JP5294266B2 - Seafloor observation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a structure of a sensor casing by avoiding connection at a sensor part of an optical fiber in a sea-floor observation system. <P>SOLUTION: This sea-floor observation system includes: a terminal device for receiving a plurality of sensor signals; a plurality of sensor casings (2a-2d) having a plurality of built-in sensors for detecting a physical phenomenon and generating a plurality of sensor signals; a transmission device for transmitting the plurality of sensor signals to the terminal device; a repeater casing 28 having the built-in transmission device; and a sea-floor cable having first communication lines (253a-253f) that are made of conductive material and constituted of a plurality of lines, and a second communication line that is stored between a plurality of sheathing iron wires twisted so as to surround the first communication lines and is formed of an optical fiber for multiplexing and transmitting an individual sensor signal. The terminal device, sensor casings, and the repeater casing are interconnected in series via the sea-floor cable. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a seafloor observation system that monitors a sensor signal from a sensor disposed on the seabed in order to detect a physical phenomenon that has occurred on the seabed, and more particularly to a technique for transmitting a signal from the sensor.

  In recent years, a technology that incorporates a submarine cable into a submarine observation system that detects physical phenomena occurring on the seabed, for example, vibrations caused by earthquakes, water pressure changes, magnetic changes, etc., and sends signals to the ground ( (See Patent Document 1 and Patent Document 2). Patent Documents 1 and 2 propose a technique for transmitting a detection signal from a sensor incorporated in a submarine cable to a terminal device (terminal station) installed on the ground.

  FIG. 6 shows a technique described in Patent Document 1. The technique described in Patent Document 1 will be described with reference to FIG. 6 (the code in Patent Document 1 is changed to the 500s). In the seafloor observation system 500 described in Patent Document 1, the optical fibers 530, 532, and 534 in the seafloor cables 522, 524, 526, and 528 correspond to the seafloor observation devices 504, 506, and 508, respectively. The optical fibers corresponding to the observation devices are all connected in series except for the connection portions of the corresponding seabed observation devices. At the connection point, the two ports 516 and 518 of the submarine observation device are connected to corresponding optical fibers of different submarine cables, and the ends of the optical fibers 530, 532, and 534 of the submarine cables 522 and 528 are the land terminal devices 536. 538, respectively.

  FIG. 7 shows a technique described in Patent Document 2. The technique described in Patent Document 2 will be described with reference to FIG. The submarine power composite cable described in Patent Document 2 includes a power cable core 61 including a conductor 53, an insulator 55, a lead coat 57, and a polyethylene anticorrosion layer 59. On the outer periphery of the power cable core 61, a communication optical fiber unit 63 and an external pressure detection optical fiber unit 65 are twisted together with a large number of plastic intervening wires 67. The wearing iron wire 71 is twisted together. When storing a communication line in such a submarine cable, twisting a communication line around the outer periphery, or connecting multiple sensors or repeaters with submarine cables, At the retaining portion, the communication line was connected and the connection portion was housed in the housing.

  FIG. 8 shows a technique described in Patent Document 3. The technique described in Patent Document 3 will be described with reference to FIG. 8 (the code in Patent Document 3 is changed to the 400s). When the submarine optical cable 402 and the circuit unit 400 are connected, a retaining portion 401, an anchor disk 404d, a storage portion (extra length storage space) 404c are provided, and a connection surplus length 406 is provided.

JP 2002-40152 A JP-A-8-195131 JP 2006-78677 A

  In order to increase the communication distance, if an optical fiber is used for the communication line, communication over a longer distance becomes possible than with the coaxial line. However, when connecting optical fibers, fusion connection is required to reduce connection loss. And the extra length of an optical fiber is needed for the connection location of an optical fiber, and the extra length storage space for not giving a bending loss to an optical fiber is needed. For this reason, the sensor housing and the repeater housing require a retaining member for the communication line and a storage space for the communication line. Therefore, there has been a problem that the sensor casing and the relay casing are increased in size and weight.

  The present invention solves the above-described problems, facilitates connection of the communication line connecting the sensor housing and the repeater housing, the communication line, the retaining member of the sensor housing, and the extra length storage space of the communication line The technique which can abbreviate | omit is provided.

