JPH11288315A - Wagon operating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely perform communication with a conveyance controller while utilizing a power line and a pickup coil for power concerning all wagons on a track. SOLUTION: This wagon operating system is provided with a loop-shaped power line 2 wired along with the endless track spread in a clean room, wagon 9 to be traveled on the track while utilizing power guided from the pickup coil for power without contact from this power line 2 and conveyance controller 3 for performing control concerning the conveyance of the wagon 9 by performing communication with the wagon 9 and by superimposing a communication signal at a digital modulated frequency different from the frequency of power to be supplied to the power line 2 through the pickup coil for power onto this power, the information concerning the conveyance is exchanged between the wagon 9 and the conveyance controller 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a truck operation system for driving a truck traveling on an endless track laid in a clean room under operation control by communication with a transfer control device.

[0002]

2. Description of the Related Art A semiconductor wafer process performed in a clean room is a batch process involving several hundred processes.
Conventionally, a person transports a wafer cassette to each processing apparatus for this batch processing. However, since workers are the largest source of contamination, it is common practice to automate transportation in a clean room for the purpose of improving production yield. In the inter-process transfer in this clean room, a transfer system that uses a linear motor to transfer a carriage carrying a wafer cassette at a high speed has been proposed, and the wafer cassette is automatically transferred through a stocker. became.

[0003] However, in an automatic transfer system using a truck driven by the linear motor, a system in which a collector provided on the truck is brought into contact with a power line to supply electric power,
Since abrasion powder and dust such as current collectors are most likely to be generated in a clean room, it is desired to employ a non-contact type current collector.

On the other hand, the transport control along the track of the truck is performed based on a command from a transport control device remote from the truck, and therefore, the transport control device communicates with the truck in a manner necessary for transport control. Is done wirelessly. Then, in order to perform this communication regardless of the moving position of the cart, the radio equipment of the transport control device is installed at a plurality of places such as a station where the cart works, and for communication with the cart. Was laid between the radio and the transport control device.

[0005]

However, in such a communication method for automatic transfer control, in order to perform reliable communication, it is laborious to select a position for installing the wireless device of the transfer control device. For example, when the radio is installed in a station, there is a restriction that the dolly must stop at the station and receive a command. There has been a problem that radio waves (microwaves) are shielded by objects, and commands cannot be reliably transmitted to the bogie.
It should be noted that even when the command is given by light, the influence of the obstacle is more frequently received.

On the other hand, a communication line for supplying a command signal from the transport control device is laid along a guide rail in parallel with the power line of the transport control device in order to avoid a communication failure due to the shielding of the radio waves and light. However, there has been proposed a method in which the bogie communicates with the transfer control device via the communication line.However, in this case, since the communication line is laid in addition to the power line, the laying work and maintenance work are troublesome. In addition, there was a problem that the cost was high.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and enables any of the trucks at any position on the track to reliably communicate with the transport control device through the electric power pickup coil. It is an object of the present invention to obtain a truck operation system that can be realized extremely simply and at low cost.

[0008]

To achieve the above object, a truck operation system according to the first aspect of the present invention comprises a loop-shaped power line wired along an endless track laid in a clean room, and the power line. By using the electric power induced by the electric power pick-up coil in a non-contact manner, the automatic transfer of the conveyed goods is performed, and the bogie traveling on the track and the bogie communicate with each other. A transfer control device for controlling the transfer of the power line, the power supplied to the power line, a communication signal of a frequency that has been subjected to digital modulation different from the frequency of the power, superimposed through a power pickup coil In this configuration, information on the transfer is transmitted and received between the carriage and the transfer control device.

Further, in the truck operation system according to the present invention, a plurality of loop-shaped power lines are provided adjacent to each other along one endless track, and power is supplied from these power lines to the truck. In the switching portion, the power lines are arranged so as to overlap each other.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block connection diagram conceptually showing a truck operation system of the present invention. In FIG. 1, reference numeral 1 denotes an AC power supply of, for example, 50 amperes (A) and 10 kilohertz (KHz), to which a power line (feeding line) 2 of, for example, 300 meters is connected in a loop. The power line 2 is wired along a track (not shown) on which one or more trucks 3 travel.

Reference numeral 3 denotes a carrier control device, which is connected to the power line 2 in a contactless manner, and has a pickup coil 4 for transmission and a receiver coil 4 for reception for superimposing a carrier of a communication signal on the power on the power line 2. A pickup coil 5 and a modulator 7 for digitally modulating a communication signal from a host computer 6 and outputting the digitally modulated signal to a pickup coil 4 for transmission.
And a demodulator 8 which demodulates a communication signal guided from the power line 2 to the pickup coil 5 for reception and inputs the communication signal to the host computer 6.

