JP2001186063A - Power-line carrier communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power-line carrier communication system that can execute communication between a carrier on a track and a ground side on all the tracks even when a standing wave by a communication signal is in existence on feeder wires in power-line carrier communication. SOLUTION: A ground side communication transformer 41 is installed nearly in the middle between a start point Ta and an end point Tb of feeder lines 21, and a communication unit (not shown) at a ground side is connected to the feeder lines 21 via the ground side communication transformer 41. On the other hand, a carrier side communication transformer 50 is mounted on a carrier 100 on a track and a communication unit (not shown) at a carrier side is connected to the feeder lines 21 via the carrier side communication transformer 50. The length of the feeder lines 21 from the ground side communication transformer 41 to the start point Ta and to the end point Tb is a half the entire feeder lines 21 respectively, no node of a standing wave appears on the feeder lines 21 and then the communication on all the tracks can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power line carrier communication device for performing communication via a power supply line, and more particularly to a non-contact power supply device for supplying power to a moving body such as a carrier from a ground side in a non-contact manner. To a power line carrier communication device.

[0002]

2. Description of the Related Art Conventionally, unmanned factories have been promoted as a part of factory automation, and materials are transported on premises by unmanned transport vehicles.
According to a command from a control unit installed on the ground side, this transport vehicle travels on a track to the place where the material to be transported is placed, stops at a predetermined position, loads the material and reaches the destination. It is designed to be transported.

There is a so-called non-contact power supply device for supplying power to a transport vehicle from the ground side without directly contacting the transport vehicle as a power supply device for the transport vehicle. This power supply device is a primary-side circuit and power supply line that is installed on the ground side and generates a high-frequency magnetic field, and a secondary circuit that is mounted on the carrier and magnetically coupled to the primary-side power supply line. And supplies electric power from the primary side to the secondary side circuit in a non-contact state. In the case of this non-contact power supply device, unlike the so-called trolley power supply or the like, power is supplied in a non-contact manner, so that maintenance work for brushes and the like is unnecessary, and above all, dust and dust due to contact with the running brushes and the like are eliminated. There is no generation of dust and the like, which is convenient for application in a clean atmosphere such as a clean room.

FIG. 8 schematically shows a primary side of a non-contact power supply device to which a conventional power line communication device is applied. In FIG. 1, reference numeral 10 denotes a high-frequency power supply that generates a high-frequency current. A power supply line 20 is supplied with a high-frequency current from the high-frequency power supply 10 to generate a magnetic field. The feeder line 20 is folded near the middle thereof, and the one line 20A and the other line 20B up to the turn point (termination Tb) are formed as a pair of parallel lines on a track 30 which is a traveling path of the carrier. It is attached. The end of the power supply line 20 is connected to the high-frequency power supply 10, and each line 20A, 20A
B is supplied with a high-frequency current having a phase difference of 180 degrees.

[0005] On the power supply line 20 near the high-frequency power supply 10,
A ground-side communication transformer 40 of a communication device (not shown) installed on the ground is magnetically coupled and arranged. On the other hand, a carrier on the track 30 is equipped with a carrier-side communication transformer 50 magnetically coupled to the power supply line 20.
A communication device (not shown) on the carrier side is connected to the power supply line 20 via the communication transformer 50. As described above, the power line carrier communication device uses the power supply line of the non-contact power supply device as a transmission path for communication signals, and the power supply line includes communication between the communication devices on the ground side and the carrier side. The transformer is magnetically coupled.

According to this power line communication device, when communication is performed between the ground side and the carrier side, a frequency component representing a logical value "0" and a frequency component representing a logical value "1" are communicated. The power is superimposed on the power component on the feed line via a transformer, and the code is transmitted by combining these frequency components. Here, for example, the logical value “0” is several hundreds of kHz.
Corresponding to the lower order of the frequency of the z order, the logical value “1”
Is associated with a higher frequency.

[0007]

By the way, the feeder line 20
When the line length up to the turnback point is close to one-half wavelength of the communication signal, there is a problem that a standing wave due to the communication signal is generated on the feeder line 20, and an area where communication is impossible occurs on the track.

