Energy supply system for underwater vehicle and energy supply method thereof

Abstract

The application provides an energy supply system of an underwater vehicle and an energy supply method thereof, and the energy supply system comprises a control system, a laser emission system, a laser transmission system and a photoelectric conversion system, wherein the laser emission system and the laser transmission system are installed on a mobile underwater device, and the photoelectric conversion system is installed on the underwater vehicle; the laser transmission system has a laser input end and a laser output end; the control system controls the distance between the laser output end and the photoelectric conversion system to be within a preset range; laser provided by the laser emission system enters the laser transmission system after being incident on the laser input end, is transmitted to the photoelectric conversion system through the laser output end, and is converted into electric energy by the photoelectric conversion system. Through high-power laser, by virtue of the directional transmission characteristics of the high-power laser, by designing the laser transmission system and the photoelectric conversion system, the transmission distance of the laser in seawater is shortened, the utilization efficiency of the laser is improved, the cooling performance of seawater is utilized to realize efficient heat dissipation, and the conversion efficiency and stable working capacity of the photovoltaic receiver are improved.

Description

Technical Field

[0001] This invention relates to the field of underwater vehicles, and particularly to the power supply system and power supply method for underwater vehicles. Background Technology

[0002] Underwater unmanned vehicles (UAVs) are widely used in marine environmental monitoring, seabed surveying, and underwater biological monitoring. However, limited by their own power supply systems, underwater UAVs currently face technical challenges such as short range and limited mission duration, restricting their further application. Therefore, how to power underwater UAVs and improve their endurance has become an important issue that needs to be addressed.

[0003] To address this issue, research into technologies for powering underwater unmanned vehicles (UAVs) has received significant attention and has seen corresponding development. Examples include microwave charging technology for underwater UAVs. However, due to the complexity of the marine environment, these technologies are still in the exploratory research stage.

[0004] With the development of laser technology, laser energy transfer has become a research hotspot in the field. Due to the high coherence of lasers, they are suitable for long-distance transmission, and research on laser-to-unmanned aerial vehicle (UAV) energy transfer technology has been carried out both domestically and internationally. High-power lasers are emitted from a laser transmitting station, and the UAV receives the laser, converting the light energy into electrical energy for the UAV system, thus extending the UAV's loiter time. However, this technology still needs improvement and maturation due to limitations such as laser emission angle, atmospheric attenuation, photoelectric conversion efficiency, and waste heat dissipation techniques.

[0005] Unlike power transfer to unmanned aerial vehicles (UAVs), powering underwater UAVs can be done at a relatively short distance. However, seawater has a significant attenuation effect on lasers. Therefore, this invention proposes a laser-based power supply method for small underwater UAVs. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a wireless power supply system and method for short-range underwater unmanned vehicles.

[0007] To achieve the above objectives, the present invention adopts the following specific technical solution:

[0008] The power supply system of the underwater vehicle includes a control system, a laser emitting system and a laser transmission system, all installed on the underwater mobile equipment, and a photoelectric conversion system installed on the underwater vehicle;

[0009] The laser transmission system has a laser input end and a laser output end, with the laser input end fixedly connected to the laser emission system; the control system controls the length of the laser transmission system, changing the distance between the laser output end and the photoelectric conversion system;

[0010] The laser emitted by the laser emitting system enters the laser transmission system after being incident on the laser input end, and is then transmitted to the photoelectric conversion system via the laser output end; the photoelectric conversion system converts the received laser into electrical energy.

[0011] Furthermore, the laser transmission system includes a sealed cavity with an extendable length; the two ends of the cavity are a laser input end and a laser output end, respectively; an optical lens is installed at the laser output end for laser transmission.

[0012] Furthermore, the cavity contains pure gas for transmitting laser light.

[0013] Furthermore, the pure gas is nitrogen.

[0014] Furthermore, the photoelectric conversion system includes a housing, an optical focusing structure, a photovoltaic receiver, and a heat dissipation structure;

[0015] The housing provides a sealed space, within which the optical focusing structure and photovoltaic receiver are housed.

