JP5056368B2 - Transport system - Google Patents

Description

  The present invention relates to a transport system that transports an object to be transported to a transport carriage.

  In a conveyance system that conveys various articles, there is a conveyance system that conveys an object to be conveyed to a conveyance carriage or the like. In Patent Document 1, a traveling body that travels along a rail includes a support body that supports an object to be transported and a lifting body that supports the support body. The lifting / lowering body is suspended from the traveling body by a suspension rope, and the traveling body raises / lowers the lifting / lowering body by extending or winding the suspension rope. When transporting the transported object, the traveling body moves above the placement position in a state where the transported object is supported by the support. Then, the lifting rope is extended to lower the lifting body, and the object to be conveyed is placed at the placement position. Thereafter, the object to be conveyed is released from the support, the hoisting line is wound up, and the lifting body is returned to the fixed position.

JP 2003-238070 A

  However, according to Patent Literature 1, since the lifting body is suspended from the traveling body by the suspension rope, it may swing like a pendulum when descending. Such shaking is generated, for example, by an airflow generated in a place where the conveyance system is installed, inertia when the traveling body stops, or vibration accompanying the extending operation of the suspension rope. In such a case, the object to be transported may not be normally placed at a predetermined placement position, and when the placement position is largely displaced, it may be necessary to temporarily stop the transportation. In this case, the conveyance process is not smoothly executed.

  An object of the present invention is to provide a transport system in which an object to be transported is suppressed from being normally placed.

Means and effects for solving the problems

The transport system according to the present invention includes a gripping unit that grips an object to be transported, a suspension member that suspends the gripping unit, and a lifting unit that lifts and lowers the gripping unit by winding and unwinding the suspension member. A transport carriage that lifts and lowers the transported object, a mounting port on which the transported object is mounted, and the transport to a position at which the transported object is disposed above the mounting port. A moving mechanism for moving a carriage and the carriage to control the carriage so that the article to be conveyed is lowered and placed on the placement port after the carriage is placed above the placement port. A placement control means; a first detection means provided in the gripping portion for detecting whether the object to be transported gripped by the gripping portion is placed on the placement port; light of the reflected light emitted in the transported object on the port By detecting the object to be conveyed is detected whether or not it is placed at a predetermined area, and a second detection means provided in the mounting port, the previous described置制control means And a placement determination means for judging whether or not the object to be transported is normally placed in the predetermined area based on both detection results from the first and second detection means, When the placement determining means determines that the transported object is not normally placed in the predetermined area, the transported object is once raised and then the transported object is lowered again. A re-execution operation of placing on the loading port is caused to be executed by the transport carriage.

When the object to be transported is lifted and lowered as in the present invention, placement displacement may occur due to pendulum-like shaking. In contrast, according to the present invention, if it is determined that the object to be conveyed is not normally placed in the predetermined area on the placement port, the object to be conveyed is placed again. Here, when placed for the second time, it is considered that the shaking is smaller than that for the first placement, so that the object to be conveyed is likely to be placed normally. Thus, according to the present invention, it becomes easier to finally place the object to be transported normally. Further, there is a risk that the gripping portion is likely to swing like a pendulum depending on the shape, material, and the like of the suspension member. Therefore, it is significant that the present invention is applied to such a configuration.

  Further, in the present invention, when the placement determination unit determines that the transported object is not normally placed in the predetermined area even if the re-execution operation is continuously performed a predetermined number of times. It is preferable to further include warning means for executing a predetermined warning operation. According to the present invention, for example, the frequency of issuing a warning can be suppressed as compared with a case where the operation of placing a transported object is executed only once and the warning is issued immediately when the object cannot be normally placed. For this reason, a conveyance process can be advanced more smoothly.

  Further, in the present invention, the number of times that the re-execution operation is continuously executed by the transport carriage when the placement determination unit determines that the transported object is not normally placed in the predetermined area. However, it is preferable that the maximum is 3 times. According to this, the frequency | count of mounting a to-be-conveyed object can be suppressed to a moderate frequency | count.

