JP6725835B2 - Underwater optical communication device - Google Patents

Description

The present invention relates to an underwater optical communication device.

Conventionally, as a spatial optical communication device that transmits information by an optical signal emitted into space, a transmission unit that converts an electrical signal into an optical signal, and emits the converted optical signal into the space to transmit information through the space, 2. Description of the Related Art There is known one that converts a light input from the outside into an electric signal and transmits a mutual transmission/reception signal including a receiving unit that receives information transmitted from an external device.

In such a spatial light communication device, the communication partner is searched by emitting light from the transmitter while moving the transmitter and the receiver in the horizontal direction and the elevation angle direction before starting communication with the communication partner.

Then, when the light emitted from the communication partner is received, the search for the communication partner is terminated, and thereafter, in order to efficiently transmit the optical signal, the arrival of the optical signal by the two-dimensional sensor in which a large number of light receiving elements are two-dimensionally arranged. In order to execute so-called tracking control, which detects the deviation of the direction and continues the communication while adjusting the position and angle of the device so that the light receiving part faces the arrival direction of the optical signal based on the detection result. (For example, refer to Patent Document 1 below).

JP, 6-11559, A

However, the present inventor, while diligently studying transmission of an optical signal in the sea or underwater (hereinafter, generally referred to as underwater), searches for a communication partner at the time of receiving light emitted from the communication partner. When we finished, we found that the optical signal was diffusely reflected by obstacles such as marine snow and bubbles floating in the water, and it was difficult to find the communication partner because it was difficult to see the arrival direction of the light.

Further, in water, the attenuation of the optical signal is larger than that in the atmosphere. Therefore, in order to extend the transmission distance, it is necessary to use a highly sensitive light receiving element such as APD or PMT in the receiving unit. Therefore, when trying to execute the tracking control as described above in the transmission of an optical signal in water, it is necessary to form a two-dimensional sensor with a high-sensitivity light-receiving element, but a large number of high-sensitivity light-receiving elements are arranged in a two-dimensional array. There is a problem that configuring the sensor is too costly. On the other hand, when a small number of high-sensitivity light receiving elements are arranged to form a two-dimensional sensor, the arrival direction of the optical signal can only be roughly and fragmentally captured, and diffuse reflection light generated by an obstacle floating in water can be detected. It was found that the deviation of the arrival direction of the optical signal cannot be detected accurately due to the influence.

The present invention has been made in view of the above circumstances, and it is possible to find a communication partner in water without misunderstanding the arrival direction of light, or to accurately detect a deviation in the arrival direction of light. It is an object of the present invention to provide an underwater optical communication device that can be used.

An underwater optical communication device according to a first aspect of the present invention is an underwater optical communication device that performs communication by an optical signal between optical communication devices at distant positions in water, wherein the optical communication device emits an optical signal into water. And a transmitting unit that transmits information to the optical communication device of the communication partner, and receives an optical signal emitted by the optical communication device of the communication partner into the water to receive the information transmitted from the optical communication device of the communication partner. a receiving unit, the transmitting unit and the receiving direction adjustment unit for changing the direction of the front Symbol receiving unit, a first detector for detecting the direction of arrival of light emitted from the optical communication apparatus of the communication partner, the communication partner The optical communication device includes a second detection unit that detects a deviation between a direction of arrival of light emitted from the optical communication device and a direction of receiving an optical signal of the reception unit, and the first detection unit includes the optical communication of the communication partner. A first detection light-receiving unit that receives light emitted from the machine; and a detection direction changing unit that changes the direction of the first detection light-receiving unit, wherein the detection direction changing unit covers the entire predetermined region. While moving the first detection light receiving unit, the first detection light receiving unit receives the light emitted from the optical communication device of the communication partner, and from the light intensity distribution at the position where the first detection light receiving unit receives the light of the communication partner. The transmission/reception direction adjustment is performed such that the arrival direction of the light emitted from the optical communication device is detected and the direction in which the optical signal of the receiving unit is received matches the arrival direction of the light detected by the first detection light receiving unit. A part changes the direction of the transmitter and the receiver, and the second detector receives the light emitted from the optical communication device of the communication partner, and the second detector. And a moving unit that moves the second detection light receiving unit so that the second detection light receiving unit repeatedly moves in a predetermined area during communication between the optical communication devices. Meanwhile, the second detection light receiving unit receives the light emitted from the optical communication device of the communication partner, detects the deviation from the light intensity distribution at the position where the second detection light receiving unit receives the light, and the optical communication device Is transmitted from the transmitting unit to the optical communication device of the communication partner, and the transmitting/receiving direction adjusting unit of the optical communication device of the communication partner transmits the detected displacement to the optical communication device of the communication partner so as to reduce the displacement. By changing the direction of the section, the moving section rotationally moves the second detection light receiving section within a plane perpendicular to the direction in which the optical signal of the receiving section is received .

