JP2001223618A - Truck running system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a truck running system that enables communication of high reliability between a communication device installed on the ground and a truck. SOLUTION: The truck running system is provided with a track installed at a prescribed position, a truck 3 that runs along this track to carry a cargo, a looped feeder 2 that is wired along the track, a power supply 1 that supplies power to the feeder 2, a communication device 4 that transmits/receives a communication signal to/from the truck 3 via the feeder 2 for the communication purpose, and a capacitor 15 that is provided between two points of the feeder 2. The truck 3 is provided with communication means 10, 11, 12, 13, 14 that transmit/receive the communication signal to/from the communication device 4 via the feeder 2.

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 controlling the operation of a truck by communication between a truck running on a track laid inside a clean room or the like and a communication device installed on the ground.

[0002]

2. Description of the Related Art A semiconductor wafer process performed in a clean room is a batch process of hundreds of processes. For this batch process, at an early stage, an operator transports a wafer cassette to each processing apparatus. Was. But,
Workers are the largest source of contamination, and therefore, in order to improve production yield, the transfer of wafer cassettes in a clean room is automated. That is, a track is laid in the clean room, and along this track,
A transport system for automatically transporting a wafer cassette by moving a cart carrying a wafer cassette is also one method.

[0003] In the case of the transport system of this track traveling vehicle, since the generation of dust is disliked in the clean room, the non-contact type current collecting mechanism that does not generate abrasion powder by a brush or the like is used to supply power to the vehicle.

On the other hand, the control of the bogie is also performed by a control device installed on the ground. That is, similarly to the power line carrier communication, the control device includes a communication device, and the communication device and the bogie exchange signals via the power supply line.

That is, a feeder line connected to a power supply is wired along the track on both sides of the track or on one side of the branch road. A communication device installed on the ground superimposes a communication signal on a power supply line and communicates with a bogie traveling on a track.

As described above, since the devices in the clean room do not like dust generation, the power supply is often installed on a floor separate from the clean room, and the distance between the track and the power supply is tens to hundreds of meters away. Sometimes. In this case, in order to suppress the power loss and the inductance component in the power transmission section of the power supply line from the power supply to the track, the power transmission section is a coaxial cable or a twisted pair cable.

[0007]

However, the above prior art has the following problems. That is, the coaxial cable or the twisted pair cable has a larger inter-line stray capacitance than the parallel line, and the inter-line stray capacitance of the power transmission unit which is a coaxial cable or a twisted pair cable and the track portion (the feeder line) Resonance may occur due to the inductance of the portion wired along the track). When the frequency of the resonance overlaps the frequency band of the communication signal, there is a problem that the reliability of communication is reduced.

The present invention has been made in order to solve the above-mentioned problem, and has as its object to provide a truck operating system capable of highly reliable communication.

[0009]

According to a first aspect of the present invention, there is provided a track laid at a predetermined position, a truck for transporting a conveyed object traveling along the track, and a track along the track. A power supply for supplying power to the power supply line, a communication device for transmitting or receiving a communication signal for communication with the bogie via the power supply line, and a power supply line for the power supply line. A bogie operating system comprising: a capacitor provided between two points, wherein the bogie has communication means for transmitting or receiving a communication signal for communication with a communication device via a power supply line. is there.

According to a second aspect of the present invention, the capacitor is provided at a position where a track portion, which is a portion along a track of a power supply line, and a power transmission portion for transmitting power from a power source to the track portion are connected. The trolley | bogie operation system of Claim 1 characterized by the above-mentioned.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a truck operation system according to an embodiment of the present invention will be described below with reference to FIG. Symbol 1 is, for example, 10 to 200 A (ampere), 1 to 10
A power supply that outputs 0 kHz (kilohertz) AC,
The power supply 1 is connected to a loop-shaped power supply line 2 of, for example, 400 m (meter). The power supply line 2 includes a track portion 2a that is a portion wired along a track on which the truck 3 travels, and a power transmission portion 2b that transmits power to the track portion 2a.
It is composed of

