JP2005115590A - Collision prevention control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collision prevention control system capable of avoiding a collision of carrier trucks when a communication line built in a junction area is single and also when defect occurs in the communication line. <P>SOLUTION: A carrier truck 1a entering the junction area 10 receives a signal of the communication line 7 with a receiver 3a, analyzes it, and it is decided by a control part 8a if a signal waveform transmitted by another carrier truck in another junction area has been received. When it is decided that the signal waveform transmitted by the carrier 1b has been received, running is stopped. When it is decided that the signal waveform indicating that the carrier truck 1b exits the junction area 10 is not received a signal meaning the junction area of its own car is transmitted by a transmitter 2a, a signal on the communication line 7 is received by the receiver 3a and analyzed, and it is decided if the signal transmitted by its own car can be detected by the control part 8a. When it is detected, running in the junction area 10 is continued, but when it cannot be detected, it is determined that an abnormality has occurred to the communication line 7 to stop all the carrier trucks. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a collision prevention control system for controlling traveling of a transport carriage to prevent a collision of a plurality of transport carriages traveling on a track.

  In manufacturing processes such as semiconductor manufacturing, liquid crystal manufacturing, and FA, the FOUP (Front Opening Unified Pod) runs on a track suspended from the ceiling as a transport means for transporting products in the manufacturing process from equipment to equipment according to the process. Mainly used are unmanned transport systems using transport carts that run on tracks, such as OHT (Over Head Hoist Transport), OHS (Over Head Shuttle) transport, and transport systems that use transport carts that run on the floor independently.

  In these unmanned transport systems, the track on which the transport carriage travels is laid in alignment with the arrangement of the manufacturing apparatus. The track is formed in a closed loop, and branching / merging is provided as necessary. The traveling direction of the carriage traveling on the track is usually one-way. In other words, at the junction of the tracks, the transport carts that have traveled from a plurality of routes merge into one route. Therefore, if the transport cart reaches the junction at the same time from a plurality of routes, a collision naturally occurs. . Therefore, conventionally, in an unmanned conveyance system in which a conveyance carriage travels on a track, a collision prevention technique in a merging region including a merging point has been developed.

  As a conventional collision prevention technology, for example, a conductive wire (communication line) is laid on a track, and an induction signal transmitter and an induction signal receiver for inducing an electromotive force in an automatic guided vehicle (conveyance carriage) are mounted. Patent Document 1 describes a technique for preventing a collision in a merging region of a plurality of automatic guided vehicles. In the technique of Patent Document 1, the automatic guided vehicle that has reached the merging area moves forward when the signal is not received by the guidance signal receiver and transmits a signal by the guidance signal transmitter while traveling in the merging area. When the signal is received by the induction signal receiver, the traveling to the merging area is stopped to prevent the collision in the merging area of the plurality of automatic guided vehicles.

  In addition, when two conductive wires (communication lines) are laid on both sides of the track and transmitters / receivers are mounted on both sides of the unmanned vehicle (conveyance carriage), multiple unmanned vehicles enter the merge area at the same time. Patent Document 2 discloses a technique for performing appropriate control to prevent a collision. In the technique of Patent Document 2, signals are transmitted and received between the transmission means mounted on the unmanned vehicle on one inflow path and the reception means mounted on the unmanned vehicle on the other inflow path in each of the two conductive wires. By configuring so that transmission of the detection signal of the own vehicle and reception of the detection signal of the other vehicle are performed in parallel, and the unmanned vehicle that has reached the merge area does not receive the signal by the receiving means While traveling forward and traveling in the merging area, a signal is transmitted by the transmission means, and when the signal is received by the receiving means, the traveling to the merging area is stopped, thereby causing a collision in the merging area of a plurality of unmanned vehicles. Is preventing. In addition, when a plurality of unmanned vehicles arrive at the merge area at the same time, priority is given to the inflow path in advance, and the unmanned vehicles on the priority track are prioritized to enter.

Japanese Utility Model Publication No. 2-95404 JP-A-10-301626

However, in the conventional technology, the signals transmitted by the transport carriage are all the same, and if the communication line is a single line, whether the received signal is a signal transmitted by the own vehicle or a signal transmitted by another vehicle Cannot be judged. Therefore, in patent document 1, when the own vehicle is transmitting the signal, it is made not to receive a signal. In such a case, there is a problem that when the transport carriage enters the junction area at the same time, the signal cannot be received and collides.
On the other hand, in Patent Document 2, the communication line is not a single line, but two communication lines on the right and left sides are provided for the track, and each carrier vehicle uses a communication line for reception and a communication line for transmission separately. It is configured to be able to. However, in the case of such a configuration, there is a problem in that the laying of the communication line becomes complicated if the merge area is formed by a plurality of tracks or additional work for the tracks is performed.

  Furthermore, the track of the automated transport system is often subjected to additional work for various reasons. In addition, in such additional construction, there are many troubles that inadvertently damage the communication line laid in the junction area on the track, and possibly cause the communication line to be disconnected. In such a case, in the technique of Patent Document 1 or Patent Document 2, if a problem occurs in the conductive wire such as disconnection, a signal transmitted from the transport carriage that has entered the junction area first enters the junction area later. There is a possibility that the transported carriages cannot receive and the transported carriages collide with each other.

  The present invention has been made in view of the above problems, and even when the communication line laid in the merge area is a single line, even when a failure occurs in the communication line, the collision between the carriages can be detected. An object is to provide a collision prevention control system that can be avoided.

Means and effects for solving the problems

  In order to solve the above-mentioned problem, a collision prevention control system according to a first aspect of the present invention is a communication means laid in a predetermined merging area including a merging point where a plurality of inflow routes in a track on which a transport carriage travels are merged. A transmission means that is installed in the transport carriage and transmits a unique identification signal indicating an inflow route to the communication means in the junction area; and is installed in the transport carriage from the communication means in the junction area. A collision prevention control system comprising: a receiving unit that receives the identification signal; and a control unit that is installed in the transport cart and analyzes the identification signal received by the receiving unit to control traveling. Means is a single-wire communication means laid in a loop in the merge area, and the control means receives the identification signal indicating an inflow route different from its own inflow route. In the while sensing it is characterized by stopping the driving.