An underwater optical communication device according to a second aspect of the present invention is an underwater optical communication device that performs communication by an optical signal between optical communication devices located at distant positions in water, wherein the optical communication device emits an optical signal into water. And a transmitting unit that transmits information to the optical communication device of the communication partner, and receives an optical signal emitted by the optical communication device of the communication partner into the water to receive the information transmitted from the optical communication device of the communication partner. a receiving unit, the transmitting unit and the receiving direction adjustment unit for changing the direction of the front Symbol receiver, the direction in which the receiving unit and the arrival direction of light emitted from the optical communication apparatus of the communication partner receives the light signal A second detection unit for detecting a deviation of the second detection unit, and the second detection unit moves the second detection light receiving unit that receives the light emitted from the optical communication device of the communication partner and the second detection light receiving unit. And a moving unit for moving the second detection light receiving unit such that the second detection light receiving unit repeatedly moves in a predetermined area during communication between the optical communication devices, The second detection light receiving unit receives the light emitted from the optical communication device of the communication partner, detects the deviation from the light intensity distribution at the position received by the second detection light receiving unit, and the optical communication device, transmits the detected the deviation to said optical transceiver of the communication partner from said transmitting section, so as to reduce the deviation, the transmitting portion and the receiving direction adjustment unit of the optical communication apparatus of the communication partner and before Symbol receiver And the moving unit rotates the second detection light receiving unit in a plane perpendicular to the direction in which the optical signal of the receiving unit is received.

An underwater optical communication device according to a third aspect of the invention is an underwater optical communication device that performs communication by an optical signal between optical communication devices located at distant positions in water, wherein the optical communication device emits an optical signal into water. And a transmitting unit that transmits information to the optical communication device of the communication partner, and receives an optical signal emitted by the optical communication device of the communication partner into the water to receive the information transmitted from the optical communication device of the communication partner. a receiving unit, the transmitting unit and the receiving direction adjustment unit for changing the direction of the front Symbol receiver, the direction in which the receiving unit and the arrival direction of light emitted from the optical communication apparatus of the communication partner receives the light signal A second detection unit for detecting a deviation of the second detection unit, and the second detection unit moves the second detection light receiving unit that receives the light emitted from the optical communication device of the communication partner and the second detection light receiving unit. And a moving unit for moving the second detecting light receiving unit with respect to the transmitting unit so that the second detecting light receiving unit repeatedly moves in a predetermined area during communication between the optical communication devices. While changing the relative position of the second detection light-receiving unit, the second detection light-receiving unit receives the light emitted from the optical communication device of the communication partner, and shifts from the light intensity distribution at the position received by the second detection light-receiving unit. The optical communication device , the optical communication device transmits the detected deviation from the transmission unit to the optical communication device of the communication partner, and adjusts the transmission/reception direction of the optical communication device of the communication partner so as to reduce the deviation. parts are intended to change the direction of the transmission portion and the front Symbol receiver.

According to the first aspect of the present invention, it is possible to find a communication partner in water without mistaking the arrival direction of light. According to the second aspect of the invention, it is possible to accurately detect the deviation of the light arrival direction in water.

It is a figure which shows an example of an underwater optical communication apparatus typically. It is a block diagram which shows the structure of an underwater optical communication device. It is a front view which shows a 1st optical communication device typically. FIG. 4 is a sectional view taken along line AA of FIG. 3. It is a flowchart which shows control of an underwater optical communication device. It is a figure which shows the communication state of the (a)-(c) underwater optical communication apparatus typically. It is a figure which shows typically the communication state of the (a)-(b) underwater optical communication apparatus.

An embodiment of the present invention will be described below with reference to the drawings.

The underwater optical communication device according to the present embodiment is an underwater optical communication device that performs communication using visible light between a first optical communication device 10 and a second optical communication device 50 that are located apart from each other in water. For example, as shown in FIG. 1, a first optical communication device 10 attached to a submersible boat that sails underwater, and a second light provided on a marine (water) boat or another submersible boat that sails underwater. An optical signal using visible light is transmitted to the communication device 50 through the water.

The first optical communication device 10 includes a housing 11, a transmitter 12 and a receiver 14 housed inside the housing 11, a transmission/reception direction adjuster 15 connected to the housing 11, and a first communication partner. 2 The deviation between the arrival direction of the light emitted from the second optical communication device 50 and the direction in which the reception unit 14 receives the optical signal is deviated from the first detection unit that detects the arrival direction of the light emitted from the optical communication device 50. And a main control unit 28 that controls the transmission unit 12, the reception unit 14, the transmission/reception direction adjustment unit 15, the first detection unit, and the second detection unit.

As shown in FIG. 2, the housing 11 has a transmitter 12 and a receiver 14 housed therein, and is hermetically sealed in a watertight state. The visible light transmitted to and received from the second optical communication device 50 is The window part 11a which penetrates is provided.

The transmitter 12 includes a modulator 16 that modulates information to be transmitted to the receiver 54 of the second optical communication device 50 into an optical control signal, and a light emitter 18 to which the optical control signal generated by the modulator 16 is input. Prepare

The light emitting unit 18 is arranged on the optical axis of the light emitting element 20 including a blue laser that emits laser light in the blue wavelength band, in this example, the first wavelength band having a center wavelength of 430 nm, and is corrected on the optical axis of the light emitting element 20. The optical control signal input from the modulator 16 is converted into an optical signal.

