An automatic charging system and method for automobiles based on strongly coupled wireless charging technology

Abstract

This invention discloses an automatic charging system and method for automobiles based on strongly coupled wireless charging technology, relating to the field of automotive wireless charging technology. The system uses a visually guided camera to search for and locate the receiving coil. This location is then transmitted to a controller, which drives a multi-dimensional moving platform to adjust the position of the transmitting coil, aligning it with the receiving coil and gradually bringing them closer together, minimizing the distance between them. Finally, the coupling coefficient between the receiving and transmitting coils is optimized, ensuring that it remains essentially constant even with small misalignments. When there are large misalignments between the receiving and transmitting coils, this invention achieves fully automatic alignment with a substantially unchanged coupling coefficient, while effectively removing metallic foreign objects from the transmitting coil, providing an effective method for fully automatic and efficient charging of electric vehicles.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology for electric vehicles, and in particular to an automatic charging system and method for automobiles based on strong coupling wireless charging technology. Background Technology

[0002] The charging system is one of the core components of an electric vehicle, and its performance directly affects the safety and convenience of the vehicle. Currently, there are two main charging methods for electric vehicles: plug-in wired charging and wireless charging.

[0003] The main problems with plug-in wired charging are as follows:

[0004] (1) The presence of charging sockets and cables greatly reduces the flexibility of electric vehicle charging;

[0005] (2) The large charging current poses a potential danger of leakage and electric shock, and is prone to generating contact sparks, making it not very safe.

[0006] Wireless charging primarily transmits electrical energy through magnetic fields, eliminating the need for direct wire connections between the power supply and load, thus removing the need for sockets and plugs. The load and power supply can be intelligently connected via network commands, facilitating smart power supply. However, during dynamic wireless charging of electric vehicles, the transmitting and receiving coils inevitably shift, causing changes in the coupling coefficient between the coils. This leads to drastic voltage fluctuations and reduced efficiency at the output, jeopardizing the safety and stability of the dynamic wireless power supply system for electric vehicles.

[0007] Therefore, ensuring that the coupling coefficient between coils remains as constant as possible, and on this basis, maximizing transmission efficiency to achieve stable and efficient wireless power transmission is a challenging problem. Summary of the Invention

[0008] To address the above problems, this invention provides an automatic charging system and method for automobiles based on strong coupling wireless charging technology. When the receiving coil and transmitting coil of the electric vehicle wireless charging system are offset within a large range, this invention can achieve fully automatic alignment of the receiving coil and transmitting coil while keeping the coupling coefficient basically unchanged. At the same time, it can remove metal foreign objects on the transmitting coil, providing an effective method for fully automatic and efficient charging of electric vehicles.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] An automatic charging system for automobiles based on strongly coupled wireless charging technology includes a grid-side rectifier, an inverter, a transmitting coil, a receiving coil, a multi-dimensional moving platform, and a vision-guided camera. The position of the receiving coil is obtained through the vision-guided camera, and the multi-dimensional moving platform is moved by a controller. With the help of a coupling coefficient optimization algorithm between the transmitting and receiving coils, the transmitting and receiving coils of the wireless charging system are precisely aligned and tightly fitted. Even if the receiving and transmitting coils are offset, the coupling coefficient between the receiving and transmitting coils remains basically unchanged, thus completing automatic charging.

[0011] This system achieves precise alignment and tight fit between the transmitting and receiving coils by using a grid-side rectifier, inverter, transmitting coil, and receiving coil, combined with a multi-dimensional moving platform and a vision-guided camera. The vision-guided camera acquires the position information of the receiving coil, and the controller uses this information to drive the multi-dimensional moving platform to adjust the position of the transmitting coil to achieve alignment. Simultaneously, with the help of a coupling coefficient optimization algorithm, even when the receiving and transmitting coils are misaligned, the coupling coefficient remains essentially constant, enabling automatic charging.

[0012] This system can achieve fully automatic alignment with a essentially unchanged coupling coefficient even when the receiving and transmitting coils of an electric vehicle wireless charging system are significantly misaligned, thus improving the stability and efficiency of wireless charging. Simultaneously, the system can remove metallic foreign objects from the transmitting coil, providing a fully automatic, efficient, and safe charging method for electric vehicles.

