Overhead carrier

Abstract

To provide an overhead carrier capable of reducing generation of work for an operator caused by a communication failure.SOLUTION: An overhead carrier 1 comprises: a body 20 that can travel on a track 4; a lifting part 30 provided so as to be able to be liftable with respect to the body 20 by winding and delivering a suspension member 28A; a body side controller 50 provided in the body 20; and a plurality of communication devices 51 and 53 provided in the lifting part 30 to communicate with a lifting part side controller 36. The body side controller 50 sets at least one of the communication devices 51 and 53 as a first communication device used for normal communication, sets at least one different from the first communication device as a second communication device used for non-normal communication disabling the use of the first communication device, and switches to communication by the second communication device when the communication by the first communication device is disabled.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Overhead transport vehicles that travel along a track to transport an article are known. Patent Document 1 describes an overhead transport vehicle that includes a vehicle body that travels along rails installed on the ceiling, a lifting platform that is installed so as to be able to rise and fall relative to the vehicle body, and a gripper that is installed on the lifting platform and grips an article. Such a gripper is configured to be able to open and close by being driven by a motor installed on the lifting platform. A control device installed on the vehicle body controls the motor for the gripper wirelessly (see Patent Document 1, for example) or via a wired connection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-105391 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional ceiling transport vehicle, if a communication failure occurs between one of the control unit provided on the vehicle body and the controlled unit provided on the lifting platform, and the other of the control unit and the controlled unit, manual recovery work becomes necessary, which can place a burden on the workers.

[0005] Therefore, an object of one aspect of the present invention is to provide an overhead transport vehicle that can reduce the occurrence of work by workers caused by communication problems. [Means for solving the problem]

[0006] (1) A ceiling transport vehicle according to one aspect of the present invention comprises a main body capable of running along a track, a lifting section that can be raised and lowered relative to the main body by winding and unwinding a suspension member, a holding section that is provided on the lifting section and hangs and holds an item, a main body side controller that is provided on the main body, and a plurality of communication devices for communicating with the lifting section side controller that is provided on the lifting section and controls the drive of the holding section, and a controller that sets at least one of the plurality of communication devices as a first communication device to be used for communication under normal circumstances and sets at least one other than the first communication device as a second communication device to be used for communication under abnormal circumstances when the first communication device becomes unavailable, and that switches to communication using the second communication device when communication using the first communication device becomes unavailable.

[0007] With this configuration, a ceiling transport vehicle automatically switches to communication via the second communication device if communication via the first communication device becomes impossible, thereby reducing the amount of work that workers have to do due to communication problems.

[0008] (2) In the overhead transport vehicle described in (1) above, the multiple communication devices may include at least a wired communication device that communicates via a communication line provided on the suspending member and a wireless communication device that communicates wirelessly via terminals disposed on the main body and the lifting unit. In this configuration, since the communication devices are of different types, even if one communication device becomes disabled, the possibility that the other communication device will become disabled for the same reason can be reduced. As a result, it is possible to reduce the likelihood of communication being disabled when switching to the second communication device.

[0009] (3) In the overhead transport vehicle described in (2) above, the wireless communication device may be an optical communication device that performs optical communication via terminals that are arranged to face each other in the main body and the lifting part. In this configuration, the optical communication device can be used as the wireless communication device.

[0010] (4) In the overhead transport vehicle described in (3) above, the controller may set the optical communication device as the second communication device and, under normal circumstances, acquire information about the tilt of the lifting unit based on the communication status of the optical communication device. In this configuration, under normal circumstances, the optical communication device is not used for communication but is used as a device for acquiring information about the tilt of the lifting unit. As a result, under normal circumstances, abnormal tilt of the lifting unit can be detected when transferring an item, thereby preventing damage to the item during transfer.