The correction unit 22 includes a convex lens, corrects the light emitted from the light emitting element 20 to be uniform, and then diffuses the entire window 51a provided in the housing 51 of the second optical communication device 50 so as to irradiate the window 51a. Outputs light to the outside.

The reception unit 14 receives the optical signal transmitted from the transmission unit 52 of the second optical communication device 50 and converts it into an electric signal, and the demodulation unit 26 demodulates the electric signal converted by the light reception unit 23. With.

The light receiving unit 23 includes a filter 24 to which light is incident from the outside through the window 11 a, and one light receiving element 25 to which the light transmitted through the filter 24 is input.

The filter 24 absorbs the laser light of the first wavelength band emitted by the light emitting element 20 of the first optical communication device 10 among the light incident from the outside, and also transmits the light from the transmitter 52 of the second optical communication device 50 which is a communication partner. It consists of a bandpass filter that transmits the laser light emitted from the.

The light receiving element 25 receives the light that has absorbed the laser light in the first wavelength band by the filter 24, converts the light into an electric signal, and outputs the electric signal to the demodulation unit 26. The light receiving element 25 is provided in the housing 11 such that the direction of the light receiving axis for receiving the optical signal is the same as the direction of the optical axis for the light emitting element 20 of the transmitter 12 to emit the optical signal.

As the light receiving element 25, for example, a photodiode (PD), an avalanche photodiode (APD), a photomultiplier tube (PMT), or the like can be used.

In particular, if a photomultiplier tube is used for the light receiving element 25, it is possible to detect light incident from the outside even if it is weak, and the photomultiplier tube outputs the amount of change in the detected light amount. Even if the light amount of the optical signal input to the light receiving unit 23 is large, the pulse of the optical signal can be detected without saturation of the detection output. In other words, by using a photomultiplier tube as the light receiving element 25, switching from light receiving elements with different detection ranges is performed from long-distance optical transmission in which the light amount of the optical signal decreases to short-distance optical transmission in which the light amount of the optical signal increases. It is possible without using a neutral density filter or a neutral density filter.

The demodulation unit 26 demodulates the electric signal input from the light receiving unit 23, and acquires the information transmitted from the second optical communication device 50 by the optical signal of the second wavelength band from the light incident from the outside.

The transmission/reception direction adjustment unit 15 includes a gimbal mechanism or a pan/tilt mechanism, and includes a housing 11 provided with a transmission unit 12 and a reception unit 14 in a first direction (planar angle direction) and a second direction perpendicular to the first direction. By rotating in each direction (elevation angle direction), the transmitting unit 12 emits an optical signal (optical axis direction of the light emitting element 20) and the receiving unit 14 receives optical signal (light receiving axis of the light receiving element 25). Direction).

The first detection unit includes a first detection light receiving unit 32 that receives the optical signal emitted from the transmission unit 52 of the second optical communication device 50, and a detection direction that changes the direction in which the first detection light receiving unit 32 receives light. The changing unit 34 is provided, and the signal received by the first detection light receiving unit 32 is input to the main control unit 28. The main control unit 28 detects the arrival direction of the light emitted from the second optical communication device 50, based on the signal input from the first detection light receiving unit 32.

The second detection unit includes a second detection light receiving unit 42 that receives the optical signal emitted from the transmission unit 52 of the second optical communication device 50, and a moving unit 44 that moves the second detection light receiving unit 42. The signal received by the detection light receiver 42 is input to the main controller 28. The main controller 28 detects a deviation between the arrival direction of the light emitted from the second optical communication device 50 and the optical axis direction of the receiver 14 based on the signal input from the second detection light receiver 42.

In this embodiment, the light receiving unit 23 provided in the receiving unit 14 that receives the information (optical signal) transmitted from the second optical communication device 50 includes the first detection light receiving unit 32 and the second detection light receiving unit. The transmission/reception direction adjusting unit 15 that also changes the direction of the receiving unit 14 also functions as the detection direction changing unit 34.

The moving unit 44 moves the second detection light receiving unit 42 so as to repeatedly move in a predetermined region inside the housing 11, and moves the second detection light receiving unit 42 (light receiving unit 23) to the transmission unit 12. Change the relative position. In this example, as shown in FIGS. 3 and 4, the moving unit 44 continuously moves the second detection light receiving unit 42 around the transmission unit 12 in a plane perpendicular to the light receiving axis direction of the second detection light receiving unit 42. Then, it is rotated at a rotation speed of, for example, 50 rpm. As a result, the second detection light receiving unit 42 is repeatedly moved in a predetermined area.

The main control unit 28 is provided outside the housing 11, for example, and controls the transmission unit 12, the reception unit 14, the transmission/reception direction adjustment unit 15, the first detection unit, and the second detection unit to perform the first optical communication. Before the communication is started between the device 10 and the second optical communication device 50, the second optical communication device 50 of the communication partner is searched, and when the communication partner is found, the second optical communication device 50 of the communication partner is released. Communication is performed with the second optical communication device 50 while performing tracking control to match the arrival direction of the optical signal with the light receiving axis of the light receiving element 25 of the receiving unit 14.

