JP4799284B2 - Telemetry system - Google Patents

Description

In the present invention, laser light is sent from a host device to a remote terminal device via an optical fiber, and a part of the laser light is photoelectrically converted on the terminal device side to drive an electric circuit, while using the above power. about telemetry system for measuring the operating state of the subject at a remote location from the host device side by using the data transmission system capable of transmitting the modulated transmission data do this to the host device.

2. Description of the Related Art Conventionally, for example, a system for monitoring the state of a monitoring target (for example, the value of an insulating oil level and the value of an insulating oil temperature) such as an oil-filled transformer located remotely from a host device is known (Patent Document 1, etc. reference).
In this type of monitoring system, the status of the oil-filled transformer at a remote location is monitored by the host device. The oil-filled transformer includes a monitoring circuit, an oil level sensor that detects the value of the insulating oil level, and the insulating oil temperature. And a data transmission circuit are provided. The monitoring circuit monitors the state of the transformer by taking a signal from the oil level sensor or the temperature sensor, and the data transmission circuit transmits the monitoring result to the host device.

  However, in the above monitoring system, since the transmission path of the monitoring result is configured by the electric signal cable, the host device may acquire an erroneous monitoring result due to noise mixing in the electric signal cable. In addition, since the electric signal cable is vulnerable to lightning strikes and easily deteriorates with time, it takes time and effort for maintenance.

In order to eliminate this inconvenience, the inventors of the present invention have less maintenance work than the conventional monitoring system using an electric signal cable, and can eliminate malfunction caused by external noise. Has previously proposed a monitoring system that can be constructed at low cost (see Patent Document 2). In this monitoring system, an optical signal switch that is driven by electric power obtained by photoelectrically converting laser light is provided on an optical fiber of the laser light, and the supply of drive power to the optical signal switch is controlled in the event of an abnormality. Thus, it is possible to know whether there is an abnormality in the remote facility on the host device side.
In addition, a system in which a control device is provided with a light source and an electric circuit of the sensor device is driven by light energy from the light source is also known (Patent Document 3). This technology can eliminate electromagnetic interference and reduce the weight of wiring between the sensor and the control device.
JP 2001-196231 A JP 2006-120008 A Japanese Patent Laid-Open No. 7-151563

By the way, there are cases where some remote facilities want to know not only the presence / absence of an abnormality, but also the quality level and risk level of operation in detail. However, in the technique described in Patent Document 1, the quality level and risk level of the operation cannot be detailed, and it cannot be said that sufficient monitoring is performed.
Further, in the technique of Patent Document 3, after converting light energy into electrical energy by a light-power converter, in order to further convert the electrical energy into light energy by an electrical-light converter (light emitting diode) at the time of data transmission, The energy conversion efficiency is extremely poor and is not suitable for application to a remote monitoring system.

In the present invention, laser light is sent from a host device to a remote terminal device via an optical fiber, and a part of the laser light is photoelectrically converted on the terminal device side to drive an electric circuit, while using the above power. providing a telemetry system using the data transmission system that can transmit this modulates the transmission data with very small power to the host device, for measuring the operating state of the target at a remote location from the host device With the goal.