This mechanism will be described with reference to FIGS. 9 and 10. The feeder line 20 shown in FIG. 8 forms a distributed constant circuit, and as shown in FIG.
This is equivalent to a short circuit of the terminal Tb of the parallel line composed of Therefore, reflection occurs at the end Tb, and the start T
When the line length between a and the end Tb becomes approximately a quarter wavelength of the communication signal, as shown in FIG. 10, the standing of the communication signal (communication current) having a node (resonance point) near the start end Ta. Waves are generated. As a result, as shown in FIG. 9, when the transport vehicle 100 is located near the start end Ta, the transport vehicle 100 cannot receive a communication signal from the ground side.

For example, when the frequency of a communication signal is set to around several hundred kHz as described above, the wavelength is at least 1000 m or more in a vacuum, but the propagation speed is reduced inside the power supply line. It is reduced to about 3/5. As a result, depending on the setting of the frequency of the communication signal, when the line length between the start end Ta and the end Tb becomes about 100 m, a standing wave appears on the line, and the area where the power line carrier wave communication becomes impossible is on the orbit. Occurs.

To avoid this, the line length of the power supply line may be changed. However, if the power supply line is lengthened, power loss may increase, which may hinder power supply.
If the power supply line is divided and shortened, there is an inconvenience that the configuration of the device becomes complicated.

[0011] The present invention has been made in view of the above circumstances, and even when a standing wave due to a communication signal is present on a feeder line in power line carrier communication, the carrier between a carrier on a track and the ground side. It is an object of the present invention to provide a power line communication device capable of performing communication on all orbits.

[0012]

In order to solve the above-mentioned problems, the present invention has the following arrangement. That is, the present invention supplies AC power to a power supply line (for example, a component corresponding to a power supply line 21 described later) attached to a track of a moving body (for example, a component corresponding to a transport vehicle 100 described later), and A non-contact power supply device for performing non-contact power supply to a moving body, wherein the power line carrier communication device performs communication between the ground side and the moving body via the power supply line, and is magnetically coupled to the power supply line. A communication transformer provided on the ground side (for example, a component corresponding to a ground-side communication transformer 41 to be described later) is disposed substantially at the center between the start end and the end of the power supply line. Power line carrier communication is performed with a magnetically coupled communication transformer (for example, a component corresponding to a carrier-side communication transformer 50 described later) mounted on the moving body.

According to this configuration, the ground-side communication transformer is located substantially at the center between the start end and the end of the power supply line, so that the line length of the power supply line viewed from the ground-side communication transformer is equal to the power supply line length. It is approximately half of the total line length of the electric wire. For this reason, the line length of the feed line (parallel line) is, for example, ４ of the communication signal.
Even if it is the wavelength, the line length of the feed line viewed from the communication transformer on the ground side becomes smaller than a quarter wavelength of the communication signal,
The effect of standing waves does not appear. That is, according to this configuration,
If the line length from the beginning to the end of the feed line is less than half the wavelength of the communication signal, there will be no resonance point of the standing wave on the feed line, and communication over the entire orbit will be possible. Become.

Further, according to the present invention, AC power is supplied to a power supply line (for example, a component corresponding to a power supply line 22 described later) attached to a track of a moving body (for example, a component corresponding to a transport vehicle 100 described later). A non-contact power supply device for performing non-contact power supply to the moving body, wherein the power line carrier communication device for performing communication between the ground side and the moving body via the power supply line; (For example, a ground-side communication transformer 42 described later)
A, 42B) on the ground side,
Each of them is disposed at the start end and the end side of the power supply line, and is magnetically coupled to the power supply line and mounted on the moving body (for example, a carrier-side communication transformer 5 described later).
Power line carrier communication is performed between the power line communication device and a component corresponding to 0.