Reference numeral 4 denotes a communication device. The communication device 4 is connected to the power supply line 2 in a non-contact manner, and superimposes a communication signal on the power supply line 2. The communication device 4 includes a pickup coil 5 for transmission,
A pickup coil 6 for reception, a host computer 7, a modulator 8 for digitally modulating a communication signal from the host computer 7 and outputting the modulated signal to a pickup coil 5 for transmission, and a pickup coil 6 for reception from the power supply line 2. And a demodulator 9 for demodulating a communication signal inputted through the interface and sending the demodulated signal to the host computer 7.

The carriage 3 is also connected to the power supply line 2 in a non-contact manner. That is, the truck 3 digitally modulates a transmission pickup coil 10 for superimposing a communication signal on the power supply line 2, a pickup coil 11 for reception, a truck computer 12, and a communication signal from the truck computer 12. Modulator 13 for outputting a signal to pickup coil 10 for transmission, and pickup coil 11 for reception
Demodulates the communication signal guided to the trolley side computer 1
And a demodulator 14 for sending the signal to the demodulator 2.

The frequency of the communication signal is set to a frequency higher than the frequency output from the power supply 1. That is, 10 to 100 kHz or more is used for communication from the communication device 4 fixed on the ground to the trolley 3 moving on the track, and 10 to 100 kHz or more is used for communication from the trolley 3 to the communication device 4. Therefore, the frequency of the communication signal transmitted from the modulator 8 in the communication device 4 fixed on the ground via the pickup coil 5 for transmission is set to 10 to 100 kHz or more,
The frequency of a communication signal transmitted from the modulator 13 in the truck 3 moving on the track via the pickup coil 10 for transmission is 10 to 100 kHz or more. The demodulator 9 in the communication device 4 fixed on the ground is 10 to 100 kHz.
The above communication signal is demodulated, and the demodulator 14 in the carriage 3 moving on the track demodulates the communication signal of 10 to 100 kHz or more. Each of the demodulators 9 and 14 is provided with a band-pass filter that separates and passes a specific frequency.

The transmission pickup coil 10 and the reception pickup coil 11 of the truck 3 are also used as a power pickup coil for inducing electric power for traveling of the truck 3 from the power supply line 2. That is, the cart 3
Is supplied with power for traveling via pickup coils 10 and 11. With such a configuration, it is possible to reduce the number of parts constituting the truck 3, simplify the configuration, and reduce the cost of the truck 3.

The frequency of the communication signal sent from the modulator 8 or 13 to the feed line 2 is determined in consideration of the Radio Law. Further, it is determined according to the entire length of the power supply line 2 that the communication becomes impossible due to reflection or phase difference due to the wavelength becoming too short. Further, the frequency is set higher than the frequency of the power supply 1 so as not to be affected by the frequency of the power transmitted from the power supply 1.

That is, in order to avoid the interference with the return signal, the wavelength of the communication signal must be in principle a loop-shaped feed line 2.
It is sufficient if the length is at least four times the length of the power supply 52 and the length of the power transmitted from the power supply 1.

In the feeder line 2, a parallel line is used for the track portion 2a wired along the track, and a coaxial cable or a twisted pair cable is used for the power transmission portion 2b connecting the power source 1 and the track portion 2a. Is done.

For example, a coaxial cable and a twisted pair cable have a small inductance and a large stray capacitance. Conversely, the inductance of the parallel lines is large and the stray capacitance is small. Therefore, the inductance of the feeder line 2 is dominated by the inductance of the portion of the track portion 2a which is wired along the track and uses parallel wires, and the stray capacitance is power transmission using a coaxial cable or a twisted pair cable. The stray capacitance of the portion 2b is dominant. Therefore, feed line 2
Is determined by the inductance of the parallel wire and the capacity of the coaxial cable or the twisted pair cable.

