Movable wireless charging coil device of underwater equipment

Abstract

The invention provides a movable wireless charging coil device for underwater equipment, a transmitting end magnetic core is fixedly connected to a support and is in a circular ring shape, and a transmitting end coil on the surface of the transmitting end magnetic core is used for being aligned with a receiving end coil on the underwater equipment. The detection coil parallel to the transmitting end coil can detect a current value generated by offset between the receiving end coil and the transmitting end coil. The electromagnet assembly holds the equipment and the charging coil device together when the transmitting and receiving end coils are aligned. The underwater thruster assembly can translate the bracket in the axial direction and the radial direction of the transmitting end coil. A BP neural network model is also established, a calculation matrix of coil offset and detection coil current is obtained, and rapid and accurate alignment of the transmitting end coil and the receiving end coil can be realized during charging docking, so that the charging docking time is shortened, and after the alignment is completed, the charging docking efficiency is improved. The electromagnet can ensure that the transmitting end coil and the receiving end coil do not move relatively in the charging process and keep accurate alignment, so that the wireless electric energy transmission efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless charging of underwater equipment, and in particular relates to a movable wireless charging coil device for underwater equipment. Background Art

[0002] Underwater equipment, including autonomous underwater vehicles (UUVs), has attracted much attention due to its importance in ocean exploration. It is small in size, highly maneuverable, well concealed, highly adaptable to the environment, and has no risk of casualties. Currently, there are two main ways to increase the endurance of underwater equipment: one is to use high-energy-density batteries as a power source, and the other is to use an underwater electric energy supply system to supply energy to the equipment.

[0003] The underwater wireless power transmission technology has the advantages of strong safety, high automation level and strong concealment, which can better solve the power supply needs of underwater equipment. The underwater wireless charging base station transmits wireless power to the underwater equipment by aligning the receiving coil on the underwater equipment with the transmitting coil at the base station to achieve power supply for the equipment.

[0004] At present, when underwater equipment uses underwater wireless charging base stations to replenish power, it usually relies on the underwater equipment to autonomously approach the transmitting coil fixed at the base station and align its receiving coil with the transmitting coil, and then start power transmission. During the charging process, the underwater equipment is in a free state. In this case, in some areas with complex sea conditions, the underwater equipment is easily affected by the flow of seawater during the power transmission process and rotates, deviates, etc., resulting in two problems in the current wireless power transmission of underwater equipment using underwater wireless charging base stations: First, during the wireless power transmission between the underwater equipment and the base station underwater, it is difficult for the transmitting end and the receiving end to be accurately aligned for a long time, resulting in low power transmission efficiency of the base station and long charging time; second, it is difficult for the underwater equipment to accurately and quickly align with the base station underwater, resulting in a high time cost for charging the underwater equipment. Summary of the invention

[0005] The purpose of the present invention is to solve the problem in the prior art that when underwater equipment uses a wireless charging base station for energy replenishment, it is difficult to accurately align it for a long time under complex sea conditions, and it is difficult to accurately and quickly align it, resulting in low power transmission efficiency and high charging time cost. A movable wireless charging coil device for underwater equipment is provided, which can assist the underwater wireless charging base station and can quickly, stably and efficiently replenish power for underwater equipment under complex sea conditions.

[0006] To achieve the above purpose, the technical solution provided by the present invention is:

[0007] A movable wireless charging coil device for underwater equipment, used to be connected to an underwater wireless charging base station to dock with the underwater equipment for wireless charging, comprising a bracket, a transmitting end magnetic core, a transmitting end coil, a detection coil, a sensor, an electromagnet assembly, an underwater thruster assembly and a controller;

[0008] The bracket is used to support the movable wireless charging coil device;

[0009] The transmitting end magnetic core is fixedly connected to the bracket and is in a ring shape. The conductor of the transmitting end coil is coaxially wound on the surface of the transmitting end magnetic core and is used to align with the receiving end coil arranged on the underwater equipment to perform electromagnetic coupling and charge the underwater equipment.