According to this configuration, the two communication transformers on the ground are located at both ends of the feeder line (parallel line), respectively, so that the waveforms of the communication signals output from the respective communication transformers are superimposed. For this reason, the line length of the feed line is
Even if a standing wave appears as a quarter wavelength of a communication signal, communication in an area where communication cannot be performed by one communication transformer is supplemented by the other communication transformer, and the effect of the standing wave is reduced. It does not appear. That is, according to this configuration, if the line length of the feed line is less than half the wavelength of the communication signal, a node (resonance point) of a standing wave does not appear on the line of the feed line, and Communication becomes possible in all areas.

Further, a line length of the power supply line is less than a half wavelength of a communication signal transmitted through the power supply line. According to this configuration, the resonance point does not exist on the feeder line for the set frequency of the communication signal, and the power line carrier communication can be performed in the entire area on the track. That is, even if the frequency of the communication signal is arbitrarily set, the power line carrier communication can be performed over the entire orbit by setting the line length of the power supply line to less than half the wavelength of the communication signal.

Still further, a half wavelength of a communication signal transmitted through the power supply line is longer than a line length of the power supply line. According to this configuration, there is no resonance point on the line of the feed line for the set line length of the feed line, and power line carrier communication can be performed over the entire area on the track. That is, even if the line length of the power supply line is arbitrarily set, by making the half wavelength of the communication signal longer than the line length of the power supply line, power line carrier communication can be performed over the entire area on the track.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a non-contact power supply device according to an embodiment of the present invention will be described with reference to the drawings. In each drawing, common elements are denoted by the same reference numerals,
The description is omitted as appropriate.

<First Embodiment> FIG. 1 schematically shows a configuration of a ground-side (primary circuit) of a non-contact power supply device to which a power line communication device according to a first embodiment is applied. In FIG. 1, reference numeral 10 denotes a high-frequency power supply that generates a high-frequency current. Reference numeral 21 denotes a power supply line to which a high-frequency current is supplied from the high-frequency power supply 10 to generate a magnetic field. This feeder line 21 is folded back near its middle to form a line 21
A and a track 21B form a parallel track, which is attached to a track 30 which is a traveling path of a carrier (not shown).

That is, the start end Ta of this parallel line is connected to the high frequency power supply 10, and its end Tb is short-circuited to each other via a resistance of 0 ohm. Also, the track 21A
And the line 21B has a phase of 18
High-frequency currents different by 0 degrees are supplied, and high-frequency currents in opposite directions flow. However, if the power supply line 21 is viewed as a single line, these currents are in phase.

A substantially central portion between the start end Ta and the end Tb of each of the lines 21A and 21B is drawn out of the track 30, and a communication device ( Ground side communication transformer 4 (not shown)
1 are magnetically coupled. That is, the ground-side communication transformer 41 is disposed substantially at the center of the power supply line 21. On the other hand, a carrier (not shown) on the track 30 is
A carrier-side communication transformer 50 magnetically coupled to the vehicle is mounted, and a carrier-side communication device (not shown) is connected to the power supply line 21 via the communication transformer 50.

Here, as shown in FIG. 2A, the ground-side communication transformer 41 is magnetically coupled to the lines 21A and 21B at the leading portions of the lines. Primary winding 41 of this ground-side communication transformer 41
A is supplied with a current having a frequency corresponding to the communication signal, and this current induces currents in opposite directions to the line 21A and the line 21B.

As shown in FIG. 2B, the carrier-side communication transformer 50 includes a feeder line 21 attached to the track 30.
(Lines 21A and 21B) are magnetically coupled to
A and the secondary winding 5 due to the current flowing through the line 21B.
A current in the same direction is induced at 0A. The carrier-side communication transformer 50 is connected to the power supply line 21 as the carrier moves.
It moves along the feed line 21 in a state where it is magnetically coupled.

In the first embodiment, the line length of the feed line 21 is referred to as the line 21A and the line 21A.
B represents the line length of the parallel line, and the beginning of the feed line 21 represents the start end Ta of the parallel line, and the end of the feed line 21 represents the end Tb of the parallel line. Shall be. Further, it is assumed that the line length of the power supply line 21 is substantially a quarter wavelength of the communication signal.

