A bionic sunflower type underwater wireless laser communication system and a link establishment method

Abstract

The present application relates to underwater laser communication system and method, specifically relates to a kind of bionic sunflower type underwater wireless laser communication system and chain building method, solve the technical problems that the mechanical structure and control strategy of existing underwater wireless laser communication system are complex, scanning chain building is lower in efficiency, flexibility and reliability is poorer.This application utilizes four-quadrant micro-light detection unit, light regeneration unit to convert, regenerate the weak light signal detected underwater, utilizes bionic sunflower structure unit to simulate the natural tracking mechanism of sunflower to light, instead of traditional two-dimensional rotary table, with the characteristics of automatic tracking, fast response, reduce the demand of instrument logic structure, reduce the system complexity and energy consumption, improve the flexibility and reliability of laser communication, solve the problem that underwater wireless laser communication system beam is not easy to align, reduce the difficulty of re-alignment after underwater wireless laser communication link is disturbed, shorten the re-alignment time.

Description

TECHNICAL FIELD

[0001] The present application relates to an underwater optical communication system and method, in particular to a bionic sunflower type underwater wireless laser communication system and a link establishment method. BACKGROUND

[0002] With the increasing demand for underwater high-capacity data transmission, underwater wireless optical communication technology has emerged. Underwater wireless optical communication has the advantages of high bandwidth, low delay, 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, and on the other hand, in order to solve the alignment problem of underwater wireless optical communication terminals, the actual application of underwater wireless optical communication system is often based on large divergence angle light emitting diode (LED) design, and the geometric loss of the communication signal beam is large. The high attenuation loss of water and the high geometric loss of wide beam together lead to increased 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 beam geometric loss of underwater wireless optical communication system to increase the communication distance of underwater wireless optical communication has become a problem to be solved.

[0003] Underwater wireless laser communication can concentrate the communication beam, which can greatly reduce the geometric loss of underwater beam. Traditional underwater wireless laser communication systems usually use a turntable or a galvanometer to align the optical path to establish a link. After capturing, the underwater wireless laser communication system remains stable, and after the communication link is disconnected, it needs to be captured again. However, the underwater environment is complex, with uncertain factors such as water flow, turbulence, and biological obstruction, and the probability of disconnection is high. The traditional underwater wireless laser communication system needs a complex mechanical control system to achieve accurate alignment of the laser light source and the receiving end, and the efficiency of re-scanning 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

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

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0006] A biomimetic sunflower-shaped underwater wireless laser communication system includes two identical wireless optical communication units, which are respectively installed on the local and remote end devices. Each wireless optical communication unit includes an optical window, and an optical transmitting unit, an optical receiving unit, and a control unit disposed within 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] Its special feature is that the wireless optical communication device also includes a four-quadrant low-light detection unit and a biomimetic sunflower structure unit set in the optical window. A light regeneration unit is set at the rear end of each of the four quadrants of the four-quadrant low-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 low-light detection unit. The biomimetic sunflower structure unit is set at the rear end of the light regeneration unit. The optical transmitting unit and the optical receiving unit are set in parallel on the biomimetic sunflower structure unit.

[0008] The four-quadrant low-light detection unit is used to detect underwater light signals and convert them into electrical signals to drive the light regeneration unit at the rear of its maximum light intensity quadrant to emit light.

[0009] The biomimetic sunflower structural unit uses a photothermal responsive actuation material, which can deform in the direction of the light-emitting regeneration unit, thereby causing the optical emitting unit and the optical receiving unit to deflect in the direction of the light-emitting regeneration unit, so that the optical receiving unit points to the underwater light signal.

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

[0011] Furthermore, the biomimetic 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 biomimetic sunflower structure unit and feed it back to the control unit, and the control unit sends a control signal to the light regeneration unit of the biomimetic sunflower structure unit according to the feedback signal of the tracking unit, so as to increase the light emission power.

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

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

[0014] Furthermore, the optical emitting unit includes a laser, a signal modulator, and a collimating lens and a beam expander arranged sequentially along the laser transmission optical path;

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

[0016] Further, the optical regenerative unit comprises an LED and a driving circuit thereof, and the driving circuit is connected with the control unit and the four-quadrant detector.

[0017] The application also provides a method for establishing a link of the bionic sunflower type underwater wireless laser communication system, and the method comprises the following steps:

[0018] Step 1: adjusting the initial pointing of the two wireless optical communication machines so that the initial alignment deviation of the two wireless optical communication machines is less than the alignment adjustment range of the bionic sunflower structure unit.