[0011] (5) In the overhead transport vehicle described in (3) above, the controller may set the wired communication device as the second communication device and may normally detect whether or not the suspension members are damaged based on the communication status of the wired communication device. In this configuration, the wired communication device is normally not used for communication but is used as a device for detecting whether or not the suspension members are damaged. This allows for early detection of damage to the suspension members. [Effects of the Invention]

[0012] According to one aspect of the present invention, it is possible to reduce the occurrence of work that must be done by workers due to communication problems. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a side view showing an overhead transport vehicle according to one embodiment. [Figure 2] FIG. 2 is a block diagram showing the functional configuration of the ceiling transport vehicle according to one embodiment. [Figure 3] FIG. 3 is a flowchart showing the control of switching the communication method in the overhead transport vehicle. [Figure 4] FIG. 4 is a block diagram showing the functional configuration of an overhead transport vehicle according to a modified example. [Figure 5] FIG. 5 is a flowchart showing the control of switching the communication method in the overhead transport vehicle according to the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] As shown in Fig. 1, an overhead transport vehicle 1 in one embodiment is a ceiling transport vehicle that can move along a track 4, and is used in a system for transporting a FOUP (Front Opening Unified Pod) 10 between placement units (not shown). Instead of the FOUP (item) 10, the ceiling transport vehicle 1 may transport, for example, a container such as a reticle pod that stores multiple glass substrates, as well as general parts. Here, an explanation will be given using an example of the ceiling transport vehicle 1 moving along a one-way track 4 installed on the ceiling of a factory, for example.

[0015] The track 4 is installed, for example, near the ceiling, which is the overhead space for the worker. The track 4 is suspended from the ceiling, for example. The track 4 is a predetermined travel path along which the overhead transport vehicle 1 travels. The placement unit is arranged along the track 4 and is provided at a position where the overhead transport vehicle 1 can deliver and receive the FOUP 10. The placement unit includes a buffer and a delivery port. The buffer is a placement unit where the FOUP 10 is temporarily placed. The buffer is a placement unit where the FOUP 10 is temporarily placed when, for example, the FOUP 10 being transported by the overhead transport vehicle 1 cannot be transferred to the delivery port to which it is being transported because another FOUP 10 is placed at the delivery port. The delivery port is a placement unit where the FOUP 10 is delivered to and received from semiconductor processing equipment (not shown), such as a cleaning equipment, a film forming equipment, a lithography equipment, an etching equipment, a heat treatment equipment, or a planarization equipment. The delivery port is not particularly limited and may be an input / output port of a stocker or the like.

[0016] The overhead transport vehicle 1 travels along a track 4 and transports a FOUP 10. The overhead transport vehicle 1 is an overhead traveling automatic guided vehicle. As shown in FIGS. 1 and 2, the overhead transport vehicle 1 includes a main body 20 and an elevating unit 30. The main body 20 includes a traveling unit 18, a frame 22, a lateral feed unit 24, a θ drive 26, an elevating drive unit 28, a main body controller (main body side controller) 50, and an optical communication terminal (E84 communication sensor) 53A.

[0017] The travel unit 18 includes a motor and other components, and drives the overhead transport vehicle 1 along the track 4. The travel unit 18 is connected to a frame 22. The frame 22 has a main frame 22A and front and rear frames 22B, 22B. The main frame 22A supports the lateral feed unit 24, the θ drive 26, the lift drive unit 28, and the lift unit 30. The front and rear frames 22B, 22B have protruding and retracting claws and the like (not shown) to prevent the FOUP 10 from falling during transport. The front and rear frames 22B, 22B are provided at the front and rear of the overhead transport vehicle 1 in the direction of travel.

[0018] The traverse unit 24 collectively moves the θ drive 26, the lifting drive unit 28, and the lifting unit 30 laterally in a direction perpendicular to the running direction of the track 4. The θ drive 26 rotates at least one of the lifting drive unit 28 and the lifting unit 30 within a predetermined angular range in a horizontal plane. The lifting drive unit 28 raises and lowers the lifting unit 30 by winding or unwinding a suspension member 28A such as a wire, rope, or belt.

[0019] The main body controller 50 is an electronic control unit including a CPU, a ROM, a RAM, etc. The main body controller 50 controls the various operations of the various parts of the ceiling transport vehicle 1. Specifically, as shown in FIG. 2, the main body controller 50 controls the traveling unit 18, the lateral feed unit 24, the θ drive 26, and the lifting drive unit 28. The main body controller 50 can be configured as software in which a program stored in the ROM is loaded onto the RAM and executed by the CPU, for example. The main body controller 50 may also be configured as hardware including electronic circuits, etc.