[0010] The detection coil is a coil array composed of multiple annular coils, which is used to detect the current value generated by the offset between the receiving end coil and the transmitting end coil. The detection coil is arranged in parallel with the transmitting end coil and is located between the transmitting end coil and the receiving end coil during the charging process;

[0011] The sensor is used to monitor the position and attitude of the underwater equipment and is mounted on the bracket;

[0012] The electromagnet assembly is used to hold the underwater equipment and the movable wireless charging coil device together when the transmitting end coil is aligned with the receiving end coil, and is arranged on the bracket;

[0013] The underwater propeller assembly is used to make the bracket translate along the axial direction and radial direction of the transmitting end coil, and is installed on the bracket;

[0014] The controller is used to perform a control operation of powering underwater equipment through a movable wireless charging coil device, wherein the alignment control method of the transmitting end coil and the receiving end coil comprises the following steps:

[0015] Step 1, designing the structure of the detection coil according to the transmitting end coil, includes the following sub-steps:

[0016] Step 1.1, determine the number, size and array arrangement structure of the detection coils according to the size of the transmitting coil;

[0017] Step 1.2, measure the self-inductance of the detection coil and calculate the compensation capacitance value according to the resonance condition;

[0018] Step 1.3, derive the expression of the detection coil current, and determine that the detection coil current can represent the change of the mutual inductance coefficient between the detection coil and the receiving end coil;

[0019] Step 2, using BP neural network to perform offset solution, includes the following sub-steps:

[0020] Step 2.1, construct a BP neural network model. The model input is the current value of each ring coil in the detection coil. The number of nodes in the input layer is the same as the number of ring coils. The model output is the offset of the receiving end coil on the X, Y, and Z axes and the deflection around three directions. The number of nodes in the output layer is 6;

[0021] Step 2.2, simulating the offset of the transmitting coil and the receiving coil under various charging conditions, measuring the offset under each offset condition and the current value of each annular coil in the detection coil as a data set for the BP neural network;

[0022] Step 2.3, using the obtained data set to train and verify the constructed BP neural network model, obtain the output and input solution matrix of the model and store it in the controller;

[0023] Step 3, during the docking process during charging, the current value of the detection coil is monitored in real time. The controller determines the offset direction and offset of the transmitting end coil and the receiving end coil through the obtained solution matrix based on the collected current value, and controls the underwater thruster assembly to adjust the position of the transmitting end coil to align it with the receiving end coil.

[0024] Furthermore, the movable wireless charging coil device also includes a detection coil mounting ring, which is coaxially fixed to the bracket with the transmitting end magnetic core, and the detection coil is mounted in the detection coil mounting ring.

[0025] Furthermore, a ring magnet is provided at one end of the detection coil mounting ring connected to the bracket so as to be connected to the bracket by magnetic attraction.

[0026] Furthermore, the underwater propeller assembly includes two horizontal propellers for moving the bracket along the radial direction of the transmitting end coil and two vertical propellers for moving the bracket along the axial direction of the transmitting end coil.

[0027] Furthermore, the bracket is in the shape of a stepped shaft and includes a hollow large diameter section, a hollow small diameter section and a connecting section connecting the two. The underwater thruster assembly is arranged outside the large diameter section, the transmitting end magnetic core and the sensor are arranged at the bottom of the small diameter section, and the electromagnet assembly is arranged outside the edge of the small diameter section.

[0028] Furthermore, the detection coil is a coil array consisting of 12 annular coils.

[0029] Furthermore, the movable wireless charging coil device also includes an anchor transmitter and an anchor connected thereto via an anchoring chain. The anchor transmitter is mounted on a bracket and is capable of moving the anchor from a retracted state to an extended state. In the retracted state, the anchor is located in the anchor transmitter, and in the extended state, the anchor is stuck in the seabed.