  The seafloor observation system of the present invention includes a terminal device that receives a plurality of individual sensor signals, a plurality of sensors that detect a physical phenomenon and generate the plurality of individual sensor signals, and each of the sensors. A plurality of sensor housings, a transmission device for transmitting the plurality of individual sensor signals to the terminal device, a repeater housing incorporating the transmission device, and a plurality of lines formed of a conductive material. A first communication line comprising: a plurality of exterior iron wires twisted so as to surround the first communication line and the sensor housing; and the individual sensor signals are multiplexed between the exterior iron wires. A submarine observation system comprising: a second communication line formed by an optical fiber that is transmitted in the form of a submarine cable, the terminal station device, the sensor casing, and the repeater The case is the seabed Each of the plurality of sensors and the transmission device are connected by the first communication line, and the terminal device and the transmission device are the second communication device. Are connected by a communication line.

  In the seafloor observation system of the present invention, the first communication line formed of a conductive material and composed of a plurality of lines is housed between a plurality of exterior iron wires twisted so as to surround the first communication line, and individually. A submarine cable having a second communication line formed of an optical fiber that multiplexes and transmits the sensor signal. The terminal device, the sensor housing, and the repeater housing are connected to each of the plurality of sensors and the transmission device via a first communication line via the submarine cable. Are connected in series so as to be connected by a second communication line.

  In the seafloor observation system of the present invention, each sensor casing and a relay casing having a transmission device are connected by a first communication line formed of a conductive material and made up of a plurality of lines. Connection of the communication line connecting the instrument housing is facilitated. In addition, the second communication line formed by the optical fiber that relays from the terminal station to the repeater is twisted around the outer periphery of the first communication line and the sensor housing, and the sensor part of the second communication path Therefore, the structure of the sensor housing can be simplified.

It is a figure which shows the structure of the submarine cable used for a submarine observation system. It is a conceptual diagram which shows how a sensor housing | casing and a repeater housing | casing are connected with a submarine cable. It is a conceptual diagram which shows the mutual arrangement | positioning relationship between a sensor housing | casing and a submarine cable. It is a figure which shows the structure of a seafloor observation system. It is a figure which shows the connection of a sensor housing | casing, a repeater housing | casing, and a submarine cable in a seabed observation system. This is a technique described in Patent Document 1. This is the technique described in Patent Document 2. This is the technique described in Patent Document 3.

  In an embodiment for carrying out the invention, in a submarine observation system configured by connecting a sensor and a repeater in series with a submarine cable, a communication line (second communication line) that relays from a terminal station to a repeater is a first communication line. Is twisted around the outer circumference of the communication line and the sensor casing to avoid the connection of the second communication line at the sensor section, thereby simplifying and reducing the weight of the sensor casing retaining structure. Hereinafter, an example which is a specific example of the embodiment will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a submarine cable 25 used in a submarine observation system. The submarine cable 25 includes a tensile body 251, a metal cable 252, a covering 253, an exterior stranded wire 256, and a power supply line. The strength member 251 serves as a core material of the submarine cable 25 and maintains the strength of the submarine cable 25. The metal cable 252 (first communication line) is composed of a plurality of cables paired with two cores, and is arranged around the strength member 251 via a feeder line. Since FIG. 1 is a conceptual diagram, the metal cable 252 is described as 17 wires, but actually has, for example, 50 conductive wires as a whole.

  The metal cable 252 is covered with a cover 253 so that the metal cable 252 is not flooded. The exterior stranded wire 256 is formed of a plurality of exterior iron wires and a stainless steel tube 254 disposed between the plurality of exterior iron wires. The exterior stranded wire 256 is wound around the metal cable 252 (directly around the coating 253) (see FIG. 3). An optical fiber 255 is internally (interpolated) inside the stainless steel tube 254.

  In FIG. 1, the exterior stranded wire 256 is formed such that a plurality of exterior iron wires and a stainless steel tube 257 are disposed between the plurality of exterior iron wires. An optical fiber 258 is internally (interpolated) inside the stainless steel tube 257. As will be described later, the optical fiber 255 is used as a common sensor signal line for transmitting signals from a plurality of sensors. As will be described later, the optical fiber 257 is an information transmission for transmitting information between terminal stations. Although it is used as a track, if an optical fiber 255 is provided as an undersea observation system, its function can be sufficiently achieved. It is also possible to multiplex the common sensor signal and the information signal and transmit both signals using only the optical fiber 255.

