Underwater operation equipment, underwater wireless charging system and wireless charging method thereof

Abstract

The invention provides underwater operation equipment, an underwater wireless charging system and a wireless charging method thereof. The underwater wireless charging system comprises a wireless charging transmitting device and a wireless charging receiving device, the wireless charging transmitting device comprises a control module and a coil antenna array, the coil antenna array comprises a plurality of transmitting coils, and the transmitting coils are used for transmitting electromagnetic waves. The control module is used for adjusting the phase angle and the power of each transmitting coil according to the offset distance and the offset angle between the receiving coil and the transmitting coil, the wireless charging receiving device comprises a receiving coil, the receiving coil is used for receiving electromagnetic waves to generate charging current, and the wireless charging receiving device is used for being installed on an unmanned underwater vehicle.

Description

Technical Field

[0001] The present application belongs to the field of underwater wireless charging technology, and specifically, relates to underwater operation equipment, a wireless charging system and a charging method thereof. Background Art

[0002] In recent years, my country's exploration, research and application of marine resources have become increasingly advanced. Unmanned underwater vehicles (AUVs) have been applied to underwater mineral monitoring, military reconnaissance and other fields due to their safety and intelligence. However, due to the space limitations of the payload platform, AUVs currently have defects such as limited battery power and short endurance.

[0003] There are currently two ways to charge AUV batteries: the first is for the AUV to set a battery warning and actively float up, return to port, dock at the mother ship, or manually salvage and recharge. However, this method has high labor costs, and the AUV cannot be far away from the base or mother ship, making it difficult to operate in the open sea. The second method is to charge using underwater cables and wet plug-in interfaces, with rubber rings sealing both sides of the interface. However, since seawater has good conductivity, this method is prone to leakage due to aging and wear of the interface. Therefore, marine resource exploration and development urgently need a new type of energy replenishment method.

[0004] Wireless Power Transfer (WPT) can solve the problem of AUV power replenishment with its outstanding safety, automation level, and concealment. The mature wireless charging systems on the market are all wireless charging systems on land and above the water surface. However, seawater has extremely strong conductivity, and electromagnetic waves will have eddy current losses when transmitted underwater. At the same time, the impact of underwater water flow can easily cause the primary and secondary coils to be eccentric and offset, resulting in charging losses. Summary of the invention

[0005] The technical problem solved by the present application is: how to reduce the charging loss caused by the eccentricity and offset of the primary and secondary coils in the underwater wireless charging system.

[0006] The present application provides an underwater wireless charging system, the underwater wireless charging system comprising:

[0007] A wireless charging transmitting device, the wireless charging transmitting device comprising a control module and a coil antenna array, the coil antenna array comprising a plurality of transmitting coils, the transmitting coils being used to transmit electromagnetic waves, the control module being used to adjust the phase angle and power of each transmitting coil according to an offset distance and an offset angle between the receiving coil and the transmitting coil;

[0008] A wireless charging receiving device, comprising a receiving coil, wherein the receiving coil is used to receive electromagnetic waves to generate a charging current, and the wireless charging receiving device is used to be installed on an unmanned underwater vehicle.

[0009] Optionally, the coil antenna array includes five transmitting coils, one transmitting coil is located in the center, and the other four transmitting coils surround the transmitting coil located in the center.

[0010] Optionally, the control module includes a main control unit and multiple high-frequency inverter circuits, each of the high-frequency inverter circuits is connected to the transmitting coil, the high-frequency inverter circuit is used to process the input current and output the processed current to the transmitting coil, and the main control unit is used to control the current processing process of the high-frequency inverter circuit to adjust the phase angle and power of the transmitting coil.

[0011] Optionally, the control module further includes a plurality of composite compensation circuits, each of which is connected in series between each of the high-frequency inverter circuits and the transmitting coil, and the composite compensation circuit is used to switch between different charging modes.

[0012] Optionally, the charging mode includes a constant current charging mode and a constant voltage charging mode.

[0013] Optionally, the control module is used to adjust the phase angle and power of each transmitting coil according to the offset distance and the offset angle between the receiving coil and the transmitting coil, including:

[0014] Constructing the transmission coefficient equations of coil antenna array based on magnetic beamforming method;

[0015] Solving the amplitude value of the transmission coefficient equation group according to the offset distance, and determining the power of the transmitting coil according to the amplitude value;

[0016] Solve the transmission coefficient equations for the phase angle based on the offset angle.

[0017] Optionally, solving the phase angle of the transmission coefficient equation group according to the offset angle includes:

[0018] The particle swarm algorithm is used to solve the transmission coefficient equations and obtain the optimal phase angle of each transmitting coil.