  Thereby, on the single-line communication means laid in a loop shape, the receiving carriage detects an identification signal indicating an inflow route different from its own inflow route. It will be confirmed that the transport cart that has entered already exists in the merge area. And if there is a preceding transport cart that has entered from another inflow route, it waits to pass through the merging area, and if there is no preceding transport cart that has entered from another inflow route, By traveling while transmitting an identification signal indicating its own inflow route to the communication means, it is possible to avoid a collision between transport carts in the merging area. In addition, when the inflow route which drive | works is the same inflow route, driving | running | working of a some conveyance trolley is possible. Also, if there is an abnormality in the communication means such as disconnection, since the communication means is a single line laid in a loop in the merge area, the identification signal transmitted by its own transmission means can not be received by its own reception means, An abnormality in the communication means can be easily recognized. And it becomes possible to avoid a collision by stopping immediately all the conveyance trolleys which drive | work at the time of abnormality being detected.

  Further, as the identification signal, it is preferable to use any one of an AC waveform signal, a pulse frequency waveform signal, a digital communication signal composed of a plurality of bits, or a combination of two or more thereof, which is different for each inflow route.

  As a result, AC waveform signals (signals having different frequencies and / or voltages for each inflow route), pulse frequency waveform signals (signals having different frequencies for each inflow route), and a plurality of bits are different for each inflow route. Since any one signal of digital communication signals (digital communication system signals composed of a plurality of bits different for each inflow route) or a signal obtained by arbitrarily combining two or more of these signals is used as an identification signal, crosstalk also occurs in bidirectional communication. It is possible to discriminate an inflow route that is different from the self inflow route.

  In addition, the control means further determines that the communication means is abnormal when the identification signal transmitted by itself is not detected by the reception means of itself, stops its own traveling, and It is preferable to stop the travel of all the transport carts that travel.

  As a result, when there is an abnormality in the communication means such as disconnection, the communication means is a single line laid in a loop in the merge area, so the identification signal transmitted by its own transmission means cannot be received by its own reception means. Therefore, it is possible to easily recognize the abnormality of the communication means. And it becomes possible to avoid a collision by stopping immediately all the conveyance trolleys which drive | work at the time of abnormality being detected.

  Further, it is preferable that a capacitor having a capacity that substantially compensates the inductance of the communication means is connected in series to the communication means.

  Thereby, an increase in impedance that increases with an increase in the length of the single-wire communication means can be reduced, and a decrease in the signal level of the identification signal can be prevented.

  In addition, it is preferable that a tie wire for electrically short-circuiting the transmission unit and the reception unit is laid on the transport carriage, and a capacitor is connected in series to the short-circuit line.

  Thereby, it is possible to eliminate noise caused by electromagnetic field induced interference propagating in the air generated by placing the transmitting unit and the receiving unit close to each other on the carriage.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

An embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a case where the present invention is applied to an unmanned conveyance system that conveys a processing object such as a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, and an optical disk substrate in a semiconductor product manufacturing facility will be described. To do.

  First, a collision prevention control system according to this embodiment will be described with reference to FIG. FIG. 1 is a diagram showing the configuration of the collision prevention control system, and is a top view of the entire merging region in the track of the OHT conveyance system.

  As shown in FIG. 1, a confluence area (inflow route) Pa including the trajectory A and the trajectory C and a confluence area (inflow route) Pb including the trajectory B and the trajectory C are formed in the trajectory of the OHT conveyance system described later. The region where Pa and Pb are combined constitutes a merge region including a merge point where the track A and the track B merge with the track C. In the present embodiment, it is assumed that the track A and the track B travel on OHT transport carts (hereinafter abbreviated as “transport carts”) 1a and 1b, respectively. A transmission side communication line 5a and a reception side communication line 6a are laid in the merge area Pa, and a transmission side communication line 5b and a reception side communication line 6b are laid in the merge area Pb. The transmission side communication lines 5a and 5b and the reception side communication lines 6a and 6b constitute a communication line 7 (communication means) by a single loop-shaped conductive line. The transmission side communication lines 5a and 5b are laid from the beginning to the end of each merge area in the merge area in order to continue transmitting signals in the merge area, and the reception side communication lines 6a and 6b are used for signal reception. Since it is only used, it is laid short with respect to each merge area in a merge area. Also, guide line control valid marks 12a and 12b, transmission point marks 14a and 14b, and stop point marks 13a and 13b are provided on the tracks A and B, respectively, and the guide line control is disabled on the track C. A mark 15 is provided.

In addition, as shown in FIG. 1, the transport carriage 1a is equipped with a right induction signal transmitter / receiver 2a (reception means / transmission means) and a left induction signal transmitter / receiver 3a (reception means / transmission means). The right induction signal transmitter / receiver 2a is electromagnetically coupled to the transmission side communication line 5a, and the left induction signal transmitter / receiver 3a is electromagnetically coupled to the reception side communication line 6a. The transport carriage 1b is equipped with a right induction signal transmitter / receiver 2b and a left induction signal transmitter / receiver 3b. In the junction Pb, the left induction signal transmitter / receiver 3b is electromagnetically coupled to the transmission side communication line 5b, and the right induction signal is transmitted. The transceiver 2b is electromagnetically coupled to the receiving communication line 6b. In addition, the right side induction signal transmitter / receiver 2a and the left side induction signal transmitter / receiver 3a of the transport carriage 1a, and the right side induction signal transmitter / receiver 2 and the left side induction signal transmitter / receiver 3b of the transport carriage 1b are respectively matched to the proceeding merging area. It is comprised so that the function of a transmitter (transmission means) and a receiver (reception means) may be switched. In FIG. 1, the conveyance carriage 1a has a right induction signal transceiver 2a as a transmitter and a left induction signal transceiver 3a as a receiver, and the conveyance carriage 1b has a right induction signal transceiver 2b as a receiver and a left induction signal. The transceiver 3b is a transmitter.
The carriages 1a and 1b are equipped with mark readers 4a and 4b, respectively, and guide line control effective marks 12a and 12b on the tracks A and B, transmission point marks 14a and 14b, and stop point marks 13a and 13b. The guide line control invalid mark 15 on the trajectory C is read. Furthermore, the transport carts 1a and 1b are provided with control units 8a and 8b (control means), respectively, and based on the processing (see FIG. 5) of the collision prevention control system 11 described later, 2b or left guidance signal transmitters / receivers 3a and 3b transmit / receive / analyze signals to control the operation, control the operation according to the marks read by the mark readers 4a and 4b, and a FOUP transfer described later. It also controls the loading work.