A capacitor 15 is provided between the two tracks of the track section 2a, which is closest to the point where the track section 2a using parallel wires is connected to the power transmission section 2b using coaxial cable or twisted pair cable. ing. This capacitor 15 increases the capacitance component of the power supply line 2 and lowers the resonance frequency, so that the resonance frequency of the power supply line 2 can be separated from the communication signal frequency band.

FIG. 2 is a view of the track 16 on which the truck 3 travels as viewed from above. The carriage 3 travels along a track 16. Electric power for traveling is obtained from the track portion 2a of the feeder line 2 provided on both sides of the track 16. At the same time, the traveling trolley 3 and the communication device 4 fixed on the ground communicate via the power supply line 2.

FIG. 3 is a sectional view of the truck 3 traveling on the track 16. The cross section of the track 16 is substantially U-shaped, and L-shaped guide rails 17 are provided symmetrically on the left and right surfaces of its inner surface. Further, on the inner surface of the track 16, above the guide rail 17, there are provided a total of four feeder line supporting members 18 made of an insulating material, two on each side, upper and lower. These feeder line support members 18 support the track portion 2 a of the feeder line 2.

A caster 19 is provided at the bottom of the trolley 3, and the trolley 3 runs on the track 16 by the casters 19. Support arms 20 are provided on the left and right sides of the trolley 3, and guide rollers 21 that contact the guide rails 17 of the track 16 are provided on these support arms 20.
Therefore, when the truck 3 branches and runs, the guide rollers 21
The right branch or the left branch is determined by raising and lowering. A load 22 such as a wafer cassette is loaded on the carriage 3.

Pick-up means 23 is provided on the left and right side surfaces of the cart 3. This pickup means 23
Is constituted by an E core wound with a pickup coil (not shown). E of the pickup means 23
The core groove 23a is fitted with the track 2a of the power supply line 2.
The pickup means 23 is provided from the track portion 2a of the feed line 2
Electric power for traveling is obtained by electromagnetic induction, and a transmission / reception signal such as a control signal superimposed on the power supply line is also transmitted to the power supply line 2.
From the track portion 2a.

The track portion of the feeder line is provided only on one side of the truck 3, that is, on the right or left side, at the branch position on the track 16, and the truck 3 receives power supply from only one side. , And a communication signal is transmitted and received on only one side.

[0026]

According to the present invention, since the resonance frequency of the power supply line can be separated from the frequency band of the communication signal, highly reliable communication can be performed.

[Brief description of the drawings]

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

FIG. 2 is a view of a track 16 on which the cart 3 travels as viewed from above.

FIG. 3 is a sectional view of the truck 3 traveling on a track 16;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Power supply 2 Power supply line 2a Track part 2b Power transmission part 3 Dolly 4 Communication device 5, 6 Pickup coil 7 Host computer 8 Modulator 9 Demodulator 10, 11 Pickup coil (communication means) 12 Dolly side computer (communication means) 13 Modulator (Communication Means) 14 Demodulator (Communication Means) 15 Capacitor 16 Track 17 Guide Rail 18 Feeding Line Support Member 19 Caster 20 Support Arm 21 Guide Roller 22 Load 23 Pickup Mean 23a E Core Groove

Claims (2)

[Claims] 1. A track laid at a predetermined position, a truck for transporting a conveyed object running along the track, a loop-shaped power supply line wired along the track, A power supply that supplies power to the electric wire, a communication device that transmits or receives a communication signal for communication with the bogie via the power supply line, and a capacitor provided between two points of the power supply line, The bogie operation system, wherein the bogie includes communication means for transmitting or receiving a communication signal for communication with a communication device via a power supply line. 2. The capacitor is provided at a position where a track portion, which is a portion along a track of a power supply line, and a power transmission unit that transmits power from a power source to the track portion are connected. The truck operation system according to claim 1.