[0020] The lifting unit 30 is provided with a gripper (holding unit) 32, a gripper driving unit 34, a gripper controller (lifting unit side controller) 36, and an optical communication terminal (E84 communication sensor) 53B. The gripper 32 holds the flange portion of the FOUP 10 while supporting it from below. The gripper 32 is capable of freely holding or releasing the FOUP 10. The gripper driving unit 34 holds or releases the flange portion of the FOUP 10 by opening and closing the gripper 32. The gripper controller 36 can be configured as software, for example, in which a program stored in a ROM is loaded onto a RAM and executed by a CPU. The gripper controller 36 may also be configured as hardware such as an electronic circuit.

[0021] The ceiling transport vehicle 1 includes a plurality of communication devices for communication between the main body controller 50 provided in the main body unit 20 and the gripper controller 36 provided in the lifting unit 30 and controlling the gripper driving unit 34. In the ceiling transport vehicle 1 of this embodiment, the plurality of communication devices include a wired communication device 51 that communicates via a communication line 51A provided in the suspending member 28A, and an optical communication device 53 that communicates wirelessly via optical communication terminals 53A and 53B provided in the main body unit 20 and the lifting unit 30, respectively. The wired communication device 51 is a communication device that connects an interface (communication port) on the main body controller 50 side to an interface (communication port) on the gripper controller 36 side via the communication line 51A. The optical communication device 53 is a communication device that connects the interface on the main body controller 50 side to the interface on the gripper controller 36 side via the optical communication terminals 53A and 53B.

[0022] For example, when the suspending member 28A is formed in a belt shape, the communication line 51A may be built in so that the surface is covered by the belt-shaped member, or may be attached to the surface of the belt-shaped member. The optical communication terminals 53A and 53B are respectively arranged on the main body 20 and the lifting unit 30 so that the light incident surface and light exit surface face each other.

[0023] The main body controller 50 sets the optical communication device 53 as a first communication device to be used for normal communication, and sets the wired communication device 51 as a second communication device (backup communication device) to be used for abnormal communication when the optical communication device 53 becomes unavailable. When communication using the optical communication device 53 becomes unavailable, the main body controller 50 switches to communication using the wired communication device 51. Examples of when communication using the optical communication device 53 becomes unavailable include, for example, when a signal is transmitted via the optical communication terminal 53A and the optical communication terminal 53A fails to receive a response signal from the optical communication terminal 53B.

[0024] The main body controller 50 of this embodiment sets the wired communication device 51 as the second communication device, and normally detects whether or not the suspension member 28A is damaged based on the communication status of the wired communication device 51. Specifically, when the main body controller 50 transmits a signal via the communication line 51A but does not receive a response signal from the communication line 51A, the main body controller 50 determines that the communication line 51A is disconnected and that the suspension member 28A is damaged. When the main body controller 50 determines that the suspension member 28A is damaged, it may, for example, bring the ceiling transport vehicle 1 to an emergency stop or notify an operator that the suspension member 28A is damaged.

[0025] Next, the operation of the ceiling transport vehicle 1 in this embodiment will be described mainly with reference to Figure 3. In this embodiment, the main body controller 50 sets the optical communication device 53 as a first communication device to be used for communication during normal times, and sets the wired communication device 51 as a second communication device to be used for communication during abnormal times when the optical communication device 53 is unavailable. When starting to transfer the FOUP 10 onto the ceiling transport vehicle 1 (step S1), the traveling unit 18 is stopped at a predetermined position above the placement unit that received the transfer command, and the lifting unit 30 is lowered (step S2).

[0026] While the lifting unit 30 is being lowered, the main body controller 50 lowers the lifting unit 30 to a predetermined height while communicating with the gripper controller 36 at predetermined intervals via the optical communication device 53. The main body controller 50 monitors whether communication via the optical communication device 53 becomes unavailable while the lifting unit 30 is being lowered to the predetermined height (step S3). If communication via the optical communication device 53 does not become unavailable while the main body controller 50 controls the lifting drive unit 28 to lower the lifting unit 30 to the predetermined height (S3: NO), the main body controller 50 controls the gripper drive unit 34 via the gripper controller 36 to open or close the gripper 32, thereby holding or releasing the flange portion of the FOUP 10. This completes the transfer operation by the ceiling transport vehicle 1 (step S7).

