Bionic sunflower type underwater wireless laser communication system and link establishing method

Abstract

The invention relates to an underwater laser communication system and method, in particular to a bionic sunflower type underwater wireless laser communication system and a link establishment method, and solves the technical problems that the mechanical structure and the control strategy of the existing underwater wireless laser communication system are complex, the scanning link establishment efficiency is low, and the flexibility and the reliability are poor. The four-quadrant low-light detection unit and the light regeneration unit are used for converting and regenerating detected underwater weak light signals, the bionic sunflower structure unit is used for simulating a natural tracking mechanism of a sunflower to light, a traditional two-dimensional rotary table is replaced, the device has the advantages of automatic tracking and quick response, the requirement for an instrument logic structure is reduced, and the detection efficiency is improved. The system complexity and energy consumption are reduced, the flexibility and reliability of laser communication are improved, the problem that beams of an underwater wireless laser communication system are not easy to align is solved, the difficulty of re-alignment after an underwater wireless laser communication link is interfered is reduced, and the re-alignment time is shortened.

Description

Technical Field

[0001] The invention relates to an underwater optical communication system and method, and in particular to a bionic sunflower-type underwater wireless laser communication system and a link establishment method. Background Art

[0002] As the demand for high-speed transmission of large-capacity data underwater continues to increase, underwater wireless optical communication technology has emerged. Underwater wireless optical communication has the advantages of high bandwidth, low latency, low power consumption, and spectrum freedom. However, on the one hand, due to the high attenuation characteristics of the underwater channel, the optical power decays exponentially. On the other hand, in order to solve the alignment problem of underwater wireless optical communication terminals, the underwater wireless optical communication system in actual application is often designed based on a light-emitting diode (LED) with a large divergence angle, and the geometric loss of its communication signal beam is large. The high attenuation loss of the water body and the high geometric loss of the wide beam jointly lead to an increase in optical power loss, which limits the communication rate and communication distance of the LED-based wireless optical communication system, which limits the development of underwater wireless optical communication technology. How to reduce the geometric loss of the beam of the underwater wireless optical communication system and thus increase the communication distance of the underwater wireless optical communication has become an urgent problem to be solved.

[0003] Underwater wireless laser communication can concentrate the communication beam, which can greatly reduce the geometric loss of underwater beams. Traditional underwater wireless laser communication systems usually use turntables or galvanometers to align the optical path to establish a link. After capture, the underwater wireless laser communication system remains stable and re-captures after the communication link is disconnected. However, the underwater situation is complex, with uncertain factors such as water swaying, turbulence, and biological occlusion, and the probability of link breaking is high. Traditional underwater wireless laser communication systems require complex mechanical control systems to achieve precise alignment of the laser light source and the receiving end. The efficiency of rescanning and link establishment is not high, and the control strategy is complex. This not only increases the complexity and alignment time of the system, but also limits the flexibility and reliability of underwater wireless laser communication. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems of the existing underwater wireless laser communication system, such as complex mechanical structure and control strategy, low scanning and link establishment efficiency, poor flexibility and reliability, and to provide a bionic sunflower-type underwater wireless laser communication system and link establishment method.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A bionic sunflower-type underwater wireless laser communication system, comprising two wireless optical communication machines with the same structure, the two wireless optical communication machines are respectively installed on a local end device and a peer end device; the wireless optical communication machine comprises an optical window, and an optical transmitting unit, an optical receiving unit and a control unit arranged in the optical window, the input end of the optical transmitting unit is electrically connected to the first input end of the control unit, and the output end of the optical receiving unit is electrically connected to the first input end of the control unit;

[0007] The special feature is that: the wireless optical communication device also includes a four-quadrant micro-light detection unit and a bionic sunflower structure unit arranged in the optical window, a light regeneration unit is respectively arranged at the rear end of each of the four quadrants of the four-quadrant micro-light detection unit, the first input end of the light regeneration unit is electrically connected to the output end of the corresponding quadrant of the four-quadrant micro-light detection unit, the bionic sunflower structure unit is arranged at the rear end of the light regeneration unit, and the optical transmitting unit and the optical receiving unit are arranged in parallel on the bionic sunflower structure unit;