  Thus, since the exterior stranded wire 256 is twisted and wound around the sheath 253, even if an object having unevenness exists inside the exterior stranded wire 256, it is deformed according to the unevenness. , The object inside can be covered with a series of exterior stranded wires 256.

  FIG. 2 is a conceptual diagram showing how to connect a sensor housing 2 and a repeater housing 28 to be described later with a submarine cable 25. The exterior stranded wire 256 twists the sensor casing 2a, sensor casing 2b, sensor casing 2c, sensor casing 2d, repeater casing 28, metal cable 252a, metal cable 252b, metal cable 252c, and metal cable 252d. Covering while winding.

  FIG. 3 is a conceptual diagram showing a mutual arrangement relationship between the sensor housing 2 a and the submarine cable 25. FIG. 3 is a partially enlarged view of the vicinity of the sensor housing 2a. The exterior stranded wire 256 of the submarine cable 25 covers the sensor housing 2a, the metal cable 252a, and the metal cable 252b, and is twisted. In FIG. 3, since it is a conceptual diagram, the number of the exterior stranded wires 256 is represented by 9 unlike the embodiment, and the description of the sensor housing 2a, the metal cable 252a, and the metal cable 252b is omitted.

  FIG. 4 is a diagram showing the configuration of the seabed observation system. FIG. 5 is a diagram showing in more detail the configuration of the sensor casing, the repeater casing, and the submarine cable in the submarine observation system shown in FIG. The seabed observation system will be described with reference to FIGS.

  The seabed observation system 51 illustrated in FIG. 4 includes a terminal device 41, a seabed cable 25, sensor housings 2a to 2d, and a relay housing 28. Each cross-sectional structure of the submarine cable 25a to the submarine cable 25e, which is each section of the submarine cable 25, is basically the same as the structure shown in FIG. However, in the part where the sensor casing 2a to the sensor casing 2d and the repeater casing 28 are arranged, the exterior stranded wire 256 is not the covering 253 but the sensor casing 2a to the sensor casing 2d and the repeater casing. 28 is covered.

  Each length of the submarine cable 25a to the submarine cable 25e is referred to as a system length of the submarine cable 25. The structures of the sensor housing 2a to the sensor housing 2d are the same.

  The meaning of the terms used here will be described. As indicated by the submarine cable 25a, the submarine cable 25b, the submarine cable 25c, and the submarine cable 25d, each part indicated by the reference numerals a, b, c, and d indicates the respective sections of the submarine cable 25. Shall. Moreover, the term of the submarine cable 25 indicates a submarine cable composed of the entire submarine cable 25a to the submarine cable 25e, which is each section of the submarine cable, and also indicates a generic name for each of the submarine cable 25a to the submarine cable 25e. Shall.

  Moreover, since the optical fiber 255 functions as a common sensor signal line 255, which will be described later, the following description will be made using the same reference numerals. The number of conductive material lines constituting the metal cable 252 is 50 in the embodiment. Since each of them functions as a sensor signal line, the same reference numerals are given. The entire sensor signal line is denoted by reference numeral 252, and in the drawings of the following description, two of the sensor signal lines are representatively shown in the drawing, and reference numerals of the sensor signal line 2521 and the sensor signal line 2522 are denoted. Represent. Further, since the optical fiber 258 functions as an information signal line for transmitting information, the information signal line described below is also used with reference numeral 258.

  Also, the common sensor signal line 255a to the common sensor signal line 255d, the sensor signal line 2521a to the sensor signal line 2521d, the sensor signal line 2522a to the sensor signal line 2522d, and the information signal line 258a to the information signal line 258e are also submarine cables 25. Similar terms to are used. That is, the term common sensor signal line 255 indicates the entire common sensor signal line 255a to common sensor signal line 255d, which is each section of the common sensor signal line, and includes the common sensor signal line 255a to common sensor signal line 255d. The generic name for each shall be indicated.

