Float-type cross-medium communication device, system and algorithm thereof

Abstract

The invention relates to the technical field of communication, and discloses a buoy-type cross-medium communication device, system and algorithm wherein the device comprises a buoy comprising a water surface mechanism and an underwater mechanism; the system comprises a water surface control module and an underwater control module. The water surface control module comprises a TCP / IP (Transmission Control Protocol / Internet Protocol) processor and is wirelessly connected with a remote terminal through WiFi (Wireless Fidelity) communication; the underwater control module comprises a visible light communication control unit, a visual positioning unit, a tracking power unit and an environment perception and self-adaption unit; the algorithm comprises the following steps: step 1, an initialization stage; 2, a communication establishment stage; 3, a dynamic tracking stage; and 4, an energy efficiency management stage. According to the float-type cross-medium communication device, system and algorithm, seamless connection of water surface WiFi and underwater visible light communication is realized, and meanwhile, the communication stability in a complex marine environment is ensured through a visual positioning and active tracking mechanism.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and particularly to a buoy-type cross-media communication device, system and its algorithm. Background Art

[0002] An underwater robot is an intelligent device capable of performing tasks in an underwater environment, and is widely used in fields such as ocean scientific research, ocean resource development, seabed exploration, environmental monitoring, emergency rescue, etc. Currently, the wireless communication between an underwater robot and a surface terminal or other devices mainly relies on the following technical solutions: underwater acoustic communication, underwater radio frequency (RF) communication, and underwater blue-green laser communication; among them, underwater acoustic communication realizes data transmission through the propagation of sound waves in the water medium, and is currently the most mature underwater communication method. Its advantage is that it can achieve kilometer-level long-distance communication, but there are significant defects: extremely low bandwidth (usually only at the kbps level), making it difficult to support the transmission of large-capacity data such as high-definition videos and images; high latency (the speed of sound is about 1500 m / s), unable to meet the requirements of real-time control; vulnerable to multipath effect interference, and the communication stability is poor in complex seabed terrain or dynamic water flow environments.

[0003] Underwater radio frequency (RF) communication uses low-frequency electromagnetic waves (such as 30 - 300 Hz) to penetrate water bodies, but its limitations include: short transmission distance (usually <10 meters), requiring extremely high transmission power; limited spectrum resources, prone to frequency band conflicts with marine biological monitoring devices, etc.; the antenna size is too large, making it difficult to integrate into small underwater robots.

[0004] Underwater blue-green laser communication uses lasers with wavelengths of 470 - 550 nm to penetrate water bodies, and can achieve Mbps-level high-speed communication, but there are technical bottlenecks: the alignment accuracy requirements are extremely strict, and a precise mechanical servo mechanism needs to be equipped, increasing the system complexity and cost; significantly affected by water turbidity, the performance drops sharply in turbid waters or suspended particle environments; single-point-to-single-point communication mode, unable to support multi-device dynamic networking.

[0005] Therefore, in order to achieve cross-media communication between underwater devices such as underwater robots and surface / air terminals, the existing technologies mainly adopt the relay buoy scheme to solve the above problems. However, there are still some problems. Existing buoys usually adopt the dual-mode relay of underwater acoustic + radio frequency (such as satellite). Due to the incompatibility of underwater acoustic and radio frequency protocols, multiple protocol conversions are required, resulting in an increase in end-to-end delay (usually >1 second), and it is easy to cause data packet loss due to protocol conversion errors, that is, the communication protocol fragmentation problem. Moreover, traditional buoys lack the ability of autonomous positioning and motion compensation, and the dynamic tracking ability is missing. When an underwater robot or device moves due to task requirements, the buoy cannot actively adjust its position to maintain the communication link, resulting in a deviation of the field of view angle or an interruption of optical communication, especially prominent in a strong ocean current environment. At the same time, the buoy needs to continuously turn on the underwater acoustic communication module to listen for underwater signals, and its power consumption is as high as 10 - 20W. The solar power supply system is difficult to support long-term operation in rainy weather, resulting in insufficient endurance and low energy efficiency. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the present invention provides a buoy-type cross-media communication device, system and its algorithm, which have the advantages of high bandwidth, low latency, and adaptability to dynamic environments, realizing seamless connection between surface WiFi and underwater visible light communication. At the same time, through visual positioning and active tracking mechanisms, it ensures communication stability in complex marine environments, etc. It solves the contradictions between the long underwater acoustic communication distance but low bandwidth and the medium penetration ability and communication rate of traditional buoys, the high optical communication rate but limited by the medium transmittance; the problem of low cross-protocol cooperation efficiency due to the independent design of surface and underwater communication protocols and large data conversion overhead; the lack of a real-time tracking and compensation mechanism for the movement of underwater devices; the poor adaptability to dynamic environments due to insufficient system integration: the communication, positioning, and energy modules are designed separately, making it difficult to meet the requirements of miniaturization and low power consumption.