The gist of the telemetry system of the present invention is (1) to (6).
(1)
A host device that acquires time-series optical data from a plurality of terminal devices, and the plurality of terminal devices that are remotely located from the host device. The host device is connected to the plurality of terminal devices via optical fibers. The laser light is transmitted, the plurality of terminal devices separate the optical fiber into two optical paths, the laser light received through one optical path is converted into electric power, and the laser light received through the other optical path Is a telemetry system that modulates the time-series optical data corresponding to transmission data and transmits the time-series optical data to the host device via the optical fiber or a data transmission-dedicated optical fiber,
The host device is
A laser device for generating the laser beam;
An optical data receiver for receiving the time-series optical data,
The plurality of terminal devices are:
An optical branching device for branching the laser light into the two optical paths;
A photoelectric converter that converts laser light received through the one optical path into electric power;
A liquid crystal light modulator that receives supply of electric power from the photoelectric converter and modulates laser light received via the other optical path into the time-series optical data;
A liquid crystal light modulator control circuit that receives power from the photoelectric converter and controls the liquid crystal light modulator with a modulation control signal;
A sensor for detecting the state of the measurement object;
With
In the plurality of terminal devices, the liquid crystal light modulator control circuit controls the liquid crystal light modulator, converts the detection result by the sensor into the time-series light data, and converts the time-series light data into the terminal device. Embedded in the identification data, and transmits the time-series optical data to the host device at a time interval randomly selected for each transmission,
The host device recognizes the identification data embedded in the time-series optical data received by the optical data receiver.
A telemetry system characterized by that.
(2)
The liquid crystal light modulator includes a liquid crystal device and a reflection mirror,
The liquid crystal device transmits laser light received through the other optical path according to transmission data, and the reflection mirror reflects the laser light that has passed through the liquid crystal device toward the liquid crystal device, and thus the host. By sending back to the device, the time-series optical data is transmitted to the host device.
The telemetry system according to (1), characterized in that:
(3)
The liquid crystal light modulator includes a liquid crystal device,
The liquid crystal device transmits the time-series light data to the host device by passing the laser light received through the other optical path according to transmission data and returning it to the host device.
The telemetry system according to (1) or (2), wherein
(4)
The laser device includes two laser light sources that generate power laser light and signal laser light having different wavelengths as the laser light,
The optical splitter transmits the power laser light to the photoelectric converter via the one optical path, and sends the signal laser light to the liquid crystal optical modulator via the other optical path. The telemetry system according to any one of (1) to (3).
(5)
Furthermore, the host device includes a data processing circuit that processes the time-series optical data received by the optical data receiver, and an information output device that outputs a processing result by the data processing circuit as image information and / or audio information. The telemetry system according to any one of (1) to (4), wherein

  In the present invention, a laser beam is sent from a host device to a remote terminal device via an optical fiber, and a part of the laser beam is photoelectrically converted on the terminal device side to drive an electric circuit, while using the above power. By driving the liquid crystal device on and off, the original laser light is modulated and returned to the host device as optical data, so that efficient optical data transmission can be performed with small energy.

<< First Embodiment >>
FIG. 1 is an explanatory diagram showing a first embodiment in which a data transmission system 1 of the present invention is applied to a telemetry system 2 of the present invention . In FIG. 1, a data transmission system 1 includes a host device 11, terminal devices 12 (k) (k = 1, 2,..., N) disposed remotely from the host device 11, and an optical amplifier 13. Thus, the telemetry system 2 includes the data transmission system 1, and a sensor 125, a data processing circuit 114, and an information output device 115 added to the system.
In FIG. 1, the host device 11 includes a laser device 111, an optical data receiver 112, and an optical amplification laser device 113. The laser device 111 is connected to the terminal device 12 (k through the optical fiber F _1. ) For the laser beam L (wavelength λ).
The optical amplification laser device 113 generates an optical amplification laser beam AL, and this optical amplification laser beam AL is an optical amplifier provided on the terminal device side on the optical fiber F ₁ through the optical amplification optical fiber F _2. 13 is sent out. The optical amplifier 13 can compensate for attenuation of propagating light in the optical fiber F ₁ .

The terminal device 12 (k) includes an optical branching device 121, a photoelectric converter 122 (P / E), a liquid crystal light modulator 123, a liquid crystal light modulator control circuit 124, and a sensor 125. The optical splitter 121 splits the laser light L transmitted through the optical fiber F ₁ into two optical paths, and a part of the laser light L (L _A ) propagating through one optical path is directed to the photoelectric converter 122. A part (L _B ) of the laser beam L that is transmitted and propagates through the other optical path is transmitted toward the liquid crystal light modulator 123.

The photoelectric converter 122 converts the received L _A power and supplies the power to the liquid crystal light modulator 123 and the liquid crystal light modulator control circuit 124. The liquid crystal light modulator control circuit 124 controls the liquid crystal light modulator 123 with a modulation control signal. The liquid crystal light modulator 123 receives power from the photoelectric converter 122 and transmits another part of the received laser light. Modulate to time-series optical data SD corresponding to the data. This transmission data is detection data such as the temperature detected by the sensor 125.