  The collision prevention control system 11 according to the present embodiment includes the communication line 7 described above, the right induction signal transmitter / receiver 2a and the left induction signal transmitter / receiver 3a of the transport carriage 1a, and the right induction signal transmitter / receiver 2b of the transport carriage 1b and the left side. It is comprised from the control part 8a, 8b mounted in the induction | guidance | derivation signal transmitter-receiver 3b, the conveyance trolley 1a, and the conveyance trolley 1b.

Here, based on FIG.6 and FIG.7, it demonstrates in detail about a communication line. FIG. 6 is a diagram illustrating a configuration of a communication line. FIG. 7 is a diagram showing a result of measuring an actual measurement value of the received signal level of the communication line using the capacitance C of the capacitor as a parameter.
As shown in FIG. 6, the communication line 7 is formed in a loop, and a capacitor 21 is directly connected in the middle of the loop. In general, as the communication line 7 becomes longer, the inductance increases and the impedance increases, so that it becomes difficult for the induced current to flow, and the transmitter (the right-side induced signal transceivers 2a and 2b of the transport carriages 1a and 1b shown in FIG. 1). Alternatively, with respect to the signal transmitted by the left induction signal transmitter / receiver 3a, 3b), the receiver (the right induction signal transmitter / receiver 2a, 2b of the transport carriage 1a, 1b shown in FIG. 1 or the left induction signal transmitter / receiver 3a). The signal level that can be received by any one of 3b is also lowered. Therefore, it is effective to directly connect the capacitor 21 to the communication line 7 in order to compensate for the increase in inductance.
The capacitance C of the capacitor 21 that compensates for the inductance L of the communication line 7 can be generally expressed by the following equation where the signal frequency of the transmitter is f.
C = 1 / (2πf) ² / L (Formula 1)
Hereinafter, based on FIG. 7, the result of actually measuring the actual measurement value of the received signal level of the communication line 7 using the capacitance C of the capacitor 21 as a parameter will be described. The set value of the capacitance C of the capacitor 21 and the circuit conditions of the communication line 7 were set as follows.
Set value of capacitance C: 0, 0.15, 0.225, 0.3, 0.45 μF
Circuit conditions L (inductance): 13.78 μH
R (electric resistance): 1.54Ω
Z (impedance): 8.97Ω
Transmitter signal frequency: 94 kHz
As shown in FIG. 7, it is confirmed that the received signal level reaches its maximum value when the capacitance C of the capacitor 21 is in the vicinity of 0.225 μF. That is, it can be said that the impedance Z is minimized under the condition where the maximum received signal level is obtained, and it is preferable to install a capacitor 21 having a capacitance value near this value.

Here, based on FIG. 9, it demonstrates in detail about a control part. FIG. 9 is a block diagram illustrating the control unit of the transport carriage.
As shown in FIG. 9, the control unit 8 includes a mark reading unit 80, an identification signal receiving unit 81, an identification signal transmitting unit 82, an identification signal analyzing unit 83, an identification signal forming unit 84, and a traveling unit 85a. And a travel control unit / stop unit 85 including a stop unit 85b. In FIG. 9, the control unit 8 corresponds to the control units 8a and 8b in FIG. 1, the mark reader 4 corresponds to the mark readers 4a and 4b in FIG. 1, and the right induction signal transceiver 2 in FIG. The left induction signal transmitter / receiver 3a corresponds to the right induction signal transmitter / receiver 2a and 2b, and the left induction signal transmitter / receiver 3 corresponds to the left induction signal transmitter / receiver 3a and 3b in FIG.
The mark reading unit 80 outputs the mark read by the mark reader 4 to the identification signal receiving unit 81, the identification signal transmitting unit 82, the identification signal forming unit 84, and the travel control unit / stop unit 85.
Based on the guide line control effective mark read by the mark reading unit 80, the identification signal receiving unit 81 receives and receives the identification signal on the communication line 7 with the right induction signal transmitter / receiver 2 or the left induction signal transmitter / receiver 3. The identification signal is output to the identification signal analyzer 83.
The identification signal transmitting unit 82 transmits the identification signal formed by the identification signal forming unit 84 using the right induction signal transmitter / receiver 2 or the left induction signal transmitter / receiver 3, and the guide line control invalid mark read by the mark reading unit 80. Stop calling based on.
The identification signal analyzing unit 83 analyzes the identification signal received by the identification signal receiving unit 81, and passes through the identification signal forming unit 84, the travel control unit / stop unit 85, and the cart side communication unit (primary power source described later) 50. To the operation control device 33 (see FIG. 3). In the identification signal analysis unit 83, the analysis of the presence / absence of the identification signal in the other merging area and the presence / absence of the identification signal in the merging area of the own vehicle is performed according to whether the received identification signal matches the identification signal of the merging area of the own vehicle. Judge by no.
Based on the analysis result of the transmission point mark read by the mark reading unit 80 and the absence of the identification signal of the other merging area in the identification signal analyzing unit 83, the identification signal forming unit 84 identifies the own merging area. And output to the identification signal transmitter 82.
The traveling control unit / stop unit 85 controls the traveling mechanism 60 based on a command input from the operation control device 33 (see FIG. 3) via the cart side communication unit 50. In addition, based on the analysis result that there is no identification signal of another merging area in the identification signal analysis unit 83 or the analysis result that there is an identification signal of the merging area of the own vehicle, the traveling unit 85 a Continue running. Further, based on the analysis result of the stop point mark read by the mark reading unit 80 and the identification signal analysis unit 83 that there is an identification signal of another merging area, or the analysis result that there is no identification signal of the merging area of the own vehicle. Then, the travel of the transport carriage is stopped at the stop portion 85b. The traveling mechanism 60 is configured by a linear motor, which will be described later, and is a mechanism for causing the transport carriage 1 to travel.
In addition, the control unit 8 also controls the OHT carriage position adjusting mechanism 41, the suspension device 42, and the carrier gripping mechanism 43.