Further, reference numeral 9 denotes a plurality of trucks traveling along a track. Here, only two trucks are shown. These carts 9 are connected to the power line 2 in a contactless manner, and a pickup coil 10 for transmission and a pickup coil 11 for reception for superimposing a carrier of a communication signal on the power on the power line 2; Digitally modulates the communication signal from the pickup coil 10 for transmission.
And a demodulator 14 for demodulating a communication signal guided by the pickup coil 11 for reception and inputting the demodulated communication signal to the bogie-side computer 12.

The frequency of the communication signal output from the modulator 7 to the pickup coil 4 for transmission by the host computer 6 is, for example, 300 KHz. The frequency of the communication signal to be superimposed on the power on the power line 2 through the pickup coil 10 for transmission is
For example, it is set to 350 KHz. Each of these frequencies is set to a higher frequency different from the frequency of the AC power supply 1. Accordingly, the demodulator 8 of the host computer 6 demodulates the communication signal of 350 KHz, and the demodulator 14 of the bogie computer 12 demodulates the communication signal of 300 KHz. For this reason, each of the demodulators 8 and 14 is provided with a band-pass filter that separates and passes a specific frequency.

FIG. 1 shows only the case where the transport control device 3 and the trolley 9 are provided with their own transmission pickup coils 4, 5, 10, and 11 for transmitting and receiving communication signals. In practice, a power pickup coil for inducing electric power in a contactless manner is connected to the power line 2 for each of the transport control device 3 and the truck 9, and the transmission pickup coils 4, 5, 10, 11 are connected to these power pickup coils. Pickup coil. That is, the transport control device 3 and the trolley 9 receive power supply through the power pickup coil and transmit and receive the communication signal. As a result, the number of parts used in the system can be reduced, the configuration can be simplified, and the cost can be significantly reduced.

The frequency of the communication signal supplied from the modulators 7 and 13 to the power line 2 is such that the wavelength becomes too short from the length of the power line 2 (for example, 400 meters) in conformity with the Radio Law. In order to prevent communication from becoming impossible due to reflection or phase difference, the frequency is set as low as possible and is not affected by the power frequency of the power line.

That is, in the power line 2 of one closed circuit, the communication signal is connected to the filter from the minimum wavelength of four times or more the length of the power line to avoid interference with the return signal. A signal up to a maximum wavelength equal to or less than a half wavelength of the power wave determined from the relationship is selected and used.

FIGS. 2 and 3 show a transmission side circuit and a reception side circuit of the truck 9, respectively. Among these, the transmission-side circuit shown in FIG. 2 inputs the position and loading information of the carriage 9 determined by the carriage-side computer to a frequency displacement keying device (modulation device) 21 using a phase locked loop (PLL). Then, the digital signal is converted into an analog signal and modulated so as to be able to communicate on an analog transmission path.
The DC power supply 23 drives an inverter 24 in which two sets of two switch elements connected in series are connected in parallel.

That is, the gate driver 22 synchronously turns on and off the switch elements 24a and 24c and the switch elements 24b and 24d constituting the inverter 24,
A signal corresponding to the on / off operation is input to a resonance capacitor 26 and a coil 27 via a resistor 25 to extract a communication signal of a predetermined frequency, and this is output to the power line 2 through a pickup coil 10 for transmission. This pickup coil 10 has a normally closed switch element 2
8 are connected in parallel.

Since each truck 9 has a resonance circuit including such a capacitor 26 and a coil 27, it is conceivable that a transmission signal from one truck goes around the transmission circuit of the other truck via the power line 2. Can be For example, when a communication signal of 1.7 V is applied from one carriage, an induced voltage of 85 V is generated in the resonance circuit of the other carriage, and therefore, the output voltage of the inverter 24 also becomes, for example, 24 V.
It will rise from V to 200V.

Therefore, only at the moment when the truck 9 designated by the host computer 6 of the transport control device 3 transmits a communication signal, the switch element 28, which is normally off, is turned on, and the transport control device 3 It enables transmission of communication signals related to transport management. When the communication signal is not transmitted, the pickup coil 10 is short-circuited to prevent the communication signal from being transmitted from the other bogie.

In the receiving circuit shown in FIG.
A reception signal is obtained from a pickup coil 11 for reception, which is electrically connected to the receiver, and is passed through a band-pass filter 32 through a booster 29, a limiter 30, and a parallel resistor 31 to obtain a predetermined frequency range. 350K demodulated by a demodulation device 33 using a PLL by extracting a transmission signal.
The transmission signal of Hz is taken out and input to the bogie computer 12.

