JPS6233540B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a method (synonymous with a method) of detecting information via an optical transmission body placed in an area where information is to be detected.
In particular, the present invention relates to an information detection method that can be applied to, for example, fluid leakage detection in a long transportation path, light leakage detection in an optical transmission path, etc.

<Prior art and its problems> Conventionally, in oil transmission pipelines, electric cables whose dielectric constant changes depending on the oil are installed along the pipelines, and this is used as an oil leak detection line to detect electricity caused by oil leaks. There are devices that detect oil leak accidents by monitoring changes in impedance that occur in the cable at the end of the cable, and electric devices that use a spring-loaded rod to press down due to the weight of oil leaks collected in an oil sump to indicate oil leaks. Some systems detect oil leaks by placing spring-structured detectors with closed contacts at each detection point along the length of the pipeline, but in the former case, it is possible to identify changes in cable impedance. Since it is difficult to increase the amount of change, it must be detected by converting it into a pulse.Moreover, even if the detection signal is converted into a pulse in this way, it will be affected by loss due to electric cables and external noise added to it. However, the pulses do not travel far enough, and therefore, by installing such a means in a long oil pipeline, it has not been possible to satisfactorily detect oil leaks.

In addition, in the latter case, expensive detectors must be installed at each of the many detection points set in the long pipeline, which requires a large number of parts and a lot of work to install them. In some respects, this caused diseconomies in terms of facilities.

The above describes the case where the object to be detected is a liquid such as oil, but even when detecting a gas leak using the former detection method described above, the same problems arise as when detecting a liquid. When detecting light leakage in an optical transmission line using this method, in addition to the above-mentioned problems, there is an uneconomical need to incorporate photoelectric converters at multiple locations (each light leakage detection part) on the electric cable, and furthermore, the latter detection method Since this method detects leaked materials by weight, it cannot be applied to detect leaks of gas or light.

As other conventional techniques, means for optically detecting the presence or absence of information are disclosed in Japanese Patent Application Laid-open No. 53-37494 and Japanese Patent Application Laid-open No. 53-37494.
It is disclosed in each publication of No. 76889.

With these methods, the presence or absence of leaked information can be detected without causing the influence of external noise due to electrical means or the uneconomical effects of equipment due to mechanical means.
It is not possible to simultaneously detect the location where the information is generated.

In view of the above-mentioned problems, the present invention aims to provide an optical information detection method that can detect the presence or absence of information in an area where information should be detected, and at the same time can detect the location where the information is generated.

<Means for Solving the Problems> In order to achieve the intended purpose of the information detection method using an optical transmission body of the present invention, the area in which the presence or absence of an information medium is to be detected is divided into a plurality of detection zones. An optical transmission body for information detection is equipped with an outgoing path and a return path for reciprocating optical signals, and has a light transmitting section at the end of the outgoing path and a light receiving section at the end of the returning path. A plurality of detection units for transmitting an optical signal from the outgoing path side to the incoming path side and for receiving the information medium are provided adjacent to each other at intervals, and the outgoing path side of the optical transmission body is ,
The return route is placed in the area where information should be detected, and each detection unit is distributed in each detection section of the information detection area, and an optical signal is transmitted from the light transmitting unit to the outbound route, return route, and light receiving unit of the optical transmission body. At the same time, each optical signal transmitted from the outbound side to the return side through each detection unit is also transmitted to the light receiving unit, and when an information medium enters any detection unit in such an optical transmission state, that detection unit The light receiving unit analyzes changes in the optical signal transmitted from the outgoing path side to the incoming path side via the light receiving unit, and detects that the information medium is present in the detection area into which the information medium has entered.

<Example> Hereinafter, an example of the information detection method according to the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, in which reference numeral 1 denotes a passage as a fluid transport passage or as an optical transmission passage, and the passage 1 is as follows:
If this is a fluid transport path, it is made up of a tube or the like, and if it is an optical transmission path, it is made up of an optical fiber cable.

The feed path 1 has one end serving as a starting end 2 for fluid transport or optical transmission, and the other end serving as a terminal end 3, but in some cases, these ends 2 and 3 are , one or both of them may serve as a relay end, and when this feed line 1 is laid, erected, or buried at a required location, its entire length in the longitudinal direction corresponds to the zone in which leakage is to be detected, that is, the belt-shaped The area L is divided into a large number of detection sections l ₁ , l ₂ , l ₃ . . . ln _-2 , ln _-1 , ln.

