JP5352827B2 - Seafloor observation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of lines for transmitting sensor signals in a sea-floor observation system. <P>SOLUTION: This sea-floor observation system includes a terminal device 41 for transmitting/receiving an information signal and receiving a sensor signal, a repeater casing 28 having a built-in multiplexing transmission device 13 for multiplexing the sensor signal, a plurality of sensor casings 2a-2d having built-in sensor devices 12a-12d for detecting a physical phenomenon in a sea floor and emitting a sensor signal, and a sea-floor cable 25 having a common sensor signal line 252 for connecting the multiplexing transmission device 13 to the terminal device 41 and a plurality of sensor signal lines 253 and 254 for connecting the multiplexing transmission devices 13 to the plurality of sensor devices 12a-12d. By connecting the terminal device 41 to the termination of the sea-floor cable 25, the terminal device 41, the repeater casing 28, and each of the plurality of sensor casings 2a-2d are interconnected in series through the sea-floor cable 25. <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. 3 shows a technique described in Patent Document 1. The technique described in Patent Document 1 will be described with reference to FIG. 3 (the code in Patent Document 1 is changed to the 200th level). In the seafloor observation system 200 described in Patent Document 1, the optical fibers 230, 232, and 234 in the seafloor cables 222, 224, 226, and 228 correspond to the seafloor observation devices 204, 206, and 208, respectively. The optical fibers corresponding to the devices are all connected in series except for the connection portion of the corresponding seabed observation device. At the connection point, the two ports 216, 218 of the submarine observation device are connected to corresponding optical fibers of different submarine cables, and the ends of the optical fibers 230, 232, 234 of the submarine cables 222, 228 are the land terminal devices 236, 238. Are connected to each. Since the optical signals from each submarine observation device are transmitted to the land terminal devices 236 and 238 through different paths, the optical signal is always transmitted to one land terminal device even if one submarine cable is disconnected. The

  FIG. 4 shows a technique described in Patent Document 2. The technique described in Patent Document 2 will be described with reference to FIG. 4 (the code in Patent Document 2 is changed to the 300s). In the technique described in Patent Literature 2, optical amplifiers 303 and 305 that amplify an attenuated optical communication data signal are observed between the terminal station 301 and the terminal station 302, and an earthquake is observed, and light observation based on the observation is performed. The observation devices 304 and 306 that output data signals are each provided with n (n is a natural number of 1 or more) sets, and the optical communication data signal and the optical observation data signal are multiplexed and propagated through the communication cable 307.

JP 2002-40152 A JP-A-9-214425

  However, in the technique described in Patent Document 1, since the optical fiber in the sensor and the submarine cable is configured one-to-one, when the number of sensors increases in the submarine observation system, the number of information signal lines of the submarine cable correspondingly increases. Will also increase. And as the diameter of the submarine cable increased, the weight of the submarine cable also increased. As a result, it may be difficult to lay submarine cables.

  In the technique described in Patent Document 2, signals from sensors are multiplexed so that the number of lines for transmitting signals from the sensors is one with respect to the number of sensors, and further, a line for transmitting information Since they are common, there is no problem of an increase in the diameter and weight of the submarine cable. However, the number of multiplexing circuits equal to the number of sensors is required, which complicates the apparatus. Also, since the line for transmitting signals from the sensor and the line for transmitting information are shared, and the multiplexing circuit is connected in series to this one line, the multiplexing circuit and information are relayed. When a failure occurs in any part of the circuit or line to be transmitted, all signals from the sensor and information to be communicated are not transmitted to the terminal station.

  The present invention solves the above-mentioned problems, and when the number of lines for transmitting sensor signals constituting the submarine cable is made smaller than the number of sensors, and a failure occurs in a part of the device and a part of the submarine cable. However, it provides a seafloor observation system that can minimize the damage.

The seafloor observation system of the present invention detects a physical phenomenon on the seabed, a terminal station device that transmits and receives information signals and receives sensor signals, a repeater housing that includes a multiplexing transmission device that multiplexes the sensor signals, and the like. A plurality of sensor housings incorporating the sensor device for emitting the sensor signal, a common sensor signal line connecting the multiplexed transmission device to the terminal device, the multiplexed transmission device and a plurality of A plurality of sensor signal lines for connecting the sensor device, and a submarine cable formed, and connecting the terminal device to a terminal end of the submarine cable, By connecting a plurality of sensor casings to the submarine cable so that the sensor casings are arranged on one side and the other side of the repeater casing, the terminal device and the repeater casing Before the plurality And each of the sensor housing is configured to connect in series by the submarine cable, the sensor device and the multiplexed transmission device is connected in parallel via the plurality of sensor signals lines.

  The seafloor observation system of the present invention has a common sensor signal line for connecting the terminal station device and the multiplexing transmission device, and a plurality of sensor signal lines for connecting the multiplexing transmission device and the plurality of sensor devices. And a submarine cable formed to transmit a sensor signal to the terminal device.