[0019] Step 2: making the four-quadrant micro-light detection unit at the local end in a working state; and the control unit at the opposite end controls the optical emission unit to emit an underwater optical signal.

[0020] Step 3: after the four-quadrant micro-light detection unit at the local end receives the underwater optical signal, the four-quadrant micro-light detection unit converts the underwater optical signal into an electric signal and drives the optical regenerative unit at the rear end of the quadrant receiving the maximum light intensity to emit light.

[0021] Step 4: the bionic sunflower structure unit at the local end generates deformation towards the light-emitting optical regenerative unit, thereby driving the optical emission unit and the optical receiving unit to point to the direction of the light-emitting optical regenerative unit, so that the optical receiving unit at the local end is aligned with the optical emission unit at the opposite end, and the single-end alignment of the optical communication link is completed.

[0022] Step 5: according to the method of steps 2-4, the optical receiving unit at the opposite end is aligned with the optical emission unit at the local end, the double-end alignment of the optical communication link is completed, and the underwater wireless laser communication link is established.

[0023] Further, in step 5, the judgment standard for establishing the underwater wireless laser communication link is that the change rate of the feedback signal 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 the local end and the opposite end both detect the handshake signal.

[0024] Further, after step 5, the method further comprises the following steps of re-establishing the link when the communication process between the two ends is interrupted:

[0025] Step 6: if the link is interrupted during the communication process between the two ends, the wireless optical communication machines at the local end and the opposite end maintain the original posture, and return to step 2 when the link is re-established.

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

[0027] 1. The bionic sunflower type underwater wireless laser communication system provided by the application utilizes a four-quadrant micro-light detection unit and a light regeneration unit to convert and regenerate the detected underwater light signal, utilizes a bionic sunflower structure unit to simulate the natural tracking mechanism of the sunflower to light, realizes tracking of the underwater light signal, has the characteristics of automatic tracking and fast response, significantly reduces the external control requirement, improves the flexibility and reliability of laser communication, solves the problem of difficulty in aligning the beam of the underwater wireless laser communication system, reduces the difficulty of re-alignment after the underwater wireless laser communication link is disturbed, and shortens the re-alignment time;

[0028] 2. In the bionic sunflower type underwater wireless laser communication system provided by the application, the bionic sunflower structure unit is used to replace the traditional two-dimensional turntable, and in the process of capturing and tracking the laser signal, automatic pointing and tracking of the laser light source are realized, the requirement for the logic structure of the instrument is reduced, and the system complexity and energy consumption are reduced;

[0029] 3. In the bionic sunflower type underwater wireless laser communication system provided by the application, the bionic sunflower structure unit adopts MXene material, has high light-heat conversion efficiency, can brake the light-heat response within milliseconds, realizes automatic and efficient laser signal capture and tracking, makes the capture of the laser signal more accurate and the response speed faster, and effectively improves the stability and precision of laser signal capture and tracking;

[0030] 4. In the bionic sunflower type underwater wireless laser communication system provided by the application, the tracking unit detects the deformation direction of the bionic sunflower structure unit and feeds it back to the control unit, and then the control unit enhances the light emission power of the light regeneration unit, which can improve the deformation degree of the bionic sunflower structure unit and further improve the accuracy and working efficiency of the system. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structure principle diagram of the bionic sunflower type underwater wireless laser communication system in the embodiments of the application;

[0032] Figure 2 It is a flowchart of the bionic sunflower type underwater wireless laser communication system in the embodiments of the application;

[0033] The following is an explanation of the reference signs:

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

[0035] The application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the application, and are not intended to limit the protection scope of the application.

[0036] A bionic sunflower type underwater wireless laser communication system comprises two wireless optical communication machines with the same structure, which are respectively installed on a local device and a peer device. Figure 1 As shown in the figure, the wireless optical communication machine comprises 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 regenerating unit 5 is arranged at the rear end of each of the four quadrants of the four-quadrant micro-light detection unit 4, the first input end of the light regenerating 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 regenerating 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 regenerating 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, and the light regenerating unit 5 at the rear end of the maximum light intensity quadrant is driven to emit light. The light regenerating unit 5 emits light after receiving the electrical signal. The bionic sunflower structure unit 6 adopts a photo-thermal response actuating material, which can produce deformation in the direction of the light-emitting light regenerating unit 5, thereby driving the optical transmitting unit 1 and the optical receiving unit 2 to deflect in the direction of the lighted light regenerating unit 5, so that the optical receiving unit 2 points to the underwater light signal.