[0008] The four-quadrant micro-light detection unit is used to detect underwater light signals and convert them into electrical signals, driving the light regeneration unit at the rear end of the quadrant with the maximum light intensity to emit light;

[0009] The bionic sunflower structural unit adopts a photothermal responsive actuating material, which can produce deformation in the direction of the luminous light regeneration unit, thereby driving the optical emitting unit and the optical receiving unit to deflect in the direction of the luminous light regeneration unit, so that the optical receiving unit points to the underwater light signal.

[0010] Furthermore, the bionic sunflower structural unit is made of MXene material.

[0011] Furthermore, the bionic sunflower structure unit is also provided with a tracking unit electrically connected to the second input terminal of the control unit, and the second output terminal of the control unit is electrically connected to the second input terminal of the light regeneration unit; the tracking unit is used to detect the deformation direction of the bionic sunflower structure unit and feed it back to the control unit, and the control unit sends a control signal to the light regeneration unit in the deformation direction of the bionic sunflower structure unit according to the feedback signal of the tracking unit, so as to increase the luminous power.

[0012] Furthermore, the tracking unit adopts a strain gauge.

[0013] Furthermore, the four-quadrant micro-light detection unit includes a four-quadrant detector, and the four quadrants of the four-quadrant detector are sequentially connected to a filter and an electrical signal amplifier, and the output end of the electrical signal amplifier is electrically connected to the first input end of the corresponding light regeneration unit.

[0014] Furthermore, the optical transmitting unit includes a laser, a signal modulator, and a collimator and a beam expander arranged in sequence along the laser transmission optical path;

[0015] The input end of the signal modulator is electrically connected to the first output end of the control unit, and the output end is connected to the driving end of the laser.

[0016] Furthermore, the light regeneration unit includes an LED and a driving circuit thereof, and the driving circuit is connected to the control unit and the four-quadrant detector.

[0017] The present invention also provides a bionic sunflower-type underwater wireless laser communication link establishment method, which adopts the above-mentioned bionic sunflower-type underwater wireless laser communication system, and its special feature is that it includes the following steps:

[0018] Step 1, adjusting the initial pointing directions of the two wireless optical communication machines so that the initial alignment deviation of the two wireless optical communication machines is smaller than the alignment adjustment range of the bionic sunflower structure unit;

[0019] Step 2: The four-quadrant low-light detection unit at the local end is in working state; the control unit at the other end controls the optical transmitting unit to transmit an underwater optical signal;

[0020] Step 3: After receiving the underwater light signal, the four-quadrant micro-light detection unit at the local end converts it into an electrical signal to drive the light regeneration unit at the rear end of the quadrant receiving the maximum light intensity in the four-quadrant micro-light detection unit to emit light;

[0021] Step 4: The bionic sunflower structure unit at the local end is deformed toward the luminous light regeneration unit, thereby driving the optical emitting unit and the optical receiving unit to point toward the luminous light regeneration unit, so that the optical receiving unit at the local end is aligned with the optical emitting unit at the opposite end, completing the single-end alignment of the optical communication link;

[0022] Step 5: According to the method of steps 2 to 4, align the optical receiving unit at the other end with the optical transmitting unit at the local end to complete the double-end alignment of the optical communication link, thereby establishing an underwater wireless laser communication link.

[0023] Furthermore, in step 5, the judgment criteria for establishing an underwater wireless laser communication link are: the feedback signal change rate of the tracking unit is less than 5% or the rotation angle of the bionic sunflower structure unit per second is less than 0.08°, and the optical receiving units at both the local and opposite ends detect handshake signals.

[0024] Furthermore, after step 5, the step of re-establishing the link when the link is broken during the communication between the two ends is also included:

[0025] Step 6: If a link is broken during the communication between the two ends, the wireless optical communication devices at the local end and the other end maintain their original postures, and return to step 2 when the link is reestablished.

