[0055] In the ceiling transport vehicle 1, the lifting drive unit 6 lifts and lowers the rotation unit 7 together with the gripping unit 8, and the rotation unit 7 rotates only the gripping unit 8. In this case, the rotation that changes the orientation of the article 100 during transfer can be achieved with a small mechanism.

[0056] In the ceiling transport vehicle 1, the rotation unit 7 rotates the gripping unit 8 so that the rotation position of the gripping unit 8 around the central axis switches between a first position, a second position that is different by +90° from the first position, and a third position that is different by -90° from the first position. In this case, a device (encoder, etc.) for adjusting the angle of rotation by the rotation unit 7 is not required.

[0057] In the overhead transport vehicle 1, the sensor S includes first to third sensors S1 to S3 whose detection ranges, in a plan view, cover three directions: forward, backward, and to one side of the traveling direction of the overhead transport vehicle 1. As a result, even if the overhead transport vehicle 1 accesses the load port 210 from three directions, the presence or absence of an obstacle can be detected by appropriately using any of the first to third sensors S1 to S3 whose detection ranges cover these three directions depending on the access direction above the load port 210. Furthermore, the presence or absence of an obstacle can be detected while limiting the number of sensors S used.

[0058] In the ceiling transport vehicle 1, the transfer section includes a theta unit 5 that adjusts the rotational positions around the rotation axis of the gripping unit 8, the rotation unit 7, and the lift drive unit 6. In this case, the article 100 can be rotated in two stages by the theta unit 5 and the rotation unit 7.

[0059] In the ceiling transport vehicle 1, when the transfer section transfers the article 100, the transport vehicle controller 9 determines one or more sensors S for which detection processing will not be performed based on the sensor usage information and the rotational position around the central axis of the gripping unit 8. In this case, by using the sensor usage information stored in advance, it is possible to not perform detection processing on one or more sensors S that include the processing device 200 in their detection range.

[0060] In the overhead transport vehicle 1, the track 20 passes over the processing equipment 200 and includes a passing track 25 that passes over the first and second load ports 201, 202 of the processing equipment 200 in the front-to-rear direction of the first and second load ports 201, 202. Because the track 20 includes the passing track 25 in this way, it is possible to improve transport efficiency compared to when the track 20 includes a turning track that goes around to access the first and second load ports 201, 202.

[0061] In the ceiling transport vehicle 1, the transport vehicle controller 9 controls one or more of the sensors S1 to S3 whose detection range includes the processing device 200 not to emit a detection wave when the sensor S does not perform detection processing. In this case, unnecessary detection waves are not emitted, thereby enabling labor savings. Note that the manner in which the sensor S is not subjected to detection processing is not particularly limited to not emitting a detection wave, and may be, for example, stopping the sensor S (turning off the power), performing processing so as not to use the detection result of the sensor S, physically blocking the detection wave of the sensor S, or the like.

[0062] In the overhead transport vehicle 1, when transferring an article 100 from the load port 210 to the gripping unit 8, the transport vehicle controller 9 controls the rotation unit 7 so that the article 100 is gripped in a specified orientation by the gripping unit 8. In this case, the overhead transport vehicle 1 can always grip the article 100 in a fixed orientation, making it easy to adjust the rotation thereafter.

[0063] Although the embodiments have been described above, one aspect of the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention.

[0064] In the above embodiment, the object is the object 100, but the object is not particularly limited, and may be any object that can be transported by the ceiling transport vehicle 1. In the above embodiment, the transport vehicle controller 9 is provided as the control unit, but instead, one or more controllers other than the transport vehicle controller 9 may be provided as the control unit. In the above embodiment, the number and positions of the sensors S are not limited. It is sufficient that multiple sensors S are installed on the ceiling transport vehicle 1, and the installation locations of the sensors S may also be various.

[0065] In the above embodiment, the first position, which is the position where the gripping part does not need to be rotated the most in terms of the layout of the track, is set as the initial position, but this is not limited to this. The second position, the third position, or any other position may also be the initial position.