  In the seafloor observation system of the present invention, the number of lines that transmit sensor signals is reduced by reducing the number of lines that send sensor signals, and the number of lines that transmit sensor signals is less than the number of sensors, and multiplexed on a common sensor line. Even if a transmission device is connected in parallel and a part of the submarine cable fails, the damage can be minimized.

It is a figure which shows the structure of a seafloor observation system. It is a figure which shows the structure of the sensor housing | casing, repeater housing | casing, and submarine cable in a submarine observation system. This is a technique described in Patent Document 1. This is the technique described in Patent Document 2.

  In an embodiment for carrying out the invention, in a submarine observation system using a sensor device connected to a submarine cable, a sensor signal line for transmitting sensor information from a plurality of sensor devices and an information line for transmitting information are separated. Thus, it is necessary to prevent a failure on one line from affecting the other. In addition, the number of cables for transmitting sensor signals is reduced to reduce the diameter of the submarine cable, thereby reducing the weight. Hereinafter, an example which is a specific example of the embodiment will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a seabed observation system. FIG. 2 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.

  A seabed observation system 51 shown in FIG. 1 includes a terminal device 41, a seabed cable 25, sensor housings 2a to 2d, and a relay housing 28. The cross-sectional structures of the submarine cable 25a to the submarine cable 25e, which are sections of the submarine cable 25, are the same. 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.

  The same terms as those for the submarine cable 25 are also used for the common sensor signal line 252a to the common sensor signal line 252d, the sensor signal line 253a to the sensor signal line 253d, and the sensor signal line 254a to the sensor signal line 254d described later. That is, the term common sensor signal line 252 indicates the entire common sensor signal line 252a to common sensor signal line 252d, which is each section of the common sensor signal line, and includes the common sensor signal line 252a to common sensor signal line 252d. The generic name for each shall be indicated.

  Similarly, the term sensor signal line 253 indicates the entire sensor signal line 253a to sensor signal line 253d, which is each section of the sensor signal line, and is a generic term for each of the sensor signal line 253a to sensor signal line 253d. Shall point to. Similarly, the term sensor signal line 254 indicates the entire sensor signal line 254a to sensor signal line 254d, which is each section of the sensor signal line, and is a generic term for each of the sensor signal line 254a to sensor signal line 254d. Shall point to.

  Further, when there are a plurality of sensor housings 2, repeater housings 28, and sensor devices 12, which will be described later, each of them is specified using subscripts, a, b, c, and the like. The sensor device 12 having the same subscript as that of the sensor housing 2 represents a component included in the same housing.

  In FIG. 1, the terminal station apparatus 41, the submarine cable 25, the sensor housing | casing 2, and the repeater housing | casing 28 which are the structure parts which comprise the seafloor observation system 51 are provided. In the seabed observation system 51, the terminal device 41 is installed on land, and the sensor housing 2 is placed 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 and the line for transmitting the sensor signal may be an optical fiber or a conductive line made of a conductive material, but the feed line is formed of a conductive line.

  In FIG. 1, the number of submarine cables 25 is four, the number of sensor housings 2 is four, and the number of repeater housings 28 is one. However, it is not limited to these. 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.

  The terminal device 41 and another terminal device (not shown) are connected to a modem (not shown) for communicating with each other via the submarine cable 25 and a line connection for connecting to other facilities on the ground. A device (not shown) is provided. 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. 2, 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 253a that sends a sensor signal from the sensor housing 2a to the repeater housing 28, a sensor signal line 253b that sends a sensor signal from the sensor housing 2b to the repeater housing 28, and a sensor housing 2c. A sensor signal line 253c for sending a sensor signal to the repeater casing 28, a sensor signal line 253d for sending a sensor signal from the sensor casing 2d to the repeater casing 28, a terminal device 41 or another terminal station from the repeater casing 28 It has a common sensor signal line 252a for sending a sensor signal to one of the devices or the terminal device 41, and an information signal line (not shown) for sending communication information.

  Each of the submarine cable 25b to the submarine cable 25e has a configuration similar to that of the submarine cable 25a. Each information signal line is formed of one or a plurality of lines. When the information signal line is formed by the conductive line, the return side line is also included in the number.

  How the submarine cable 25 in the embodiment is connected to each part of the terminal device 41, the sensor casing 2, and the repeater casing 28 will be described below with reference to FIG. The submarine cable 25 is formed as a single unit from the terminal device 41.

  In the sensor signal line 253 of the submarine cable 25, along the direction in which the submarine cable 25 extends, each of the sensor device 12a and the sensor device 12d branches to a position where the distance from the terminal device 41 (base point) becomes longer in order. Connected in parallel. Further, along the direction in which the submarine cable 25 extends, the sensor device 12b and the sensor device 12c are connected to the sensor signal line 254 at a position where the distance from the base point becomes longer in order (in parallel). .

  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 253b included in the submarine cable 25b, the sensor device 12b is connected to a sensor signal line 254c included in the submarine cable 25c, and the sensor device 12c is connected to a sensor signal line 254d included in the submarine cable 25d. The sensor device 12d is connected to a sensor signal line 253e included in the submarine cable 25e.