[0019] The present application also discloses an underwater working equipment, which includes an unmanned underwater vehicle and the underwater wireless charging system described above, wherein the wireless charging receiving device is installed on the unmanned underwater vehicle.

[0020] The present application also discloses a wireless charging method for an underwater wireless charging system, the wireless charging method comprising:

[0021] After charging starts, the offset distance and offset angle between the receiving coil and the transmitting coil are obtained in real time;

[0022] According to the offset distance and the offset angle, a control module is used to adjust the phase angle and power of each transmitting coil.

[0023] The present application provides an underwater operation equipment, an underwater wireless charging system and a charging method thereof, which have the following technical effects:

[0024] The underwater wireless charging system adjusts the phase angle and power of each transmitting coil according to the real-time offset distance and offset angle to optimize the power of the charging coil and overcome the charging loss caused by the eccentricity and offset of the original secondary coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a basic principle block diagram of an underwater wireless charging system according to one or more embodiments;

[0026] Figure 2 is a detailed architecture diagram of an underwater wireless charging system according to one or more embodiments;

[0027] Figure 3 is a schematic diagram of a coil antenna array and a transmitting coil according to one or more embodiments;

[0028] Figure 4 is a schematic diagram of the principle of magnetic beamforming according to one or more embodiments;

[0029] Figure 5 It is a schematic diagram of the structure of the LCL-S compensation circuit in the prior art;

[0030] Figure 6 FIG. 4 is a schematic diagram of a composite compensation circuit structure according to one or more embodiments. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] Before describing the various embodiments of the present application in detail, the technical concept of the present application is first briefly described: when the mature wireless charging system currently used on land is applied to underwater environments such as the ocean, the impact of water flow can easily cause the primary and secondary coils to become eccentric and offset, thereby causing problems such as charging loss. To this end, the present application provides an underwater wireless charging system, including a wireless charging transmitter and a wireless charging receiver. The wireless charging transmitter has a control module and a coil antenna array composed of a number of transmitting coils. The control module can adjust the phase angle and power of each transmitting coil according to the offset distance and offset angle between the receiving coil and the transmitting coil, thereby overcoming the problem of charging loss caused by poor coupling of the underwater charging coils. The specific principles of the underwater wireless charging system and its wireless charging method of the present application are described below in conjunction with more embodiments.

[0033] Specifically, Figure 1 and Figure 2 As shown, the underwater wireless charging system of the first embodiment includes a wireless charging transmitting device and a wireless charging receiving device. The wireless charging transmitting device includes a control module and a coil antenna array. The coil antenna array includes a plurality of transmitting coils. The transmitting coil is used to transmit electromagnetic waves. The control module is used to adjust the phase angle and power of each transmitting coil according to the offset distance and offset angle between the receiving coil and the transmitting coil, so as to overcome the charging loss caused by the poor coupling of the charging coil to ensure the optimal charging power. The wireless charging receiving device is used to be installed on an unmanned underwater vehicle. The wireless charging receiving device includes a receiving coil. The receiving coil is used to receive electromagnetic waves to generate a charging current to charge the unmanned underwater vehicle. The underwater wireless charging system of the present embodiment is a multi-terminal input and single-terminal output wireless charging system, that is, multiple transmitting coils charge one receiving coil.

[0034] In one or more embodiments, Figure 3 As shown, the coil antenna array includes five transmitting coils, one of which is located in the center, and the other four transmitting coils are arranged around the transmitting coil in the center. Exemplarily, the centers of the four outer transmitting coils are located on the same circumference, the central transmitting coil is concentric with the circumference, and the angle formed by the center of two adjacent transmitting coils and the line connecting the center of the circumference of the circle is 90 degrees. Exemplarily, the transmitting coil uses W=4mm Litz wire arranged in a clockwise spiral, with an outer diameter of 345mm and the number of turns N=30 turns. The coil antenna array uses five transmitting coils, 4 of which are placed on a circle with a diameter of 691mm and 1 at the center of the circle, and a circular magnetic isolation sheet with a diameter of 1035mm is set on the bottom.

[0035] It should be noted that the number of transmitting coils can be other, and the structural parameters such as the outer diameter, number of turns, and position of the transmitting coil can be designed according to actual needs. Among them, the outer diameter and number of turns are related to the frequency bandwidth of wireless energy transmission. The placement of each transmitting coil is related to the coherence of the magnetic beam, that is, the distance between each coil on a straight line is 2^nth of the wavelength based on the wavelength of the transmission wave.