[0026] Compared with the prior art, the present invention has the following beneficial technical effects:

[0027] 1. A bionic sunflower-type underwater wireless laser communication system provided by the present invention utilizes a four-quadrant micro-light detection unit and a light regeneration unit to convert and regenerate detected underwater optical signals, and utilizes a bionic sunflower structural unit to simulate the natural tracking mechanism of sunflowers for light, thereby realizing the tracking of underwater optical signals. The system has the characteristics of automatic tracking and rapid response, significantly reduces the external control requirements, improves the flexibility and reliability of laser communication, solves the problem of difficult alignment of the light beam of the underwater wireless laser communication system, reduces the difficulty of realignment of the underwater wireless laser communication link after being disturbed, and shortens the realignment time;

[0028] 2. In a bionic sunflower-type underwater wireless laser communication system provided by the present invention, a bionic sunflower structural unit is used to replace the traditional two-dimensional turntable, and in the process of capturing and tracking laser signals, automatic pointing and tracking of the laser light source is realized, which reduces the requirements of the instrument logic structure, and reduces the system complexity and energy consumption;

[0029] 3. In a bionic sunflower-type underwater wireless laser communication system provided by the present invention, the bionic sunflower structural unit adopts MXene material, which has high light-to-heat conversion efficiency and can brake and respond to light-to-heat within milliseconds, thus realizing automatic and efficient laser signal capture and tracking, making the system more accurate in capturing laser signals and faster in responding, and effectively improving the stability and accuracy of laser signal capture and tracking;

[0030] 4. In a bionic sunflower-type underwater wireless laser communication system provided by the present invention, a tracking unit is used to detect the deformation direction of the bionic sunflower structure unit and feed it back to the control unit. The control unit then enhances the luminous power of the light regeneration unit, which can increase the deformation degree of the bionic sunflower structure unit and further improve the accuracy and work efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural principle diagram of a bionic sunflower-type underwater wireless laser communication system in an embodiment of the present invention;

[0032] Figure 2 This is a flow chart of a bionic sunflower-type underwater wireless laser communication link establishment method according to an embodiment of the present invention;

[0033] The following are the descriptions of the reference numerals:

[0034] 1-optical transmitting unit, 2-optical receiving unit, 3-control unit, 4-four-quadrant low-light detection unit, 5-light regeneration unit, 6-bionic sunflower structure unit, 7-tracking unit. DETAILED DESCRIPTION

[0035] The following is a further detailed description of a bionic sunflower-type underwater wireless laser communication system and a link establishment method proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0036] A bionic sunflower-shaped underwater wireless laser communication system includes two wireless optical communication devices with the same structure, which are respectively installed on the local and opposite end devices. Figure 1 As shown, the wireless optical communication device includes an optical window, and a control unit 3, an optical transmitting unit 1, an optical receiving unit 2, a four-quadrant micro-light detection unit 4, a bionic sunflower structure unit 6 and a tracking unit 7 arranged in the optical window. A light regeneration unit 5 is respectively arranged at the rear end of each of the four quadrants of the four-quadrant micro-light detection unit 4, and the first input end of the light regeneration unit 5 is electrically connected to the output end of the corresponding quadrant of the four-quadrant micro-light detection unit 4, and the bionic sunflower structure unit 6 is arranged at the rear end of the light regeneration unit 5. The optical transmitting unit 1, the optical receiving unit 2 and the tracking unit 7 are all arranged on the bionic sunflower structure unit 6, and the input end of the optical transmitting unit 1 is electrically connected to the first output end of the control unit 3, the output end of the optical receiving unit 2 is electrically connected to the first input end of the control unit 3, the tracking unit 7 is electrically connected to the second input end of the control unit 3, and the second output end of the control unit 3 is electrically connected to the second input end of the light regeneration unit 5; the optical transmitting unit 1 and the optical receiving unit 2 are arranged in parallel.