In the present invention, the detection by the first detection means is based on a distance from a predetermined portion of the object to be conveyed, and the detection by the second detection means is the object to be conveyed. It is preferable that it is based on the inclination of. Further, in the present invention, the placement determination unit is configured to perform a predetermined operation after the first detection unit detects that the transported object gripped by the gripping portion is placed on the placement port . When the time has elapsed, it is preferable to determine whether or not the object to be conveyed has been normally placed in the predetermined area based on the detection result from the second detection unit.

  A transport system 1 that is a preferred embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram of the transport system 1.

  The transfer system 1 is installed, for example, in a semiconductor substrate manufacturing factory or the like, and is for transferring various loads to be transferred in the factory. Various manufacturing devices are installed in the factory. In this embodiment, manufacturing apparatuses 310, 320, and 340 are provided. In addition, a storage device 330 for storing the load is provided. Each of these apparatuses 310 to 340 has mounting ports 311 to 341 for receiving a load from the transport system 1. Loads transported by the transport system 1 are placed on the placement ports 311 to 341.

  The transport system 1 includes a track 100 and a transport cart 200 that travels on the track 100. The track 100 is laid along a path that passes above the placement ports 311 to 341 in the vicinity of the ceiling of the factory. The transport carriage 200 travels along the track 100 while supporting the load, and transports the load between the placement ports 311 to 341. Further, the transport system 1 includes an operation control device 410 and a power supply device 420. The operation control device 410 monitors the operation of each transport carriage 200 and controls the operation. The power supply device 420 supplies power to power supply lines 131 and 132 (described later) installed in the track 100. An error notification unit 411 (warning means) is connected to the operation control device 410. The error notification unit 411 includes a display device that displays an alarm device and a warning message. When a trouble occurs in the transport system 1, the operation control device 410 controls the error notification unit 411 to notify the operator of the occurrence of the trouble and the content thereof.

  Hereinafter, configurations of the track 100, the transport carriage 200, the manufacturing apparatus 310, and the like will be described with reference to FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  In the present embodiment, a FOUP (Front Opening Unified Pod) F is assumed as a load to be transported by the transport carriage 200. The hoop F is comprised from the flange part Fa and the main-body part Fb. The flange portion Fa is a portion that is gripped by the grip portion 244 of the transport carriage 200 as described later. A plurality of semiconductor substrates are accommodated in the main body Fb. A plurality of alignment holes Fc are formed on the lower surface of the main body Fb.

  On the other hand, an alignment plate 312 is fixed on the placement port 311. A plurality of alignment pins 312 a are fixed to the upper surface of the alignment plate 312. Each alignment pin 312a is formed in a shape that just fits into the alignment hole Fc. These alignment pins 312a are fixed so as to have the same positional relationship with the alignment hole Fc on the hoop F side in the horizontal direction. As a result, the alignment hole Fc and the alignment pin 312a can be fitted to each other when the hoop F is placed on the alignment plate 312. By placing the hoop F on the alignment plate 312 so that the alignment hole Fc and the alignment pin 312a fit together, the hoop F is disposed in a predetermined placement region 314 on the placement port 311 in the horizontal direction. Thus, the hoop F can be positioned and placed.