  Next, an OHT transport system to which the present embodiment is applied will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the configuration of the OHT conveyance system.

  As shown in FIG. 2, the transport cart 1 (corresponding to the transport carts 1 a and 1 b in FIG. 1) is configured to travel on a track 40 that is suspended from the ceiling 54. The transport carriage 1 includes a non-contact power supply primary side power line (hereinafter abbreviated as “primary side power source”) 50 and a non-contact power supply secondary side iron core 49 (hereinafter abbreviated as “secondary side iron core”). Is provided, and power is supplied in a non-contact manner. Specifically, the high frequency power is applied to the primary power source 50, and the primary high frequency power is induced in a coil wound around the secondary iron core 49 so that power is transmitted in a non-contact manner. Has been. In addition, all the electric power required for the conveyance cart 1 is covered by this non-contact power supply.

  The linear motor of the transport carriage 1 includes a secondary permanent magnet 46 that is laid on the track 40 and serves as a linear motor stator, and a primary laminated core 47 that constitutes the linear motor. The electric power supplied to the linear motor required for traveling is first converted from a high-frequency current induced in a coil wound around the secondary side iron core 49 to a direct current by full-wave rectification, and further, a PWM system by a power controller. Is supplied to the primary laminated core 47 constituting the linear motor. When a three-phase alternating current generated by the PWM method is supplied to the primary laminated core 47 constituting the linear motor, a traveling magnetic field that moves linearly is generated in the primary laminated iron core 47, and the primary side A propulsive force is generated in the primary side laminated core 47 by a magnetic action between the laminated core 47 and the secondary side permanent magnet 46 arranged opposite to the laminated core 47. As described above, the conveyance carriage 1 travels on the track 40 by the propulsive force that is generated with the primary-side laminated core 47 and the secondary-side permanent magnet 46 being held at a constant interval. In addition, the primary side power supply 50 which comprises non-contact electric power feeding is used also as communication (cart side communication part) of the communication part 35 of the operation control apparatus 33 mentioned later, and the conveyance trolley | bogie 1. FIG.

  The transport carriage 1 is provided with a traveling roller 52, a branching guide 51 provided on the traveling track, and a branching roller 53. In the track branching portion, one of the branching guides 51 arranged on the left and right is used as a branching roller. By selecting 53, the track 40 is selected, and the traveling roller 52 is configured to travel on the track 40. Specifically, the transport carriage 1 normally travels to a target point in response to a command from a system controller described later. In a portion where there is a midway branch portion, a route is selected by a method in which one of the left and right branch guides 51 laid on the track 40 is selected by the branch roller 53.

  Further, the transport carriage 1 includes a right transmission / reception transformer 18 (corresponding to the right induction signal transceivers 2a and 2b shown in FIG. 1) and a left transmission / reception transformer 19 (corresponding to the left induction signal transceivers 3a and 3b shown in FIG. 1). The communication line 7 laid in the junction area of the track 40 described later, that is, the transmission side communication line 5 (corresponding to the transmission side communication lines 5a and 5b shown in FIG. 1) and the reception side communication line 6 ( Electromagnetically coupled to the receiving communication lines 6a and 6b shown in FIG.

Here, based on FIG. 8 and Table 1, the right side transmission / reception transformer and the left side transmission / reception transformer will be described in more detail. FIG. 8 is a diagram illustrating the configuration of the right transmission / reception transformer and the left transmission / reception transformer. Table 1 is a diagram illustrating a result of measuring a reduction rate of interference noise propagating in the air with or without a capacitor between the right transmission / reception transformer and the left transmission / reception transformer.
As shown in FIG. 8, the right transmission / reception transformer 18 and the left transmission / reception transformer 19 are the same, and a coil 26 is inserted into the E-shaped ferrite core 25. A mounting bracket 24 made of a conductive metal is screwed to the continuous flat portion of the E-shaped ferrite core 25, and a conductive wire 22 is screwed to these brackets 24. The conducting wire 22 and the ferrite core 25 of the right transmitting / receiving transformer 18 and the left transmitting / receiving transformer 19 are electrically connected and short-circuited. The other end of each conductive wire 22 is connected to both electrodes of the capacitor 23.
Hereinafter, based on Table 1, the result of measuring the reduction rate of interference noise propagating in the air with and without the capacitor 23 between the right transmitting / receiving transformer 18 and the left transmitting / receiving transformer 19 will be described. In addition, although the measurement was performed by the method of detecting the voltage that propagates in the air and is induced in the communication line 7 and detected by the receiver as an interference noise voltage, the communication line 7, the right transmission / reception transformer 18, and the left transmission / reception transformer 19 Since the measurement result changed depending on the state, the measurement was performed under the following conditions.
E-type core size: 60 mm (W) x 15 mm (D) x 40 mm (H)
Number of coil turns: 104
Distance between transformers: 190mm (between centers)
Capacitor capacity: 100PF
Transmit voltage peak value: 330V (Sin wave, maximum peak value-minimum peak value)
Transmission frequency: 94 kHz
In addition, the following four conditions were set as the state of the communication line.
Condition 1: There is a communication line on both sides of the track Condition 2: There is a communication line on the transmission side, and there is a track break on the receiving side Condition 3: There is a communication line only on the transmission side Condition 4: No communication line on both sides of the track

  From the actual measurement results in Table 1, it can be confirmed that by providing the capacitor 23 between the right transmitting / receiving transformer 18 and the left transmitting / receiving transformer 19, interference noise propagating in the air can be cut by about 60 to 80% in terms of voltage level. In other words, the electromagnetic field transmitted from either the right transmission / reception transformer 18 or the left transmission / reception transformer 19 propagates in the air and affects the other receiver of the right transmission / reception transformer 18 or the left transmission / reception transformer 19. It can be said that the interference noise given can be avoided.