The strip area L for detecting the above information includes transport route 1.
An optical transmission body 4 curved in a hairpin shape along the longitudinal direction is arranged, and in this first embodiment, information such as a leakage object is detected through the optical transmission body 4.

The optical transmission body 4 is made of an optical fiber (single-core) or an optical fiber cable (multi-core), and
In the state bent into a hairpin shape as described above, the bent part 5 is placed on the terminal end 3 side of the feeding path 1, and both ends are placed at the starting end 2 of the feeding path 1 (reverse arrangement). Furthermore, one terminal of this optical transmission body 4 is equipped with a light transmitting section 6 equipped with an optical pulse generator.
However, each of the other terminals is provided with a light receiving section 7 equipped with an optical/electrical converter that converts light into electricity, a waveform analyzer, etc. , from the bent portion 5 to the receiving portion 7 is a return path 9.

Further, the optical transmission body 4 has respective detection sections l ₁ to ln.
A plurality of detection units 10 ₁ , 10 ₂ , 10 corresponding to
₃ ......10n _-2 , 10n _-1 , 10n will be provided.

Each of these detection units 10 ₁ to 10n has a pair of optical splitter 11 and optical coupler 12 formed by cutting an optical fiber, optical fiber cable, etc. to a desired length, and one end of each of the two devices 11 and 12 is formed as a pair. are attached to the outgoing path 8 and the incoming path 9, respectively, and the other ends thereof are arranged to face each other with the information intrusion space 13 interposed therebetween.

In the case where the present invention consists of the first embodiment described above, a predetermined optical pulse is transmitted from the light transmitting section 6 of the optical transmission body 4 and received by the light receiving section 7, and the above-mentioned pulse waveform is transmitted on the light receiving section 7 side. The presence or absence of an information medium (leakage from the feed path 1) is monitored and detected in each detection section _l1 to ln while electrically analyzing the information.

To explain this point below, the optical pulse generated from the light transmitting section 6 passes through the outgoing path 8 of the optical transmission body 4, and first, in the detection section _l1 , the optical pulse is transmitted to the optical branching device ₁₁ of the detecting section 101. , enters the return path 9 via the optical coupler 12 and reaches the light receiving unit 7 from the return path 9, and in the same way, each detection section l ₂ ,
l ₃ ...... ln detection unit 10 ₂ , 10 ₃ ...... 10 n
The light pulses that have passed through will sequentially reach the light receiving section 7 with a predetermined time difference, and the remaining light pulses will reach the light receiving section 7 in the final order via the bending section 5.

In this information detection, a state in which there is no leakage accident in the transmission path 1 is regarded as normal, and in this state, the information medium (leakage) from the transmission path 1 is detected at each detection section 10 ₁ to 10n of the optical transmission body 4. Therefore, the light pulses emitted from the light transmitting section 6 are transmitted to each detection section 1.
0 ₁ to 10n and the curve setting section 5, and reach the light receiving section 7 at a predetermined time difference and in a predetermined order, and the light receiving section 7 that analyzes each of these light pulses detects each of the above-mentioned detection sections l ₁ It turns out that there is no abnormality in ~ln, that is, there is no leakage accident in the feed line 1 at all.

Furthermore, in this information detection, if a leakage accident occurs in any of _the detection sections l ₁ , _{l 2} . , an information medium (leakage material) enters into the information intrusion space 13, and the light pulse to be received by the light receiving unit 7 is changed by the medium (light is blocked, attenuated, increased, etc.), and This state is analyzed by the light receiving unit 7 and the above accident is revealed.

In other words, if the above-mentioned feed route 1 is a transport route for oil, gas, etc. and a leakage accident occurs in the above-mentioned detection section _l1 , the leaked fluid (information medium) will enter the detection section ₁₀₁ and the same section 10 Attenuates the light pulse passing through ₁ , or in severe cases blocks the light, thereby
Since the light pulses that reach the light receiving unit 7 in the first order are deformed from their normal values or do not reach the first one,
It becomes clear that there is an accident in the detection section _l1 due to the optical pulse deformation or non-arrival in the order.

Furthermore, if the above-mentioned transmission path 1 is an optical transmission path, leaked light (information medium) in the event of an accident will enter the detection unit ₁₀₁ and amplify and deform the first order optical pulse. Therefore, even in such a case, the leakage accident will be revealed in the same way as above.