[0016] The optical focusing structure focuses the laser transmitted from the laser emission system and directs it onto the photovoltaic receiver;

[0017] The heat dissipation structure is mounted on the housing and is used to dissipate heat from the housing.

[0018] Furthermore, the photovoltaic receiver has a converging structure or a photovoltaic eye structure, which focuses the received laser light onto the photovoltaic cell.

[0019] Furthermore, the heat dissipation structure includes heat dissipation fins fixed to the outer surface of the photovoltaic receiver.

[0020] Furthermore, the heat dissipation structure includes a water pipe arranged on the outer surface of the photovoltaic receiver, the water pipe having an inlet and an outlet, seawater entering from the inlet and flowing out of the water pipe from the outlet.

[0021] Furthermore, the shell is filled with nitrogen.

[0022] Furthermore, the laser emission system uses a laser with a wavelength in the blue-green spectrum as the laser source.

[0023] The underwater vehicle is powered by a laser emitting system. The laser is incident on the laser input end and then enters the laser transmission system. The laser is transmitted to the photoelectric conversion system through the laser output end. The photoelectric conversion system converts the received laser into electrical energy. The control system controls the length of the laser transmission system so that the distance between the laser output end and the photoelectric conversion system is within a preset range.

[0024] Furthermore, the underwater vehicle's detection device sends its underwater position information to the control system; based on the underwater position information, the control system controls the underwater vehicle to move within the effective transmission range of the laser transmission system.

[0025] The present invention can achieve the following technical effects:

[0026] By utilizing the directional transmission characteristics of high-power lasers, and by designing laser transmission and photoelectric conversion systems, the transmission distance of lasers in seawater can be shortened, laser utilization efficiency can be improved, and the cooling properties of seawater can be used to achieve efficient heat dissipation, thereby improving the conversion efficiency and stable operation of photovoltaic receivers. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the power supply system of the underwater vehicle disclosed in an embodiment of the present invention.

[0028] Figure label:

[0029] 1. Laser emission system; 2. Laser transmission system; 3. Photoelectric conversion system; 31. Optical focusing structure; 32. Photovoltaic receiver; 33. Heat dissipation fins; 341. Water inlet; 342. Water outlet; 4. Underwater vehicle. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0031] like Figure 1 The power supply system of the underwater vehicle shown includes a laser emitting system 1, a laser transmission system 2, and a photoelectric conversion system 3. The laser emitting system 1 and laser transmission system 2 are mounted on the underwater mobile device, while the high-efficiency photoelectric conversion system 3 is mounted on the underwater vehicle 4, which moves closely alongside it. The underwater mobile device can be a ship or boat. The laser transmission system 2 has a laser input end and a laser output end. The control system controls the lengths of these two ends, thereby controlling the distance between the laser output end and the photoelectric conversion system 3 within a preset range. The laser provided by the laser emitting system 1 enters the laser transmission system 2 after being incident on the laser input end, and is then transmitted to the photoelectric conversion system 3 via the laser output end. The photoelectric conversion system 3 converts the received laser into electrical energy. The laser attenuates significantly during underwater transmission, generally exhibiting exponential attenuation. The preset range depends on the underwater vehicle to be powered and the power of the laser used for power supply; theoretically, the shorter the range, the better.

[0032] The power supply system or method for laser-based small underwater unmanned vehicles (UAVs) utilizes the high directionality and high energy transmission of lasers. By irradiating the UAV with a photoelectric conversion system 3, the laser energy is converted into electrical energy to power the UAV. Limited by the current technological level of high-power lasers and photovoltaic equipment, this solution is suitable for small UAVs with low power requirements and can provide technical support for typical applications such as emergency power supply and extended endurance for small underwater UAVs.

[0033] In this system, the high-power laser emission system 1 preferably uses a solid-state laser with a wavelength of 532nm as the laser source, which has good transmission performance in seawater environments and mature laser technology. High-power laser light can be obtained by spatially combining multiple lasers. Alternatively, a laser with a wavelength in the blue-green spectrum that has good propagation performance in water is preferred. This laser is required to have a high power-to-volume ratio, enabling it to output high-power laser light in a small volume. The laser light is shaped to preset parameters (including at least the spot size and divergence angle) and then emitted into the laser transmission system 2. The laser divergence angle and spot size directly affect the spot size of the laser light after transmission through the cavity. For example, if the spot size is 20mm, the laser divergence angle is 5mrad, and the cavity length is 20m, the output laser spot size will be 20mm + 5*20 = 120mm.