In the second optical communication device 50, the optical signal emitted by the transmitting unit 52 into the water is set to, for example, the second wavelength band having a center wavelength of 450 nm, and the transmitting unit 12 of the first optical communication device 10 emits into the water. Different from the wavelength band of the optical signal (first wavelength band), and the wavelength band of the light absorbed by the filter provided in the receiving unit 54 is different from the wavelength band absorbed by the filter 24 of the first optical communication device 10. However, other configurations are basically common.

Therefore, although the detailed description of the second optical communication device 50 is omitted here, the second optical communication device 50 has a window portion 51a through which visible light transmitted to and received from the first optical communication device 10 is transmitted. The transmitter 51 includes a housing 51, a modulator 56, a light emitting unit 58 having a light emitting element 60 and a correction unit 62, a light receiving unit 63 having a filter 64 and a light receiving element 65, and a demodulation unit 66. The reception unit 54, the transmission/reception direction adjustment unit 55 connected to the housing 51, the first detection unit that detects the arrival direction of the light emitted from the first optical communication device 10 that is the communication partner, and the second A second detection unit that detects a deviation between the arrival direction of the light emitted from the optical communication device 50 and the direction in which the reception unit 54 receives the optical signal, the transmission unit 52, the reception unit 54, the transmission/reception direction adjustment unit 55, and the second detection unit. A main controller 68 for controlling the first detector and the second detector is provided.

The first detection unit includes a first detection light receiving unit 72 that receives an optical signal emitted from the transmission unit 12 of the first optical communication device 10, and a detection direction that changes the direction in which the first detection light receiving unit 72 receives light. And a changing unit 74. The second detection unit includes a second detection light receiving unit 82 that receives the optical signal emitted from the transmission unit 12 of the first optical communication device 10, and a moving unit 84 that moves the second detection light receiving unit 82. The first detection light receiving unit 72 and the second detection light receiving unit 82 are configured by the light receiving unit 23 provided in the receiving unit 54, and the detection direction changing unit 74 is configured by the transmission/reception direction adjusting unit 55 that changes the direction of the receiving unit 54. ing.

In the underwater optical communication device having such a configuration, in order to search for a communication partner, first, as shown in FIG. 5, the first optical communication device 10 emits light containing no information from the transmitter 12, and While the first detection light receiving unit 32 detects the light emitted from the transmission unit 52 of the second optical communication device 50 of the communication partner, the detection direction changing unit 34 is driven and the transmission unit 12 and the first detection light receiving unit 32 are driven. It is moved in the first direction and the second direction (step S1 in FIG. 5). That is, the first optical communication device 10 scans the first detection light receiving unit 32 in the first direction and the second direction orthogonal to each other on the same spherical surface, and searches for the second optical communication device 50 of the communication partner.

The angle at which the detection direction changing unit 34 moves the first detection light receiving unit 32 in the first direction and the angle at which the detection direction changing unit 34 moves in the second direction by one-time scanning are predetermined. The detection direction changing unit 34 does not stop the movement of the first detection light receiving unit 32 even if it detects the light emitted from the second optical communication device 50 while moving the first detection light receiving unit 32. , The first detection light receiving unit 32 is moved over the entire predetermined region. Thereby, the first detection light receiving unit 32 detects the light intensity distribution in the first direction and the second direction.

Note that while the first optical communication device 10 and the second optical communication device 50 are searching for a communication partner, the second optical communication device 50, like the first optical communication device 10, is an optical signal that does not include information from the transmitter 52. The first detection light receiving unit 72 is scanned in the first direction and the second direction while emitting the light, and the first optical communication device 10 of the communication partner is searched. Further, while the first optical communication device 10 and the second optical communication device 50 are searching for a communication partner, the moving parts 44 and 84 provided in the first optical communication device 10 and the second optical communication device 50 are stopped. Therefore, the relative positions of the transmission units 12 and 52 and the second detection light receiving units 42 and 82 are constant without change.

Then, when the light emitted from the second optical communication device 50 of the communication partner is not detected even if the first detection light receiving unit 32 is moved over the entire predetermined area (No in step S2 of FIG. 5), the main control The unit 28 again moves the first detection light receiving unit 32 over the entire predetermined region, and detects the light intensity distribution received by the first detection light receiving unit 32 in the first direction and the second direction. The main control unit 28 repeats such detection of the light intensity distribution until it detects the light emitted from the communication partner.

On the other hand, when the first detection light receiving unit 32 detects the light emitted from the second optical communication device 50 (Yes in step S2 of FIG. 5), the main control unit 28 causes the light intensity in the first direction and the second direction. The arrival direction of the light emitted from the second optical communication device 50 is specified based on the distribution. As a method of specifying the arrival direction of the light emitted from the second optical communication device 50, for example, the peak position of the detected light intensity distribution can be set as the arrival direction of the light (step S3 in FIG. 5).

Then, the main control unit 28 drives the transmission/reception direction adjusting unit 15 to transmit so that the light receiving axis direction of the light receiving element 25 provided in the receiving unit 14 coincides with the light arrival direction specified in step S3. The direction of the housing 11 provided with the unit 12 and the receiving unit 14 is changed (step S4 in FIG. 5).