[0066] In the above embodiment, the detection ranges R1 to R3 of the first to third sensors S1 to S3 are not particularly limited. The first to third sensors S1 to S3 may be sensors whose detection ranges R1 to R3 are appropriately changeable (switchable). For example, as shown in FIG. 6(a), when articles 100A and 100B are placed side by side in the Y direction on the second load port 202, the second sensor S2 may switch the detection range R2 to a detection range R2A corresponding to the article 100A. When viewed from the front of the second load port 202, the detection range R2A is a range that includes the article 100A but does not include the article 100B (i.e., covers only the article 100A). Furthermore, as shown in FIG. 6(b), when articles 100A and 100B are placed side by side in the Y direction on the second load port 202, the second sensor S2 may switch the detection range R2 to a detection range R2B corresponding to the article 100B. The detection range R2B is a range that includes the article 100B but does not include the article 100A (i.e., covers only the article 100B) when viewed from the front side of the second load port 202. Note that the second sensor S2 may of course have a detection range that corresponds to both the articles 100A and 100B (a range that includes the articles 100A and 100B, or a range that covers the articles 100A and 100B).

[0067] In the above embodiment, the rotation unit 7 rotates the gripping unit 8, and the rotation position of the gripping unit 8 is switched between the first to third positions. However, the rotation of the gripping unit 8 by the rotation unit 7 is not particularly limited. For example, in the above embodiment, the rotation unit 7 may rotate the gripping unit 8 so that the rotation position of the gripping unit 8 about the central axis is any position. Also, for example, in the above embodiment, the rotation unit 7 may rotate the gripping unit 8 so that the rotation position of the gripping unit 8 is switched between at least two of the first to fifth positions. The fourth position is a rotation position that differs by +180° from the first position, and the fifth position is a rotation position that differs by -180° from the first position. When the rotation position of the gripping unit 8 includes at least one of the fourth and fifth rotation positions, another sensor S may be further installed on the other side of the lifting / lowering drive unit 14 of the ceiling transport vehicle 1 in the traveling direction (the side opposite to the first sensor S1).

[0068] In the above embodiment, the port information is obtained from map data, but it may also be obtained by receiving it from a higher-level controller (not shown), for example. In the above embodiment, the layout of the track 20 is not limited to the example shown in Figure 2, and various layouts can be adopted.

[0069] The components in the above embodiments are not limited to the materials and shapes described above, and various materials and shapes can be applied. Each component in the above embodiments or modifications can be applied to each component in other embodiments or modifications as desired. Parts of each component in the above embodiments or modifications can be omitted as appropriate without departing from the spirit of one aspect of the present invention.

[0070] The constituent elements of one aspect of the present invention will be described below. <Invention 1> An overhead transport vehicle that travels along a track and transports items, a transfer unit that transfers the article between a load port of the apparatus and the transfer unit; a plurality of sensors each having a different detection range that emits a detection wave downward to detect the presence or absence of an obstacle when the transfer unit transfers the article; a control unit that controls the ceiling transport vehicle, The transfer unit includes a gripping unit that grips the article, a rotating unit that rotates the gripping unit around a rotation axis along a vertical direction, and a lifting unit that lifts and lowers the gripping unit, The control unit An overhead transport vehicle in which, when the transfer unit transfers the item, the rotation unit is controlled in accordance with the direction of access onto the load port so that the item is transferred in a specified orientation, and detection processing is not performed by one or more sensors among the multiple sensors that include the device in their detection range depending on their positional relationship with the load port. <Invention 2> the lifting unit lifts and lowers the rotating unit together with the gripping unit, The ceiling transport vehicle according to invention 1, wherein the rotating unit rotates only the gripping unit. <Invention 3> The ceiling transport vehicle described in Invention 1 or 2, wherein the rotating unit rotates the gripping unit so that the rotational position of the gripping unit around the rotation axis switches at least between a first position, a second position that is +90° different from the first position, and a third position that is -90° different from the first position. <Invention 4> The overhead transport vehicle according to any one of the first to third aspects, wherein the sensor has a detection range that covers at least three directions, forward, backward and to one side of the traveling direction of the overhead transport vehicle, in a plan view. <Invention 5> The transfer unit is An overhead transport vehicle as described in any one of inventions 1 to 4, including an adjustment unit that rotates the lifting unit together with the gripping unit and the rotating unit around the rotation axis, and adjusts the rotational positions of the gripping unit, the rotating unit, and the lifting unit around the rotation axis. <Invention 6> The control unit sensor-in-use information is stored in advance, in which a rotational position of the gripping part about the rotation axis is associated with one or more sensors to be used among the plurality of sensors; An overhead transport vehicle as described in any one of inventions 1 to 5, wherein when the transfer unit transfers the item, one or more sensors to be disabled are determined based on the sensor information in use and the rotational position of the gripping unit around the rotation axis. <Invention 7> An overhead transport vehicle as described in any one of inventions 1 to 6, wherein the track includes a passing track that passes over the device and passes over the load port of the device in the front-to-rear direction of the load port. <Invention 8> The control unit controls the ceiling transport vehicle described in any one of Inventions 1 to 7 so that an emission wave is not emitted when detection processing is not performed for one or more sensors among the multiple sensors that include the device in their detection range. <Invention 9> The control unit An overhead transport vehicle as described in any one of inventions 1 to 8, wherein when transferring the item from the load port to the gripping unit, the rotating unit is controlled so that the item is gripped in a specified orientation relative to the gripping unit. [Explanation of symbols]