[0034] The laser transmission system 2 is a retractable, sealed optical transmission cavity with a laser input end and a laser output end at its two ends. The cavity is filled with a pure gas medium, preferably nitrogen. Filling the cavity with a pure gas such as nitrogen avoids deformation caused by water pressure and ensures minimal laser attenuation during transmission. The cavity is used to transmit the laser, and the pure gas filling minimizes transmission loss. One end of the system is tightly fixed to the high-power laser emission system 1, while the other end can be lengthened / shortened according to the distance between the underwater vehicle and the high-power laser emission system 1, changing the distance between the laser input and output ends. This ensures the laser output end is within a preset range and aligned with the photoelectric receiving and conversion system installed on the underwater unmanned vehicle. Because laser attenuation is severe in water, the distance between this end and the photoelectric receiving and conversion system should not be too far. An optical lens needs to be installed at the output end, sealed within the laser transmission system by a mechanical structure. The laser must be transmitted through the optical lens.

[0035] Preferably, the laser transmission system 2 also includes an electronic control device, which includes a motor that drives the cavity to extend or shorten; the control system is connected to the electronic control device. The structural features of a cam mechanism can be utilized, as cam mechanisms convert rotation into linear motion. The electronic control device converts the motor's rotation into linear motion of the cavity, achieving cavity length adjustment, similar to the extension / retraction method of a SLR camera lens. The structure of the laser transmission system 2 can adopt that of an SLR camera, preferably with the lens barrel filled with pure gas or in a pure gas environment.

[0036] The photoelectric conversion system 3 includes a housing, an optical focusing structure 31, a photovoltaic receiver 32, and a heat dissipation structure. The housing provides a sealed space, within which the optical focusing structure 31 and the photovoltaic receiver 32 are placed. The optical focusing structure 31 focuses the laser transmitted from the laser emitting system 1 onto the photovoltaic receiver 32. The heat dissipation structure is mounted on the housing and is used to dissipate heat from the housing; preferably, the heat dissipation structure described later is used. The photovoltaic receiver 32 is a high-efficiency focusing type or photovoltaic eye structure, which focuses the received laser onto a photovoltaic cell. The heat dissipation structure includes heat dissipation fins 33 fixed to the outer surface of the photovoltaic receiver 32. The heat dissipation structure also includes a water-cooling device arranged inside the photovoltaic receiver 32, which is filled with seawater. When the photovoltaic receiver receives laser light, it converts the laser light into electrical energy. The heat generated during the conversion is transferred to the heat dissipation fins on the outer surface through the heat dissipation structure. The heat dissipation fins increase the heat dissipation area. The heat dissipation fins are in contact with seawater, and there is a temperature difference between the seawater and the heat dissipation fins. The heat is transferred from the heat dissipation fins to the seawater inside the water-cooling device. The temperature of the seawater inside the water-cooling device rises, creating a temperature difference with the seawater outside the water-cooling device. This temperature difference drives the seawater inside the cooling device to flow with the external seawater through the port of the cooling device. This causes the temperature of the seawater inside the cooling device to drop, thereby lowering the temperature of the photovoltaic receiver and effectively dissipating the waste heat during the conversion process. The cooling device has an inlet 341 and an outlet 342. Seawater enters through the inlet 341 and flows out through the outlet 342. This part utilizes the excellent heat dissipation capacity of water to cool the vehicle's battery. The structure of the cooling device can be referenced from existing technologies in the field of radiator cooling; only the cooling source has been changed and will not be described in detail here.