When the light receiving axis direction of the light receiving element 25 of the receiving unit 14 and the arrival direction of the optical signal emitted from the second optical communication device 50 match, the first optical communication device 10 causes the transmitting unit 12 to output the second optical signal. While transmitting to the communication device 50, the receiving unit 14 receives the optical signal transmitted from the second optical communication device 50, and transmits and receives information between the first optical communication device 10 and the second optical communication device 50. Is started (step S5 in FIG. 5).

Then, when communication is started between the first optical communication device 10 and the second optical communication device 50, the first optical communication device 10 and the second optical communication device 50 communicate with the light receiving axis directions of the receiving units 14 and 54. Tracking control is started to match the arrival directions of the optical signals emitted from the optical communication devices 50 and 10 of the other party.

Specifically, in the first optical communication device 10, the moving unit 44 continuously moves the second detection light receiving unit 42 around the light emitting unit 18 of the transmitting unit 12 while communicating with the second optical communication device 50. By continuing to rotate and move, the deviation between the arrival direction of the optical signal emitted from the second optical communication device 50 and the light receiving axis direction of the light receiving element 25 of the receiving unit 14 is detected. Further, also in the second optical communication device 50, as in the moving part 44 of the first optical communication device 10, the moving part 84 provided in the second optical communication device 50 is provided while communicating with the first optical communication device 10. By continuously rotating the second detection light receiving portion 82 around the light emitting portion 58 of the transmitting portion 52, the arrival direction of the optical signal emitted from the first optical communication device 10 and the light receiving element 65 of the receiving portion 54 can be obtained. The deviation from the light receiving axis direction of is detected.

In the first optical communication device 10 and the second optical communication device 50, the main control units 28 and 68 of the optical signals received by the second detection light receiving units 42 and 82 that rotate around the transmitting units 12 and 52, respectively. By continuously acquiring the intensities, the intensity distribution of the optical signal in the region where the second detection light receiving units 42 and 82 move is acquired.

Since the optical diameters of the optical signals emitted from the optical communication devices 10 and 50 are large enough to irradiate the entire window portions 51a and 11a provided in the communication partner casings 51 and 11, FIG. As shown in FIG. 5, between the first optical communication device 10 and the second optical communication device 50, the light receiving axis direction of the receiving portions 14 and 54 and the arrival direction of the optical signal emitted from the optical communication devices 50 and 10 of the communication partner. In the state where the two coincide with each other, the optical signals emitted from the first optical communication device 10 and the second optical communication device 50 are the window portions 51a provided in the casings 51 and 11 of the optical communication devices 50 and 10 of the communication partner. , 11a is irradiated. Therefore, in the state of FIG. 6A, in both the first optical communication device 10 and the second optical communication device 50, regardless of the positions of the second detection light receiving parts 42 and 82, the second detection light receiving part The intensity of the optical signal received by 42 and 82 is substantially constant.

If at least one of the first optical communication device 10 and the second optical communication device 50 moves from the state shown in FIG. 6A and the arrival direction of the optical signal emitted from the communication partner shifts, The intensity distributions of the optical signals detected by the detection light receiving units 42 and 82 become smaller in the direction opposite to the direction in which the optical communication devices 50 and 10 of the communication partner have moved. From this, the arrival direction of the light emitted from the optical communication device 50, 10 of the communication partner is deviated with respect to the light receiving axis direction of the receiving portions 14, 54 of the own optical communication device 10, 50. be able to.

For example, as shown in FIG. 6B, when the second optical communication device 50 moves downward in parallel with respect to the first optical communication device 10, the second detection light receiving unit 42 of the first optical communication device 10 detects. The intensity distribution of the optical signal becomes smaller in the direction opposite to the direction in which the second optical communication device 50 has moved (upward in FIG. 6B). Therefore, the main control unit 28 of the first optical communication device 10 determines that the arrival direction of the optical signal emitted from the second optical communication device 50 of the transmission partner is opposite to the direction in which the intensity distribution of the optical signal is reduced (see FIG. In 6(b), it is detected that it is displaced downward.

Then, the first optical communication device 10 transmits the detected deviation direction of the optical signal (downward in FIG. 6B) from the transmission unit 12 to the second optical communication device 50 of the communication partner. When the second optical communication device 50 is transmitted from the first optical communication device 10 in the direction of arrival, the deviation detected by the first optical communication device 10 is reduced (upward in FIG. 6B). The transmission/reception direction adjustment unit 55 changes the directions of the transmission unit 52 and the reception unit 54 (see FIG. 6C). As a method of reducing the deviation detected in the first optical communication device 10 by the transmission/reception direction adjusting unit 55, for example, in the direction opposite to the direction transmitted from the first optical communication device 10 (upward in FIG. 6B). To), the housing 51 is rotated and moved by a predetermined angle.