  A stock sensor 313 (detection means) is fixed on the upper surface of the alignment plate 312. The in-stock sensor 313 detects whether or not the hoop F is placed in a normal placement region 314 where the alignment hole Fc and the alignment pin 312a are fitted to each other. For example, the in-stock sensor 313 is configured by a so-called reflection type optical sensor, and the normal placement region 314 is detected by reflecting the light emitted in the horizontal direction by the side surface of the hoop F and detecting the reflected light. It may be configured to detect whether or not the hoop F is placed. When the hoop F is normally placed, the light is reflected horizontally by the side surface along the vertical direction, and thus returns to the detection unit of the optical sensor. On the other hand, when the side surface is slanted because the lower surface of the hoop F is caught by the alignment pin 312a, the light from the optical sensor is reflected in the direction inclined from the horizontal direction by the side surface and the bottom surface of the hoop F. , It will not be detected by the optical sensor. By utilizing these phenomena, it is possible to detect whether or not the hoop F is normally placed. The in-stock sensor 313 may be composed of a plurality of sensors, and when all the plurality of sensors confirm the placement of the FOUP F, it may be determined that the FOUP F has been placed normally. The manufacturing apparatus 300 includes a control unit 315 that guides the placement of the hoop F from the transport carriage 200, and the detection result of the in-stock sensor 313 is transmitted to the control unit 315. As will be described later, the control unit 315 exchanges various control signals with the transfer control unit 251 via optical communication or the like. The control unit 315 transmits a control signal indicating the detection result of the stock sensor 313 to the transfer control unit 251.

  The track 100 is fixed to the ceiling via a fixing member 110. The track 100 has a substantially rectangular cross-sectional shape with respect to a direction orthogonal to the length direction, and has a similar cross-sectional shape at different positions with respect to the length direction. A hollow space is formed inside the track 100, and the hollow space communicates with the opening 101 formed in the bottom surface 102 d in the track 100. A permanent magnet 120 is fixed to the ceiling surface 102 a in the track 100. The permanent magnet 120 functions as a secondary side mechanism of a linear motor traveling system described later. Feed lines 131 and 132 are fixed to the inner side surfaces 102b and 102c of the track 100 via support portions 131a and 132a, respectively. The feeder lines 131 and 132 are laid along the length direction of the track 100, and are arranged so as to have a predetermined relationship with the E cores 225 and 226 described later. When a current flows through the power supply lines 131 and 132 by the power supply device 420, a magnetic field is generated around the power supply lines 131 and 132. Further, guide members 141 and 142 are fixed to the inner side surfaces 102b and 102c of the track 100, respectively.

  The transport carriage 200 has a traveling mechanism 220. The transport carriage 200 has a center frame 210, and the traveling mechanism 220 is supported by the center frame 210. The traveling mechanism 220 is disposed in a space within the track 100 and includes traveling wheels 231 and guide rollers 232 and 233. The traveling wheels 231 are rotatably supported by the center frame 210 and support the entire transport carriage 200 on the bottom surface 102 d in the track 100. When the transport carriage 200 moves along the track 100, the traveling wheel 231 is rotated following the movement. The guide rollers 232 and 233 are rotatably supported by the center frame 210, respectively. The guide rollers 232 and 233 are rotated by following movement of the transport carriage 200 along the track 100 while being guided by guide members 141 and 142 fixed to the inner side surfaces 102 b and 102 c of the track 100.

  In the present embodiment, a so-called linear motor method is adopted as the traveling method of the transport carriage 200. The travel mechanism 220 has an iron core 221 fixed to the upper end of the center frame 210 as a primary side mechanism of the linear motor travel system. The iron core 221 faces the permanent magnet 120 on the track 100 side in the vertical direction. In the center frame 210, a linear motor drive circuit (not shown) is provided to flow current to the coil of the iron core 221. This linear motor drive circuit controls the current flowing through the coil of the iron core 221 so that the transport carriage 200 moves along the track 100 by the magnetic interaction between the permanent magnet 120 and the iron core 221.

  The traveling mechanism 220 further includes E cores 225 and 226 for receiving currents supplied to the linear motor drive circuit from the power supply lines 131 and 132. The E cores 225 and 226 are made of a magnetic material such as an electric iron plate, and are members having an E shape as shown in FIG. A pickup coil (not shown) is wound around the E cores 225 and 226. These pickup coils pass through the magnetic fields generated from the feeder lines 131 and 132 when the transport carriage 200 moves along the track 100, and in the E cores 225 and 226 so that an induced electromotive force is generated at that time. It is rolled up. The electromotive force generated in the pickup coil is supplied to the linear motor drive circuit.