[0007] To achieve the above-mentioned purposes of high bandwidth, low latency, adaptability to dynamic environments, realizing seamless connection between surface WiFi and underwater visible light communication, and ensuring communication stability in complex marine environments through visual positioning and active tracking mechanisms, the present invention provides the following technical solutions: A buoy-type cross-media communication device includes a buoy, and the buoy includes a surface mechanism and an underwater mechanism; The surface mechanism includes a surface WiFi communication antenna and a solar power supply module; The underwater mechanism includes a pressure-resistant sealed cabin body, and inside the pressure-resistant sealed cabin body, there are an optical communication module, a visual positioning camera, and a processing module. On both sides of the pressure-resistant sealed cabin body, there are micro thruster groups.

[0008] Preferably, the surface WiFi communication antenna specifically adopts a 2.4GHz / 5GHz dual-band antenna, and inside it also includes a processor and an encryption chip; the solar power supply unit includes a solar panel and a storage battery.

[0009] Preferably, it further includes a cross-media coupling mechanism, specifically a waterproof and light-transmitting window with an antireflection film on its surface, installed at an angle of 30°, which is used to reduce the interference of reflected light on the water surface, and an optical waveguide layer is integrated on the inner side to reduce the refraction loss.

[0010] Preferably, the optical communication module includes a transmitting LED, a photoelectric detection unit, and a modulation and demodulation unit; a wide-angle lens is provided at the lens end of the visual positioning camera; the processing module includes an MCU chip and a PHY chip.

[0011] A buoy-type cross-media communication system includes a water surface control module and an underwater control module; The water surface control module includes a TCP / IP protocol processor and simultaneously establishes a wireless connection with a remote terminal through WiFi communication; the underwater control module includes a visible light communication control unit, a visual positioning unit, a tracking power unit, and an environment perception and adaptation unit.

[0012] Preferably, the visible light communication control unit includes a transmitting end using a high-brightness blue-green LED array, and a receiving end with a PIN photodiode array and an integrated optical filter, which is used to establish a two-way optical communication link with an underwater robot or sensor and support parallel access of multiple devices; the visual positioning unit includes an LED beacon recognition unit inside, and the LED beacon recognition unit uses an underwater target detection model based on a convolutional neural network to track the position of the LED beacon carried by the underwater robot in real time, calculate the relative azimuth and distance, and the tracking power unit includes a thruster drive control group and a hydrodynamic controller, which actively adjusts the position of the buoy according to the feedback of the visual positioning unit to ensure that the optical communication field of view is covered; the thruster drive control group specifically uses multiple brushless motor-driven micro thrusters; the hydrodynamic controller dynamically adjusts the output of the thruster based on the PID algorithm and the sea current prediction model.

[0013] Preferably, the environment perception and adaptation unit includes a multi-parameter sensor and an adaptive adjustment controller; the multi-parameter sensor specifically uses a water turbidity sensor, a depth sensor, and a temperature sensor; the adaptive adjustment controller is used to dynamically optimize the optical communication parameters according to the environmental data.

[0014] Preferably, it further includes an energy collaborative management circuit module composed of a bidirectional DC-DC converter and an intelligent power distribution switch, which is used to dynamically allocate the energy of the water surface control module and the underwater control module according to the task priority, and preferentially ensure the power supply of the visible light communication control unit and the tracking power unit.