Next, an operation of the power line communication device according to the first embodiment will be described with reference to FIGS. A high-frequency current as power is supplied to the power supply line 21 from the high-frequency power supply 10 in advance.
, A high-frequency magnetic field is generated. Further, as in the above-described conventional technology, communication between the ground side and the carrier side is performed by:
This is performed by superimposing the lower frequency component corresponding to the logical value “0” and the upper frequency component corresponding to the logical value “1” on the power.

First, the vehicle 10 on the track 30 from the ground side
When a communication signal is sent to 0, the ground-side communication device outputs a communication signal to the power supply line 21 via the ground-side communication transformer 41. As a result, the communication signal from the ground is superimposed on the waveform of the high-frequency current from the high-frequency power supply 10 and
Transmitted over.

Here, when viewed from the ground-side communication transformer 41, each line length from the start point Ta to the end point Tb of the power supply line is approximately one-eighth the wavelength of the communication signal. Even if a reflected wave is generated by the signal, the node (resonance point) of the standing wave is, as shown in FIG.
It does not appear on the feed line 21. Therefore, the transport vehicle 100
Is located on the track 30, no matter where it is located.
The communication signal is guided to the carrier-side communication transformer 50 mounted on the vehicle, and the communication signal from the ground side can be received.

Conversely, when a communication signal is transmitted from the carrier 100 to the ground, the line length between the carrier 100 and the ground-side communication transformer 41 is always shorter than a quarter wavelength. Therefore, no standing wave node appears near the ground-side communication transformer 41. Therefore, no matter where the carrier is located on the track 30, the ground-side communication device can receive the communication signal from the carrier. Therefore, there is no area where communication is not possible on all orbits. Embodiment 1
According to this, communication on all orbits becomes possible without complicating the configuration of the device.

In the first embodiment, the line length of the feeder line 21 is set to a quarter wavelength of the communication signal. However, when viewed from the ground-side communication transformer 41, the start end Ta and the end T
It is sufficient that the line length up to b is less than a quarter wavelength of the communication signal. Therefore, the line length of the feed line 21 (parallel line) can be set arbitrarily to less than half the wavelength of the communication signal. . In other words, it is sufficient that a half wavelength of the communication signal transmitted via the power supply line 21 is longer than the line length of the power supply line 21.

<Second Embodiment> Next, a second embodiment of the present invention will be described. FIG. 5 schematically shows a configuration of a primary circuit of a non-contact power supply device to which the power line communication device according to the second embodiment is applied. This non-contact power supply apparatus supplies AC power to a power supply line attached to a track on which a carrier travels, and performs contact power supply to the carrier on the track, similarly to the first embodiment. Things.

In FIG. 1, reference numeral 10 denotes a high-frequency power supply for generating a high-frequency current, and reference numeral 22 denotes a power supply line to which a high-frequency current is supplied from the high-frequency power supply 10 to generate a magnetic field. The power supply line 22 is folded in the vicinity of the middle thereof to form a parallel line from the line 22A and the line 22B as in the first embodiment, and is attached to the track 30.

That is, the start end Taa of this parallel line is connected to the high-frequency power supply 10, and the end end Tbb is drawn out of the track 30 and short-circuited to each other. Also, track 2
High-frequency currents having a phase difference of 180 degrees are supplied from the high-frequency power supply 10 to the line 2A and the line 22B, respectively, and high-frequency currents in opposite directions flow through the line 22A and the line 22B. However, if the power supply line 21 is viewed as a single line, these currents are in phase.

Reference numerals 42A and 42B denote ground-side communication transformers, which are the starting ends T of the lines 22A and 22B.
They are arranged on the aa side and the end Tbb side, respectively, and are magnetically coupled to the feeder line 22. That is, two communication transformers 42A and 42B are provided on the ground side, and are arranged at the start end and the end side of the power supply line, respectively. A communication signal is commonly supplied to these ground-side communication transformers 42A and 42B from a ground-side communication device (not shown), and the ground-side communication devices are connected to the ground-side communication transformers 42A and 42B.
It is connected to the power supply line 22 via 2B. The ground-side communication transformers 42A and 42B have the same structure as the ground-side communication transformer 41 shown in FIG. In FIG. 5, reference numeral 50 denotes a carrier-side communication transformer provided in the communication device mounted on the carrier, which is shown in FIG. 2B described above.