  With the traveling mechanism 220 and the track 100 described above, the transport carriage 200 can move along the track 100 to a position above the placement ports 311 to 341. That is, these configurations function as a moving mechanism of the present invention that moves the transport carriage 200 above the placement ports 311 to 341. The operation control device 410 controls the operation of the transport carriage 200 so as to transport the hoop F between the placement ports 311 to 341 according to a predetermined transport program. The transport carriage 200 travels on the track 100 in accordance with a control command from the operation control device 410.

  Further, the transport cart 200 has a gripping mechanism 240. The gripping mechanism 240 includes a position adjustment unit 241, an elevating unit 242, and a gripping unit 244. The grip portion 244 has a finger portion 244a, and the finger portion 244a can grip or open the flange portion Fa of the hoop F. An in-stock sensor 245 is installed on the lower surface of the grip portion 244. The presence sensor 245 detects whether or not the hoop F held by the finger portion 244a is placed on the placement port. For example, when the hoop F is placed on the placement port, the flange portion Fa of the hoop F is lifted from the finger portion 244a. Utilizing this phenomenon, when the distance between the flange portion Fa and the stock sensor 245 becomes smaller than a certain value, the stock sensor detects that the hoop F is placed on the placement port. 245 may be configured. The detection result of the stock sensor 245 is transmitted to a transfer control unit 251 described later.

  The gripping part 244 is suspended from the elevating part 242 by a suspension belt 243. The upper end of the suspension belt 243 is fixed to a winding mechanism 242a in the elevating unit 242, and the winding mechanism 242a winds up or unwinds the suspension belt 243. The lifting / lowering unit 242 raises the gripping unit 244 by causing the winding mechanism to wind the suspension belt 243. Moreover, the raising / lowering part 242 lowers | hangs the holding | grip part 244 by making a winding mechanism draw | feed out the raising / lowering belt 243. FIG. The elevating unit 242 is supported by the position adjusting unit 241. The position adjustment unit 241 includes a moving mechanism 241a that moves the lifting unit 242 in the horizontal direction, thereby adjusting the horizontal position of the lifting unit 242. The position adjustment unit 241 is fixed to the lower end of the center frame 210.

  Further, the transfer system 1 is provided with a transfer control unit 251 that controls the transfer carriage 200 to load and unload the FOUP F onto the mounting port 311 and the like (mounting control means). The transfer control unit 251 includes hardware such as a general-purpose processor circuit and software such as program data that causes these to function as the transfer control unit 251. Note that part or all of the hardware may be constructed in advance as hardware dedicated to the transfer control unit 251. The transfer control unit 251 may be built inside the operation control device 410 or may be configured independently of the operation control device 410. For example, each carriage 200 may be mounted.

  For example, the transfer control unit 251 controls the unloading operation of causing the transport carriage 200 to unload the hoop F to the mounting port 311 as follows. First, according to the control of the operation control device 410, the transport carriage 200 receives the FOUP F from one of the transport ports of the transport source and moves to above the mount port 311. Then, when it reaches above the placement port 311, it stops. Here, depending on the position where the transport carriage 200 is stopped, the horizontal position of the hoop F gripped by the gripping portion 244 and the placement region 314 on the placement port 311 may be misaligned.

  Therefore, the transfer control unit 251 controls the position adjusting unit 241 to adjust the horizontal position of the elevating unit 242 so that the mounting region 314 is disposed immediately below the FOUP F. And the raising / lowering part 242 is controlled, the holding | grip part 244 is dropped, and the hoop F is mounted on the mounting port 311. FIG. Here, the adjustment of the horizontal position of the elevating unit 242 by the position adjusting unit 241 may be performed while the elevating unit 242 lowers the gripping unit 244, or the elevating unit 242 lowers the gripping unit 244. It may be executed before starting. Note that the direction in which the position adjustment unit 241 moves the elevating unit 242 horizontally during position adjustment and the amount of movement are set in advance when the transport system 1 is installed.