Here, the pickup coils 10 and 11 are separately provided for transmission and reception, and are not shared. As a result, the reception side circuit can always wait for reception, and the switch 28 can prevent the transmission signal from being transmitted from another carriage 9 to the transmission circuit. The pickup coils 10 and 11 may be secondary coils of the current transformer CT.

That is, in the carrier communication using the power line 2 as described above, digital information is superimposed on the power on the power line 2 or the digital information is extracted from the power line 2 without using a capacitor coupling or a pulse transformer. In addition, the current transformer CT can be used as each of the pickup coils. Since the current transformer CT is obtained by winding a coil around the core, a sufficient power detecting action can be obtained, and therefore, the non-contact interval between the truck 9 and the power line 2 can be sufficiently increased. As a result, there is an advantage that the design and installation conditions of the transport system are greatly reduced.

On the other hand, when the transfer distance in the clean room, that is, the orbit length is increased, the power line 2 is correspondingly elongated, and the reflection and loss of digital communication signals may be increased. For this reason, when the track becomes long, a plurality of sets of loop-shaped power lines 2 are arranged along one endless track, as shown in FIG. The connected digital / analog converter 35 corresponding to the modulator 7 and the demodulator 8
, Each power line is connected to the transport control device 3 in a multi-drop manner.

In this way, the digital communication signal from the transport control device 3 is transmitted to the power line 1 near the power supply 1 using parallel lines, and further modulated and demodulated through the digital / analog converter (modulator / demodulator) 35. After amplification, it can be supplied to each power line 2. Therefore, no matter which power line 2 the cart 9 is on, transmission and reception of communication signals with the transport control device 3 can be performed under the same conditions.

The power line 2 having the power source 1
In a trolley operating system in which a plurality of sets are laid along one track, when the trolley 9 transfers from one of the adjacent power lines 2 to the other, reception of the transmission signal from the transport control device 3 may be interrupted. For example, as shown in FIG. 5, two power lines 2A and 2B having power sources 1A and 1B
, A gap G is generated between the power lines 2A and 2B, and a communication signal from the transport control device 3 to the carriage 9 is interrupted at the gap G.

Therefore, in the present invention, as shown in FIG. 6, the power lines 2A and 2B are arranged obliquely at the gap G so as to overlap in the direction of the track C. For this reason, since the gap G has a fixed length in the direction of the track C, the power line 2A, 2B must be used whenever the bogie passes through any position of the long gap.
Since the power and communication signal are received from both of them, the power and communication signal are not interrupted on the truck 9 side, and the loss of transmitted information can be reliably prevented.

As shown in FIG. 7, the same effect as in FIG. 6 can be obtained even if the end of the power line 2A is overlapped with the end of the power line 2B in the front-rear direction or the up-down direction. In this case, there is no gap G in the orbital direction.

The truck 9 traveling on the track C is configured, for example, as shown in FIG. FIG. 8 conceptually shows the configuration. Reference numeral 41 denotes a track frame having a substantially U-shaped cross-section constituting a track C, and a plurality of strip-like magnets 44 are embedded in the center of the bottom of the track frame in the running direction of the bogie 9. Have been. further,
On the inner surface of each side plate facing the track frame 41, at the middle level,
A guide rail 42 having a guide piece 42a whose tip is bent into an L-shape is symmetrically installed.

Further, on the inner surface of the side plate above these guide rails 42, two wire support members 43 made of an insulating material are provided so as to project upward and downward, respectively. And of these,
The upper left and right electric wire support members 43 support, for example, two parallel power lines 2A having a power supply 1A as shown in FIG. 5, and the lower left and right electric power support members 43 support the power line 2A. , Two parallel power lines 2B having a power source 1B adjacent to the power line 1B are supported.

On the other hand, in the track frame 41, a carriage 9 having a caster 45 which rolls in contact with the bottom of the track frame 41 at the lower portion is provided so as to be able to travel along the track C direction. In the trolley 9, a plurality of armature coils 46 are arranged on the lower surface of the central portion in the direction of the track C so as to face the magnets 44.
The armature coil 46 and the magnet 44 constitute an induction type linear motor.

Further, on the carriage 9, support arms 47 are provided on the left and right, and are provided at the upper ends of the support arms 47 with respect to the guide pieces 42a of the guide rails 42 provided on both side plates of the track frame 41. A guide roller 48 is provided, which is freely detachable and rollable. Therefore, the truck 9 is mounted on the track frame 4
1, the traveling direction is two guide pieces 4
2a.

Further, a support bar 49 is vertically provided at the center of the carriage 9, and a wafer cassette 50 is mounted on an upper end of the support bar 49 which protrudes from an upper opening of the track frame 41. A loading platform 51 to be placed is attached. Further, a pickup means 52 is attached to a position of the support rod 49 facing the inside of the track frame 41.