[0036] In one or more embodiments, the control module includes a main control unit and a multi-channel high-frequency inverter circuit, each high-frequency inverter circuit is connected to a corresponding transmitting coil, and the high-frequency inverter circuit is used to process the input current and output the processed current to the transmitting coil, and the main control unit is used to control the current processing process of the high-frequency inverter circuit to adjust the phase angle and power of the transmitting coil. Exemplarily, the main control unit adopts an STM32F743 main controller, the main frequency operates at 216MHz, and has a hardware floating-point unit (FPU), which fully meets the charging and communication frequency requirements of this embodiment, and can design multi-channel function signal generator software and particle algorithm computing capabilities. The high-frequency inverter circuit is a power-controllable high-frequency inverter circuit, according to the charging process.

[0037] Furthermore, the control module is used to adjust the phase angle and power of each transmitting coil according to the offset distance and offset angle between the receiving coil and the transmitting coil, including constructing a transmission coefficient equation group of the coil antenna array based on the magnetic beamforming method; solving the amplitude value of the transmission coefficient equation group according to the offset distance, and determining the power of the transmitting coil according to the amplitude value; solving the phase angle of the transmission coefficient equation group according to the offset angle. Among them, magnetic beamforming is very similar to the beamforming (BF) technology in the wireless communication system, which uses each transmitting coil to transmit the same frequency signal with different phases and intensities, and interferes with each other to form an omnidirectional beam into a directional beam. Magnetic beamforming operates on the magnetic field in the near field, and adjusts the magnetic field distribution to make the magnetic field distribution more concentrated, so as to improve the transmission power of the wireless energy transmission system, reduce losses, and offset the influence of the offset distance and offset angle on energy transmission.

[0038] Specifically, magnetic waves are also a type of wave, so they also have wave-related properties. By using the coherence of waves, the waves can be enhanced in a certain direction. The coil antenna array of this embodiment forms an array-shaped wave, which is a three-dimensional beam enhancement in spatial distribution. In order to illustrate mathematical coherence, the three transmitting coils in the same column of the coil antenna array of this embodiment are taken as an example to form a linear array. The principle of beam angle change is explained on a plane, which can be extended to a three-dimensional scene. Exemplarily, O1, O2, and O3 respectively represent the center origins of the three transmitting coils in the same column, radiating magnetic waves outward.

[0039] According to the mathematical formula of waves It can be seen that A, since the center points of O1, O2, and O3 are fixed, they form a propagation array and are regarded as an antenna. By using the coherence of the wave during transmission and adjusting the phase angles of different transmitting coils, the enhancement at a specific angle in the propagation direction can be obtained, that is, the beam of the magnetic wave is constrained in the propagation direction, and the following transmission coefficient equations of the coil antenna array are constructed:

[0040]

[0041] Among them, when the phase angles ω1=ω2=ω3, the magnetic wave will be strengthened in the center direction and relatively weakened in other directions, such as Figure 4 When ω1=ω2+π / 4=ω3++π / 2, the magnetic wave will be strengthened in the direction of the offset angle θ, and will be relatively weak in other directions, such as Figure 4 As shown in the right figure of . Based on this, it can be derived to the three-dimensional sphere to calculate the phase angles of different transmitting coils. For example, this embodiment has 5 transmitting coils, and the phase angles ω1, ω2, ω3, ω4, and ω5 of each transmitting coil can be calculated. According to this principle, beam enhancement in different directions can be achieved by adjusting the phase angle combination. Among them, A represents the amplitude, which is equivalent to the power of each transmitting coil, which is adjusted according to the offset distance.

[0042] Furthermore, for the case of multiple transmitting coils, there are different combinations of phase angles. In order to quickly solve the enhanced vector angle of the magnetic wave in a specific direction on the spherical surface, a particle swarm algorithm is introduced to solve the different phase angles required. Among them, the particle swarm algorithm adopts the mature standard algorithm of this embodiment. The basic process is shown in the reference figure, and the detailed process of the algorithm is not repeated here. In the standard particle swarm algorithm, a variable inertia factor design is adopted. The learning factor controls the self-learning and group learning of the particles respectively so that the particle swarm quickly converges. Then the perturbation strategy is introduced to prevent the basic particle swarm algorithm from converging too quickly, affecting the final input current matrix and causing a large magnetic field dispersion.

[0043] In one or more embodiments, the control module further includes a plurality of composite compensation circuits, each composite compensation circuit is connected in series between each high-frequency inverter circuit and the transmitting coil, and the composite compensation circuit is used to switch different charging modes, including a constant current charging mode and a constant voltage charging mode. Figure 5 As shown, the traditional LCL-S compensation circuit structure has the problem of low voltage gain. This embodiment improves it into an LCC / SS type composite compensation circuit, such as Figure 6 S1 and S2 use programmable relay switches. When S1 is closed and S2 is open, it is in constant current charging mode. When S1 is open and S2 is closed, it is in constant voltage charging mode.