[0037] The photoelectric receiving and conversion system converts laser energy into electrical energy for the underwater unmanned vehicle. The photoelectric conversion system 3 is installed on the underwater unmanned vehicle. The optical focusing structure 31 and the photovoltaic receiver 32 form a sealed space, preferably filled with clean nitrogen. The optical focusing structure 31 focuses the laser transmitted from the laser emitting system 1 and directs it to the photovoltaic receiver 32, ensuring a high flux of laser light entering the photovoltaic converter and improving photoelectric conversion efficiency. The photovoltaic receiver 32 preferably features a high-efficiency photovoltaic eye structure, where the laser light is focused onto a small photovoltaic cell after multiple reflections. Heat dissipation fins 33 are machined onto the surface of the photovoltaic receiver 32; the size and number of fins are designed according to the volume and capabilities of the underwater vehicle. Utilizing the excellent heat dissipation properties of water, the photoelectric conversion system 3 incorporates inlet and outlet ports to ensure even distribution of water on the surface of the photovoltaic receiver 32, achieving a heat dissipation effect.

[0038] The laser emitted by the high-power laser emitting system 1 enters the laser transmission system 2. Before entering the transmission system, the laser beam is expanded and shaped to ensure that the output spot size meets the requirements after transmission. The laser spot has a preset divergence angle. When passing through the laser transmission system 2 at this divergence angle, the laser spot size at the exit of the laser transmission system 2 is within the output mirror (the output mirror is the laser output end of the laser transmission system 2, opposite the photoelectric conversion system 3 of the unmanned vehicle, and the distance between the two is the transmission distance of the laser in seawater). The laser transmission system 2 has an adjustable power supply. When powering the unmanned vehicle, it can be adjusted according to the relative position of the vehicle and the high-power laser emitting system 1 to ensure that the output mirror of the laser transmission system 2 is close to the photoelectric conversion system 3 of the unmanned vehicle. The laser transmission system 2 can use methods such as filling with clean nitrogen to ensure laser transmission efficiency. Using the underwater position detection device carried by the underwater vehicle 4, the control system uses existing detection technology to control the underwater vehicle 4 to approach the power supply system and enter the effective transmission range of the laser transmission system 2 based on the received underwater position of the underwater vehicle 4. Two preferred methods are used to further control the distance between the output end of the laser transmission system 2 and the photoelectric conversion system 3. The first method involves adjusting the electronic control device through the control system to extend the laser transmission system 2 towards the underwater vehicle 4, maintaining the distance between the output end of the laser transmission system and the underwater vehicle 4 within a preset range to prevent severe laser attenuation during transmission through seawater. During this process, the distance between the output end and the photoelectric conversion system 3 can be precisely adjusted by rotating the motor; ideally, the laser transmission system and the underwater vehicle's photoelectric conversion system can make contact. The second method, when the effective transmission range is determined to be greater than the maximum extension length of the output end, involves directly extending the laser transmission system 2 to its maximum length, facilitating rapid distance adjustment.

[0039] The underwater vehicle is powered by a laser emitting system 1, which emits laser light into the laser input end and then into the laser transmission system 2. The control system controls the distance between the laser output end and the photoelectric conversion system 3 within a preset range. The laser light is transmitted to the photoelectric conversion system 3 via the laser output end. The photoelectric conversion system 3 converts the received laser light into electrical energy.

[0040] Based on current technological levels, the photoelectric conversion efficiency of commercial products can reach 24%–25%, while that of aerospace products exceeds 30%. 532nm laser technology is relatively mature. Based on the transmission performance of this wavelength of laser in water, the laser's transmission capacity η can be estimated using the following formula:

[0041] η = η l η w η r η t (1)

[0042] Where, η l The transmittance of laser transmission system 2 is expected to be 95% based on current technology; η r The transmittance of the optical focusing structure 31 is expected to be 95% based on current technology; η t The photoelectric conversion efficiency of the photovoltaic receiver 32, referencing aerospace battery levels, is expected to be 30%; η w The transmittance of this wavelength of laser light in water is significantly affected by seawater, with large differences in different sea areas and seasons. Taking the South my country Sea as an example, a laser attenuation coefficient of 0.3 can be selected. When the output mirror of the laser transmission system 2 is 2m away from the optical focusing structure 31 of the photoelectric conversion system 3 (i.e., the laser travels 2m through seawater), the conversion efficiency is higher, reaching 16%. In this state, η represents the conversion efficiency. w The effect is significant; the closer the distance, the higher the conversion efficiency.