[0030] The advantages of the present invention are:

[0031] 1. The underwater equipment movable wireless charging coil device of the present invention can assist the underwater wireless charging base station to perform wireless power transmission on the underwater equipment. The transmitting coil in the device can move under the drive of the underwater propeller assembly. The device is also designed with a detection coil, which can detect the current generated by the displacement and deflection of the transmitting coil and the receiving coil on the underwater equipment in various directions during the docking process. A BP neural network model is established and the solution matrix of the coil offset and the detection coil current is obtained. During the docking process when the underwater equipment is charged, the controller can determine the offset of the transmitting end and the receiving end according to the current actually detected by the detection coil, using the solution matrix, thereby controlling the propeller to adjust the position of the transmitting end coil to achieve rapid and accurate alignment with the receiving end coil. In addition, the device also includes an electromagnet. After the alignment is completed, the electromagnet can be driven by the propeller to firmly adsorb the underwater equipment, so that the transmitting end coil and the receiving end coil will not move relative to each other during the charging process. Therefore, the present invention can achieve rapid and accurate alignment between the transmitting end and the receiving end, shorten the charging docking time, and ensure that the transmitting end and the receiving end are accurately aligned during the charging process, thereby improving the efficiency of wireless power transmission.

[0032] 2. The detection coil in the present invention is installed and fixed by magnetic attraction. This modular design can be directly mounted on the device without changing the structure of the wireless charging coil itself, and has strong adaptability.

[0033] 3. The device of the present invention is also provided with an anchor. After the transmitting end is aligned with the receiving end, the anchor is stuck into the seabed, which helps the underwater equipment to resist the shaking caused by the impact of the ocean current and improves the charging stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and / or other features and advantages of the present invention will become more easily understood through the following description with reference to the accompanying drawings, which are not drawn to scale and some features are exaggerated or reduced to show details of specific components. In the accompanying drawings:

[0035] Figure 1 It is a schematic three-dimensional diagram of the movable wireless charging coil device for underwater equipment of the present invention. Figure 1 ;

[0036] Figure 2 It is a schematic three-dimensional diagram of the movable wireless charging coil device for underwater equipment of the present invention. Figure 2 , in which the detection coil and underwater thruster assembly are omitted;

[0037] Figure 3 is a schematic cross-sectional view of a movable wireless charging coil device for underwater equipment of the present invention, wherein the underwater propeller assembly is omitted;

[0038] Figure 4is a schematic perspective view of the movable wireless charging coil device for underwater equipment of the present invention in use;

[0039] Figure 5 is a schematic three-dimensional diagram of a bracket in the present invention, on which an electromagnet is mounted;

[0040] Figure 6 The arrangement structure of the detection coil in the present invention is shown;

[0041] Figure 7 It is a schematic diagram of the alignment control principle of the transmitting end and the receiving end in the present invention;

[0042] Figure 8 It is a flow chart of alignment control between the transmitting end and the receiving end in the present invention.

[0043] In the figure: 1- bracket, 11- large diameter section, 12- small diameter section, 13- first thruster mounting seat, 14- second thruster mounting seat, 15- wire through hole, 16- lug; 2- transmitting end magnetic core; 3- transmitting end coil; 4- detecting coil; 5- sensor; 6- electromagnet assembly; 7- underwater thruster assembly, 71- horizontal thruster, 72- vertical thruster; 8- detecting coil mounting ring; 91- anchor transmitter, 92- mooring chain, 93- anchor; 100- underwater equipment, 101- receiving end. DETAILED DESCRIPTION

[0044] The present invention will be described in detail below with reference to the accompanying drawings by means of exemplary embodiments of the present invention. It should be noted that the following detailed description of the present invention is only for the purpose of illustration, and is not intended to limit the present invention.

[0045] The present invention provides a movable wireless charging coil device for underwater equipment, which is used to be connected to an underwater wireless charging base station to dock with underwater equipment, such as UUV, for wireless charging. The receiving end is arranged on the underwater equipment, and the transmitting end is arranged on the device. When the underwater equipment needs power replenishment, the two are docked to realize wireless power transmission. In the charging coil device of the present invention, the transmitting end coil is movable, and can realize fast and accurate alignment with the receiving end coil, shortening the charging docking time. At the same time, the transmitting end coil and the receiving end coil are kept together during the charging process without relative movement, which can ensure that the transmitting end and the receiving end are kept accurately aligned during the charging process, thereby improving the efficiency of wireless power transmission.

[0046] The movable wireless charging coil device for underwater equipment provided by the present invention is now described in detail.