  Similarly, the term sensor signal line 2521 indicates the entire sensor signal line 2521a to sensor signal line 2521d, which is each section of the sensor signal line, and is a generic term for each of the sensor signal line 2521a to sensor signal line 2521d. Shall point to. Similarly, the term sensor signal line 2522 indicates the entire sensor signal line 2522a to sensor signal line 2522d, which is each section of the sensor signal line, and is a generic term for each of the sensor signal line 2522a to sensor signal line 2522d. Shall point to. Similarly, the term “information signal line 258” indicates the whole of the information signal line 258a to the information signal line 258d, which is each section of the information signal line, and is a general term for each of the information signal line 258a to the information signal line 258d. Shall point to.

  In addition, when there are a plurality of sensor housings 2, repeater housings 28, sensor devices 12, and repeaters 14, which will be described later, subscripts a, b, c, etc., respectively, Identify. The sensor device 12 having the same subscript as that of the sensor housing 2 represents a component included in the same housing. A repeater having the same subscript as the repeater casing 28 represents a component included in the same casing. Moreover, when using it without attaching a subscript, it shall generically refer to each applicable part about each of the sensor housing | casing 2, the sensor apparatus 12, the repeater housing | casing 28, and a repeater.

  In FIG. 4, the terminal unit 41, the submarine cable 25, the sensor casing 2, the repeater casing 28, and other terminal units (not shown), which are components constituting the seafloor observation system 51. And. In the seafloor observation system 51, information to be communicated is exchanged between one terminal device 41 and another terminal device. The other terminal device is connected to the tip of the sensor housing 2d. The terminal device 41 and the other terminal devices are each installed on land, and the sensor housing 2 is arranged on the seabed. A part of the submarine cable 25 is arranged in the sea or on the ground to connect to a terminal device on the ground. Most of the submarine cables 25 are connected to the sensor casing 2 on the seabed or the relay casing 28 on the seabed. Connected and located on the sea floor. In this way, since the sensor housing 2 is arranged on the seabed, a physical phenomenon on the seabed can be detected. The physical phenomenon detected by the sensor device 12 includes vibration, water pressure change, magnetic change, water temperature change, etc. caused by an earthquake occurring on the seabed.

  The channel length (for example, the length of the submarine cable 25a), which is the length per section of the submarine cable 25, is about several kilometers in the embodiment. The submarine cable 25 includes an information signal line for transmitting information for communication (simply omitted in the following description), a line for transmitting a sensor signal detected by a sensor device described later, and a power supply line for supplying power (see FIG. (Not shown). The information signal line included in the exterior stranded wire 256 and the line transmitting the common sensor signal are optical fibers, but the power supply line and the sensor signal line included in the metal cable 252 are formed of conductive wires.

  In FIG. 4, the number of sensor casings 2 is four and the number of repeater casings 28 is one, but the number and number of these are not limited in principle. . For example, if the number of cables for transmitting information is increased, the communication capacity can be increased. Further, if the number of repeater casings 28 is increased, the communicable distance can be increased. Further, if the number of sensor housings 2 is increased, the number of observation points for physical phenomena can be increased. In the embodiment, as described above, the total number of metal cables 252 is 50.

  The terminal device 41 and the other terminal devices are a modem (not shown) for communicating with each other via the submarine cable 25 and a line connection device (not shown) for connecting to other facilities on the ground. ). Further, the terminal device 41 as at least one terminal device is a power supply device (not shown) as a voltage source for supplying electric power to the sensor housing 2 and the repeater housing 28 via a power supply line. Is arranged.

  With reference to FIG. 5, a description will be given focusing on the sensor signal transmission of the sensor housing 2 and the repeater housing 28.

  The submarine cable 25a includes a sensor signal line 2521a that transmits a sensor signal from the sensor casing 2a to the repeater casing 28, a sensor signal line 2521b that transmits a sensor signal from the sensor casing 2b to the repeater casing 28, and a sensor casing 2c. A sensor signal line 2521c for sending a sensor signal to the repeater casing 28, a sensor signal line 2521d for sending a sensor signal from the sensor casing 2d to the repeater casing 28, the terminal device 41 or other terminal station from the repeater casing 28 A common sensor signal line 255a for sending sensor signals to either one of the devices or both the terminal device 41 and the other terminal device, and an information signal line (not shown) for sending communication information It is configured. Each of the submarine cable 25b to the submarine cable 25e has a configuration similar to that of the submarine cable 25a.