In the present embodiment, in the liquid crystal light modulator control circuit 124, identification data (ID) of the terminal device 12 (k) related to the liquid crystal light modulator control circuit 124 is recorded in a storage device (ROM or the like) (not shown). The liquid crystal light modulator control circuit 124 controls the liquid crystal light modulator 123 so that the identification data is embedded in the transmission data. Thereby, in the present embodiment, the identification data (ID) is embedded in the header of the time-series optical data SD.
The liquid crystal light modulator 123 is driven with extremely small power. Moreover, the laser light that is modulated by the liquid crystal light modulator 123 and returned to the host device 11 is light from the host device 11 that originally propagated through the optical fiber F ₁ and is not made from electrical energy. Therefore, unlike the technique described in Patent Document 3, there is no inconvenience that a large amount of power is required for signal transmission.
Thus the laser beam L _B which is modulated is a time-series light data SD, indicating the time-series light data SD is an optical fiber F ₁ or the data transmission-only optical fiber F ₃ (feed only optical fiber F ₃ by a broken line ) Is returned to the host device 11. The optical data receiver 112 provided in the host device 11 receives the time-series optical data SD, and the data processing device 114 restores it and outputs it as image information or audio information by the information output device 115.
The data processing device 114 has a function of extracting the identification data of the terminal device 12 (k) from the received time-series optical data SD from the header of the time-series optical data SD. It can be recognized which terminal device 12 (k) the signal is from.
<< Second Embodiment >>

FIG. 2 is an explanatory diagram of a second embodiment that embodies the telemetry system 2 of the first embodiment of FIG. In FIG. 2, the host device 11 further includes an optical separator 116. In FIG. 2, optical couplers 131 (m) (m = 1, 2,..., N−1) are provided on the terminal device 12 (k) side of the optical fiber F ₁ .
Laser light L (wavelength λ) conveyed from the laser device 111 toward the terminal device 12 (k) through the optical fiber F ₁ is incident on the optical coupler 131 (1), and the optical coupler 131 (1). Emits the laser beam L toward the terminal device 12 (1) and the optical coupler 131 (2).
As m = 2, 3,..., N-2, the laser light L sequentially incident on the optical coupler 131 (m) is directed toward the terminal device 12 (m) and the optical coupler 131 (m + 1). Sent out.
The laser beam L incident on the optical coupler 131 (N-1) is incident on the terminal device 12 (N-1) and the terminal device 12 (N).

The terminal device 12 (k) includes an optical branching device 121, a photoelectric converter 122 (P / E), a liquid crystal light modulator 123, a liquid crystal light modulator control circuit 124, and a sensor 125. The optical branching device 121 separates the incident laser light L into two optical paths. The laser beam L _A propagating through one of the optical paths separated into the two optical paths is sent to the photoelectric converter 122. The photoelectric converter 122 converts the energy of the received light into electric power, and this electric power is converted into the liquid crystal optical modulator 123. And supplied to the liquid crystal light modulator control circuit 124.

The laser beam L _B propagating the other separated light paths to the second optical path is sent toward the liquid crystal light modulator 123. The liquid crystal light modulator 123 includes a liquid crystal device 1231 and a reflection mirror 1232, and the liquid crystal device 1231 is controlled by a modulation control signal generated by the liquid crystal light modulator control circuit 124. That is, the liquid crystal device 1231 is activated by the electric power from the photoelectric converter 122, and is modulated and driven (on / off driving) by the modulation control signal corresponding to the transmission data. The laser beam L _B having passed through the liquid crystal device 1231 is reflected by the reflection mirror 1232, through the liquid crystal device 1231, and returned toward the light path coming based (optical fiber F ₁₎ to the host device 11.

The laser beam L _B is returned to the host device 11 is reflected by the reflecting mirror 1232, a time-series light data SD. The optical separator 116 of the host device 11 separates the time series optical data SD (transmission data) to the optical data receiver 112 side, and the optical data receiver 112 receives the time series optical data SD as in the first embodiment. Then, the data processing device 114 restores it and outputs it as image information or audio information by the information output device 115.
<< Third Embodiment >>

FIG. 3 is an explanatory diagram of a third embodiment that embodies the telemetry system 2 of the first embodiment of FIG. In the second embodiment of FIG. 2, a liquid crystal light modulator 123 configured by a liquid crystal device 1231 and the reflecting mirror 1232, but it returned to the host device 11 by reflecting the laser beam L _B having passed through the liquid crystal device 1231 mirrors 1232, in the present embodiment, the laser beam L _B having passed through the liquid crystal device 1231, and returned to the host device 11 via a data transmission-only optical fiber F _3.