On the other hand, the intensity distribution of the optical signal detected by the second detection light receiving unit 82 of the second optical communication device 50 is the direction in which the first optical communication device 50 moves relative to the second optical communication device 10 (FIG. 6). It becomes smaller in the direction opposite to (upper in FIG. 6B) (lower in FIG. 6B). Therefore, the main control unit 68 of the second optical communication device 50 determines that the arrival direction of the optical signal emitted from the first optical communication device 10 of the transmission partner is the opposite direction (that is, the direction in which the intensity distribution of the optical signal is reduced). , (In FIG. 6(b), an upward shift) is detected.

Then, the second optical communication device 50 transmits the detected deviation direction of the arrival direction of the optical signal from the transmission unit 52 to the first optical communication device 10 of the communication partner. When the first optical communication device 10 is transmitted from the second optical communication device 50 in a direction shifted from the arrival direction, for example, the first optical communication device 10 moves in the opposite direction to the direction transmitted from the second optical communication device 50 (FIG. 6B). Then, the transmission/reception direction adjusting unit 15 pivotally moves the housing 11 by a predetermined angle, so that the deviation detected by the second optical communication device 50 can be reduced. Change the direction of.

As a result, the deviation of the arrival direction of the optical signal emitted from the optical communication device 10 or 50 of the communication partner is corrected, and the light receiving axis direction of the receiver 14 or 54 and the arrival of the optical signal emitted from the transmitter 52 or 12. The directions are the same (see FIG. 6C).

When the first optical communication device 10 and the second optical communication device 50 rotate and move, for example, as shown in FIG. 7A, the first optical communication device 10 and the second optical communication device 50 rotate downward. When moved, the intensity distribution of the optical signals detected by the second detection light receiving units 42 and 82 is opposite to the direction in which the optical communication devices 50 and 10 of the communication partner have moved (downward in FIG. 7A) (FIG. 7( In a), it becomes smaller in the upper part). Therefore, the main control units 28 and 68 of the optical communication devices 10 and 50 are arranged such that the arrival direction of the optical signal emitted from the optical communication device 50 or 10 of the transmission partner is the direction in which the intensity distribution of the optical signal becomes smaller. Deviation in the opposite direction (that is, downward in FIG. 7A) is detected.

Then, the optical communication device 10, 50 transmits the detected deviation direction of the arrival direction from the transmission unit 12, 52 to the communication partner optical communication device 50, 10. When the direction in which the direction of arrival is shifted is transmitted, for example, the transmission/reception direction adjusting units 55, 15 of the communication partner move the casings 51, 11 in the opposite direction of the transmitted direction (upward in FIG. 7A). By changing the direction of the transmitters 52, 12 and the receivers 54, 14 so that the displacement detected by the first optical communication device 10 and the second optical communication device 50 becomes smaller by rotating and moving by a predetermined angle. To do.

As a result, as shown in FIG. 7B, the deviation in the arrival direction of the optical signals emitted from the optical communication devices 10 and 50 is corrected, and the light receiving axis directions of the receiving units 14 and 54 and the transmitting units 52 and 12 are corrected. The arrival direction of the emitted optical signal matches.

In the underwater optical communication device according to the present embodiment as described above, the detection direction changing units 34 and 74 provided in the one optical communication device 10 and 50 move the first detection light receiving units 32 and 72 while communicating with each other. The light emitted from the optical communication devices 50, 10 is received by the first detection light receiving units 32, 72, and even if the light is detected during the movement, the movement of the first detection light receiving unit 32 is not stopped, and the predetermined detection is performed in advance. The first detection light receiving unit 32 is moved over the entire region to detect the light intensity distribution. Therefore, in the underwater optical communication device of the present embodiment, light reflected by an obstacle such as marine snow or bubbles floating in the water is less likely to be mistaken as the arrival direction of the optical signal emitted by the communication partner, and communication is promptly performed. You can find the other person.

Further, in the present embodiment, the detection direction changing units 34 and 74 move the first detection light receiving units 32 and 72 composed of one light receiving element 25 and 65 to detect the light intensity distribution, so that the number of light receiving elements is suppressed. At the same time, it is possible to continuously acquire the light intensity distribution in the predetermined region, and it is possible to accurately detect the arrival direction of the optical signal emitted by the communication partner while suppressing the manufacturing cost. Moreover, in the present embodiment, in the optical communication devices 10 and 50, the detection direction changing unit 34 scans the first detection light receiving unit 32 in the first direction and the second direction orthogonal to each other, and the optical communication device 50 of the communication partner, Since the arrival direction of the optical signal emitted from 10 is detected, it can be detected more accurately.

Further, in the present embodiment, the light receiving unit 23 provided in the receiving unit 14 that receives the information transmitted from the optical communication devices 50, 10 of the communication partner causes the light emitted from the optical communication devices 50, 10 of the communication partner. Since it also serves as the first detection light receiving units 32 and 72 that detect the arrival direction of the underwater optical communication device, the configuration of the underwater optical communication device can be simplified.