Therefore, an accident can be detected in the detection section _l1 by a change in the light pulse of the first order that should reach the light receiving section 7, and in the same way, an accident can be detected in the detection section _l2 by a change in the light pulse of the second order. In the case where each optical pulse change of the 3rd, 4th, and 5th order is recognized, the detection interval
It becomes possible to know that leakage accidents occur at l ₃ , l ₄ , and l ₅ all at once.

In addition, surplus light pulses when performing accident detection in this way, that is, via the curved part 5, are transmitted to the light receiving part 7.
The last-ranked optical pulse that reaches the optical transmitter 4 can be used for inspection of the optical transmission body 4. For example, if this final-ranked optical pulse does not reach the light receiving unit 7, the optical pulse that reaches the optical transmission unit 4 can be It turns out that a disconnection accident, etc. has occurred.

In addition, when the above-mentioned accident is detected by the information medium, the state in which the light pulse does not reach the light receiving section 7 is considered to be a normal state, and when an accident occurs, only the detection section in the detection section is set to pass light, and this is changed to the light receiving section. Even if the signal is received at 7, the desired detection can be performed.

In the first embodiment described above, the leakage is detected using the leakage material from the transmission path 1 as an information medium.In such information detection, the transmission path 1 and the optical transmission medium 4 are An outer cylinder may be provided to cover the area, and partition walls for each of the detection sections l ₁ to ln may be provided within the outer cylinder.

Furthermore, it is natural that this embodiment method can be used for purposes other than detecting leaked materials, such as determining whether liquid, gas, light, etc. have entered a specific area as an obstacle, or whether liquid, gas, or light has been shipped from a certain point, Information such as whether an information medium such as light has passed through a predetermined point can also be detected.

Next, a second embodiment of the present invention will be explained with reference to FIG. 2. In this embodiment, a large number of loops 14, 14, 14, . 14,14...... return trip 9
Each detection unit 10 ₁ , 10 ₂ , 10 3 with or without the information intrusion space 13 by being in a state of proximity or contact with the information intrusion space 13 , _{10 -2} , 10 _-1 ,
10n, and each of these detection sections 10 ₁ to 10n is connected to the detection section l ₁ , l ₂ , l ₃ . . . ln _-2 ,,
ln _-1 , which is allocated to ln.

Other points are similar to the first embodiment, and in this second embodiment as well, when a predetermined optical pulse is transmitted from the light transmitting section 6 of the optical transmission body 4, it passes through the outward path 8, and In the detection section l ₁ , the optical pulse is propagated to the return path 9 via the loop 14 and reaches the light receiving unit 7 from the return path 9 in the first order, and similarly, each detection section l ₂ , l ₃ . . . ...ln
The light pulses that have passed through the detection parts 10 ₂ , 10 ₃ .
The light reaches the light receiving unit 7 in the final order.

Therefore, in this second embodiment as well, each detection unit 10 ₁ ,
10 ₂ ......When an information medium enters into 10n,
Changes occur in the optical pulses of a predetermined order received by the light receiving unit 7 via these detection units, and by analyzing the state of this change on the light receiving unit 7 side, it is possible to determine the presence or absence of an information medium. The location of the medium can be determined, and the same information detection as in the first embodiment can be performed.

Note that in this embodiment, each loop 14, 1
4, 14, .

Next, the third embodiment will be explained with reference to FIG.
In this embodiment, the outgoing path 8 and the incoming path 9 of the optical transmission body 4 are used as a common line, and optical reflectors 15, 15, 15, which can receive (enter) an information medium, are placed at desired locations in the longitudinal direction of the optical transmission body 4. . . . are installed by optical branch couplers ₁₆ , ₁₆ , ₁₆ , .
n _-2 , 10n _-1 , 10n are provided, and each of these detection parts 1
0 ₁ to 10n to each detection section l ₁ to information detection band L
It is installed in ln.

Other points are the same as the first embodiment, and in this third embodiment, the optical transmission body 4 is
When a predetermined optical pulse is transmitted from the light transmitting section 6, in the detection section _l1 , first, optical branching, optical reflection, and optical coupling are performed in the order of optical branching coupler 16 → optical reflector 15 → optical branching coupler 16. occurs, which causes the first
The optical pulses in the order of priority reach the light receiver 7 through the optical transmission body 4 as the return path 9, and further reach the other detection unit 1.
A similar phenomenon occurs for 0 ₂ , ₁₀ 3 . . . 10n, and each optical pulse of the second, third, .