In other words, in this embodiment, the liquid crystal light modulator 123 includes the liquid crystal device 1231. The liquid crystal device 1231 is modulated and driven (on / off drive) by the modulation control signal corresponding to the transmission data, and the laser beam that has passed through is coupled to the optical coupler. 131 (1), 131 (2), ..., are integrated by 131 (N-1), and returned to the host device 11 as time-series light data SD through the data transmission-only optical fiber F _3. As in the first embodiment, the optical data receiver 112 receives the time-series optical data SD, and the data processing device 114 restores it and outputs it as image information or audio information by the information output device 115.
<< 4th Embodiment >>

FIG. 4 is an explanatory diagram of a fourth embodiment in which the telemetry system 2 of FIG. 2 is modified. In FIG. 4, the laser device 111 includes two laser light sources 111A that generate power laser light L _A (wavelength λ _A ) and signal laser light L _B (wavelength λ _B ) having different wavelengths as the laser light L. 111B.
The optical splitter 121 separates the laser light L propagating through the optical fiber F ₁ into laser light L _A (wavelength λ _A ) and laser light L _B (wavelength λ _B ), and the reflection mirror 1232 is a liquid crystal device 1231. Is reflected toward the liquid crystal device 1231. The optical separator 116 of the host device 11 separates the time series optical data SD (transmission data) to the optical data receiver 112 side, and the optical data receiver 112 receives the time series optical data SD, and the data processing device 114. Is restored and output as image information or audio information by the information output device 115 (Fifth Embodiment)

FIG. 5 is an explanatory diagram of a fifth embodiment in which the telemetry system 2 of FIG. 3 is modified. In FIG. 5, a laser device 111 includes two laser light sources 1111 that generate power laser light L _A (wavelength λ _A ) and signal laser light L _B (wavelength λ _B ) having different wavelengths as the laser light L. 1112.
The optical branching device 121 separates the laser beam L _A (wavelength λ _A ) and the laser beam L _B (wavelength λ _B ). The laser light that has passed through the liquid crystal device 1231 is sent to the host device 11 via the data transmission dedicated optical fiber F ₃ .
<Specific example of liquid crystal light modulator control circuit>

6 and 7 are explanatory diagrams of the liquid crystal light modulator control circuit 124 of the terminal device 12. FIG. 8A is a data structure diagram of time-series optical data SD, and FIG. 8B is a diagram showing a bit stream of time-series optical data SD.
6 shows a case where the liquid crystal light modulator 123 composed of the liquid crystal device 1231 and the reflection mirror 1232 is driven, and FIG. 7 shows a case where the liquid crystal light modulator 123 composed of the liquid crystal device 1231 is driven. The operation of the control circuit 124 is the same.
6 and 7, the liquid crystal light modulator control circuit 124 includes a microprocessor 1241, an oscillator 1242, a switch circuit 1243, and a timer 1244. These are driven by receiving electric power from the photoelectric converter 122. Here, the photoelectric converter 122 generates the drive voltage V _D and drives the sensor 125 in addition to the liquid crystal light modulator control circuit 124.
The oscillator 1242 drives the liquid crystal device 1231 at the drive frequency (f _LCD ), and the microprocessor 1241 modulates the switch circuit 1243 at a frequency sufficiently lower than f _LCD .
The timer 1244 can be reset every transmission and count the time since the latest transmission.
The liquid crystal light modulator control circuit 124 can be configured to refer to the count value of the timer 1244 and control the liquid crystal light modulator 123 at time intervals to transmit the time-series light data SD to the host device 11. .
For example, the liquid crystal light modulator control circuit 124 transmits the time-series optical data SD to the host device 11 every time interval X seconds (time in the range of 60 to 90 seconds) selected at random for each transmission, for example. Can be configured.
Thereby, the host device 11 is less likely to receive the time-series optical data SD from a plurality of the terminal devices 12 (k) at the same time. Even if a plurality of terminal devices 12 (k) transmit time-series optical data SD at the same time and thus cannot perform normal reception, transmission of each terminal device 12 (k) is performed in the next reception. The timing of changes. Therefore, the possibility that the time-series optical data SD can be normally received is extremely high. The liquid crystal light modulator control circuit 124 may have a built-in timer with high accuracy, and the time interval (X seconds) may be changed every transmission time. Alternatively, the time interval (X seconds) may be changed for each transmission without a predetermined control.
Of course, the liquid crystal light modulator control circuit 124 does not always need to transmit the time-series optical data SD, and when the temperature detected by the sensor 125 changes within a certain range (good / bad level, risky range). The time-series optical data SD may be transmitted to the host device 11 by controlling the liquid crystal light modulator 123.