[0013] As a further improvement to the above solution, the multi-dimensional moving platform enables three-coordinate movement and angle adjustment of the transmitting coil. This adapts to the receiving coil at different positions and angles, ensuring precise alignment between the transmitting and receiving coils. Through three-coordinate movement and angle adjustment, the system can more flexibly adapt to different charging environments and vehicle positions, improving the adaptability and accuracy of charging.

[0014] As a further improvement to the above solution, a multi-dimensional moving platform is used to control the rotation of the transmitting coil, causing foreign objects on the coil to slide off and thus removing them. Removing metallic foreign objects from the transmitting coil avoids safety hazards during charging, ensuring both safety and efficiency.

[0015] As a further improvement to the above solution, the visual guidance camera and the transmitting coil are mounted on a multi-dimensional moving platform. This allows the visual guidance camera to acquire the position information of the receiving coil in real time and guide the multi-dimensional moving platform to adjust the position of the transmitting coil.

[0016] As a further improvement to the above scheme, the coupling coefficient optimization algorithm includes the following steps:

[0017] S1, Establish the transmitting coil to receiving coil model: consisting of a transmitting coil and a receiving coil with a size larger than the transmitting coil, with the receiving coil parallel to the transmitting coil;

[0018] S2, set the main parameters: including the diameter of the copper wire, the resonant frequency, and the distance between the transmitting coil and the receiving coil;

[0019] S3, Set specification constraints: Set constraints according to actual application and design requirements; including the range of inner length of the transmitting coil, the range of inner width of the transmitting coil, the range of number of turns of the transmitting coil, the range of inner length of the receiving coil, the range of inner width of the receiving coil, the range of number of turns of the receiving coil, and the step size;

[0020] S4, calculate the mutual inductance and self-inductance values ​​of the transmitting coil and the receiving coil;

[0021] S5, set the coupling coefficient k and the coupling coefficient volatility requirements: set the coupling coefficient k≥0.12; when offset laterally by 3cm, the coupling coefficient volatility ≤5%; when offset longitudinally by 3cm, the coupling coefficient volatility ≤5%.

[0022] S6, calculate the coupling coefficient and the volatility of the coupling coefficient;

[0023] S7, Determine whether the coupling coefficient and coupling coefficient volatility meet the requirements: Compare the current coupling coefficient and coupling coefficient volatility with the set values. If they meet the requirements, save the parameters that meet the conditions; if they do not meet the requirements, further adjust the device parameters.

[0024] S8. Repeat steps S3 to S7 until all parameters reach their upper limits.

[0025] The coupling coefficient optimization algorithm includes model building, parameter setting, calculation of mutual inductance and self-inductance values, setting coupling coefficient requirements, calculating coupling coefficient and volatility, determining whether the requirements are met, and adjusting device parameters as needed until all parameters reach their upper limits. By accurately calculating and optimizing the coupling coefficient, the system can maintain a high coupling coefficient and low volatility when the transmitting coil and receiving coil are misaligned, thereby improving charging efficiency and stability.

[0026] As a further improvement to the above scheme, in S4, the self-inductance of the transmitting coil and the receiving coil is calculated according to the formula for calculating the self-inductance of a rectangular coil.

[0027] The formula is:

[0028]

[0029] Among them: B 4zIt is magnetic flux density, D is T x and R x The transmission distance between them is μ0, which is the vacuum permeability, a1 and a2 are the length and width of the transmitting coil, ξ and η are the double Fourier transform parameters, I is the excitation current added to the transmitting coil, and t represents time.

[0030] By calculating the self-inductance of the transmitting and receiving coils using the formula for rectangular coil self-inductance, the electromagnetic characteristics of the coils can be determined more accurately. This is crucial for optimizing energy transfer efficiency during wireless charging. Accurate calculation of self-inductance helps in designing more efficient wireless charging systems because it directly affects the system's energy coupling and power transfer capabilities.

[0031] As a further improvement to the above scheme, the mutual inductance between single-turn rectangular coils is calculated according to the mutual inductance formula between single-turn rectangular coils under different coil offsets.

[0032] The formula is:

[0033]

[0034] Where: B is the magnetic flux density, I is the excitation current added to the transmitting coil, and b 1d and b 2d Let b1 and b2 be the length and width of Coil2, respectively, and ξ and η be the double Fourier transform parameters. S2 is the vertical distance between the receiving coil and the ground. iz and C ix As an intermediate variable, the specific expressions are shown in formulas (3) and (4):

[0035] Formula (3) is:

[0036]

[0037] Formula (4) is:

[0038]

[0039] Where: j: imaginary unit, representing the square root of -1, μ0 is the permeability in vacuum, I is the excitation current added to the transmitting coil, and Z0 is the vertical distance between the transmitting coil and the ground. The term is an exponential term, representing the attenuation of electromagnetic waves as they propagate through space.