Further, as shown in FIG. 2, the transport carriage 1 includes an OHT carriage position adjusting mechanism 41, a suspension device 42 having a suspension belt winding function, a suspension belt 43, and a carrier grip provided at the tip of the suspension belt 43. A mechanism 44 and a finger 45 for gripping the FOUP provided at the tip of the carrier gripping mechanism 44 are provided. The transport carriage 1 is aligned by the position adjustment mechanism 41, and the carrier gripping mechanism 44 is moved up and down with the fingers 45 in a state where the FOUP is gripped or not gripped by winding or unwinding the suspension belt 43 with the suspension device 42. . The OHT transfer system is provided with a semiconductor manufacturing apparatus 57 and a FOUP input / output port 58 of the semiconductor manufacturing apparatus 57. With the FOUP input / output port 58 as a relay point, a silicon wafer can be taken into the semiconductor manufacturing apparatus 57. Removal is performed.
Specifically, the transport cart 1 performs FOUP transfer work after reaching the destination. For example, when the FOUP 55 mounted at the destination is lowered by the FOUP flange 56 mounted on the destination by the transport trolley 1 that grips the FOUP flange 56 with the fingers 45, the transport trolley 1 first stops at the transfer position, The position adjustment mechanism 41 performs accurate alignment, and then the suspension belt 43 wound up to the top is successively unwound and the FOUP is lowered to the FOUP input / output port 58 of the semiconductor manufacturing apparatus 57. When the bottom surface of the FOUP contacts the port surface, a limit switch (not shown) attached to the port base is activated. After detecting the landing of the FOUP with the limit switch on the port base, the gripping mechanism 44 opens the finger 45 and places the FOUP on the FOUP input / output port base 58. After the FOUP unloading operation is completed, the transport carriage 1 winds up the suspension belt 43, and when the gripping mechanism 44 reaches the uppermost position, it proceeds to the next destination according to the next command.

  Next, based on FIG. 3, the structure of the operation control of the OHT conveyance system to which this embodiment is applied is demonstrated. FIG. 3 is a block diagram showing a configuration of operation control of the OHT conveyance system.

  As shown in FIG. 3, the operation control device 33 includes an operation management unit 34, a communication unit 35, a cart monitoring unit 36, and a priority cart determination unit 37. The operation management unit 34 exchanges information necessary for operation management of the OHT transport system with the system controller 39 that controls the production management system of the semiconductor factory via the network 38. The communication part 35 is for communicating with each conveyance cart 1 via the primary side power supply 50 mentioned above. Specifically, a conveyance command to each conveyance carriage 1, a conveyance carriage position from the conveyance carriage 1, and a work progress report are transmitted via the non-contact power supply primary side electric wire 50. The trolley monitoring unit 36 is for monitoring to prevent a collision between the transport trolleys 1 in the merging region 10. The priority cart determination unit 37 determines the priority order of the transport carts 1 that simultaneously enter the junction area 10.

Next, processing of the collision prevention control system according to the present embodiment will be described based on FIGS.
FIG. 4 is a detailed explanatory diagram of the merging region in FIG. In FIG. 4, the same parts as those in FIG. Also, the right guide signal transmitter / receiver 2c, the left guide signal transmitter / receiver 3c, the mark reader 4c, and the control unit 8c of the transport cart 1c in FIG. 4 are the right guide signal transmitter / receiver 2b and the left guide signal transmitter / receiver 3b of the transport cart 1b. This is the same as the mark reader 4b and the controller 8b, and a description thereof will be omitted.
FIG. 5 is a flowchart illustrating the process of the collision prevention control system according to the present embodiment. In addition, the process of the collision prevention control system demonstrated in FIG. 5 is performed by control part 8a, 8b, 8c mounted in each of the conveyance trolley | bogie 1a, 1b, 1c.

  As shown in FIG. 3, in the example of the present embodiment, the following situation is shown. First, the system controller 39 issued a command to transport the FOUP from the stocker 59 to the semiconductor manufacturing apparatus 57 to the transport cart 1b. This command is transmitted to the operation management unit 34 of the operation control device 33 via the network 38 and further transmitted to the transport carriage 1b via the communication unit 35. In response to this instruction, the transport carriage 1b reaches the joining area 10 and enters the joining area 10 on the way from the stocker 59 to the semiconductor manufacturing apparatus 57. On the other hand, with a little delay from the transport carriage 1b, the transport carriage 1a is about to enter the junction area 10 in response to a command from the system controller 39. Further, following the transport carriage 1b, the transport carriage 1c is about to enter the junction area 10 in response to a command from the system controller 39.