Further, in the underwater optical communication device of the present embodiment, the moving units 44 and 84 perform the second detection so that the second detection light receiving units 42 and 82 in one of the optical communication devices 10 and 50 repeatedly move in a predetermined area. While moving the light receiving parts 42 and 82, the second detection light receiving parts 42 and 82 receive the light emitted from the optical communication devices 50 and 10 of the communication partner, and the optical communication devices 50 and 10 of the communication partner emit the light. Detect the light intensity distribution. Therefore, in the underwater optical communication device of the present embodiment, even with a small number of light receiving elements, a deviation between the arrival direction of the light emitted from the communication partner optical communication device 50, 10 and the light receiving axis direction of the receiving portion 14, 54 is detected. It is possible to increase the transmission distance by using a highly sensitive light receiving element such as PMT while suppressing the manufacturing cost.

In addition, in the present embodiment, since the second detection light receiving units 42 and 82 rotate and move around the transmitting unit 12, the arrival direction of the light emitted from the optical communication device 50, 10 of the communication partner and the receiving unit 14 are accurately measured. , 54 with respect to the direction of the light receiving axis can be detected.

Further, in the present embodiment, the light receiving unit 23 provided in the receiving unit 14 that receives the information transmitted from the optical communication devices 50, 10 of the communication partner causes the light emitted from the optical communication devices 50, 10 of the communication partner. Since it also serves as the second detection light receiving portions 42 and 82 for detecting the deviation between the arrival direction of the light and the light receiving axis direction of the receiving portions 14 and 54, the configuration of the underwater optical communication device can be simplified.

Further, since the number of the light receiving elements 25, 65 forming the first detection light receiving section 32, 72 and the second detection light receiving section 42, 82 is one, the light receiving elements required when the light receiving elements are composed of a plurality of light receiving elements are provided. It is not necessary to calibrate the variation of the light receiving sensitivity, and the arrival direction of the optical signal emitted by the communication partner can be accurately detected with a simple configuration.

(Example of change)
In the above-described embodiment, the light receiving unit 23 provided in the receiving unit 14 that receives the information transmitted from the optical communication devices 50 and 10 of the communication partner includes the first detection light receiving unit 32 and the second detection unit of the first detection unit. Although the case where it also serves as the second detection light-receiving portion 42 of the above-mentioned part has been described, the first detection light-receiving portion 32 of the first detection portion and the second detection light-receiving portion 42 of the second detection portion are provided separately from the light-receiving portion 23. Good.

Further, in the above-described embodiment, the light receiving unit 23 of the receiving unit 14, the first detection light receiving unit 32 of the first detection unit, and the second detection light receiving unit 42 of the second detection unit are configured by one light receiving element. However, it may be composed of a plurality of light receiving elements.

Although the embodiment of the present invention has been described above, this embodiment is presented as an example,
It is not intended to limit the scope of the invention. This embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the invention described in the claims and its equivalents, as well as being included in the scope and spirit of the invention.

DESCRIPTION OF SYMBOLS 10... 1st optical communication apparatus, 11... Housing|casing, 11a... Window part, 12... Transmission part, 14... Reception part, 15... Transmission/reception direction adjustment part, 16... Modulation part, 18... Light emission part, 20... Light emission element, 22... Correction unit, 23... Light receiving unit, 24... Filter, 25... Light receiving element, 26... Demodulation unit, 28... Main control unit, 32... First detection light receiving unit, 34... Detection direction changing unit, 42... Second detection Light receiving part, 44... Moving part, 50... Second optical communication device, 51... Housing, 52... Transmitting part, 54... Receiving part, 55... Transmission/reception direction adjusting part, 58... Light emitting part, 60... Light emitting element, 63... Light receiving section, 65... Light receiving element, 68... Main control section, 72... First detection light receiving section, 74... Detection direction adjusting section, 82... Second detection light receiving section, 84... Moving section

Claims (9)