[0037] The four-quadrant micro-light detection unit 4 is used to detect underwater light signals and convert them into electrical signals, driving the light regeneration unit 5 at the rear end of the maximum light intensity quadrant to emit light, and the light regeneration unit 5 emits light after receiving the electrical signal. The bionic sunflower structure unit 6 uses a photothermal responsive actuation material, which can deform in the direction of the luminous light regeneration unit 5, thereby driving the optical emitting unit 1 and the optical receiving unit 2 to deflect in the direction of the lit light regeneration unit 5, so that the optical receiving unit 2 points to the underwater light signal.

[0038] The optical transmitting unit 1 includes a laser, a signal modulator, and a collimator and a beam expander arranged in sequence along the laser transmission optical path. The input end of the signal modulator is electrically connected to the first output end of the control unit 3, and the output end is connected to the driving end of the laser. The optical transmitting unit 1 can modulate the laser emitted by the laser into a signal light with a signal, and emit it smoothly.

[0039] The four-quadrant micro-light detection unit 4 includes a four-quadrant detector, and the four quadrants of the four-quadrant detector are sequentially connected with a filter and an electric signal amplifier, and the output end of the electric signal amplifier is electrically connected to the first input end of the corresponding light regeneration unit 5. The four-quadrant micro-light detection unit 4 can filter out underwater stray signals, detect weak underwater light signals, convert them into electric signals, and can distinguish in which direction the center of the signal light is.

[0040] The bionic sunflower structure unit 6 is made of photothermal responsive braking materials such as MXene materials. It can quickly deform under the irradiation of light waves and point to the light source. It has good photothermal conversion efficiency and can brake and respond to photothermal energy within milliseconds. At the same time, it can produce a large amount of deformation in response to photothermal energy, which can drive the local optical transmitting unit 1 and the optical receiving unit 2 to automatically adjust the direction.

[0041] The tracking unit 7 uses a strain gauge to detect the deformation direction of the bionic sunflower structure unit 6 and feed it back to the control unit 3. The control unit 3 sends a control signal to the light regeneration unit 5 in the deformation direction of the bionic sunflower structure unit 6 according to the feedback signal of the tracking unit 7, so as to increase the luminous power.

[0042] The light regeneration unit 5 includes an LED and a driving circuit thereof, and an input end of the driving circuit is electrically connected to the second output end of the control unit 3 and a corresponding electric signal amplifier respectively.

[0043] The working principle of the bionic sunflower-type underwater wireless laser communication system provided in this embodiment is:

[0044] The wireless optical communication machines at both ends of the optical communication link transmit optical signals. Since the optical signals at this time are not strictly aligned, the detected optical signals are weak and the signals are not stable enough to ensure the stable communication of the link. Accurate alignment is required to maintain the stability of the communication link. When the four-quadrant micro-light detection unit 4 at this end detects a weak optical signal, it drives the optical regeneration unit 5 at the rear end of the maximum light intensity quadrant to emit light. The bionic sunflower structure unit 6 generates a braking response to the optical signal and automatically adjusts the direction of the emitting optical regeneration unit 5 to optimize the reception of the optical signal. When the bionic sunflower structure unit 6 is automatically aligned, it drives the optical transmitting unit 1 and the optical receiving unit 2 to adjust in the direction of the optical signal so that the optical receiving unit 2 receives the optical signal to the maximum extent. The optical communication machine at the opposite end then completes the above process to complete the alignment of the bidirectional simplex communication link of the optical communication link. When the optical link shakes, the receiving end can continuously self-adjust through the bionic sunflower structure unit 6 to reach the optimal state.

[0045] This embodiment also provides a bionic sunflower-type underwater wireless laser communication link establishment method, using the above-mentioned bionic sunflower-type underwater wireless laser communication system, such as Figure 2 As shown, the following steps are included:

[0046] Step 1: Adjust the initial pointing directions of the two wireless optical communication devices so that the initial alignment deviation of the two wireless optical communication devices is smaller than the alignment adjustment range of the bionic sunflower structure unit 6.