[0043] This functional system and method address the power supply problem for small underwater unmanned vehicles (UAVs). Utilizing the directional transmission characteristics of high-power lasers, a laser transmission system (2) and a photoelectric conversion system (3) are designed to shorten the laser's transmission distance in seawater, improving laser utilization efficiency. The cooling properties of seawater are leveraged for efficient heat dissipation, enhancing the conversion efficiency and stable operation of the photovoltaic receiver (32). This method is suitable for short-range wireless power supply scenarios for underwater UAVs. The variable-length laser transmission path design reduces laser transmission attenuation caused by the water medium. The photovoltaic receiver system design improves photoelectric conversion efficiency, and the excellent heat dissipation capabilities of water enhance waste heat dissipation during photoelectric conversion, thereby improving system stability.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0045] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0046] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A power supply system for an underwater vehicle, characterized in that, This includes a control system, a laser emission system and a laser transmission system, all installed on underwater mobile equipment, and a photoelectric conversion system installed on the underwater vehicle; The laser transmission system has a laser input end and a laser output end, and the laser input end is fixedly connected to the laser emission system; the control system controls the length of the laser transmission system and changes the distance between the laser output end and the photoelectric conversion system; The laser transmission system includes a sealed cavity containing a pure gas for transmitting laser light, and the length of the cavity is extendable. The two ends of the cavity are the laser input end and the laser output end, respectively. An optical lens is installed at the laser output end to allow the laser light to pass through for transmission. The laser light emitted by the laser emission system enters the laser transmission system after being incident on the laser input end, and is then transmitted to the photoelectric conversion system via the laser output end. The photoelectric conversion system converts the received laser light into electrical energy.

2. The power supply system for the underwater vehicle according to claim 1, characterized in that, The pure gas is nitrogen.

3. The power supply system for the underwater vehicle according to claim 1, characterized in that, The photoelectric conversion system includes a housing, an optical focusing structure, a photovoltaic receiver, and a heat dissipation structure; The housing provides a sealed space, within which the optical focusing structure and the photovoltaic receiver are placed; The optical focusing structure is used to focus the received laser light and then direct it onto the photovoltaic receiver; The photovoltaic receiver is used for photoelectric conversion; The heat dissipation structure is mounted on the housing and is used to dissipate heat from the housing.

4. The power supply system for the underwater vehicle according to claim 3, characterized in that, The photovoltaic receiver is a converging structure or a photovoltaic eye structure, which focuses the received laser light onto the photovoltaic cell.

5. The power supply system for an underwater vehicle according to claim 3, characterized in that, The heat dissipation structure includes heat dissipation fins fixed to the outer surface of the photovoltaic receiver.

6. The power supply system for an underwater vehicle according to claim 5, characterized in that, The heat dissipation structure also includes a cooling device arranged within the photovoltaic receiver, the cooling device having an inlet and an outlet, seawater entering through the inlet and exiting through the outlet.

7. The power supply system for an underwater vehicle according to claim 3, characterized in that, The shell is filled with nitrogen gas.

8. The power supply system for an underwater vehicle according to claim 1, characterized in that, The laser emission system uses a laser with a wavelength in the blue-green spectrum as the laser source.

9. A power supply method for an underwater vehicle, characterized in that, The laser emitted by the laser emission system enters the laser transmission system after being incident on the laser input end. The laser transmission system includes a sealed cavity containing a pure gas for transmitting the laser. The length of the cavity is extendable. The two ends of the cavity are the laser input end and the laser output end, respectively. An optical lens is installed at the laser output end to allow the laser to pass through for transmission. The laser is transmitted to the photoelectric conversion system via the laser output end, and the photoelectric conversion system converts the received laser into electrical energy; the control system controls the length of the laser transmission system so that the distance between the laser output end and the photoelectric conversion system is within a preset range.

10. The power supply method for an underwater vehicle according to claim 9, characterized in that, The underwater vehicle carries a detection device that transmits the underwater vehicle's underwater position information to the control system; the control system, based on the underwater position information, controls the underwater vehicle to move to the effective transmission range of the laser transmission system.

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