In an underwater optical communication device that performs communication by an optical signal between optical communication devices located at distant positions in water,
The optical communication device emits an optical signal into the water to transmit information to the optical communication device of a communication partner, and the optical communication device of the communication partner receives the optical signal emitted into the water to communicate with the communication partner. wherein a receiver for receiving the information transmitted from the optical transceiver, the transceiver direction adjustment unit for changing the direction of the transmission portion and the front Symbol receiver, arrival of light emitted from the optical communication apparatus of the communication partner A first detection unit that detects a direction; and a second detection unit that detects a deviation between the arrival direction of the light emitted from the optical communication device of the communication partner and the direction in which the optical signal of the reception unit is received ,
The first detection unit includes a first detection light receiving unit that receives light emitted from the optical communication device of a communication partner, and a detection direction changing unit that changes the direction of the first detection light receiving unit, and the detection is performed. While the direction changing unit moves the first detection light receiving unit over the entire predetermined area, the first detection light receiving unit receives the light emitted from the optical communication device of the communication partner, and the first detection light receiving unit. The arrival direction of the light emitted from the optical communication device of the communication partner is detected from the light intensity distribution at the position where the unit receives the light,
The transmitting/receiving direction adjusting unit changes the directions of the transmitting unit and the receiving unit so that the direction of receiving the optical signal of the receiving unit coincides with the arrival direction of the light detected by the first detection light receiving unit ,
The second detection unit includes a second detection light receiving unit that receives light emitted from the optical communication device of a communication partner, and a moving unit that moves the second detection light receiving unit.
During the communication between the optical communication devices, while the moving unit moves the second detection light receiving unit so that the second detection light receiving unit repeatedly moves in a predetermined area, the second detection light receiving unit The light emitted from the optical communication device of the communication partner is received, and the deviation is detected from the light intensity distribution at the position received by the second detection light receiving unit,
The optical communication device transmits the detected deviation from the transmitting unit to the optical communication device of a communication partner, and the transmission/reception direction adjusting unit of the optical communication device of the communication partner transmits the optical disc to transmit the deviation. The direction of the receiver and the receiver,
The underwater optical communication device , wherein the moving unit rotationally moves the second detection light receiving unit in a plane perpendicular to a direction in which the optical signal of the receiving unit is received . In an underwater optical communication device that performs communication by an optical signal between optical communication devices located at distant positions in water,
The optical communication device emits an optical signal into the water to transmit information to the optical communication device of a communication partner, and the optical communication device of the communication partner receives the optical signal emitted into the water to communicate with the communication partner. wherein a receiver for receiving the information transmitted from the optical transceiver, the transceiver direction adjustment unit for changing the direction of the transmission portion and the front Symbol receiver, arrival of light emitted from the optical communication apparatus of the communication partner A second detector that detects a deviation between the direction and the direction in which the receiver receives the optical signal,
The second detection unit includes a second detection light receiving unit that receives light emitted from the optical communication device of a communication partner, and a moving unit that moves the second detection light receiving unit, and the second communication unit is provided between the optical communication devices. During the communication, while the moving unit moves the second detection light receiving unit so that the second detection light receiving unit repeatedly moves in a predetermined area, the second detection light receiving unit is the communication partner of the optical communication. Receiving light emitted from the machine, detecting the deviation from the light intensity distribution at the position received by the second detection light receiving unit,
The optical communication device transmits the detected deviation from the transmitting unit to the optical communication device of a communication partner, and the transmission/reception direction adjusting unit of the optical communication device of the communication partner transmits the optical disc to transmit the deviation. parts and change the direction of the front Symbol receiver,
The underwater optical communication device , wherein the moving unit rotationally moves the second detection light receiving unit in a plane perpendicular to a direction in which the optical signal of the receiving unit is received . In an underwater optical communication device that performs communication by an optical signal between optical communication devices located at distant positions in water,
The optical communication device emits an optical signal into the water to transmit information to the optical communication device of a communication partner, and the optical communication device of the communication partner receives the optical signal emitted into the water to communicate with the communication partner. wherein a receiver for receiving the information transmitted from the optical transceiver, the transceiver direction adjustment unit for changing the direction of the transmission portion and the front Symbol receiver, arrival of light emitted from the optical communication apparatus of the communication partner A second detector that detects a deviation between the direction and the direction in which the receiver receives the optical signal,
The second detection unit includes a second detection light receiving unit that receives light emitted from the optical communication device of a communication partner, and a moving unit that moves the second detection light receiving unit, and the second communication unit is provided between the optical communication devices. During the communication, the moving unit changes the relative position of the second detection light-receiving unit with respect to the transmission unit so that the second detection light-receiving unit repeatedly moves in a predetermined area. The detection light receiving unit receives the light emitted from the optical communication device of the communication partner, and detects the deviation from the light intensity distribution at the position received by the second detection light receiving unit,
The optical communication device transmits the detected deviation from the transmitting unit to the optical communication device of a communication partner, and the transmission/reception direction adjusting unit of the optical communication device of the communication partner transmits the optical disc to transmit the deviation. parts and underwater optical communication apparatus for changing the direction of the front Symbol receiver. A first detection unit for detecting the arrival direction of light emitted from the optical communication device of the communication partner,
The first detection unit includes a first detection light receiving unit that receives light emitted from the optical communication device of a communication partner, and a detection direction changing unit that changes the direction of the first detection light receiving unit, and the detection is performed. While the direction changing unit moves the first detection light receiving unit over the entire predetermined area, the first detection light receiving unit receives the light emitted from the optical communication device of the communication partner, and the first detection light receiving unit. The arrival direction of the light emitted from the optical communication device of the communication partner is detected from the light intensity distribution at the position where the unit receives the light,
The transmission/reception direction adjustment unit changes the directions of the transmission unit and the reception unit so that the direction in which the optical signal of the reception unit is received matches the arrival direction of the light detected in the first detection light reception unit. 3. The underwater optical communication device according to item 3. The detection direction changing unit moves the first detection light receiving unit in two directions orthogonal to each other, and the first detection unit detects an arrival direction of light emitted from the communication partner optical communication device. Alternatively, the underwater optical communication device according to item 4 . The underwater optical communication device according to claim 3, wherein the moving unit rotationally moves the second detection light receiving unit in a plane perpendicular to a direction in which the optical signal of the receiving unit is received. The mobile unit, underwater optical communication apparatus according to claim 1, 2 or 6 rotationally moving the second detecting light-receiving part around the transmission part. The underwater optical communication device according to claim 1, 4 or 5 , wherein the receiving unit and the first detecting unit are formed of the same light receiving element. The underwater optical communication device according to claim 1, wherein the receiving unit and the second detecting unit are formed of the same light receiving element.

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