Of course, in this embodiment as well, each detection unit 10 ₁ , 1
When an information medium enters the optical reflector 15 of 0 ₂ ...10n, a change occurs in the optical pulses of a predetermined order received by the light receiving unit 7 via these detection units, and the state of this change is detected. By analyzing on the light receiving section 7 side, the presence or absence of an information medium, the position of the medium, etc. can be determined, and therefore information can be detected in the same manner as in the previous embodiment.

<Effects of the Invention> As explained above, the information detection method according to the present invention detects the desired information by optical means mainly using an optical transmission body, so it is less susceptible to the influence of external noise found in electrical means. Not only is there no diseconomie in terms of equipment that occurs with mechanical means, but the following effects can also be obtained.

In other words, the optical transmission body for information detection includes a plurality of detection sections for transmitting optical signals from the outgoing path side to the returning path side, and also for receiving the information medium, in the longitudinal direction midway between these outgoing and incoming paths. , are provided at adjacent intervals, and these detectors are distributed in each detection section of the area where information is to be detected. Therefore, in a predetermined optical transmission state, the optical signal (optical signal) passing through each detector (pulses) reach the light receiving section with a time difference, and these optical signals correspond to each detection section individually.

Therefore, when the transmission state of the optical signal is monitored through the light receiving section, the presence or absence of an information medium in each detection section can be detected based on whether or not the optical signals that arrive with a time difference change. Furthermore, depending on which optical signal has changed, the position of the information medium can be detected at the same time.

Furthermore, the presence of multiple information media at the same time can also be detected together with the location of each information media by changing the respective optical signals.

[Brief explanation of the drawing]

1 to 3 are schematic illustrations showing various embodiments of the system of the present invention. 4... Optical transmission body, 5... Curved section, 6... Light transmitting section, 7... Light receiving section, 8... Outward path, 9... Return path, 1
0 ₁ to 10n...detection unit, 11...optical splitter, 1
2... Optical coupler, 15... Optical reflector, 16... Optical branching coupler, L... Strip area, l ₁ - ln... Detection section.

Claims (1)

[Claims] 1. An area in which the presence or absence of an information medium is to be detected is divided into a plurality of detection sections, and includes an outgoing path and a returning path for reciprocating optical signals, and a light transmitting section at the end of the outgoing path. The optical transmission body for information detection, which has a light receiving section at the end of the return path, has an optical transmitter for transmitting an optical signal from the outbound path side to the return path side, and for receiving the information medium at the longitudinal intermediate point of these outbound and return paths. The detection part is
A plurality of detectors are provided at intervals adjacent to each other, and the outward and return routes of the optical transmission body are arranged in the area where information is to be detected, and the respective detectors are distributed in each detection section of the information detection area. From the above light transmitting section,
In addition to transmitting optical signals over the outgoing path, incoming path, and light receiving section of the optical transmission body, each optical signal transmitted from the outgoing path side to the returning path side through each detection section is also transmitted to the light receiving section, and the optical transmission state is determined. When an information medium intrudes into an arbitrary detection section, the light receiving section analyzes changes in the optical signal transmitted from the outbound side to the inbound side through the detection section, and detects the intrusion of the information medium. An information detection method using an optical transmission body that detects the presence of an information medium in a detection area. 2. An optical transmission body having a light transmitting section at one end and a light receiving section at the other end is bent into a hairpin shape to form an outgoing path and a return path, and in the parallel portions of these outgoing paths and return paths, there are pairs facing each other. A plurality of pairs of optical splitters and optical couplers are arranged at intervals adjacent to each other in the longitudinal direction of the outgoing and returning routes, and these optical splitters and optical couplers are attached to the outgoing and returning routes to perform each detection. An information detection method using an optical transmission body according to claim 1, wherein the information detection method comprises: 3. An optical transmission body having a light transmitting section at one end and a light receiving section at the other end is bent into a hairpin shape to form an outbound route and a return route. Information detection by the optical transmission body according to claim 1, wherein a plurality of loops are formed at intervals adjacent to each other, and each detection section is configured by these loops being close to or in contact with the other line. Method. 4. A light transmitting section and a light receiving section are provided at one end of an optical transmission body in which an outgoing path and a returning path are formed by a common route,
Claim 1, wherein a plurality of light reflectors are attached to the longitudinal center of the optical transmission body at intervals adjacent to each other and each detecting section is configured by an optical branching coupler. An information detection method using the optical transmission body described above.