[0047] Step 2: put the local four-quadrant micro-light detection unit 6 into working state; the other-end control unit 3 controls the optical transmitting unit 1 to transmit underwater optical signals.

[0048] Step 3: After receiving the underwater light signal, the local four-quadrant micro-light detection unit 4 converts it into an electrical signal to drive the light regeneration unit 5 at the rear end of the quadrant receiving the maximum light intensity in the four-quadrant micro-light detection unit 4 to light up.

[0049] Step 4: The bionic sunflower structure unit 6 at the local end is deformed toward the lighted light regeneration unit 5, thereby driving the optical transmitting unit 1 and the optical receiving unit 2 to point toward the lighted light regeneration unit 5, so that the optical receiving unit 2 at the local end is aligned with the optical transmitting unit 1 at the opposite end, completing the single-end alignment of the optical communication link.

[0050] Step 5: According to the method of step 2 to step 4, align the optical receiving unit 2 at the other end with the optical transmitting unit 1 at the local end to complete the double-end alignment of the optical communication link, thereby establishing an underwater wireless laser communication link. The judgment criteria for establishing an underwater wireless laser communication link are: the feedback signal change rate of the tracking unit 7 is less than 5% or the rotation angle of the bionic sunflower structure unit 6 is less than 0.08° per second, and the optical receiving units 2 at both the local end and the other end detect handshake signals.

[0051] Step 6: If a link is broken during the communication between the two ends, the wireless optical communication devices at the local end and the other end maintain their original postures, and return to step 1 when the link is reestablished.

[0052] The bionic sunflower-type underwater wireless laser communication link establishment method provided in this embodiment establishes an underwater wireless laser communication link. When the optical link shakes during the communication between the two ends, the optical receiving unit 2 can continuously self-adjust through the bionic sunflower structure unit 6 to reach the optimal state.

[0053] The bionic sunflower-type underwater wireless laser communication system and link establishment method of the present invention can simplify the design and operation requirements of the underwater wireless laser communication system while ensuring the communication quality, opening up new possibilities for the future development of laser communication technology. It can also be flexibly adjusted according to different laser wavelengths and environmental conditions, and has broad application prospects, including but not limited to ocean exploration, space communication, remote sensing monitoring and other fields.

Claims

1. A bionic sunflower-type underwater wireless laser communication system, comprising two wireless optical communication machines of the same structure, the two wireless optical communication machines being respectively mounted on a local end device and a remote end device; the wireless optical communication machine comprising an optical window, and an optical transmitting unit (1), an optical receiving unit (2) and a control unit (3) arranged in the optical window, the input end of the optical transmitting unit (1) being electrically connected to a first output end of the control unit (3), and the output end of the optical receiving unit (2) being electrically connected to a first input end of the control unit (3); Features: The wireless optical communication device further comprises a four-quadrant micro-light detection unit (4) and a bionic sunflower structure unit (6) arranged in the optical window; a light regeneration unit (5) is respectively arranged at the rear end of each of the four quadrants of the four-quadrant micro-light detection unit (4); a first input end of the light regeneration unit (5) is electrically connected to an output end of a corresponding quadrant of the four-quadrant micro-light detection unit (4); the bionic sunflower structure unit (6) is arranged at the rear end of the light regeneration unit (5); and the optical transmitting unit (1) and the optical receiving unit (2) are arranged in parallel on the bionic sunflower structure unit (6); The four-quadrant micro-light detection unit (4) is used to detect underwater light signals and convert them into electrical signals, driving the light regeneration unit (5) at the rear end of the quadrant with the maximum light intensity to emit light; The bionic sunflower structural unit (6) adopts a photothermal responsive actuation material and can be deformed in the direction of the luminous light regeneration unit (5), thereby driving the optical emitting unit (1) and the optical receiving unit (2) to deflect in the direction of the luminous light regeneration unit (5), so that the optical receiving unit (2) points to the underwater light signal.