In the second embodiment, the line length of the feed line 22 is referred to as the line length of the line 22A and the line length of the line 22A.
B indicates the line length of the parallel line, and the start of the feed line 22 indicates the start end Taa of the parallel line, and the end of the feed line 22 indicates the end Tbb of the parallel line. Shall be. Further, it is assumed that the line length of the power supply line 22 is substantially a quarter wavelength of the communication signal.

The operation of the power line communication device according to the second embodiment will be described below with reference to FIGS. A high-frequency current as power is supplied to the power supply line 22 from the high-frequency power supply 10 in advance.
It is assumed that a high-frequency magnetic field is generated around 2.
Similarly to the above-described conventional technology, the communication between the ground side and the carrier side uses the lower frequency component corresponding to the logical value “0” and the upper frequency component corresponding to the logical value “1” in power. It is performed by superimposing on.

First, the transport vehicle 10 on the track 30 from the ground side
When a communication signal is sent to 0, the ground-side communication device outputs the communication signal to the power supply line 22 via the ground-side communication transformers 42A and 42B. Thus, the communication signal from the ground is superimposed on the waveform of the high-frequency current from the high-frequency power supply 10 and transmitted on the power supply line 22.

At this time, the end Tbb of the parallel line is viewed from the ground-side communication transformer 42A installed on the start end Taa side.
The line length up to is approximately a quarter wavelength of the communication signal,
As shown in FIG. 7A, a node (resonant point) of a standing wave due to a communication signal (communication current) from the ground-side communication transformer 42A is generated near the starting end Taa where the ground-side communication transformer 42A is installed. I do.

On the other hand, when viewed from the ground-side communication transformer 42B installed on the end Tbb side, the line length from the parallel line to the start end Taa is also about a quarter wavelength of the communication signal in the same manner. As shown in FIG.
A node (resonance point) of a standing wave due to a communication signal (communication current) from the ground-side communication transformer 42B is generated near the terminal Tbb where B is installed.

Here, the ground-side communication transformers 42A, 42
The standing waves due to the respective communication signals from B are combined on the feed line 30. As a result, the node of one standing wave is supplemented by the other standing wave, and the node (resonance point) of the standing wave does not become apparent over the entire area of the feed line 22 as shown in FIG.
Therefore, the transport vehicle 100 can receive a communication signal from the ground side regardless of where it is located on the track 30.

Considering a case where a communication signal is transmitted from the carrier 100 to the ground, a node of a standing wave by the communication signal transmitted from the carrier 100 is connected to the ground-side communication transformer 4.
Even if it exists on either side of 2A or 42B, it does not exist on the other side, so the communication signal from the carrier is received by either the ground-side communication transformer 42A or 42B. Therefore, the communication device on the ground side can receive a communication signal from the carrier regardless of where the carrier is located on the track 30. Therefore, there is no area where communication is not possible on all orbits. According to the first embodiment, it is possible to cope with a line length of less than a half wavelength of a communication signal, and communication with a high SN ratio can be performed on all orbits.

In the second embodiment, the line length of the power supply line 22 is set to approximately one-quarter wavelength of the communication signal.
It is sufficient that the line length is less than approximately one-half wavelength of the communication signal. Therefore, the line length of the power supply line 22 can be arbitrarily set to be less than approximately one-half wavelength of the communication signal. In other words, it is sufficient that the half wavelength of the communication signal transmitted via the power supply line 22 is longer than the line length of the power supply line 22.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described first and second embodiments, and there are design changes and the like within a range not departing from the gist of the present invention. Are also included in the present invention. For example, in each of the above-described embodiments, the line length of the power supply lines 20 and 21 is set to approximately one quarter wavelength of the communication signal. However, the present invention is not limited to this. May be set appropriately according to the orbit length of the transport system.