The data transmission system is an explanatory view of the first embodiment is applied to a telemetry system of the present invention. It is explanatory drawing of 2nd Embodiment which actualized the telemetry system of 1st Embodiment of FIG. FIG. 3 is an explanatory diagram of a third embodiment that embodies the telemetry system of the first embodiment of FIG. It is explanatory drawing of 4th Embodiment which deform | transformed the telemetry system of FIG. It is explanatory drawing of 5th Embodiment which modified the telemetry system 2 of FIG. It is explanatory drawing of the liquid crystal light modulator control circuit of the terminal device in the case of driving the liquid crystal light modulator which consists of a liquid crystal device and a reflective mirror. It is explanatory drawing of the liquid crystal light modulator control circuit of the terminal device in the case of driving the liquid crystal light modulator which is not provided with a reflective mirror. (A) is a data structure diagram of time-series optical data SD, and (B) is a diagram showing a bit stream of time-series optical data.

DESCRIPTION OF SYMBOLS 1 Data transmission system 2 Telemetry system 11 Host apparatus 12 (k) Terminal apparatus 114 Data processing circuit 115 Information output apparatus 111 Laser apparatus 112 Optical data receiver 113 Laser apparatus for optical amplification 122 Photoelectric converter 123 Liquid crystal light modulator 124 Liquid crystal Optical modulator control circuit 125 Sensor 121 Optical splitter 131 (m) Optical coupler 1241 Microprocessor 1242 Oscillator 1243 Switch circuit 1244 Timer

Claims (5)

And a host device for obtaining the series light data when a plurality of terminal devices, the composed and arranged the plurality of terminal devices in a remote location from the host device, said host device to said plurality of terminals via the optical fiber It sends a laser beam, wherein the plurality of terminal devices to separate the optical fiber to the second optical path to convert the laser light received via one of the optical path to the power, the laser light received via the other optical path Is a telemetry system that modulates the time-series optical data corresponding to transmission data and transmits the time-series optical data to the host device via the optical fiber or a data transmission-dedicated optical fiber,
The host device is
A laser device for generating the laser beam;
An optical data receiver for receiving the time-series optical data,
The plurality of terminal devices are:
An optical splitter for branching the laser beam into the second optical path,
A photoelectric converter that converts laser light received through the one optical path into electric power;
A liquid crystal light modulator that receives supply of electric power from the photoelectric converter and modulates laser light received via the other optical path into the time-series optical data;
A liquid crystal light modulator control circuit that receives power from the photoelectric converter and controls the liquid crystal light modulator with a modulation control signal;
A sensor for detecting the state of the measurement object;
With
In the plurality of terminal devices, the liquid crystal light modulator control circuit controls the liquid crystal light modulator, converts the detection result by the sensor into the time-series light data, and converts the time-series light data into the terminal device. Embedded in the identification data, and transmits the time-series optical data to the host device at a time interval randomly selected for each transmission,
The host device recognizes the identification data embedded in the time-series optical data received by the optical data receiver.
A telemetry system characterized by that. The liquid crystal light modulator includes a liquid crystal device and a reflection mirror,
The liquid crystal device transmits laser light received through the other optical path according to transmission data, and the reflection mirror reflects the laser light that has passed through the liquid crystal device toward the liquid crystal device, and thus the host. By sending back to the device, the time-series optical data is transmitted to the host device.
The telemetry system according to claim 1. The liquid crystal light modulator includes a liquid crystal device ,
The liquid crystal device transmits the time-series light data to the host device by passing the laser light received through the other optical path according to transmission data and returning it to the host device.
The telemetry system according to claim 1 or 2 , characterized in that The laser device includes two laser light sources that generate power laser light and signal laser light having different wavelengths as the laser light,
The optical splitter transmits the power laser light to the photoelectric converter via the one optical path , and sends the signal laser light to the liquid crystal optical modulator via the other optical path. The telemetry system according to any one of claims 1 to 3, wherein the telemetry system is characterized . Furthermore, the host device includes a data processing circuit that processes the time-series optical data received by the optical data receiver, and an information output device that outputs a processing result by the data processing circuit as image information and / or audio information. The telemetry system according to any one of claims 1 to 4, wherein

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