As shown in FIGS. 4 and 5, first, the transport carriage 1 b travels on the track B in the direction of the arrow and reaches the merging area Pb in the merging area 10. Then, the transport carriage 1b reads the guide line control effective mark 12b as the first mark installed on the track B by the mark reader 4b mounted on the own vehicle (step S1), and the joining area in the joining area 10 Recognize that Pb has been invaded. Then, the right induction signal transmitter / receiver 2b mounted on the host vehicle is operated (step S2), and a signal waveform riding on the receiving communication line 6b is detected and analyzed (step S3). Subsequently, the transmission point mark 14b provided in the vicinity of the guide line control effective mark 12b is read by the mark reader 4b (step S4) and analyzed in step S3. It is determined whether there is a signal waveform (step S5). Here, the determination is made based on whether or not the received signal waveform does not match the signal waveform of its own merge area Pb.
In this embodiment, there is no conveyance carriage in the merge area Pa, which is another merge area, and the signal waveform analysis result of the signal waveform that can be detected by the conveyance carriage 1b is the signal waveform transmitted by the conveyance carriage in the merge area Pa, which is another merge area. This means that there is no first-entry vehicle that has entered the merging area 10 from the merging area Pa, which is another merging area (step S5: NO). A signal indicating the merge area Pb, which is a merge area, is put on the transmission side communication line 5b and transmission is started (step S8). The signal meaning the merge area Pb includes an AC waveform signal (a signal whose frequency or voltage is different for each merge area or both), a pulse frequency waveform signal (a signal whose frequency is different for each merge area), multiple bits A digital communication signal (digital communication system signal consisting of a plurality of bits different for each merging area) or a signal obtained by arbitrarily combining these two or more is selected as necessary.
At this time, since the carriage 1b operates the right induction signal transmitter / receiver 2b already mounted on the own vehicle in step S2, it can detect the signal waveform carried on the receiving communication line 6b. That is, the signal transmitted by the left guidance signal transmitter 3b mounted on the host vehicle can be received by the right guide signal transmitter / receiver 2b mounted on the host vehicle. Accordingly, the transport carriage 1b detects and analyzes the signal waveform on the receiving side communication line 6b by the right side induction signal transmitter / receiver 2b mounted on the own vehicle (step S9), and transmits the left side induction signal transmitted by the own vehicle. It is determined whether or not the signal transmitted by the device 3b has been received by the right guidance signal transmitter / receiver 2b mounted on the vehicle (step S10). Here, the determination is made based on whether or not the received signal waveform matches the signal waveform of its own merge zone Pb.
When the carrier cart 1b cannot detect the signal transmitted by the own vehicle as a result of the analysis of the received signal of the right guidance signal transmitter / receiver 2b (step S10: NO), it determines that the communication line 7 has an abnormality such as disconnection, Along with stopping the traveling immediately, a command is issued to stop all the carriages via the operation management unit 34 (step S11), and the process is terminated. Thereby, the collision accident resulting from falling into an uncontrolled state by the disconnection of the communication line 7 can be avoided. On the other hand, the conveyance cart 1b determines that the communication line 7 is not disconnected when the signal transmitted from the own vehicle can be detected as a result of the analysis of the received signal of the right guidance signal transceiver 2b (step S10: YES), The running is continued until the passage through the merge area Pb is completed (step S12). Then, the transport carriage 1b reads the guide line control invalid mark 15 with the mark reader 4b on the track C at the end of the merge area Pb (step S13). That is, since the guide line control invalid mark 15 is a mark that means that the passage through the merging region 10 has been completed, the transport carriage 1b stops the transmission to the transmission side communication line 5b by the left guide signal transmitter / receiver 3b ( Step S14), the process ends, and the merging area 10 goes straight in the right direction.

Next, the transport carriage 1a enters the joining area 10 with a delay from the transport carriage 1b. The transport carriage 1a reaches the joining area Pa in the joining area 10, and reads the guide line control effective mark 12a which is the first mark installed on the track A by the mark reader 4a mounted on the own vehicle (step S1). ), It is recognized that it has entered the merge area Pa of the merge area 10. Then, the left induction signal transmitter / receiver 3a mounted on the own vehicle is operated (step S2), and a signal waveform placed on the receiving side communication line 6a is detected and analyzed (step S3). Subsequently, the transmission point mark 14a provided in the vicinity of the guide line control effective mark 12a is read by the mark reader 4a (step S4), and analyzed in step S3. It is determined whether there is a signal waveform (step S5). Here, the determination is made based on whether or not the received signal waveform does not match the signal waveform of its own merge zone Pa.
In this embodiment, the conveyance carriage of the merge area Pb which is another merge area is the conveyance carriage 1b, and the analysis result of the signal waveform that can be detected by the conveyance carriage 1a is the signal waveform transmitted by the conveyance carriage of the other merge area. That is, since this means that there is a first-entry vehicle that has entered the merge area 10 from another merge area (step S5: YES), the transport carriage 1a stops at the stop point mark 13a (step S6). And the conveyance cart 1a continues operating the left side induction signal transmitter / receiver 3a in a stopped state, and continues detection and analysis of the signal waveform carried on the receiving side communication line 6a (step S7). In the present embodiment, during this stop period, the transport carriage 1b continues to travel toward the end portion of the merge area Pb, but the transport carriage 1c does not finish passing through the merge area Pb. Intrusion into the basin Pb is started. At this time, the transport carriage 1a remains stopped at the stop point mark 13a.