[0027] If communication via the optical communication device 53 becomes impossible before the main body controller 50 controls the lift drive unit 28 to lower the lift unit 30 to a predetermined height position (S3: YES), the main body controller 50 switches the communication method (step S4). Specifically, the optical communication device 53, which had been set as the normally used communication device (first communication device), is now set as the normally used communication device (first communication device). In other words, the main body controller 50 switches the normally used communication device from the optical communication device 53 to the wired communication device 51.

[0028] After setting the wired communication device 51 as the normally used communication device (first communication device), the main body controller 50 checks whether communication between the main body controller 50 and the gripper controller 36 is possible (step S5). If communication is possible (S5: YES), the main body controller 50 notifies the operator that an abnormality has occurred in the optical communication device 53, and the transfer operation by the overhead transport vehicle 1 continues (step S6). In step S6, the abnormality in the optical communication device 53 may be notified to the operator but to a server device such as an area controller (not shown) that controls multiple overhead transport vehicles 1. Information stored in the server device may also be used for maintenance purposes, such as to predict the timing of a malfunction. The main body controller 50 communicates with the gripper controller 36 via the wired communication device 51. The main body controller 50 controls the gripper driver 34 via the gripper controller 36 to open and close the gripper 32, thereby holding or releasing the flange portion of the FOUP 10. This completes the transfer operation by the overhead transport vehicle 1 (step S7).

[0029] When the main body controller 50 confirms that communication is not possible between the main body controller 50 and the gripper controller 36 (S5: NO), it notifies the worker that an abnormality has occurred in both the optical communication device 53 and the wired communication device 51 (i.e., the ceiling transport vehicle 1 is unable to continue work) and brings the ceiling transport vehicle 1 to an emergency stop (step S8).

[0030] In steps S1 to S3, the main body controller 50 detects whether or not the suspending member 28A is damaged based on the communication status of the wired communication device 51. Specifically, when the main body controller 50 transmits a signal via the communication line 51A but does not receive a response signal from the communication line 51A, the main body controller 50 determines that the communication line 51A is disconnected and that the suspending member 28A is damaged. When the main body controller 50 determines that the suspending member 28A is damaged, it may, for example, bring the ceiling transport vehicle 1 to an emergency stop, or notify an operator that the suspending member 28A is damaged.

[0031] The effects of the overhead transport vehicle 1 of the above embodiment will be described. The overhead transport vehicle 1 of the above embodiment makes an emergency stop if communication via the normally used optical communication device 53 becomes impossible. In this case, a worker had to go to the position where the overhead transport vehicle 1 made an emergency stop and manually restore the overhead transport vehicle 1. In this embodiment, if communication via the normally used optical communication device 53 becomes impossible, communication is automatically switched to communication via the wired communication device 51 provided as a backup communication device, thereby reducing the amount of work required by workers due to communication problems.

[0032] The ceiling transport vehicle 1 of the above embodiment includes a wired communication device 51 that communicates via a communication line 51A provided on the suspending member 28A, and an optical communication device 53 that performs optical communication via optical communication terminals 53A, 53B arranged on the main body 20 and the lifting unit 30. In this embodiment, since communication devices of different systems are provided, even if the optical communication device 53 becomes disabled, the possibility that the wired communication device 51 will also become disabled for the same reason can be reduced. As a result, the possibility that communication will become disabled via the wired communication device 51, which is used as a replacement when the optical communication device 53 becomes disabled, can be reduced.

[0033] The ceiling transport vehicle 1 of the above embodiment employs an optical communication device 53 as a wireless communication device, which performs optical communication via optical communication terminals 53A and 53B arranged to face each other in the main body 20 and the lifting unit 30. In this configuration, the optical communication device 53 that is likely to be used in a semiconductor manufacturing factory or the like can be used as the wireless communication device.

[0034] In the ceiling transport vehicle 1 of the above embodiment, the main body controller 50 sets the wired communication device 51 as the second communication device, and normally detects whether or not the suspending member 28A is damaged based on the communication status of the wired communication device 51. In the ceiling transport vehicle 1 of the above embodiment, normally the wired communication device 51 is not used for communication, but is used as a device for detecting whether or not the suspending member 28A is damaged. This allows early detection of damage to the suspending member 28A.