[0015] A buoy-type cross-media communication algorithm includes the following steps: Step 1: Initialization phase. After the buoy enters the water, the automatic deployment of the solar panel is started, and it enters the standby state. The buoy performs a perturbation motion with small random displacements within the horizontal plane at a preset step size to detect the changing trend of signal quality. Meanwhile, GPS positioning is started and a WiFi connection is established with the remote terminal. The underwater control module activates the visible light communication control unit to scan the LED beacon within the field of view angle. Step 2: Communication establishment phase. After detecting the underwater robot beacon, the visual positioning unit calculates the relative pose, and the power system adjusts the position of the buoy to the optimal communication area. The protocol conversion module sends the surface WiFi instructions to the underwater robot through OFDM digital modulation technology. Step 3: Dynamic tracking phase. The motion trajectory of the underwater robot is monitored in real time. Combining with the ocean current prediction model, the micro thruster group finely adjusts the position of the buoy to maintain the field of view angle deviation ≤ ±5°. The environment perception and adaptive unit adjusts the light intensity and divergence angle according to the turbidity data to ensure that the bit error rate ≤ 10⁻ 6 ; Step 4: Energy efficiency management phase. During low load periods, redundant sensors are turned off, and it switches to the energy-saving mode. The energy storage battery preferentially powers the underwater mechanism.

[0016] Preferably, in the communication establishment phase of step 2, it also includes optical signal acquisition and demodulation processing of collecting optical signals through the underwater visible light receiver, extracting modulation information, obtaining the original data packet after demodulation, and calculating the signal-to-noise ratio of the current signal. Comparing the real-time signal-to-noise ratio with the preset threshold as the input error signal of the control system for signal-to-noise ratio feedback and differential control; Calculate the displacement adjustment amount through a proportional-integral-derivative controller:

[0017] where is the signal-to-noise ratio deviation, is the dynamic adjustment coefficient; According to the differential output result, select the moving direction with the fastest signal-to-noise ratio improvement. At the same time, adopt an initial step size of 0.2 m. If the signal-to-noise ratio has not improved after 3 consecutive moves, increase the step size to 0.5 m to quickly approach the optimal position with an adaptive step size strategy for direction determination and step size optimization; In the dynamic tracking phase of step 3, it also includes after the signal reaches the target signal-to-noise ratio, switching to the steady-state tracking mode, compensating for ocean current disturbances through periodic fine-tuning (±0.1 m) to maintain the directivity of the optical communication link for moving tracking.

[0018] Compared with the prior art, the present invention provides a buoyant cross-media communication device, system and its algorithm, which have the following beneficial effects: 1. The buoy-type cross-media communication device adopts a split integrated design that divides the buoy into a water surface mechanism and an underwater mechanism. Through physical separation design, it realizes the independent optimization of the communication modules in the water surface (air medium) and underwater (water medium), effectively avoiding signal crosstalk, effectively avoiding the contradiction between the medium penetration ability and the communication rate. Moreover, through the setting of the solar power supply unit, the device can achieve solar charging, effectively extending the operation time of the device. And through the cross-media coupling mechanism, it reduces the interference of reflected light on the water surface, integrates an optical waveguide layer on the inner side, reduces the refraction loss, realizes lossless transmission, and avoids the situation where underwater acoustic communication has a long distance but a low bandwidth, and optical communication has a high rate but is limited by the medium transmittance. It establishes a wireless connection with a remote terminal through a WiFi communication unit, and can establish a two-way optical communication link with an underwater robot or a sensor, supporting parallel access of multiple devices.

[0019] 2. The buoy-type cross-media communication device system uses an underwater target detection model based on a convolutional neural network through an LED beacon recognition unit to real-time track the position of the LED beacon carried by the underwater robot, calculate the relative azimuth and distance, and then cooperate with the thruster drive control group and the hydrodynamic controller in the tracking power unit. According to the feedback of the visual positioning unit, it actively adjusts the position of the buoy to ensure that the optical communication field of view angle is covered, and conducts a real-time tracking and compensation mechanism for the movement of underwater devices, improving the adaptability to the dynamic environment. It also has the energy efficiency management of turning off redundant sensors and switching to the energy-saving mode during low-load periods, and the energy storage battery preferentially powers the underwater control module.