The transport cart 1c that has entered the junction Pb basically performs the same operation as the preceding transport cart 1b. That is, first, the guideline control effective mark 12b, which is the first mark installed on the track B, is read by the mark reader 4c mounted on the own vehicle (step S1), and enters the joining area Pb of the joining area 10. Recognize that. Then, the right induction signal transmitter / receiver 2c mounted on the host vehicle is operated (step S2), and the signal waveform placed on the receiving communication line 6b is detected and analyzed (step S3). Subsequently, the transmission point mark 14b provided in the vicinity of the guide line control effective mark 12b is read by the mark reader 4c (step S4), and analyzed in step S3. It is determined whether there is a signal waveform (step S5). Here, the determination is made based on whether or not the received signal waveform does not match the signal waveform of its own merge area Pb.
In the present embodiment, there is no carriage in the junction area Pa, which is another junction area, and the signal waveform analysis result of the signal waveform that can be detected by the carriage 1c is the signal waveform transmitted by the carriage truck in the junction area Pa, which is another junction area. This means that there is no first-entry vehicle that has entered the merging area 10 from the merging area Pa, which is another merging area (step S5: NO). A signal indicating the merge area Pb, which is a merge area, is put on the transmission side communication line 5b and transmission is started (step S8). Even if the transport carriage 1b still exists in the merge area Pb and transmits a signal waveform indicating the own merge area Pb, the signal waveform received by the transport carriage 1c matches the signal waveform of the own merge area Pb. Therefore, it is determined that there is no signal waveform transmitted by the transport carriage in the other merging zone, and the transport cart 1c can enter the merging zone Pb.
At this time, since the conveyance carriage 1c operates the induction signal receiver 2c already mounted on the own vehicle in step S2, the signal waveform carried on the communication line 6b can be detected. In other words, a signal transmitted by the left guidance signal transmitter 3c mounted on the host vehicle can be received by the right guidance signal transmitter / receiver 2c mounted on the host vehicle. Accordingly, the transport carriage 1c detects and analyzes the signal waveform on the receiving communication line 6b by the right side induction signal transmitter / receiver 2c mounted on the own vehicle (step S9), and transmits the left side induction signal mounted on the own vehicle. It is determined whether or not the signal transmitted by the device 3c has been received by the right guidance signal transmitter / receiver 2c mounted on the host vehicle (step S10). Here, the determination is made based on whether or not the received signal waveform matches the signal waveform of its own merge zone Pb.
When the carrier cart 1c cannot detect the signal transmitted by the own vehicle as a result of the analysis of the received signal from the right guidance signal transmitter / receiver 2c (step S10: NO), it determines that the communication line 7 has an abnormality such as disconnection, Along with stopping the traveling immediately, a command is issued to stop all the carriages via the operation management unit 34 (step S11), and the process is terminated. Thereby, the collision accident resulting from falling into an uncontrolled state by the disconnection of the communication line 7 can be avoided. On the other hand, the conveyance carriage 1c determines that the communication line 7 is not disconnected when the signal transmitted by the own vehicle can be detected as a result of the analysis of the received signal of the right guidance signal transceiver 2c (step S10: YES), The running is continued until the passage through the merge area Pb is completed (step S12). If the transport carriage 1b is still present in the merge area Pb and is transmitting a signal waveform indicating the own merge area Pb, the signal waveform received by the transport carriage 1c is the signal waveform of the own merge area Pb. Therefore, the right guidance signal transmitter / receiver 2c mounted on the host vehicle is used as the signal transmitted by the left guidance signal transmitter 3c mounted on the own vehicle as a signal transmitted by the left guidance signal transmitter 3b mounted on the transport cart 1b. In this case, there is no problem because the communication line 7 is considered to have no abnormality such as disconnection. Then, the transport carriage 1c reads the guide line control invalid mark 15 by the mark reader 4c on the track C at the end of the merge area Pb (step S13). That is, since the guide line control invalid mark 15 is a mark that means that it has passed through the merging region 10, the transport carriage 1c stops the transmission to the transmission side communication line 5b by the left guide signal transmitter / receiver 3c ( Step S14), the process ends, and the merging area 10 goes straight in the right direction.

On the other hand, while the processing of steps S5 to S7 is repeated, the transport cart 1a that is stopped at the stop point mark 13a passes through the merge area Pb of the transport cart 1c and the left guidance signal transceiver 3c is stopped. First, the analysis result of the signal waveform that can be detected by the transport carriage 1a is no signal waveform transmitted by the transport carriage in the joining area Pb that is another joining area, that is, the joining area 10 from the joining area Pb that is another joining area. This means that there is no first-arrival vehicle that has entered (step S5: NO). Then, the transport carriage 1a immediately starts the stop point mark 13a and proceeds rightward in the merge area Pa, and at the same time transmits a signal indicating the merge area Pa that is the merge area of the own vehicle by the right guidance signal transmitter 2a. Transmission is started on the side communication line 5a (step S8). In addition, the signal meaning the merge area Pa includes an AC waveform signal (a signal in which one or both of the frequency and the voltage is different for each merge area), a pulse frequency waveform signal (a signal having a different frequency for each merge area), multiple bits A digital communication signal (digital communication system signal consisting of a plurality of bits different for each merging area) or a signal obtained by arbitrarily combining these two or more is selected as necessary.
At this time, since the transport carriage 1a operates the left-side induction signal transmitter / receiver 3a already mounted in the own vehicle in step S2, the signal waveform carried on the receiving communication line 6a can be detected. That is, the signal transmitted by the right-side induction signal transmitter 2a mounted on the own vehicle can be received by the left-side induction signal transmitter / receiver 3a mounted on the own vehicle. Accordingly, the transport carriage 1a detects and analyzes the signal waveform on the receiving communication line 6a by the left guidance signal transmitter / receiver 3a mounted on the own vehicle (step S9), and transmits the right guidance signal transmitted by the own vehicle. It is determined whether or not the signal transmitted by the device 2a has been received by the left guidance signal transmitter / receiver 3a mounted on the vehicle (step S10). Here, the determination is made based on whether or not the received signal waveform matches the signal waveform of its own merge area Pa.
The carrier cart 1a determines that the communication line 7 has an abnormality such as disconnection when the signal transmitted from the own vehicle cannot be detected as a result of analyzing the received signal of the left guidance signal transmitter / receiver 3a (step S10: NO), Along with stopping the traveling immediately, a command is issued to stop all the carriages via the operation management unit 34 (step S11), and the process is terminated. Thereby, the collision accident resulting from falling into an uncontrolled state by the disconnection of the communication line 7 can be avoided. On the other hand, the transport carriage 1a determines that the communication line 7 is not disconnected when the signal transmitted from the own vehicle can be detected as a result of the analysis of the reception signal of the left guidance signal transceiver 3a (step S10: YES), The running is continued until the passing through the merge area Pa is completed (step S12). Then, the transport carriage 1a reads the guide line control invalid mark 15 by the mark reader 4a on the track C at the end of the merge area Pa (step S13). That is, the guide line control invalid mark 15 is a mark that means that it has passed through the merging region 10, and the transport carriage 1a stops transmission to the transmission side communication line 5a by the right guide signal transceiver 2a ( Step S14), the process is terminated, and the merging area 10 is further straightened in the right direction.