[0044] Furthermore, the wireless charging receiving device also includes a secondary side compensation circuit, a rectifier circuit and a main control unit. The main control unit here adopts an STM32F743 main controller. The rectifier circuit rectifies the current generated by the receiving coil to form a charging current to charge the battery.

[0045] In one or more embodiments, the underwater working equipment includes an unmanned underwater vehicle and the underwater wireless charging system described above, and the wireless charging receiving device is installed on the unmanned underwater vehicle.

[0046] In one or more embodiments, the wireless charging method of the underwater wireless charging system includes the following steps:

[0047] Step S10: After charging starts, the offset distance and the offset angle between the receiving coil and the transmitting coil are obtained in real time;

[0048] Step S20: According to the offset distance and the offset angle, the phase angle and power of each transmitting coil of the control module are controlled.

[0049] Wherein, step S10 uses conventional electromagnetic wave distance measurement and antenna direction measurement methods to determine the offset distance and offset angle between the receiving coil and the transmitting coil. Exemplarily, each coil of this embodiment is integrated with a transmitter and receiver, and can be used for communication and measurement when no energy transmission is performed.

[0050] Exemplarily, the detailed process of adjusting the phase angle and power of each transmitting coil by using the control module according to the offset distance and the offset angle in step S20 can be referred to the relevant description of the above embodiment, which will not be described in detail here.

[0051] The specific implementation methods of the present application are described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments can be modified and improved without departing from the principles and spirit of the present application whose scope is defined by the claims and their equivalents. These modifications and improvements should also be within the scope of protection of the present application.

Claims

1. An underwater wireless charging system, characterized in that: The underwater wireless charging system comprises: A wireless charging transmitting device, the wireless charging transmitting device comprising a control module and a coil antenna array, the coil antenna array comprising a plurality of transmitting coils, the transmitting coils being used to transmit electromagnetic waves, the control module being used to adjust the phase angle and power of each transmitting coil according to an offset distance and an offset angle between the receiving coil and the transmitting coil; A wireless charging receiving device, comprising a receiving coil, wherein the receiving coil is used to receive electromagnetic waves to generate a charging current, and the wireless charging receiving device is used to be installed on an unmanned underwater vehicle.

2. The underwater wireless charging system according to claim 1, characterized in that: The coil antenna array includes five transmitting coils, one of which is located at the center, and the other four transmitting coils surround the transmitting coil at the center.

3. The underwater wireless charging system according to claim 1, characterized in that: The control module includes a main control unit and multiple high-frequency inverter circuits, each of which is connected to the transmitting coil. The high-frequency inverter circuit is used to process the input current and output the processed current to the transmitting coil. The main control unit is used to control the current processing process of the high-frequency inverter circuit to adjust the phase angle and power of the transmitting coil.

4. The underwater wireless charging system according to claim 3, characterized in that: The control module further includes a multi-channel composite compensation circuit, each of which is connected in series between each of the high-frequency inverter circuits and the transmitting coil, and the composite compensation circuit is used to switch between different charging modes.

5. The underwater wireless charging system according to claim 4, characterized in that: The charging mode includes a constant current charging mode and a constant voltage charging mode.

6. The underwater wireless charging system according to claim 1, characterized in that: The control module is used to adjust the phase angle and power of each transmitting coil according to the offset distance and offset angle between the receiving coil and the transmitting coil, including: Constructing the transmission coefficient equations of coil antenna array based on magnetic beamforming method; Solving the amplitude value of the transmission coefficient equation group according to the offset distance, and determining the power of the transmitting coil according to the amplitude value; Solve the transmission coefficient equations for the phase angle based on the offset angle.

7. The underwater wireless charging system according to claim 6, characterized in that: Solving the transmission coefficient equations for the phase angle based on the offset angle includes: The particle swarm algorithm is used to solve the transmission coefficient equations and obtain the optimal phase angle of each transmitting coil.

8. An underwater operation equipment, characterized in that: The underwater operation equipment includes an unmanned underwater vehicle and an underwater wireless charging system according to any one of requirements 1 to 7, and the wireless charging receiving device is installed on the unmanned underwater vehicle.

9. A wireless charging method for an underwater wireless charging system according to any one of claims 1 to 7, characterized in that: The wireless charging method comprises: After charging starts, the offset distance and offset angle between the receiving coil and the transmitting coil are obtained in real time; According to the offset distance and the offset angle, a control module is used to adjust the phase angle and power of each transmitting coil.

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