[0020] 3. The algorithm of the buoy-type cross-media communication device uses a visual positioning system based on the underwater feature point SLAM (Simultaneous Localization and Mapping) algorithm, cooperates with a camera to capture the LED beacon of the underwater robot, and combines the feedback control of the thruster group to realize the dynamic adjustment of the buoy position, ensuring that the deviation of the optical communication field of view angle coverage ≤ ±5°. By fusing the monitoring of communication performance quality, it solves the stability problem of traditional optical positioning and tracking. At the same time, it also performs a perturbed motion with a small random displacement in the horizontal plane at a preset step length to detect the change trend of signal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a buoy-type cross-media communication device proposed by the present invention; Figure 2 It is a schematic diagram of the water surface mechanism in a buoy-type cross-media communication device proposed by the present invention; Figure 3 It is a schematic diagram of the underwater mechanism in a buoy-type cross-media communication device proposed by the present invention; Figure 4 It is a schematic diagram of a buoy-type cross-media communication system proposed by the present invention; Figure 5Schematic diagram of a buoy - type cross - medium communication algorithm proposed by the present invention; Figure 6 Schematic diagram of visual positioning and motion compensation tracking in a buoy - type cross - medium communication algorithm proposed by the present invention; Figure 7 Schematic diagram of a simple scenario of a buoy - type cross - medium communication system proposed by the present invention. Specific implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] Please refer to Figures 1 to 3 , a buoy - type cross - medium communication device, including a buoy. The buoy includes a water - surface mechanism and an underwater mechanism with a split - type modular design, and also includes a cross - medium coupling mechanism. Specifically, it uses a waterproof and light - transmitting window with an anti - reflection coating on the surface (light transmittance ≥ 95%), installed at an angle of 30° to reduce the interference of water - surface reflected light. An optical waveguide layer is integrated inside to reduce refraction loss, and a cross - medium signal is transmitted without loss through a waterproof and light - transmitting coupling structure. By adopting a split - type integrated design that divides the buoy into a water - surface mechanism and an underwater mechanism, and through its physical separation design, independent optimization of the communication modules on the water surface (air medium) and underwater (water medium) is realized, effectively avoiding signal crosstalk; The water - surface mechanism includes a water - surface WiFi communication antenna and a solar power supply module. The water - surface WiFi communication antenna specifically uses a 2.4GHz / 5GHz dual - band antenna, and also includes a processor and an encryption chip inside; The solar power supply unit includes a solar panel and a storage battery. Through the setting of the solar power supply unit, the device can be charged by solar energy, effectively extending the operation time of the device; The underwater mechanism includes a pressure - resistant sealed cabin to strengthen the protection of internal components. Inside the pressure - resistant sealed cabin, there are an optical communication module, a visual positioning camera, and a processing module. The optical communication module includes a transmitting LED, a photoelectric detection unit, and a modulation and demodulation unit; A wide - angle lens is provided at the lens end of the visual positioning camera; The visual positioning camera can specifically use a 2 - megapixel CMOS sensor with a frame rate of 30fps (horizontal field of view >= 120°). The processing module specifically includes an MCU chip and a PHY chip. Micro - thruster groups are provided on both sides of the pressure - resistant sealed cabin. The micro - thruster groups specifically use 4 groups of brushless motor - driven ducted thrusters to miniaturize the device.