  How the submarine cable 25 in the embodiment is connected to each part of the terminal device 41, the sensor housing 2, the repeater housing 28, and other terminal devices will be described below with reference to FIG. do. The submarine cable 25 is formed as a single unit from the terminal station device 41 to other terminal devices. In the following description, the distance from the base point to each point of the submarine cable 25 is expressed by the term “distance from the base point of the submarine cable” with the terminal device 41 as the base point.

  The sensor device 12a and the sensor device 12d are connected to the sensor signal line 2521 of the submarine cable 25 in such a manner that the distance from the base point is sequentially increased (in parallel) along the direction in which the submarine cable 25 extends. Is done. Further, along the direction in which the submarine cable 25 extends, each of the sensor device 12b and the sensor device 12c is branched and connected to the sensor signal line 2522 at a position where the distance from the base point becomes longer in order (in parallel). .

  The connection mode between the information signal line of the submarine cable 25 and the repeater (both not shown) will be described. The terminal device 41 and one terminal (left side of the drawing) of the repeater are connected via an information signal line. Here, since the information signal line is an unbroken exterior stranded wire, there is no connection portion of the optical fiber in these sections of the optical fiber. The information signal line of the submarine cable 25 connects the other terminal (right side of the drawing) of the repeater to another terminal device (not shown in FIG. 2) via the information signal line. Here, since the information signal line is an unbroken exterior stranded wire, there is no connection portion of the optical fiber in these sections of the optical fiber. In this way, the information signal line connects the terminal device 41 and the other terminal device via the repeater, and the optical fiber passes through the repeater only in the method shown in the background art in the repeater. Connected. Therefore, the number of connection portions of the optical fiber can be reduced.

  The above-described connection mode between the submarine cable 25 and each device is a description of the block 51a which is one block, and the submarine cable 25 may connect a plurality of blocks in series (see FIG. 3). In such a case, four or more sensor devices 12 are used, and a plurality of repeaters are used. In such a case, the sensor device 12 disposed at a position where the distance from the base point of the submarine cable is different from each other (hereinafter, abbreviated as a different position) is connected via the sensor signal line 2521 and the sensor signal line 2522. Connected in parallel. Moreover, the some repeater arrange | positioned in a different position is connected in series via an information signal track | line.

  Each of the sensor housing 2a to the sensor housing has a waterproof structure. The sensor housing 12a has a sensor device 12a, the sensor housing 2b has a sensor device 12b, and the sensor housing 2c has a sensor device 12c. The sensor device 12a is connected to a sensor signal line 2521b included in the submarine cable 25b, the sensor device 12b is connected to a sensor signal line 2522c included in the submarine cable 25c, and the sensor device 12c is connected to a sensor signal line 2522d included in the submarine cable 25d. The sensor device 12d is connected to a sensor signal line 2521e included in the submarine cable 25e.

  Here, although there are 50 sensor signal lines 252 including the sensor signal line 2521 and the sensor signal line 2522 in the embodiment, each sensor signal line 252 and each sensor device 12 are connected to each sensor signal. Since the line 252 is a conductive wire, it can be connected by a simple connection method such as connection to a connector or solder connection. Therefore, there is no great difficulty in connecting 50 large numbers of sensor signal lines 252.

  The sensor signal obtained from the sensor device 12a is input to the multiplexing transmission device 13 via the sensor signal line 2521b and the sensor signal line 2521c. The sensor signal obtained from the sensor device 12b is input to the multiplexing transmission device 13 via the sensor signal line 2522c. The sensor signal obtained from the sensor device 12c is input to the multiplexing transmission device 13 via the sensor signal line 2522d. A sensor signal obtained from the sensor device 12d is input to the multiplexing transmission device 13 via the sensor signal line 2521e and the sensor signal line 2521d. As will be described later, when the terminal device 41 sends a control command to the sensor device 12, the above input / output relationship is reversed.