[0047] First refer to Figures 1 to 4As an exemplary embodiment of the present invention, a movable wireless charging coil device for underwater equipment includes a bracket 1, a transmitting end magnetic core 2, a transmitting end coil 3, a detection coil 4, a sensor 5, an electromagnet assembly 6, an underwater thruster assembly 7 and a controller. The bracket 1 is used to support various components of the movable wireless charging coil device. The transmitting end magnetic core 2 is a soft magnetic ferrite, which is connected to the cable of the underwater wireless charging base station and has a large activity space. The transmitting end coil 3 is used to dock with the receiving end coil of the receiving end 101 set on the underwater equipment 100 to perform electromagnetic coupling and charge the underwater equipment. On the one hand, the detection coil 4 can take the current parameter as the monitoring object, realize the offset and deflection detection through the coil array current sampling, and perform active anti-offset. On the other hand, it can enhance the coil coupling coefficient, expand the electromagnetic field transmission distance to realize passive anti-offset, so as to realize accurate alignment between the transmitting end and the receiving end, and improve the wireless power transmission efficiency. The sensor 5 is used to monitor the position and posture of the underwater equipment during the charging docking process, which can be a camera. The electromagnet assembly 6 can keep the underwater equipment and the movable wireless charging coil device together. The underwater propeller assembly 7 is used to realize the movement of the transmitting coil and to realize its alignment with the receiving coil. The controller is not shown in the figure and is used to perform control operations for supplying power to underwater equipment through the movable wireless charging coil device.

[0048] Combined with reference Figure 5 The bracket 1 may be in the shape of a stepped shaft and include a hollow large diameter section 11, a hollow small diameter section 12 and a connecting section connecting the two, so as to realize the installation and / or fixation of various components in the device and their connecting cables. A first thruster mounting seat 13 and a second thruster mounting seat 14 are provided on the periphery of the large diameter section 11, which will be described in detail below. A wire through hole 15 is also provided for the connecting cables of the components to pass through the bracket. A lug 16 is provided on the outside of the small diameter section 12 and axially extends from the large diameter section 11. The lug 16 is roughly L-shaped and includes two legs, one leg extending coaxially with the large diameter section 11, and the other leg extending radially outward to install the electromagnet assembly 6 to ensure that it can contact the underwater equipment. A plurality of lugs 16 may be provided corresponding to the electromagnets.

[0049] The transmitting end magnetic core 2 is fixedly connected to the bracket 1 and is in a circular ring shape. Figure 3 As clearly shown in the figure, the transmitter magnetic core 2 and the sensor 5 are optionally arranged at the bottom of the small diameter section 12 of the bracket 1, and the sensor 5 is located in the middle. The thickness of the transmitter magnetic core 2 is mainly determined by the working gap of the wireless charging. The transmitter coil 3 is wound by an anti-eddy current wire, and the wire is coaxially wound on the surface of the transmitter magnetic core 2. Its diameter is slightly smaller than the diameter of the transmitter circular magnetic core and can be wound just right. The transmitter coil 3 can be wound on the transmitter magnetic core 2 on the outside of the sensor 5. The receiving end magnetic core is generally fixed at the bottom of the underwater equipment. When charging is needed, the transmitter circular coupling coil can be aligned with the receiving circular coupling coil for charging.

[0050] The detection coil 4, also known as a relay coil, is a coil array composed of multiple annular coils, which is used to detect the current value generated by the offset between the receiving coil and the transmitting coil 3. Each relay coil is composed of a Litz coil, a resonant capacitor and an alternating current detection module, and transmits the detected alternating current to the data bus through a shielded wire, and then transmits it to the controller. The shielded wire is used to prevent the rapidly changing electromagnetic field between the power coils from interfering with the data. The detection coil 4 is arranged in a plane parallel to the transmitting coil 3, and the plane may be 10-20 mm away from the coil plane of the transmitting coil 3. During the charging process, the detection coil 4 is located between the transmitting coil 3 and the receiving coil. The relay coil is arranged between the transmitting coil and the receiving coil, which can improve the coupling coefficient, increase the effective transmission distance of wireless charging, and enhance the charging efficiency. Since in the present invention, the relay coil is mainly relied on for active anti-offset, each relay coil can be made smaller. In some embodiments, the diameter of each annular coil in the detection coil 4 can be set to 1 / 6 of the diameter of the transmitting coil 3. In particular, if Figure 6 As shown, the detection coil 4 may include 12 annular coils, which may be arranged in a hexagram structure symmetrically about the axis of the transmitting coil 3 as shown. However, those skilled in the art will understand that the number of annular coils in the detection coil 4 is not limited thereto, and is preferably 6-12, more preferably 8-12, and most preferably 12. At any number, the diameter of the annular coil can be set to 1 / 6 of the diameter of the transmitting coil 3. In addition, the arrangement structure of the detection coil 4 is not particularly limited.