[0024] Please refer toFigure 4 , a buoy-type cross-media communication system, including a water surface control module and an underwater control module, further including an energy collaborative management circuit module composed of a bidirectional DC-DC converter (efficiency ≥ 92%) and an intelligent power distribution switch, which is used to dynamically allocate the energy of the water surface control module and the underwater control module according to the task priority, giving priority to ensuring the power supply of the visible light communication control unit and the tracking power unit, greatly reducing the power consumption demand of the device, and effectively extending the operation time of the device; The water surface control module includes a TCP / IP protocol processor and simultaneously establishes a wireless connection with a remote terminal through WiFi communication, with a maximum communication distance ≥ 10 meters; The underwater control module includes a visible light communication control unit, a visual positioning unit, a tracking power unit, and an environment perception and adaptation unit, enabling the system to integrate communication, positioning, and energy module designs. The visible light communication control unit includes a transmitting end using a high-brightness blue-green LED array (wavelength 470 - 530nm) with adjustable peak power (0.1 - 5W), and a receiving end with a PIN photodiode array and an integrated optical filter to suppress background light interference, which is used to establish a two-way optical communication link with an underwater robot or sensor and support parallel access of multiple devices; The visual positioning unit includes an LED beacon recognition unit inside. The LED beacon recognition unit uses an underwater target detection model based on a convolutional neural network (CNN) to real-time track the position of the LED beacon carried by the underwater robot, with an identification delay ≤ 100ms, calculating the relative azimuth and distance, greatly improving the adaptability to the dynamic environment; The tracking power unit includes a thruster drive control group and a hydrodynamic controller. According to the feedback of the visual positioning unit, it actively adjusts the position of the buoy to ensure that the optical communication field of view is covered, and has a real-time tracking and compensation mechanism for the movement of underwater devices such as underwater robots; the thruster drive control group specifically uses multiple groups of brushless motors to drive micro thrusters, and the micro thrusters use ducted thrusters, with a single-group thrust ≥ 20N; the hydrodynamic controller dynamically adjusts the thruster output based on the PID algorithm and the sea current prediction model; The environment perception and adaptation unit includes multi-parameter sensors and an adaptive adjustment controller; the multi-parameter sensors specifically use a water turbidity sensor, a depth sensor, and a temperature sensor; the adaptive adjustment controller is used to dynamically optimize the optical communication parameters (such as transmission power, modulation frequency) according to the environmental data.

[0025] Please refer to Figures 4 to 6 , a buoy-type cross-media communication algorithm, including the following steps: Step 1: Initialization phase. After the buoy (mobile station) enters the water, it automatically unfolds the solar panel and enters the standby state. The buoy performs a perturbation motion with small random displacements in the horizontal plane at a preset step size (such as ±0.2 m) to detect the change trend of signal quality. At the same time, it activates GPS positioning and establishes a WiFi connection with the remote terminal. The underwater control module activates the visible light communication control unit and scans the LED beacons within the field of view angle. Step 2: Communication establishment phase. After detecting the underwater robot beacon, the visual positioning unit calculates the relative pose, and the power system adjusts the position of the buoy to the optimal communication area. The protocol conversion module sends the surface WiFi instructions to the underwater robot through OFDM digital modulation technology. The communication establishment phase also includes collecting optical signals through the underwater visible light receiver, extracting the modulation information (such as OOK / PPM coding specifically), obtaining the original data packet after demodulation, and calculating the signal-to-noise ratio (SNR) of the current signal. Comparing the real-time SNR with a preset threshold (such as ≥20 dB) as the input error signal of the control system for SNR feedback and differential control. Calculate the displacement adjustment amount through a proportional-integral-derivative (PID) controller:

[0026] Where, is the SNR deviation, is the dynamic adjustment coefficient (such as ); According to the differential output result, select the moving direction (such as forward, backward, left, right) with the fastest SNR (SNR optimal is the expectation) improvement. At the same time, adopt an initial step size of 0.2 m. If the SNR has not improved after 3 consecutive moves, increase the step size to 0.5 m to quickly approach the optimal position with an adaptive step size strategy for direction decision and step size optimization. Step 3: Dynamic tracking phase. Real-time monitor the movement trajectory of the underwater robot, combine with the ocean current prediction model, and the micro thruster group finely adjusts the position of the buoy to maintain the field of view angle deviation ≤ ±5°. The environment perception and adaptive unit adjusts the light intensity and divergence angle according to the turbidity data to ensure that the bit error rate ≤ 10⁻ 6 . The dynamic tracking phase also includes that after the signal reaches the target SNR, switch to the steady-state tracking mode, and compensate for the ocean current disturbance through periodic fine adjustment (±0.1 m) to maintain the directivity of the optical communication link for mobile tracking. Step 4: Energy efficiency management phase. During low-load periods, turn off redundant sensors, switch to the energy-saving mode, and the energy storage battery preferentially powers the underwater mechanism.