[0038] The optical transmitting unit 1 comprises a laser, a signal modulator, and a collimating mirror and a beam expander arranged in sequence along the laser transmission light 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 signal light with signals, and make it emit smoothly.

[0039] The four-quadrant micro-light detection unit 4 comprises a four-quadrant detector, each of the four quadrants of the four-quadrant detector is sequentially connected with a filter and an electrical signal amplifier, and an output end of the electrical signal amplifier is electrically connected with a 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, and convert the weak underwater light signals into electrical signals, and can distinguish in which direction the center of the signal light is.

[0040] The bionic sunflower structure unit 6 is made of a light-thermal response braking material such as MXene material, can rapidly produce deformation under light wave irradiation, and point to the light source, has good light-thermal conversion efficiency, and can brake the light-thermal response within milliseconds, while a large amount of deformation is generated by the light-thermal response, and can drive the optical transmitting unit 1 and the optical receiving unit 2 to automatically adjust the pointing direction.

[0041] The tracking unit 7 adopts a strain gauge, is used for detecting the deformation direction of the bionic sunflower structure unit 6, and feeds back the deformation direction of the bionic sunflower structure unit 6 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 that the light regeneration unit 5 increases the light emitting power.

[0042] The light regeneration unit 5 comprises an LED and a driving circuit thereof, and input ends of the driving circuit are electrically connected with a second output end of the control unit 3 and a corresponding electrical signal amplifier respectively.

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

[0044] The wireless optical communication machines at both ends of the optical communication link emit light signals. Since the light signals are not strictly aligned at this time, the detected light signals are weak, the signals are not stable enough, and the stability of the link cannot be guaranteed. Precise alignment is required to maintain the stability of the communication link. When the four-quadrant micro-light detection unit 4 detects a weak light signal, the light regeneration unit 5 at the rear end of the maximum light intensity quadrant is driven to emit light. The bionic sunflower structure unit 6 produces a braking response to the light signal and automatically adjusts the pointing direction to the light emitting light regeneration unit 5, thereby optimizing the reception of the light signal. When the bionic sunflower structure unit 6 is automatically aligned, the optical transmitting unit 1 and the optical receiving unit 2 are adjusted to the direction of the light signal, so that the optical receiving unit 2 maximally receives the light signal. The optical communication machine at the other end also completes the above process, and the alignment of the bidirectional simplex communication link of the optical communication link is completed. When the optical link shakes, the receiving end can continuously adjust itself through the bionic sunflower structure unit 6 to reach the optimal state.

[0045] The embodiment also provides a bionic sunflower type underwater wireless laser communication link building method, which adopts the bionic sunflower type underwater wireless laser communication system described above, as shown in the figure, comprising the following steps: Figure 2 ​

[0046] Step 1, adjust the initial direction of the two wireless optical communication machines, so that the initial alignment deviation of the two wireless optical communication machines is less than the alignment adjustment range of the bionic sunflower structure unit 6.

[0047] Step 2, the local four-quadrant micro-light detection unit 6 is in working condition; the optical emission unit 1 controlled by the control unit 3 at the other end emits an underwater optical signal.

[0048] Step 3, after the local four-quadrant micro-light detection unit 4 receives the underwater optical signal, it is converted into an electrical signal to drive the light regeneration unit 5 at the rear end of the quadrant receiving the maximum light intensity to light up.

[0049] Step 4, the bionic sunflower structure unit 6 at the local end generates deformation in the direction of the light regeneration unit 5 that is lit, thereby driving the optical emission unit 1 and the optical receiving unit 2 to point in the direction of the light regeneration unit 5 that is lit, so that the local optical receiving unit 2 is aligned with the optical emission unit 1 at the other end, and the single-end alignment of the optical communication link is completed.

[0050] Step 5, according to the method of steps 2-4, the optical receiving unit 2 at the other end is aligned with the optical emission unit 1 at the local end, and the double-end alignment of the optical communication link is completed, thereby establishing an underwater wireless laser communication link. The judgment standard for establishing an underwater wireless laser communication link is that 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 unit 2 at the local end and the other end detects the handshake signal.

[0051] Step 6, if a link is broken during communication at both ends, the wireless optical communication machines at the local end and the other end maintain the original posture, and when the link is re-established, return to step 1.

[0052] The bionic sunflower type underwater wireless laser communication link establishment method provided in the embodiment can continuously self-adjust through the bionic sunflower structure unit 6 when the optical link shakes during communication at both ends after establishing an underwater wireless laser communication link, and reach an optimal state.