[0035] Although one embodiment of one aspect of the present invention has been described above, one aspect of the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the spirit of the invention.

[0036] In the above embodiment, the main body controller 50 and the gripper controller 36 are provided with multiple interfaces (communication ports), and examples have been described in which communication devices (wired communication device 51 and optical communication device 53) with different communication methods are connected to each interface, but this is not limiting. The main body controller 50 in the above embodiment does not need to be provided with multiple interfaces, and may be connected to multiple communication devices by connecting a communication expansion board 54 having multiple interfaces, as shown in FIG. 4, for example. The gripper controller 36 may also be connected to a communication expansion board 54 without preparing a controller provided with multiple interfaces (communication ports).

[0037] In the above embodiment and the above modified example of the ceiling transport vehicle 1, as shown in Fig. 3, an example has been described in which the optical communication device 53 is set as the first communication device to be used for communication in normal times, but it is also possible to set the wired communication device 51 as the first communication device and the optical communication device 53 as the second communication device to be used for communication in abnormal times when the wired communication device 51 is no longer available. The operation of the ceiling transport vehicle 1 in this case will be described mainly with reference to Fig. 5.

[0038] In this case as well, when starting to transfer the FOUP 10 onto the ceiling transport vehicle 1 (step S11), the traveling unit 18 is stopped at a predetermined position above the placement unit that received the transfer command, and the lifting unit 30 is lowered (step S2).

[0039] While the lifting unit 30 is being lowered, the main body controller 50 communicates with the gripper controller 36 at predetermined intervals via the wired communication device 51 while lowering the lifting unit 30 to a predetermined height. The main body controller 50 monitors whether communication via the wired communication device 51 becomes unavailable while the lifting unit 30 is being lowered to the predetermined height (step S13). If communication via the wired communication device 51 does not become unavailable while the main body controller 50 controls the lifting drive unit 28 to lower the lifting unit 30 to the predetermined height (S13: NO), the main body controller 50 controls the gripper drive unit 34 via the gripper controller 36 to open or close the gripper 32, thereby holding or releasing the flange portion of the FOUP 10. This completes the transfer operation by the ceiling transport vehicle 1 (step S7).

[0040] If communication via the wired communication device 51 becomes impossible while the main body controller 50 controls the lift drive unit 28 to lower the lift unit 30 to a predetermined height position (S13: YES), the main body controller 50 switches the communication method (step S14). Specifically, the main body controller 50 changes the communication method from setting the wired communication device 51 as the normally used communication device (first communication device) to setting the optical communication device 53 as the normally used communication device (first communication device). In other words, the main body controller 50 switches the normally used communication device from the wired communication device 51 to the optical communication device 53.

[0041] After setting the optical communication device 53 as the normally used communication device (first communication device), the main body controller 50 checks whether communication is possible between the main body controller 50 and the gripper controller 36 (step S5). If it checks that communication is possible (S5: YES), it notifies the worker that an abnormality has occurred in the wired communication device 51, and continues the transfer operation using the ceiling transport vehicle 1 (step S6). The main body controller 50 communicates with the gripper controller 36 using the optical communication device 53. The main body controller 50 controls the gripper driver 34 via the gripper controller 36 to open and close the gripper 32, thereby holding or releasing the flange portion of the FOUP 10. This completes the transfer operation using the ceiling transport vehicle 1 (step S7).

[0042] When the main body controller 50 confirms that communication is not possible between the main body controller 50 and the gripper controller 36 (S5: NO), it notifies the worker that an abnormality has occurred in both the optical communication device 53 and the wired communication device 51 (i.e., the ceiling transport vehicle 1 is unable to continue work) and brings the ceiling transport vehicle 1 to an emergency stop (step S8).