[0027] The algorithm of the buoy-type cross-media communication device realizes the dynamic adjustment of the buoy position through a vision positioning system based on the underwater feature point SLAM (Simultaneous Localization and Mapping) algorithm, cooperating with a camera to capture the LED beacon of the underwater robot, and combining the feedback control of the thruster group, ensuring that the coverage deviation of the optical communication field of view is ≤ ±5°. By fusing the communication performance quality monitoring, it solves the stability problem of traditional optical positioning and tracking, ensuring the communication stability in complex marine environments.

[0028] All the electrical components mentioned in this article are electrically connected to the external main controller and the 220V / 380V mains, and the main controller can be a conventional known device such as a computer for control.

[0029] In summary, combined with Figure 7 When in use, the buoy of the buoy-type cross-media communication device, system and its algorithm floats on the water surface, and its surface mechanism is exposed above the water surface. On the water surface, a wireless connection is established with remote terminals (mobile phones, computers, shipborne base stations) through WiFi communication, enabling the water operators to send instructions through the user interaction to control the remote terminals. The underwater mechanism emits visible light through the transmitting end of the visible light communication control unit in the system underwater, and then a two-way optical communication link is established with the receiving end of the visible light communication control unit connected by the communication cable on the underwater robot, supporting multi-device parallel access, controlling the operation of the underwater robot for marine environment monitoring and scientific research, intelligent management of aquaculture, underwater equipment collaborative operation, underwater rescue and salvage, and entertainment and marine tourism. Through visible light communication, traditional cables can be replaced, avoiding the restriction of the movement freedom of the experience personnel by traditional communication cables. This invention can also be applied to underwater pool robots. Through the buoy as a water surface communication relay station, it is connected to the shore-based / ship-based terminals (mobile phones, computers) through WiFi, and the underwater part uses visible light communication to interact with the robot in real time, and can transmit sensor data (such as temperature, depth, image) back to the mobile phone remote terminal.

[0030] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one" does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0031] In this application, the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "middle", "outer", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

[0032] Moreover, in addition to being used to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0033] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A buoy-type cross-media communication device, comprising a buoy, characterized in that: The buoy includes a water surface mechanism and an underwater mechanism; The water surface mechanism includes a water surface WiFi communication antenna and a solar power supply module; The underwater mechanism includes a pressure-resistant sealed cabin body, inside which an optical communication module, a visual positioning camera, and a processing module are arranged, and micro thruster groups are arranged on both sides of the pressure-resistant sealed cabin body.

2. The buoyant cross-media communication device according to claim 1, characterized in that: The water surface WiFi communication antenna specifically uses a 2.4GHz / 5GHz dual-band antenna, and also includes a processor and an encryption chip inside; the solar power supply unit includes a solar panel and a storage battery.

3. The buoyant cross-media communication device according to claim 1, characterized in that: It also includes a cross-media coupling mechanism, specifically a waterproof and light-transmitting window with an anti-reflection film on the surface, installed at an angle of 30°, used to reduce the interference of water surface reflected light, and an optical waveguide layer is integrated on the inner side to reduce the refraction loss.

4. The buoyant cross-media communication device according to claim 1, characterized in that: The optical communication module includes a transmitting LED, a photoelectric detection unit, and a modulation and demodulation unit; a wide-angle lens is arranged at the lens end of the visual positioning camera; the processing module includes an MCU chip and a PHY chip.

5. A buoy-type cross-media communication system, characterized in that: It includes a water surface control module and an underwater control module; The water surface control module includes a TCP / IP protocol processor and establishes a wireless connection with a remote terminal through WiFi communication at the same time; The underwater control module includes a visible light communication control unit, a visual positioning unit, a tracking power unit, and an environment perception and adaptation unit.