In the first embodiment, the power supply line 2
Although the ground-side communication transformer is installed substantially at the center of the device 1, as a modified example, a plurality of ground-side communication transformers may be provided between the start end Ta and the end Tb. Thereby, the S / N ratio of the communication signal can be improved. Further, the above-described first and second embodiments may be combined to install the ground-side communication transformer at the start end, the end, and the center of the feeder line.
As a result, a better SN ratio can be obtained.

[0044]

As described above, according to the present invention, the power supply line and the magnetic field are provided substantially at the center between the start and end of the power supply line attached to the track, or at the start and end of the power supply line. Since the ground-side communication transformer coupled to is installed, the nodes of the standing wave do not appear over the entire area of the feeder line.Therefore, in the case where the standing wave due to the communication signal exists on the feeder line in the power line carrier communication, Also, communication between the carrier on the track and the ground side can be performed on the entire track.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a non-contact power supply device to which a power line communication device according to Embodiment 1 of the present invention is applied.

FIG. 2 is a circuit diagram showing a configuration of a ground-side communication transformer and a carrier-side communication transformer of the power line carrier communication device according to Embodiment 1 of the present invention.

FIG. 3 is a diagram for explaining an operation of the power line carrier communication device according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a waveform of a standing wave on a power supply line by the power line carrier communication device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a non-contact power supply device to which a power line communication device according to Embodiment 2 of the present invention is applied.

FIG. 6 is a diagram for explaining an operation of the power line carrier communication device according to Embodiment 2 of the present invention.

FIG. 7 is a diagram showing a waveform of a standing wave on a power supply line by the power line carrier communication device according to Embodiment 2 of the present invention.

FIG. 8 is a diagram illustrating a configuration of a non-contact power supply device to which a power line carrier communication device according to a conventional technique is applied.

FIG. 9 is a diagram for explaining the operation of the power line carrier communication device according to the related art.

FIG. 10 is a diagram showing a waveform of a standing wave on a power supply line by a power line carrier communication device according to the related art.

[Explanation of symbols]

 10: high-frequency power supply 21, 22: power supply line 21A, 21B, 22A, 22B; line (parallel line) 30: track 41, 42A, 42B; terrestrial communication transformer 41A: primary winding of terrestrial communication transformer 50A; Secondary winding 50 of the vehicle-side communication transformer 50; Carrier-side communication transformer 100; Carrier Ta, Taa; Starting end Tb, Tbb; Ending

Continuation of the front page (72) Inventor Atsushi Okuno 100 Takekahana-cho, Ise City, Mie Prefecture Shinko Electric Co., Ltd. Ise Works F-term (reference) 5K046 AA03 CC09 CC17 CC23 PP01 PS09 PS17 PS31 PS51 YY04

Claims (4)

[Claims] 1. A non-contact power supply apparatus for supplying AC power to a power supply line attached to a track of a moving body to perform non-contact power supply to the moving body, wherein the non-contact power supply apparatus includes: In a power line carrier communication device for performing communication with a moving body, a communication transformer magnetically coupled to the power supply line and provided on the ground side is disposed substantially at a center between a start end and an end of the power supply line. And a power line carrier communication device for performing power line carrier communication with a communication transformer mounted on the mobile body by being magnetically coupled to the power supply line. 2. A non-contact power supply device for supplying AC power to a power supply line attached to a track of a moving body to perform non-contact power supply to the moving body, wherein the non-contact power supply device is connected to the ground via the power supply line. In a power line carrier communication device that performs communication with a moving body, two communication transformers magnetically coupled to the power supply line are provided on the ground side, and each of the communication transformers has a start end side and an end side of the power supply line. And a power line carrier communication device for performing power line carrier communication with a communication transformer mounted on the mobile body by being magnetically coupled to the power supply line. 3. The power supply line according to claim 1, wherein a line length of the power supply line is less than a half wavelength of a communication signal transmitted through the power supply line. Power line carrier communication device. 4. The power supply line according to claim 1, wherein a half wavelength of a communication signal transmitted through the power supply line is longer than a line length of the power supply line. Power line carrier communication device.