[0051] To facilitate the connection and fixation of the detection coil 4, for example Figure 3 As shown, the present invention may further include a detection coil mounting ring 8, which is coaxially fixed to the bracket 1 with the transmitting end magnetic core 2, and the detection coil 4 is installed in the detection coil mounting ring 8. The fixing method of the detection coil 4 on the detection coil mounting ring 8 is not subject to specific restrictions, and welding and the like can be used.

[0052] In addition, the detection coil mounting ring 8 may be provided with a ring magnet at one end connected to the bracket 1, so as to be connected to the bracket 1 by magnetic attraction. This modular design in which the detection coil is mounted and fixed by magnetic attraction can be directly mounted on the device without changing the structure of the wireless charging coil itself, and has strong adaptability.

[0053] The electromagnet assembly 6 is used to keep the underwater equipment and the movable wireless charging coil device together when the transmitting end coil 3 is aligned with the receiving end coil to prevent the two from offsetting and affecting the charging efficiency. The electromagnet assembly 6 is arranged on the bracket 1 and outside the edge of the small diameter section 12 to avoid being blocked and unable to contact the underwater equipment. In particular, it can be arranged on the radially outwardly protruding legs of the lug 16 of the bracket 1. The electromagnet assembly 6 may include a plurality of electromagnets evenly distributed on the bracket 1 to ensure firm adsorption with the underwater equipment.

[0054] The underwater thruster assembly 7 is used to make the support 1 translate along the axial and radial directions of the transmitting end coil 3, thereby achieving docking and accurate alignment with the receiving end. It is installed on the support 1, especially outside the large diameter section 11 of the support 1. The base station transmits control signals, such as PWM (pulse width modulation) signals or digital signals, through cables to achieve control of the thruster. The control signal sent by the controller is transmitted to the motor of the thruster through the cable, thereby driving the movement of the thruster and the support 1. In a specific embodiment of the present invention, Figure 1 As shown, the underwater propeller assembly 7 includes two horizontal propellers 71 for moving the bracket 1 along the radial direction of the transmitting end coil 3 and two vertical propellers 72 for moving the bracket 1 along the axial direction of the transmitting end coil 3. As mentioned above, the horizontal propellers 71 can be respectively mounted on two symmetrical first propeller mounting seats 13, and the two vertical propellers 72 can be respectively mounted on two symmetrical second propeller mounting seats 14, and the four propellers are circumferentially arranged around the bracket 1 at equal intervals.

[0055] In order to ensure the stability of the coil position and improve the charging stability, in a preferred embodiment of the present invention, the device also includes an anchor transmitter 91 and an anchor 93 connected thereto by a mooring chain 92. The anchor transmitter is installed on the bracket 1, especially in the middle of the bottom of the large-diameter section 11, and can move the anchor 93 from a retracted state to an extended state. During the charging and docking process, the anchor 93 is in a retracted state and is located in the anchor transmitter 91. After alignment, the anchor 93 is in an extended state and is stuck in the seabed, which helps the underwater equipment to resist the shaking caused by the impact of the ocean current and improves the charging stability under the influence of the seawater flow.