  When the FOUP F is placed on the placement port 311, the stock sensor 245 detects the placement of the FOUP F. When the transfer control unit 251 determines that the FOUP F is placed on the placement port 311 based on the detection result of the presence sensor 245, the transfer control unit 251 causes the lifting unit 242 to stop the lowering of the grip unit 244. Further, the transfer control unit 251 determines whether or not the FOUP F is placed on the normal placement region 314 on the placement port 311 based on the detection result of the stock sensor 313. When it is determined that the hoop F is normally placed, the transfer control unit 251 raises the grip unit 244 to the lifting unit 242. Then, when the grip portion 244 rises to a predetermined position in the lift unit 242, the lift unit 242 stops the lift of the grip unit 244.

  In the above-described unloading operation, the presence sensor 245 detects that the hoop F is placed on the placement port 311, but the hoop F is not properly placed on the placement port 311. The load sensor 313 may detect. Such a situation is likely to occur when a load such as the hoop F is lifted and lowered in a suspended state like the transport carriage 200 of the present embodiment. That is, the transport cart 200 suspends the gripping mechanism 240 downward by the center frame 210. Therefore, the transport carriage 200 is likely to swing in a pendulum shape along the direction of the white arrow in FIG. 2 with the contact point between the traveling wheel 231 and the track 100 as a fulcrum. Also in the configuration of the gripping mechanism 240 itself, the elevating unit 242 is suspended from the position adjusting unit 241. Furthermore, the gripping portion 244 is also suspended from the lifting / lowering portion 242 by the suspension belt 243, and the gripping portion 244 is likely to swing like a pendulum around the upper end of the suspension belt 243.

  The above-described shaking is generated by, for example, an air current generated in a place where the transport system 1 is installed, inertia when the transport carriage 200 stops, or vibration generated when the lifting unit 242 feeds the suspension belt 243. To do. When such shaking occurs, the hoop F may not be normally placed on the placement region 314 on the placement port 311 even if the position adjustment unit 241 adjusts the horizontal position of the elevating unit 242.

  In order to solve such a problem, the present embodiment is configured as follows. FIG. 3 shows each control process of the unloading operation performed by the transfer control unit 251. The following control process shows a case where the transport carriage 200 unloads the hoop F to the mounting port 311 of the manufacturing apparatus 310. In the present embodiment, the control process executed by the transfer control unit 251 is executed according to the E84 communication sequence defined in the so-called SEMI (Semiconductor Equipment and Materials International) standard. That is, it is assumed that an interlock is executed between the transfer control unit 251 and the manufacturing apparatus 310 by exchanging control signals conforming to the E84 communication sequence.

  When the transport carriage 200 arrives above the placement port 311, the transfer control unit 251 starts control processing for unloading operation. First, the transfer control unit 251 executes an initial sequence based on the E84 communication sequence (S1). In such an initial sequence, the transfer control unit 251 executes control for initializing various control signals to the manufacturing apparatus 310 and starting various timers. Also in the manufacturing apparatus 310, the initial sequence is executed based on the control signal from the transfer control unit 251. For example, in the initial sequence, the manufacturing apparatus 310 sets an L_REQ signal, which will be described later, to an on state or starts measurement of a TP3 timer.

  Next, the transfer control unit 251 causes the elevating unit 242 to start lowering the gripping unit 244 (S2). And the transfer control part 251 stops the raising / lowering part 242 from lowering | hanging of the holding | grip part 244 based on the detection result of the stock sensor 245 (S3). Here, the transfer control unit 251 refers to the timer started in the initial sequence of S <b> 1, and acquires the detection timing by the occupancy sensor 245 that the FOUP F is placed on the placement port 311. Such timing is used in S10 described later.