  As described above, in the collision prevention control system 11 according to the present embodiment, as shown in FIG. 1, the identification indicating the merge area Pb different from the own merge area Pa on the single-line communication line 7 laid in a loop shape. By detecting the signal with the left guidance signal transmitter / receiver 3 a, the transport carriage 1 a that has entered the joining area 10 confirms that the transport carriage 1 b that has entered from the other joining area already exists in the joining area 10. And when the preceding conveyance trolley 1b which approached from the other merging area Pb exists, it waits for the preceding conveyance trolley 1b to pass through the merging area 10. When the preceding transport carriage 1b that has entered from the other merge area Pb and the subsequent transport carriage 1c that has entered from the other merge area Pb no longer exist, the communication line 7 is connected to the communication line 7 by the right-side guidance signal transmitter / receiver 2a that is mounted on itself. By traveling while transmitting an identification signal indicating its own merged area Pa, it is possible to avoid a collision between the transport carts 1a, 1b, 1c in the merged area 10. The transport carts 1b and 1c have the same traveling track, and can travel in a plurality of merging areas Pb.

  Further, the identification signal indicating the merging area Pa or the merging area Pb is an AC waveform signal that is different for each merging area (a signal in which one or both of the frequency and the voltage is different for each merging area), and a pulse frequency waveform signal (for each merging area). A signal having a different frequency), a digital communication signal consisting of a plurality of bits (a digital communication system signal consisting of a plurality of bits different for each merging region), or a signal obtained by arbitrarily combining two or more of these signals. Therefore, it is possible to discriminate a merging area different from its own merging area without crosstalk even in bidirectional communication.

  In addition, as shown in FIG. 1, when there is an abnormality in the communication line 7 such as disconnection, the communication line 7 is a single line laid in a loop shape in the merge region 10, so The identification signal transmitted by the receiver 2a, the left induction signal transmitter / receiver 3b, and the left induction signal transmitter / receiver 3c) is received by its own receiver (left induction signal transmitter / receiver 3a, right induction signal transmitter / receiver 2b, right induction signal transmitter / receiver 2c). It becomes impossible to receive, and the abnormality of the communication line 7 can be easily recognized. And it becomes possible to avoid a collision by stopping immediately all the conveyance trolley | bogies 1a, 1b, 1c which drive | work at the time of abnormality being detected.

  Further, as shown in FIG. 6, the capacitor 21 having a capacity that substantially compensates the inductance of the communication line 7 is provided in series on the communication line 7, thereby increasing with an increase in the length of the single-line communication line 7. The increase of the impedance to be reduced can be reduced, and the decrease in the signal level of the identification signal can be prevented.

  Further, as shown in FIG. 8, a right transmission / reception transformer 18 and a left transmission / reception transformer 19 are provided by laying a conductive wire 22 that electrically short-circuits the right transmission / reception transformer 18 and the left transmission / reception transformer 19 and providing a capacitor 23 on the conductive wire 22. Can be eliminated by the electromagnetic field induced interference propagating in the air generated by placing the vehicle close to the transport carriage 1.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

  In the above-described embodiment, the collision prevention control system according to the present invention is transported to transport a processing object such as a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, or an optical disk substrate in a semiconductor product manufacturing facility. Although it is applied to the system, it is not limited to this. For example, in addition to the facility transportation system that transports objects to be processed in and between processes, and processes them as final products, it also transports all electronic goods, machine parts, chemicals, food, documents, etc. It can be applied to industry transportation systems.

It is a figure which shows the structure of a collision prevention control system, and is a top view of the whole confluence | merging area | region in the track | orbit of an OHT conveyance system. It is sectional drawing which shows the structure of an OHT conveyance system. It is a block diagram which shows the structure of the operation control of an OHT conveyance system. FIG. 4 is a detailed explanatory diagram of a merging region in FIG. 3. It is the flowchart explaining the process of the collision prevention control system which concerns on this embodiment. It is a figure which shows the structure of a communication line. It is a figure which shows the result of having measured the actual value of the received signal level of a communication line by using the capacity | capacitance C of a capacitor | condenser as a parameter. It is the figure explaining the structure of the right side transmission / reception transformer and the left side transmission / reception transformer. It is the block diagram explaining the control part of the conveyance trolley.

Explanation of symbols

1, 1a, 1b, 1c Carriage cart 2, 2a, 2b, 2c Right-side induction signal transmitter / receiver (transmitter or receiver)
3, 3a, 3b, 3c Left side induction signal transmitter / receiver (transmitter or receiver)
5a, 5b Transmission side communication line 6a, 6b Reception side communication line 7 Communication line 8, 8a, 8b, 8c Control unit 10 Junction area 11 Collision prevention control system 18 Right side transmission / reception transformer 19 Left side transmission / reception transformer 21 Capacitor 23 Capacitor 40 Orbit

Claims (5)

A communication means laid in a predetermined merging area including a merging point where a plurality of inflow routes in a track on which the transport carriage travels, and a communication means installed in the transport trolley and flowing into the communication means in the merging area A transmitting means for transmitting a unique identification signal indicating a route; a receiving means for receiving the identification signal from the communication means in the merging area; and a receiving means for receiving the identification signal from the communication means in the merging region; A control means for controlling the running by analyzing the identification signal received in step, and a collision prevention control system comprising:
The communication means is a single-wire communication means laid in a loop in the merge area,
The collision prevention control system characterized in that the control means stops traveling while the receiving means detects the identification signal indicating an inflow route different from its own inflow route.   2. The identification signal according to claim 1, wherein any one of an alternating current waveform signal, a pulse frequency waveform signal, and a digital communication signal composed of a plurality of bits, or a combination of two or more thereof, is used as the identification signal. The collision prevention control system described.   The control means further determines that the communication means is abnormal when the identification signal transmitted by the control means is not detected by the receiving means of the control means, stops its own travel, and travels on the track. 3. The collision prevention control system according to claim 1, wherein travel of all the transport carts to be stopped is stopped.   The collision prevention control system according to any one of claims 1 to 3, wherein a capacitor having a capacity to substantially compensate the inductance of the communication unit is connected in series to the communication unit.   5. A connecting wire for electrically short-circuiting the transmitting means and the receiving means is laid on the transport carriage, and a capacitor is connected in series to the short-circuited wire. The anti-collision control system according to item.

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