[0056] By using the underwater equipment movable wireless charging coil device of the present invention, when the underwater equipment needs energy replenishment, it approaches the underwater wireless charging base station and maintains a stable underwater positive floating posture. When the base station receives the signal that the underwater equipment is approaching, the sensor and the detection coil on the transmitting end start to work. The sensor continuously monitors the position and posture changes of the receiving end coil on the equipment. If it is found that the position and posture of the underwater equipment are inconsistent with expectations, the control system will timely adjust the position and posture of the transmitting end coil through the underwater propeller assembly according to the current value sent by the detection coil to adapt to the changes of the underwater equipment. The alignment control method of the transmitting end coil and the receiving end coil will be described in detail below. Finally, the underwater propeller can be controlled to transport the transmitting end to the position aligned with the receiving end on the underwater equipment, and then the electromagnet is energized to absorb the underwater equipment. It is also preferred to launch the mooring chain to be firmly fixed to the seabed to ensure the stability of the coil position. After that, the base station sends high-frequency alternating current, controls the output, and conducts energy transfer through the divergent magnetic field coupling of the transmitting end coil and the receiving end coil. During the energy transfer process, the electromagnet is always powered on, so that the transmitter and the receiver are always precisely aligned, thus ensuring that the entire process is fully coupled and that energy can be efficiently and quickly transferred to the underwater equipment. The underwater equipment then receives the electrical energy, obtains stable direct current through internal rectification and filtering, and transmits it to the energy storage battery inside the underwater equipment. When the charging is completed, the electromagnet is powered off, and the anchor is pulled out under the action of the underwater thruster and automatically retracted into the device. The underwater thruster controls the transmitter to return to the underwater wireless charging base station. From then on, the work of the device is completed and the base station enters the standby state.

[0057] Next, refer to Figure 7 and Figure 8 The alignment control method of the transmitting end coil and the receiving end coil in the present invention is described, and the method may include the following steps:

[0058] Step S1, designing the structure of the detection coil 4 according to the transmitting end coil 3;

[0059] Step S2, using BP neural network to perform offset solution to obtain a solution matrix of coupler offset and relay coil current;

[0060] Step S3, during the docking process during charging, the current value of the detection coil is monitored in real time. The controller determines the offset direction and offset of the transmitting end coil 3 and the receiving end coil through the obtained solution matrix based on the collected current value, and controls the underwater thruster assembly 7 to adjust the position of the transmitting end coil 3 so that it performs motion compensation and aligns with the receiving end coil.

[0061] Step S1 is used to design the detection coils, and may include step S1.1: determining the number, size and array arrangement structure of the detection coils 4 according to the size of the transmitting end coil 3 .

[0062] Step S1 also includes: step S1.2, measuring the self-inductance of the detection coil 4 and calculating the compensation capacitance value according to the resonance condition; and step S1.3, deriving the expression of the current of the detection coil 4, and determining that the current of the detection coil 4 can characterize the change of the mutual inductance coefficient between the detection coil 4 and the receiving end coil.

[0063] Since the relay coil array used in the present invention is in the same detection plane, has a small diameter, a relatively long relative distance, and a relative facing area of ​​0, the mutual inductance between the relay coils can be ignored. In order to simplify the system, the SSS compensation topology is adopted, that is, the transmitting coil, the receiving coil, and the detection coil all adopt a series compensation method.

[0064] Since the offset of the receiving coil and the transmitting coil will cause the mutual inductance of the relay coil array to change, it is first demonstrated that the relay coil current detection can reflect the change of mutual inductance, and there is a unique representation relationship between the relay coil current and the mutual inductance.

[0065] According to Kirchhoff's voltage law, the following equation can be derived:

[0066]

[0067] In the formula, is the AC output voltage of the transmitter inverter; j is a complex unit; ω represents the circuit frequency; Z P , Z S and Z i are the equivalent impedances of the transmitting coil, receiving coil and detection coil respectively; and are the transmitting coil current, receiving coil current and detection coil current respectively; M PS is the mutual inductance of the transmitting coil, M Pi is the mutual inductance between the transmitting coil and the single toroidal coil in the detection coil, M iS It is the mutual inductance between the detection coil and the receiving coil.