  Next, the transfer control unit 251 determines whether or not the L_REQ signal from the manufacturing apparatus 310 is in an off state (S4). The L_REQ signal is a signal conforming to the E84 communication sequence. The manufacturing apparatus 310 holds the L_REQ signal in the ON state until the occupancy sensor 313 detects the normal placement of the FOUP F according to the E84 communication sequence. That is, when the L_REQ signal is in the on state, the hoop F has not been normally placed on the placement region 314 on the placement port 311. When the L_REQ signal is turned off, the hoop F is normally placed on the placement area 314 on the placement port 311. That is, the transfer control unit 251 determines whether or not the FOUP F has been normally mounted by determining whether or not the L_REQ signal from the manufacturing apparatus 310 is in an off state (mounting determination). means).

  If it is determined that the L_REQ signal from the manufacturing apparatus 310 is in an off state (S4, YES), the transfer control unit 251 assumes that the hoop F has been normally placed, and causes the gripping unit 244 to release the hoop F ( S5). Next, the transfer control unit 251 causes the lifting unit 242 to start lifting the grip unit 244 (S6). Then, when the gripping part 244 is raised to a predetermined position, the transfer control part 251 stops the lifting part 242 from raising the gripping part 244 (S7). Thereafter, the transfer control unit 251 executes an end sequence based on the E84 communication sequence (S8). In the end sequence, the transfer control unit 251 executes control such as turning off various control signals to the manufacturing apparatus 310 and stopping the timer. And the transfer control part 251 complete | finishes the control processing of unloading operation | movement. In this case, the transport system 1 processes the unloading process as being normally completed.

  On the other hand, when it is determined in S4 that the L_REQ signal is on (S4, NO), the transfer control unit 251 determines whether or not a retry operation described later has been performed a predetermined number of times (S9). . If it is determined that the number of retry operations has not reached the predetermined number (S9, NO), the transfer control unit 251 refers to the timing acquired in S3 and the timer started in S1. Then, it is determined whether or not a predetermined time has elapsed since it was detected that the hoop F was placed on the placement port 311 (S10). If it is determined that the predetermined time has passed (S10, YES), the transfer control unit 251 once raises the gripping unit 244, assuming that the FOUP F has not been normally placed on the placement port 311, and then A retry operation (re-execution operation) for lowering again is executed as follows.

  The determination of whether or not a predetermined time has elapsed in S10 is as follows. In other words, it may take some time from when the occupancy sensor 245 detects that the hoop F is placed to when the occupancy sensor 313 detects that the hoop F is normally placed. For example, the hoop F is slightly deviated from the placement region 314, and the alignment pin 312a and the alignment hole Fc slide slowly with each other. In such a case, if it is determined that the FOUP F is not normally placed without taking time, an unnecessary retry operation is executed. This is to prevent such a situation.

  In S <b> 11, the transfer control unit 251 once raises the grip unit 244 to the lifting unit 242. And if the holding part 244 raises to a predetermined position, the raising / lowering part 242 will stop the raising of the holding part 244 in S12. And the transfer control part 251 performs the process of S2 and S3 again, and lowers the holding | grip part 244 again. A series of processes of S11, S12, S2, and S3 is a control process for one retry operation. Here, it is preferable that the position at which the grip portion 244 is stopped in S12 is a position where the lower surface of the hoop F is separated from the tip of the alignment pin 312a and not too far from the tip of the alignment pin 312a. This is because if the gripping portion 244 is raised too much, the time required to lift the gripping portion 244 once or place it again on the placement port 311 becomes longer.

  On the other hand, if it is determined in S9 that the retry operation has already been performed a predetermined number of times (S9, YES), the transfer control unit 251 has detected a TP3 timeout in the manufacturing apparatus 310 according to the control signal from the manufacturing apparatus 310. It is determined whether or not (S13).