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

Claims

1. A bionic sunflower type underwater wireless laser communication system, comprising two wireless optical communication machines with the same structure, which are respectively installed on the local and opposite end devices; the wireless optical communication machine comprises 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) is electrically connected with the first output end of the control unit (3), and the output end of the optical receiving unit (2) is electrically connected with the first input end of the control unit (3); characterized in that the wireless optical communication machine further comprises a four-quadrant micro-light detection unit (4) and a bionic sunflower structure unit (6) arranged in the optical window, one light regenerating unit (5) is arranged at the rear end of each quadrant of the four-quadrant micro-light detection unit (4), the first input end of the light regenerating unit (5) is electrically connected with 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 regenerating unit (5); 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 for detecting underwater light signals and converting them into electrical signals, and driving the light regenerating unit (5) at the rear end of the maximum light intensity quadrant to emit light; the bionic sunflower structure unit (6) adopts a photo-thermal response actuating material, can produce deformation towards the light-emitting light regenerating unit (5), thereby driving the optical transmitting unit (1) and the optical receiving unit (2) to deflect towards the light-emitting light regenerating unit (5), and making the optical receiving unit (2) point to the underwater light signal; the bionic sunflower structure unit (6) is further provided with a tracking unit (7) electrically connected with the second input end of the control unit (3), and the second output end of the control unit (3) is electrically connected with the second input end of the light regenerating unit (5); the tracking unit (7) is used for detecting the deformation direction of the bionic sunflower structure unit (6) and feeding back to the control unit (3), and the control unit (3) sends a control signal to the light regenerating 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.

2. The bionic solar-like underwater wireless laser communication system according to claim 1, characterized in that: The bionic sunflower structure unit (6) adopts MXene material.

3. The bionic solar-like underwater wireless laser communication system according to claim 2, characterized in that: The tracking unit (7) adopts a strain gauge.

4. The bionic sunflower type underwater wireless laser communication system according to any one of claims 1-3, characterized in that: The four-quadrant micro-light detection unit (4) comprises a four-quadrant detector, and each quadrant of the four-quadrant detector is sequentially connected with a filter and an electrical signal amplifier, and the output end of the electrical signal amplifier is electrically connected with the first input end of the corresponding light regenerating unit (5).

5. The bionic solar-like underwater wireless laser communication system according to claim 4, characterized in that: The optical transmitting unit (1) comprises a laser, a signal modulator, a collimating mirror and a beam expander which are arranged in sequence along the laser transmission light path; the input end of the signal modulator is electrically connected with the first output end of the control unit (3), and the output end is connected with the driving end of the laser.

6. The bionic solar-like underwater wireless laser communication system according to claim 5, characterized in that: The light regenerating unit (5) comprises an LED and a driving circuit thereof, and the input end of the driving circuit is electrically connected with the second output end of the control unit (3) and the corresponding electrical signal amplifier respectively.

7. A method for building a link of a bionic sunflower type underwater wireless laser communication, using the bionic sunflower type underwater wireless laser communication system of any one of claims 1-6. comprising the following steps: Step 1, adjust the initial direction of the two wireless optical communication machines, so that the initial alignment deviation of the two wireless optical communication machines is less 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 optical emission unit (1) is controlled by the control unit (3) at the opposite end to emit underwater optical signals; Step 3, after the four-quadrant micro-light detection unit (4) at the local end receives the underwater optical signals, it converts them into electrical signals to drive the light regeneration unit (5) at the rear end of the quadrant receiving the maximum light intensity quadrant to emit light; Step 4, the bionic sunflower structure unit (6) at the local end produces deformation towards the light-emitting light regeneration unit (5), thereby driving the optical emission unit (1) and the optical receiving unit (2) to point to the light-emitting light regeneration unit (5), so that the optical receiving unit (2) at the local end aligns with the optical emission unit (1) at the opposite end, completing the single-end alignment of the optical communication link; Step 5, according to the method of steps 2-4, the optical receiving unit (2) at the opposite end aligns with the optical emission unit (1) at the local end, completing the double-end alignment of the optical communication link, thereby establishing the underwater wireless laser communication link.

8. The method according to claim 7, wherein, In step 5, the judgment standard for establishing the underwater wireless laser communication link is that 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 unit (2) at the local end and the opposite end detects the handshake signal.

9. The method according to claim 8, wherein, After step 5, it also includes the step of re-establishing the link when the communication process between the two ends is interrupted: Step 6, if the communication process between the two ends is interrupted, the wireless optical communication machines at the local end and the opposite end maintain the original posture, and return to step 2 when re-establishing the link.

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