[0068] Solving the above equation, we can get the expression for the required detection coil current:

[0069]

[0070] Considering the case of complete resonance, Z P =R P ,Z S =R L ,Z i =R i , R P is the equivalent series resistance of the transmitting coil, R L is the equivalent resistive load, R i is the internal resistance of the detection coil.P and R i It is only the line resistance, which is very small, only at the milliohm level, and is approximately considered to be 0. Therefore, the above formula can be simplified to:

[0071]

[0072] Since the position of the detection coil relative to the transmitting coil does not change, M Pi It is also a constant, and there is only one variable M in the formula iS , when the transmitting coil is offset, M iS will change.

[0073] β=2jω 3 M Pi M PS ,γ=ω 2 M PS 2 R L , then illustrate

[0074] By measuring the current of the detection coil, the change in the mutual inductance coefficient between the coil and the receiving end coil can be characterized, thereby reflecting the relative position of the transmitting end coil and the receiving end coil.

[0075] In the case of complete resonance, the following relationship holds:

[0076]

[0077] In the formula, C P is the transmitting coil capacitance, C S is the receiving coil capacitance, C i is the detection coil capacitance. P is the self-inductance of the transmitting coil, L S is the self-inductance of the receiving coil, L i is the self-inductance of the detection coil. When the transmitting coil and the receiving coil are determined, the compensation capacitors, namely the transmitting coil compensation capacitor C, can be solved separately. P , receiving coil compensation capacitor C S And the detection coil compensation capacitor C i size.

[0078] Step S2 includes step S2.1: constructing a BP neural network model, the model input is the current value of each relay coil, the number of nodes in the input layer is the same as the number of relay coils, the model output is the offset of the secondary side coil on the X, Y, and Z axes and the deflection around three directions, and the number of nodes in the output layer is 6. In order to ensure the fitting accuracy and prevent overfitting, the number of hidden layer nodes can be selected as 10.

[0079] Step S2 also includes step S2.2: simulating the offset of the primary coil and the secondary coil under various charging conditions, detecting the offset amount under each offset condition and the corresponding current value of each relay coil as a data set of the BP neural network. In this step, the secondary coil can be manually moved to simulate various offsets.

[0080] Step S2 also includes step S2.3: using the obtained data set to train and verify the constructed BP neural network model to obtain the output and input solution matrix of the model. In particular, the gradient descent method can be used to train the BP neural network model to obtain the solution matrix. The solution matrix can be saved in the controller ROM, that is, the offset can be calculated through the matrix after the relay coil array current parameters are detected.

[0081] After obtaining the solution matrix, as described in step S3, the controller can perform active control when the underwater equipment is docked with the charging coil device for wireless charging and during the entire charging process. Specifically, according to the current value detected by the detection coil 4 and the solution matrix, the offset direction and offset distance of the transmitting end coil 3 and the receiving end coil are determined, that is, the motion compensation value required for the transmitting end coil 3 to be aligned with the receiving end coil is determined, and then the underwater thruster assembly 7 is controlled to drive the transmitting end coil 3 to perform motion compensation so as to align it with the receiving end coil. Thereafter, the controller controls the electromagnet assembly 6 to energize so that the transmitting end coil 3 and the receiving end coil are kept together, and the anchor can also be controlled to launch. At this point, the coil position is stable and the equipment charging can begin.

[0082] As described above, the present invention can achieve rapid and accurate alignment between the transmitter and the receiver, shorten the charging docking time, and at the same time ensure that the transmitter and the receiver remain accurately aligned during the charging process, thereby improving the efficiency of wireless power transmission.

[0083] Finally, it should be noted that the features mentioned and / or shown in the above description of the exemplary embodiments of the present invention may be combined in the same or similar manner into one or more other embodiments, combined with the features in other embodiments or substituted for the corresponding features in other implementations. The technical solutions obtained by these combinations or substitutions shall also be deemed to be included in the protection scope of the present invention.