  The output side of the multiplexing transmission device 13 is connected to the common sensor signal line 255c and the common sensor signal line 255d. The multiplex transmission device 13 multiplexes the sensor signals input from each of the sensor devices 12 a to 12 e and outputs them to the output side of the multiplex transmission device 13. In this way, the multiplexed sensor signal can be transmitted to the terminal device 41 via the common sensor signal line 255c, and the multiplexed sensor signal is transmitted to the other terminal via the common sensor signal line 255d. It can be transmitted to the station device. As will be described later, when the terminal device 41 sends a control command to the sensor device 12, the above input / output relationship is reversed.

  A method of multiplexing in the multiplex transmission apparatus 13 and transmission between the multiplex transmission apparatus 13 and the terminal station apparatus 41 or / and other terminal station apparatuses will be briefly described. Multiplexing can be performed by either frequency division or time division. An example of time division will be described below. An example of a communication protocol is also described, but the embodiment is not limited to this protocol. That is, another known communication technique may be applied.

  The terminal device 41 and / or another terminal device transmits a control command for controlling the sensor devices 12a to 12d via the common sensor signal line 255 and the multiplexing transmission device 13, and transmits / receives data. A decoder / encoder (not shown). Each sensor device 12 is assigned a unique sensor device address for specifying the device, and the sensor device 12 to be controlled can be specified by the sensor device address included in the control command. Has been made. Also, the physical quantity (vibration, temperature, pressure change, etc.) to be detected can be specified by the control command.

  The terminal device 41 or / and another terminal device issues a control command that instructs the sensor device 12a to send vibration data, for example. The multiplex transmission device 13 decodes the command to the sensor device 12a which is a device in its own block, and transfers this control command to the sensor device 12a.

  Upon receiving this control command, the sensor device 12a transmits the sensor information with its own sensor device address to the vibration data obtained from the seismometer (not shown) inside the sensor device 12a, and the multiplexed transmission device 13. To the common sensor signal line 255.

  The terminal device 41 and / or another terminal device decodes the sensor information transmitted to the common sensor signal line 255, specifies that the sensor device 12 is the sensor device 12a, and detects the sensor device 12a. Vibration data from can be obtained. Similarly, the sensor device 12 can be scanned to obtain vibration data from all the sensor devices 12. When data other than vibration is desired, a command to that effect is sent to each sensor device 12 by a control command.

  Even when a plurality of multiplexing transmission devices 13 are connected to the same common sensor signal line 255 and each of the multiplexing transmission devices 13 is connected to a plurality of sensor devices 12 other than four, the above method is used. Can be adopted. The terminal device 41 and / or other terminal devices can obtain sensor information from all the sensor devices 12.

  The repeater casing 28 incorporates the multiplexing transmission device 13 and the repeater. The information signal line is connected to the input side (left side of the drawing) of the repeater, and the information signal line is connected to the output side (right side of the drawing) of the repeater. The repeater casing 28 amplifies the information signal attenuated by the information signal line, converts it to an appropriate level, and outputs it to the information signal line. Note that the terms on the input side and output side of the repeater are used on the assumption that information is transmitted from the left side to the right side of the drawing. When information is transmitted bidirectionally, from the input side described above. Information is output, and information is input from the output side described above.

  A comparison with the technique described in Patent Document 2 will be made below. In the seafloor observation system of the embodiment, all the multiplexed transmission devices are connected in parallel to the common sensor signal line. Therefore, in the case where there are a plurality of multiplexed transmission devices, even if a failure occurs in a part of them, the sensor signal handled by the normal multiplexed transmission device can be detected by the terminal device. On the other hand, in the technique described in Patent Document 1, since all the sensor devices are connected in series, if a failure occurs in a part of them, the sensor signal can be completely detected by the terminal device. It will disappear.

  Further, in the seafloor observation system, as in the embodiment, when a common sensor signal is transmitted to both of the two terminal devices, even if one common sensor signal line is disconnected, the signal is obtained from both terminal devices. It is possible to obtain sensor signals from all of the sensor devices by combining the sensor information obtained. Also, when a common sensor signal is transmitted to both of the two terminal devices, even when a plurality of common sensor signal lines are disconnected, the common sensor signal is transmitted only to one terminal device. More information can be obtained.