2. The bionic sunflower-type underwater wireless laser communication system according to claim 1 is characterized in that: The bionic sunflower structural unit (6) is made of MXene material.

3. The bionic sunflower-type underwater wireless laser communication system according to claim 2 is characterized in that: The bionic sunflower structure unit (6) is also provided with a tracking unit (7) electrically connected to the second input end of the control unit (3); the second output end of the control unit (3) is electrically connected to the second input end of the light regeneration unit (5); the tracking unit (7) is used to detect the deformation direction of the bionic sunflower structure unit (6) and feed it back to the control unit (3); the control unit (3) sends a control signal to the light regeneration unit (5) in the deformation direction of the bionic sunflower structure unit (6) according to the feedback signal of the tracking unit (7), so as to increase the light emitting power.

4. The bionic sunflower-type underwater wireless laser communication system according to claim 3 is characterized by: The tracking unit (7) uses a strain gauge.

5. A bionic sunflower-type underwater wireless laser communication system according to any one of claims 1 to 4, characterized in that: The four-quadrant micro-light detection unit (4) comprises a four-quadrant detector, the four quadrants of which are sequentially connected to filters and electrical signal amplifiers, and the output end of the electrical signal amplifier is electrically connected to the first input end of the corresponding light regeneration unit (5).

6. The bionic sunflower-type underwater wireless laser communication system according to claim 5 is characterized by: The optical transmitting unit (1) comprises a laser, a signal modulator, and a collimator and a beam expander arranged in sequence along the laser transmission optical path; The input end of the signal modulator is electrically connected to the first output end of the control unit (3), and the output end is connected to the driving end of the laser.

7. The bionic sunflower-type underwater wireless laser communication system according to claim 6 is characterized by: The light regeneration unit (5) comprises an LED and a driving circuit thereof, wherein the input end of the driving circuit is electrically connected to the second output end of the control unit (3) and the corresponding electric signal amplifier respectively.

8. A bionic sunflower-type underwater wireless laser communication link establishment method, using a bionic sunflower-type underwater wireless laser communication system according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1, adjusting the initial pointing directions of the two wireless optical communication devices so that the initial alignment deviation of the two wireless optical communication devices is smaller than the alignment adjustment range of the bionic sunflower structure unit (6); Step 2: The four-quadrant micro-light detection unit (6) at the local end is in working state; the control unit (3) at the other end controls the optical transmitting unit (1) to transmit an underwater optical signal; Step 3: After receiving the underwater light signal, the local four-quadrant micro-light detection unit (4) converts it into an electrical signal to drive the light regeneration unit (5) at the rear end of the quadrant receiving the maximum light intensity in the four-quadrant micro-light detection unit (4) to emit light; Step 4: The local bionic sunflower structure unit (6) is deformed in the direction of the luminous light regeneration unit (5), thereby driving the optical emitting unit (1) and the optical receiving unit (2) to point in the direction of the luminous light regeneration unit (5), so that the local optical receiving unit (2) is aligned with the opposite optical emitting unit (1), thereby completing the single-end alignment of the optical communication link; Step 5: According to the method of steps 2 to 4, align the optical receiving unit (2) at the other end with the optical transmitting unit (1) at the local end to complete the double-end alignment of the optical communication link, thereby establishing an underwater wireless laser communication link.

9. A bionic sunflower-type underwater wireless laser communication link establishment method according to claim 8, characterized in that: In step 5, the judgment criteria for establishing an underwater wireless laser communication link are: the feedback signal change rate of the tracking unit (7) is less than 5% or the rotation angle of the bionic sunflower structure unit (6) per second is less than 0.08°, and the optical receiving units (2) at both the local end and the opposite end detect handshake signals.

10. A bionic sunflower-type underwater wireless laser communication link establishment method according to claim 9, characterized in that: Step 5 also includes the steps of re-establishing the link when the link is broken during the communication between the two ends: Step 6: If a link is broken during the communication between the two ends, the wireless optical communication devices at the local end and the other end maintain their original postures, and return to step 2 when the link is reestablished.

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