Claims

1. A movable wireless charging coil device for underwater equipment, used to connect to an underwater wireless charging base station to dock with the underwater equipment for wireless charging, characterized in that: It includes a bracket, a transmitting end magnetic core, a transmitting end coil, a detection coil, a sensor, an electromagnet assembly, an underwater thruster assembly and a controller; The bracket is used to support the movable wireless charging coil device; The transmitting end magnetic core is fixedly connected to the bracket and is in a ring shape. The conducting wire of the transmitting end coil is coaxially wound on the surface of the transmitting end magnetic core and is used to align with the receiving end coil arranged on the underwater equipment to perform electromagnetic coupling and charge the underwater equipment. The detection coil is a coil array composed of multiple annular coils, which is used to detect the current value generated by the offset between the receiving end coil and the transmitting end coil. The detection coil is arranged in parallel with the transmitting end coil and is located between the transmitting end coil and the receiving end coil during the charging process; The sensor is used to monitor the position and posture of the underwater equipment and is installed on the bracket; The electromagnet assembly is used to hold the underwater equipment and the movable wireless charging coil device together when the transmitting end coil is aligned with the receiving end coil, and is arranged on the bracket; The underwater propeller assembly is used to make the bracket translate along the axial direction and radial direction of the transmitting end coil, and is installed on the bracket; The controller is used to perform a control operation of powering underwater equipment through the movable wireless charging coil device, wherein the alignment control method of the transmitting end coil and the receiving end coil comprises the following steps: Step 1, designing the structure of the detection coil according to the transmitting end coil, includes the following sub-steps: Step 1.1, determine the number, size and array arrangement structure of the detection coils according to the size of the transmitting coil; Step 1.2, measure the self-inductance of the detection coil and calculate the compensation capacitance value according to the resonance condition; Step 1.3, derive the expression of the detection coil current, and determine that the detection coil current can represent the change of the mutual inductance coefficient between the detection coil and the receiving end coil; Step 2, using BP neural network to perform offset solution, includes the following sub-steps: Step 2.1, construct a BP neural network model. The model input is the current value of each ring coil in the detection coil. The number of nodes in the input layer is the same as the number of ring coils. The model output is the offset of the receiving end coil on the X, Y, and Z axes and the deflection around three directions. The number of nodes in the output layer is 6; Step 2.2, simulating the offset of the transmitting coil and the receiving coil under various charging conditions, measuring the offset under each offset condition and the current value of each annular coil in the detection coil as a data set for the BP neural network; Step 2.3, using the obtained data set to train and verify the constructed BP neural network model, obtain the output and input solution matrix of the model and store it in the controller; Step 3, during the docking process during charging, the current value of the detection coil is monitored in real time. The controller determines the offset direction and offset of the transmitting coil and the receiving coil based on the collected current value and the obtained solution matrix, and controls the underwater thruster assembly to adjust the position of the transmitting coil to align it with the receiving coil.

2. The movable wireless charging coil device for underwater equipment according to claim 1, characterized in that: It also includes a detection coil mounting ring, which is coaxially fixed to the bracket with the transmitting end magnetic core, and the detection coil is mounted in the detection coil mounting ring.

3. The movable wireless charging coil device for underwater equipment according to claim 2, characterized in that: The detection coil mounting ring is provided with an annular magnet at one end connected to the bracket so as to be connected to the bracket by magnetic attraction.

4. The movable wireless charging coil device for underwater equipment according to claim 1 or 2, characterized in that: The underwater propeller assembly includes two horizontal propellers for moving the bracket along the radial direction of the transmitting end coil and two vertical propellers for moving the bracket along the axial direction of the transmitting end coil.

5. The movable wireless charging coil device for underwater equipment according to claim 1 or 2, characterized in that: The bracket is in the shape of a stepped shaft and includes a hollow large-diameter section, a hollow small-diameter section and a connecting section connecting the two. The underwater thruster assembly is arranged outside the large-diameter section, the transmitting end magnetic core and the sensor are arranged at the bottom of the small-diameter section, and the electromagnet assembly is arranged outside the edge of the small-diameter section.

6. The movable wireless charging coil device for underwater equipment according to claim 1 or 2, characterized in that: The detection coil is a coil array consisting of 12 annular coils.

7. The movable wireless charging coil device for underwater equipment according to claim 1 or 2, characterized in that: It also includes an anchor transmitter and an anchor connected to the anchor transmitter via an anchor chain. The anchor transmitter is mounted on the bracket and can move the anchor from a retracted state to a sent-out state. In the retracted state, the anchor is located in the anchor transmitter. In the sent-out state, the anchor is stuck in the seabed.

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