  As described above, the manufacturing apparatus 310 starts measuring the TP3 timer in the initial sequence. The TP3 timer is a timer conforming to the E84 communication sequence. Then, when the time indicated by the TP3 timer reaches a preset TP3 timeout time, the manufacturing apparatus 310 turns off the HO_AVBL signal or the ES signal that conforms to the E84 communication sequence. Therefore, the transfer control unit 251 determines whether the TP3 timeout is detected based on whether the HO_AVBL signal or the ES signal from the manufacturing apparatus 310 is turned off. If it is determined that the TP3 timeout has not been detected (S13, NO), the transfer control unit 251 returns to the process from S4. If it determines with TP3 timeout having been detected (S13, YES), the transfer control part 251 will notify the operation control apparatus 410 that the mounting abnormality of the FOUP F occurred on the mounting port 311. The operation control device 410 causes the error notification unit 411 to notify the operator of the abnormal mounting of the hoop F based on the notification.

  Hereinafter, examples of the unloading operation by the transport system 1 of the present embodiment will be described. In the present embodiment, the predetermined number of retry operations determined in S9 in FIG. 3 is set to three times, the predetermined time from the placement detection of the hoop F determined in S10 is set to 10 seconds, and the TP3 timeout detected in S13 The case where the set time is set to 1 minute is shown. Note that the following symbols in parentheses indicate the flow of processing according to the flowchart of FIG.

[Example 1]
An example of the processing flow when the FOUP F is normally placed on the placement port 311 by the retry operation of S11 and S12 of FIG.

[1] An initial sequence is executed (S1). [2] The gripping portion 244 is lowered and the hoop F is placed on the placement port 311 (S2 to S3). [3] Even after 10 seconds have elapsed since the FOUP F was placed on the placement port 311, the L_REQ signal does not turn off, so the grip 244 is temporarily raised (S 4, NO → S 9, NO → S10, YES → S11 to S12). [4] The gripping portion 244 descends again (S2). [5] Since the L_REQ signal is turned off, the hoop F is released (S4, YES → S5). [6] The gripper is raised to a predetermined position (S6 to S7). [7] An end sequence is executed (S8).

[Example 2]
An example of the flow of processing when the FOUP F is not normally placed on the placement port 311 even if the retry operation is repeated three times is shown.

  [1] An initial sequence is executed (S1). [2] The gripping portion 244 is lowered and the hoop F is placed on the placement port 311 (S2 to S3). [3] Even after 10 seconds have elapsed since the FOUP F was placed on the placement port 311, the L_REQ signal does not turn off, so the grip 244 is temporarily raised (S 4, NO → S 9, NO → S10, YES → S11 to S12).

  [4] The gripping portion 244 is lowered and the hoop F is placed again on the placement port 311 (S2 to S3). [5] Even if 10 seconds have elapsed after the FOUP F is placed on the placement port 311 again, the L_REQ signal does not turn off, so the grip 244 is temporarily raised (S4, NO → S9, NO-> S10, YES-> S11-S12). [6] The gripping portion 244 is lowered and the FOUP F is placed on the placement port 311 for the third time (S2 to S3).

  [7] Even when 10 seconds have elapsed after the hoop F is placed on the placement port 311 for the third time, the L_REQ signal does not turn off, so the grip 244 is temporarily raised (S4, NO → S9, NO-> S10, YES-> S11-S12). [8] The gripping portion 244 is lowered and the hoop F is placed on the placement port 311 for the fourth time (S2 to S3). [9] Although the L_REQ signal does not turn off even after 10 seconds have passed since the hoop F was placed on the placement port 311 for the fourth time, the retry operation has already been executed three times, so that the state remains unchanged. The L_REQ signal is waited (S4, NO → S9, YES → S13, NO → S4). [10] Since one minute has passed since the initial sequence, a TP3 timeout is detected (S4, NO → S9, YES → S13, YES). [11] A placement abnormality on the placement port 311 is notified (S14).

  Table 1 below shows the results when unloading various loading ports by the transport system 1 of the present embodiment is performed a plurality of times. Here, various conditions such as the number of retry operations are the same as those shown in the above embodiment. In Table 1, the relief rate is the number when the hoop F is normally placed in the first retry operation by the retry operation immediately after the number when the hoop F is not normally placed only once. The ratio of the number when placed normally in the retry operation up to the second time, and the ratio of the number when placed normally in the retry operation up to the third time are shown.