  The seafloor observation system of the embodiment includes a terminal device that transmits and receives an information signal and receives a sensor signal, a multiplexing transmission device that multiplexes the sensor signal, and a repeater housing that includes a repeater that relays the information signal. , A plurality of sensor housings incorporating sensor devices that detect physical phenomena on the seabed and emit sensor signals, a common sensor signal line that connects multiplexed transmission devices in parallel to terminal devices, and multiplexed transmission A submarine cable having a plurality of sensor signal lines connecting the device and the plurality of sensor devices. And a terminal station apparatus, a repeater housing | casing, and each of several sensor housing | casing are connected in series with a submarine cable so that a terminal station apparatus may be connected to the termination | terminus of a submarine cable. Further, the plurality of sensor signal lines connecting the multiplex transmission device and the plurality of sensor devices may be cut for each length capable of connecting the sensor devices of the number of multiplexed sensor signals.

  In this way, it is possible to reduce the number of lines that transmit sensor signals included in the submarine cable. As a result, the increase in the diameter of the submarine cable can be suppressed, the weight of the submarine cable can be reduced, the refraction is facilitated, and the handling characteristics are good.

  Also, in order to increase the communication distance, when an optical fiber is used for the communication line, the sensor and repeater housing require a retaining member for the communication line and an extra length storage space for the communication line. Since the pipe communication cable is twisted around the submarine cable and the outer periphery of the sensor housing, the connection of the communication line is avoided in the sensor housing portion, the retaining member of the communication line and the sensor housing, and the communication line Since the extra length storage member can be omitted, the retention structure of the sensor housing can be simplified and reduced in weight.

  That is, as described above, the feature of the present invention is that, as described above, an information signal line, for example, a cable in which an optical fiber for long-distance transmission is inserted into a metal tube, is twisted around the outer periphery of the cable and the sensor housing together with the exterior wire. It is something to wind. When an optical fiber is used as the information signal line, in the case of a metal wire, the communication distance limited to a length of several km at the longest can be about 100 km to 200 km at the longest. However, unlike a metal wire, when a fiber is connected, fusion splicing is required, resulting in an extra connection length. When using a cable with an optical fiber built in the sensor housing as before, the optical fiber of the cable before and after the housing must be connected in the housing, so there is a connection extra length and a space to store the extra length Is required. For this reason, there exists a problem that the enlargement and weight of a housing | casing arise. In addition, since the exterior line is also connected to the housing by being retained, the exterior wire retaining structure is also increased in size and weight. The present invention solves the problems of increasing the size and weight of an enclosure by twisting an optical fiber housed in an exterior wire or a metal tube around the outer circumference of the enclosure and omitting the connection at the enclosure. is there.

  2, 2a to 2d sensor housing, 12, 12a to 12d sensor device, 13 multiplexing transmission device, 28 repeater housing, 41 terminal device, 51 seafloor observation system, 25, 25a to 25e seafloor cable, 256 exterior twist Wire, 255, 256 optical fiber

Claims (2)

A terminal device for receiving a plurality of individual sensor signals;
A plurality of sensors for detecting a physical phenomenon and generating the plurality of individual sensor signals;
A plurality of sensor housings incorporating each of the sensors;
A transmission device for transmitting the plurality of individual sensor signals to the terminal device;
A repeater housing containing the transmission device;
A first communication line formed of a conductive material and comprising a plurality of lines;
A plurality of exterior iron wires that are wound so as to surround the first communication line and the sensor housing;
A submarine cable configured to include a second communication line that is housed between the exterior iron wires and is formed of an optical fiber that multiplexes and transmits the individual sensor signals;
An undersea observation system comprising:
The terminal device, the sensor housing, and the repeater housing are configured to be connected in series via the submarine cable, and each of the plurality of sensors and the transmission device includes the first device. A submarine observation system, characterized in that the terminal station device and the transmission device are connected by a communication line, and the terminal device and the transmission device are connected by the second communication line.   The seafloor observation system according to claim 1, wherein the second communication line is built in a metal pipe.

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