  The sensor signal obtained from the sensor device 12a is input to the multiplexing transmission device 13 via the sensor signal line 253b and the sensor signal line 253c. The sensor signal obtained from the sensor device 12b is input to the multiplexing transmission device 13 via the sensor signal line 254c. A sensor signal obtained from the sensor device 12c is input to the multiplexing transmission device 13 via the sensor signal line 254d. The sensor signal obtained from the sensor device 12d is input to the multiplexing transmission device 13 via the sensor signal line 253e and the sensor signal line 253d. 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 252c and the common sensor signal line 252d. 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 252c. 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.

  Here, the total number of lines for transmitting the sensor signal for transmitting the sensor signal to the terminal device 41 or another terminal device is one common sensor signal line 252 and the sensor signal line 253 which is a sensor signal line. The number of sensor signal lines 254 and the total of three are three. That is, signals from four sensor devices can be transmitted with three lines. On the other hand, although not shown, when the technique described in Patent Document 1 is used, the number of sensor signal lines is four, which is equal to the number of sensor devices. That is, the number of lines for transmitting sensor signals by four to three and one is reduced.

  A method of multiplexing in the multiplex transmission apparatus 13 and a transmission method between the multiplex transmission apparatus 13 and the terminal station apparatus 41 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 transmits a control command for controlling the sensor devices 12a to 12d via the common sensor signal line 252 and the multiplex transmission device 13, and a decoder / encoder (not shown) for transmitting and receiving data. Z). 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.

  For example, the terminal device 41 issues a control command that instructs the sensor device 12a to send vibration data. For example, the multiplexing transmission device 13 decodes the command to the sensor device 12a 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 252.

  The terminal device 41 decodes the sensor information transmitted to the common sensor signal line 252, specifies that the sensor device 12 is the sensor device 12 a, and obtains vibration data from the sensor device 12 a Can do. 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 multiplexed transmission devices 13 are connected to the same common sensor signal line 252 and a plurality of sensor devices 12 other than four are connected to each multiplexed transmission device 13, the above method is used. Can be adopted. Then, the terminal device 41 can obtain sensor information from all the sensor devices 12. The repeater housing 28 incorporates the multiplex transmission device 13.

  The number of lines for transmitting sensor signals in the seafloor observation system 51 having such a configuration is compared with the number of lines for transmitting sensor signals in the case of the technique described in Patent Document 1.

  An example in which the number of sensors is n (integer) will be compared. In this case, the total number of sensor devices is n. In the embodiment, since the number of sensor signal lines in this case is n / 2 and the number of common sensor signal lines is one, the number of lines for transmitting sensor signals is (n / 2 + 1). On the other hand, the technique described in Patent Document 1 requires the number of lines for transmitting n sensor signals equal to the total number of sensor devices.

  For example, a comparison is made for the case where the number of sensors n = 100. In the seafloor observation system of the embodiment, the number of lines for transmitting sensor signals is (n / 2 + 1) = 51. On the other hand, in the case of Patent Document 1, n = 100. Thus, according to this embodiment, the number of lines for transmitting sensor signals can be significantly reduced to (n / 2 + 1) / n.

  Further, a comparison with the technique described in Patent Document 2 will be made below. In the seafloor observation system of the embodiment, a multiplexed transmission device is connected to the common sensor signal line. Therefore, even when a failure occurs in a part of the sensor device, the sensor signal from the normal sensor 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.

  Furthermore, in the seafloor observation system, when a common sensor signal is transmitted to both of the two terminal devices, the sensor information obtained from both terminal devices is integrated even if one common sensor signal line is disconnected. Thus, sensor signals from all of the sensor devices 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 the multiplexed transmission device to the terminal device; and a multiplexed transmission device; A submarine cable having a plurality of sensor signal lines connecting 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.

  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.

  2, 2a to 2d sensor housing, 12, 12a to 12d sensor device, 13, 13a to 13z multiplexed transmission device, 28 repeater housing, 41 terminal device, 51 submarine observation system, 25, 25a to 25e submarine cable 252 and 252a to 252e common sensor signal lines, 253, 253a to 253e, 254, 254a to 254e sensor signal lines

Claims (1)

A terminal device that transmits and receives information signals and receives sensor signals;
A repeater housing containing a multiplexed transmission device for multiplexing the sensor signals;
A plurality of sensor housings incorporating a sensor device for detecting a physical phenomenon on the seabed and emitting the sensor signal;
A common sensor signal line for connecting the multiplexed transmission device to the terminal device and a plurality of sensor signal lines for connecting the multiplexed transmission device and the plurality of sensor devices. A submarine cable, and
The terminal unit is connected to a terminal end of the submarine cable, and the sensor casing includes a plurality of sensor casings so that the sensor casing is arranged on one side and the other side of the repeater casing on the submarine cable. By connecting the sensor casing, the terminal device, the repeater casing, and each of the plurality of sensor casings are connected in series by the submarine cable ,
The multiplexed transmission device and the sensor device are connected in parallel via the plurality of sensor signal lines.
Undersea observation system.

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