  As shown in Table 1, even if the FOUP F is not normally placed on the placement port, by executing the retry operation, 70% of the FOUP F is normally placed again by one retry operation. Yes. Moreover, even if the retry operation is limited to three times, eventually 90% of them are normally remounted. Therefore, by limiting the retry operation to three times, the FOUP F can be placed normally almost completely and the number of retry operations can be limited to an appropriate number.

<Modification>
The above is a description of a preferred embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the means for solving the problem. It is possible.

  For example, in the above-described embodiment, the grip portion 244 is suspended using a suspension belt, but the grip portion 244 may be suspended using other means such as a suspension rope. Moreover, even if the structure in which the gripping portion 244 is suspended by using the suspension member is not adopted, if the configuration is such that the object to be conveyed is suspended as the entire conveyance carriage, shaking is likely to occur. Therefore, the situation to which a to-be-conveyed object is not normally mounted normally can be suppressed by applying this invention.

  In the above-described embodiment, the load sensor 245 is provided not only on the placement port 311 side but also on the grip portion 244, but the load sensor 245 may not be provided on the grip portion 244. . That is, based on only the detection result of the loading sensor 313 on the loading port 311 side, if the loading sensor 313 does not detect normal loading within a predetermined time, the FOUP F is not normally mounted. You may judge.

It is a top view of the conveyance system concerning one embodiment of the present invention. It is the II-II sectional view taken on the line of the conveyance system of FIG. It is a flowchart of the control processing which the transfer control part of FIG. 2 performs.

Explanation of symbols

311-341 Placement port 1 Transport system 200 Transport carriage 240 Grasping mechanism 241 Position adjustment unit 242 Lifting unit 243 Suspension belt 244 Grasping unit 251 Transfer control unit 313 Loading sensor 314 Mounting region 411 Error notification unit F Hoop

Claims (5)

A gripping part for gripping the object to be transported; a suspension member for suspending the gripping part; and a lifting part for lifting and lowering the gripping part by winding and unwinding the suspension member. A transport carriage that lifts and lowers while hanging,
A mounting port on which the object to be transported is mounted;
A moving mechanism for moving the transport carriage to a position where the object to be transported is disposed above the placement port;
A placement control means for controlling the transport carriage so that the transported object is lowered and placed on the mounting port after the transported object is disposed above the mounting port;
First detection means provided in the gripping part for detecting whether or not the object to be transported gripped by the gripping part is placed on the placement port;
Provided in the mounting port for detecting whether or not the transported object is placed in a predetermined area by detecting reflected light of the light emitted to the transported object on the mounting port. Second detecting means,
The above-mentioned position control means is
Based on both detection results from the first and second detection means, having a placement determination means for judging whether or not the object to be transported has been normally placed in the predetermined area;
When the placement determination means determines that the transported object is not normally placed in the predetermined area, the transported object is once lifted, and then the transported object is lowered again. A transport system that causes the transport cart to execute a re-execution operation to be placed on the placement port. The above-described position determination means is
When a predetermined time elapses after the first detection means detects that the object to be conveyed gripped by the gripping part is placed on the placement port , the second detection means The transport system according to claim 1 , wherein it is determined whether or not the object to be transported is normally placed in the predetermined area based on the detection result. Even if the re-execution operation is continuously executed a predetermined number of times, a predetermined warning operation is executed when the placement determination means determines that the transported object is not normally placed in the predetermined area. conveying system according to claim 1 or 2, characterized in that it further comprises a warning means. The maximum number of times that the re-execution operation is continuously executed by the transport carriage when the placement determination unit determines that the transported object is not normally placed in the predetermined area is 3 times. The conveyance system according to any one of claims 1 to 3, wherein the conveyance system is provided. The detection by the first detection means is based on a distance from a predetermined portion of the transported object, and the detection by the second detection means is based on the inclination of the transported object. The conveyance system according to any one of claims 1 to 4 , wherein

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