[0043] In steps S1 to S3, the main body controller 50 acquires information about the tilt of the lifting / lowering unit 30 based on the communication status of the optical communication device 53. Specifically, when the lifting / lowering unit 30 tilts at a predetermined angle or more relative to the horizontal, communication between the optical communication terminal 53A on the main body 20 side and the optical communication terminal 53B on the lifting / lowering unit 30 side becomes impossible. Utilizing this, the main body controller 50 detects whether an abnormality has occurred in the lifting / lowering unit 30, causing the lifting / lowering unit 30 to tilt at a predetermined angle or more relative to the horizontal. If the main body controller 50 transmits a signal via the optical communication terminals 53A and 53B but does not receive a response signal from the optical communication terminals 53A and 53B, the main body controller 50 determines that the lifting / lowering unit 30 is abnormally tilted. If the main body controller 50 determines that the lifting / lowering unit 30 is abnormally tilted, it may, for example, urgently stop the transfer by the ceiling transport vehicle 1 or notify the operator that the lifting / lowering unit 30 is abnormally tilted.

[0044] In the ceiling transport vehicle 1 according to this modified example, the optical communication device 53 is not normally used for communication but is used as a device for acquiring information regarding the tilt of the lifting unit 30. As a result, abnormal tilt of the lifting unit 30 can be detected during normal operation when the FOUP 10 is transferred, thereby preventing damage to the FOUP 10 during transfer.

[0045] Although the above-described embodiment and modified example of the ceiling transport vehicle 1 have been described with reference to an example in which one wired communication device 51 and one optical communication device 53 are provided, the present invention is not limited to this. For example, two wired communication devices 51 may be provided, with one of the two wired communication devices 51 set as a first communication device and the other of the two wired communication devices 51 set as a second communication device. Furthermore, for example, two optical communication devices 53 may be provided, with one of the two optical communication devices 53 set as a first communication device and the other of the two optical communication devices 53 set as a second communication device.

[0046] Although the ceiling transport vehicle 1 of the above embodiment and the above modified example has been described as being provided with two communication devices (the wired communication device 51 and the optical communication device 53), three or more communication devices may be provided. In this case, the type of communication device provided may be either the wired communication device 51 or the optical communication device 53, and is not particularly limited.

[0047] In the above embodiment, the optical communication terminals 53A and 53B have been described as an example of the optical communication device 53, but the present invention is not limited to this. For example, instead of the optical communication terminals 53A and 53B, a wireless communication device using infrared rays, radio waves, or the like other than the optical communication terminals 53A and 53B may be applied. [Explanation of symbols]

[0048] 1...ceiling transport vehicle, 4...track, 20...main body, 30...lifting section, 32...gripper (holding section), 34...gripper drive section, 36...gripper controller (lifting section side controller), 50...main body controller (main body side controller), 51...wired communication device (communication device), 51A...communication line, 53...optical communication device, 53A, 53B...optical communication terminal, 54...communication expansion board.

Claims

1. a main body portion capable of traveling along a track; a lifting unit that can be raised and lowered relative to the main body by winding and unwinding a suspending member; a holding section provided in the lifting section for suspending and holding an article; a plurality of communication devices for communicating between a main body-side controller provided in the main body and an elevator-side controller provided in the elevator and controlling the driving of the holding unit; A ceiling transport vehicle comprising: a controller that sets at least one of the plurality of communication devices as a first communication device to be used for communication under normal circumstances, and sets at least one other than the first communication device as a second communication device to be used for communication under abnormal circumstances when use by the first communication device becomes impossible, and switches to communication by the second communication device when communication by the first communication device becomes impossible.

2. The ceiling transport vehicle of claim 1, wherein the plurality of communication devices include at least a wired communication device that communicates via a communication line provided on the suspension member, and a wireless communication device that communicates wirelessly via terminals arranged on the main body unit and the lifting unit.

3. 3. The overhead transport vehicle according to claim 2, wherein the wireless communication device is an optical communication device that performs optical communication via the terminals that are arranged so as to face each other on the main body and the lifting section.

4. The ceiling transport vehicle described in claim 3, wherein the controller sets the optical communication device as the second communication device and, during the normal state, acquires information regarding the inclination of the lifting section based on the communication status of the optical communication device.

5. The ceiling transport vehicle described in claim 3, wherein the controller sets the wired communication device as the second communication device and, during normal operation, detects whether or not the suspension member is damaged based on the communication status of the wired communication device.

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