The pickup means 52 includes a pickup coil (not shown) provided in close proximity to the power lines 2A and 2B, and a core 53 wound with the pickup coil to form a current transformer CT. The core 53 has a notch 54 for guiding each of the power lines 2A and 2B in a state close to the pickup coil.
Are provided as shown. That is, each power line 2
A and 2B are inserted into each notch 54 in the state of being close to the pickup coil. Therefore, the power lines 2A, 2B
Therefore, power and communication signals can be guided to the pickup coil with high sensitivity.

The power lines 2A and 2B may be provided on both sides of the truck 9 as shown in FIG. 8, or may be provided on one of the left and right sides of the truck 9, depending on the condition of the track C. Therefore, in order to induce a communication signal from the power line in the power carrier communication, the above-described pickup coils are required on the left and right sides of the carriage 9.

When the power line 2A or 2B is provided only on the left or right side of the carriage 9 as described above, the pickup coils are switched by a command from the transfer control device 3, It is necessary to extract a communication signal guided by this, so that it becomes necessary to provide a switching means. However, in such a case, by connecting the left and right pickup coils in parallel with each other, the communication signal induced by any of the pickup coils can be reliably taken into the bogie-side computer 12 of the bogie 9, The switching means for the pickup coil becomes unnecessary.

It is to be noted that, even if a filter and an amplifier are provided for the left and right pickup coils, respectively, and the communication signals obtained from the left and right pickup coils are added in the amplification stage, the same applies to the case of the parallel connection. The communication signal induced from the power line can be reliably taken out.

Further, among the communication signals obtained from the left and right pickup coils, one of the pickup coils having the higher signal level is determined by the signal strength discriminator, and the communication signal on the pickup coil having the higher signal strength is automatically selected. May be taken out.

[0039]

As described above, according to the present invention, a loop-shaped power line laid along an endless track laid in a clean room and a power pickup coil for contactlessly inducing power from the power line. Using the power
A carriage that travels on the track while performing automatic transfer of the conveyed goods, and a carrier control device that performs communication between the carriage and the carriage to control the carriage of the carriage, and is supplied to the power line. The transmission signal is transmitted and received between the carriage and the transport control device by superimposing a communication signal of a frequency obtained by performing digital modulation different from the frequency of the power on the power through a pickup coil for power. With such a configuration, any of the trucks at all positions on the track can reliably communicate with the transport control device using the power line and the power pickup coil, and this can be achieved with a very simple configuration and low cost. And the power line can also be used for transmitting communication signals. Need to have eliminated, the effect is obtained that can realize further simplification and cost reduction of the system configuration and maintenance.

According to the present invention, a plurality of loop-shaped power lines are provided adjacent to each other along one endless trajectory, and the power supply from these power lines to the bogie is switched, and Since the power lines are arranged so as to overlap each other, even when the bogie moves on another adjacent power line, it is possible to surely prevent the interruption of communication signals and power supply transmitted and received between the transport control device and the bogie. Is obtained.

[Brief description of the drawings]

FIG. 1 is a block connection diagram showing a truck operation system according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a transmission-side circuit of the bogie in FIG. 1;

FIG. 3 is a circuit diagram showing a receiving-side circuit of the cart in FIG. 1;

FIG. 4 is a block connection diagram showing a truck operation system having a plurality of power lines according to the present invention.

FIG. 5 is an explanatory diagram showing an example of arrangement of a plurality of power lines according to the present invention.

FIG. 6 is an explanatory diagram showing an example of arrangement of a plurality of power lines according to the present invention.

FIG. 7 is an explanatory diagram showing an example of arrangement of a plurality of power lines according to the present invention.

FIG. 8 is a conceptual diagram showing a configuration of a truck and a track of the present invention.

[Explanation of symbols]

 1, 1A, 1B power supply 2, 2A, 2B power line 3 transport control device 4, 5, 10, 11 pickup coil 9 trolley 28 switch element 35 digital / analog conversion unit C track

Claims (2)

[Claims] 1. A method for automatically transporting a conveyed object using a loop-shaped power line laid along an endless track laid in a clean room and electric power induced from the power line by a contact coil for electric power in a non-contact manner. A truck that travels on the track while performing the transfer, and a transport control device that performs communication between the truck and the transport to control the transport of the truck. A communication signal of a frequency obtained by performing digital modulation different from the frequency of the power,
A bogie operation system, wherein information about the conveyance is transmitted and received between the bogie and a conveyance control device by superimposing the information through the power pickup coil. 2. A plurality of loop-shaped power lines are provided so as to be adjacent to each other along one endless track, and the power lines are connected to each other at a portion where power supply from each of the power lines to the bogie is switched. The truck operation system according to claim 1, wherein the truck operation system is arranged so as to overlap.