[0071] 1...ceiling transport vehicle, 4...lateral unit (transfer section), 5...theta unit (transfer section, adjustment section), 6...lifting drive unit (transfer section, lifting section), 7...rotation unit (transfer section, rotation section), 8...gripping unit (transfer section, gripping section), 9...transport vehicle controller (control section), 20...track, 100...article, 200...processing device (device), 201...first load port (load port), 202...second load port (load port), 203...third load port (load port), 210...load port, S...sensor, S1...first sensor (sensor), S2...second sensor, S3...third sensor.

Claims

1. An overhead transport vehicle that travels along a track and transports items, a transfer unit that transfers the article between a load port of the apparatus and the transfer unit; a plurality of sensors each having a different detection range that emits a detection wave downward to detect the presence or absence of an obstacle when the transfer unit transfers the article; a control unit that controls the ceiling transport vehicle, The transfer unit includes a gripping unit that grips the article, a rotating unit that rotates the gripping unit around a rotation axis along a vertical direction, and a lifting unit that lifts and lowers the gripping unit, The control unit When the transfer unit transfers the item, the rotation unit is controlled in accordance with the direction of access onto the load port so that the item is transferred in a specified orientation, and the detection process of one or more sensors that include the device in their detection range is not performed among the multiple sensors depending on their positional relationship with the load port.

2. the lifting unit lifts and lowers the rotating unit together with the gripping unit, The ceiling transport vehicle according to claim 1 , wherein the rotating unit rotates only the gripping unit.

3. The ceiling transport vehicle described in claim 1 or 2, wherein the rotating unit rotates the gripping unit so that the rotational position of the gripping unit around the rotation axis switches at least between a first position, a second position that is +90° different from the first position, and a third position that is -90° different from the first position.

4. 3. The overhead transport vehicle according to claim 1, wherein the sensor has a detection range that covers at least three directions, that is, the front, rear, and one side of the traveling direction of the overhead transport vehicle, in a plan view.

5. The transfer unit is The ceiling transport vehicle according to claim 1 or 2, further comprising an adjustment unit that rotates the lifting unit together with the gripping unit and the rotating unit around the rotation axis, and adjusts the rotational positions of the gripping unit, the rotating unit, and the lifting unit around the rotation axis.

6. The control unit sensor-in-use information is stored in advance, in which a rotational position of the gripping part about the rotation axis is associated with one or more sensors to be used among the plurality of sensors; The ceiling transport vehicle according to claim 1 or 2, wherein when the transfer unit transfers the item, one or more of the sensors to be disabled are determined based on the sensor information in use and the rotational position of the gripping unit around the rotation axis.

7. 3. The overhead transport vehicle according to claim 1, wherein the track includes a passing track that passes over the device and passes over the load port of the device in the front-to-rear direction of the load port.

8. The ceiling transport vehicle according to claim 1 or 2, wherein the control unit controls the sensors so as not to emit an emission wave when one or more sensors among the plurality of sensors that include the device in their detection ranges are not performing detection processing.

9. The control unit 3. The ceiling transport vehicle according to claim 1, wherein when the article is transferred from the load port to the gripper, the rotation unit is controlled so that the article is gripped by the gripper in a specified orientation.

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