6. The buoyant cross-media communication system according to claim 5, characterized in that: The visible light communication control unit includes a transmitting end using a high-brightness blue-green light LED array and a receiving end with a PIN photodiode array and an integrated optical filter, used to establish a two-way optical communication link with an underwater robot or sensor and support parallel access of multiple devices; the visual positioning unit includes an LED beacon recognition unit inside, and the LED beacon recognition unit uses an underwater target detection model based on a convolutional neural network to real-time track the position of the LED beacon carried by the underwater robot, calculate the relative azimuth and distance, and the tracking power unit includes a thruster drive control group and a hydrodynamic controller, which actively adjusts the position of the buoy according to the feedback of the visual positioning unit to ensure that the optical communication field of view angle is covered; The thruster drive control group specifically uses multiple groups of brushless motors to drive micro thrusters; The hydrodynamic controller dynamically adjusts the thruster output based on the PID algorithm and the sea current prediction model.

7. A buoyant cross-media communication system according to claim 5, characterized in that: The environment perception and adaptation unit includes a multi-parameter sensor and an adaptive adjustment controller; The multi-parameter sensor specifically uses a water turbidity sensor, a depth sensor, and a temperature sensor; The adaptive adjustment controller is used to dynamically optimize the optical communication parameters according to the environmental data.

8. A buoyant cross-media communication system according to claim 5, characterized in that: It also includes an energy collaborative management circuit module composed of a bidirectional DC-DC converter and an intelligent power distribution switch, used to dynamically allocate the energy of the water surface control module and the underwater control module according to the task priority, and give priority to ensuring the power supply of the visible light communication control unit and the tracking power unit.

9. A buoy-type cross-media communication algorithm, characterized in that: It includes the following steps: Step 1: Initialization phase. After the buoy enters the water, the automatic deployment of the solar panel is started, and it enters the standby state. The buoy performs a perturbation motion with small random displacements within the horizontal plane at a preset step size to detect the change trend of signal quality. At the same time, GPS positioning is started and a WiFi connection is established with the remote terminal. The underwater control module activates the visible light communication control unit to scan the LED beacon within the field of view angle. Step 2: Communication establishment phase. After detecting the underwater robot beacon, the visual positioning unit calculates the relative pose, and the power system adjusts the position of the buoy to the optimal communication area. The protocol conversion module sends the surface WiFi command to the underwater robot through OFDM digital modulation technology. Step 3: Dynamic tracking phase. The movement trajectory of the underwater robot is monitored in real time. Combining with the ocean current prediction model, the micro thruster group finely adjusts the position of the buoy to maintain the field of view angle deviation ≤ ±5°. The environment perception and adaptive unit adjusts the light intensity and divergence angle according to the turbidity data. Step 4: Energy efficiency management phase. During low-load periods, redundant sensors are turned off, and the energy-saving mode is switched. The energy storage battery preferentially powers the underwater mechanism.

10. A buoyant cross-media communication algorithm according to claim 9, characterized in that: In the communication establishment phase of Step 2, it also includes optical signal acquisition and demodulation processing of collecting optical signals through the underwater visible light receiver, extracting modulation information, obtaining the original data packet after demodulation, and calculating the signal-to-noise ratio of the current signal. Comparing the real-time signal-to-noise ratio with the preset threshold as the input error signal of the control system for signal-to-noise ratio feedback and differential control. Calculate the displacement adjustment amount through a proportional-integral-differential controller: ， Among them, is the signal-to-noise ratio deviation, is the dynamic adjustment coefficient; According to the differential output result, select the moving direction with the fastest signal-to-noise ratio improvement. At the same time, adopt an initial step size of 0.2 m. If the signal-to-noise ratio has not improved after 3 consecutive moves, increase the step size to 0.5 m to quickly approach the optimal position with an adaptive step size strategy for direction determination and step size optimization. In the dynamic tracking phase of Step 3, it also includes after the signal reaches the target signal-to-noise ratio, switching to the steady-state tracking mode, and compensating for ocean current disturbances through periodic fine-tuning to maintain the directivity of the optical communication link for moving tracking.

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