[0040] Under different coil offset conditions, the mutual inductance between single-turn rectangular coils is calculated using the formula for mutual inductance between single-turn rectangular coils. This allows the system to adapt to different relative positions between coils, thus maintaining high charging efficiency under various offset conditions. This calculation method helps optimize coil design, ensuring that the charging system maintains effective energy transfer even under non-ideal alignment conditions.

[0041] As a further improvement to the above scheme, the total mutual inductance value is calculated according to the mutual inductance calculation formula between multi-turn coils;

[0042] The formula is:

[0043] Where: N1 and N2 are the number of turns of the transmitting coil and the receiving coil, respectively; m is the m-th turn of the transmitting coil; and n is the n-th turn of the receiving coil.

[0044] Calculating the total mutual inductance using the formula for mutual inductance between multi-turn coils allows for more accurate prediction and control of energy transfer between coils. This calculation method is crucial for ensuring optimal performance of wireless charging systems under various operating conditions, as it involves complex electromagnetic interactions between coils.

[0045] An automatic charging method for automobiles based on strongly coupled wireless charging technology, used in an automatic charging system for automobiles, includes the following steps:

[0046] S1, Set the X, Y, Z axis coordinate error and angle rotation error requirements: Set the error between the actual coordinate and the set coordinate in the X direction to be less than 3cm; set the error between the actual coordinate and the set coordinate in the Y direction to be less than 3cm; set the error between the actual coordinate and the set coordinate in the Z direction to be less than 0.1cm;

[0047] S2, after the electric vehicle arrives at the parking area, the visual guidance camera searches for the location of the receiving coil on the electric vehicle and obtains the coordinate position and deflection angle of the receiving coil.

[0048] S3, the controller obtains the coordinate position of the receiving coil, drives the multi-dimensional moving platform to move, and adjusts the position of the transmitting coil so that the transmitting coil is basically aligned with the receiving coil;

[0049] S4, by controlling the flipping of the transmitting coil through a multi-dimensional moving platform, causes foreign objects on the surface to slide off, thereby clearing the foreign object target from the transmitting coil, and then resets it;

[0050] S5, and then the transmitting coil and receiving coil are gradually brought into close contact through the multi-dimensional mobile platform control;

[0051] S6. Repeat steps S2 to S5 until all coordinate position parameters reach the set target.

[0052] An automatic charging method for automobiles based on strong-coupled wireless charging technology is provided. This method achieves efficient and stable wireless charging through precise coordinate and angle control, as well as automatic alignment and tight contact between the transmitting and receiving coils. This method not only improves charging efficiency but also ensures safety during the charging process by removing foreign objects from the transmitting coil. Furthermore, by repeatedly adjusting the process until the set target is reached, it ensures the accuracy and reliability of the charging process.

[0053] The beneficial effects of this invention are:

[0054] When the receiving coil and transmitting coil of an electric vehicle wireless charging system are significantly misaligned, this invention can achieve fully automatic alignment of the receiving and transmitting coils while maintaining a substantially constant coupling coefficient. Even if errors occur in the fully automatic alignment device, the coupling coefficient between the receiving and transmitting coils can still be kept essentially constant due to the use of an asymmetric coil device and coupling coefficient optimization method. Simultaneously, flipping the transmitting coil allows foreign objects to slide off, achieving the goal of removing metallic foreign objects from the transmitting coil, thus providing a safe and effective method for fully automatic and efficient charging of electric vehicles. Attached Figure Description

[0055] Figure 1 This is the overall block diagram of the system.

[0056] Figure 2 The flowchart for this invention has been optimized.

[0057] In the diagram: 1. X-axis motor; 2. Y-axis motor; 3. Z-axis motor; 4. Lifting mechanism; 5. First angle adjustment motor; 6. Second angle adjustment motor; 7. Visual guidance camera. Detailed Implementation

[0058] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0059] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0060] An automatic charging system for automobiles based on strongly coupled wireless charging technology includes a grid-side rectifier, an inverter, a transmitting coil, a receiving coil, a multi-dimensional moving platform, and a vision-guided camera. The position of the receiving coil is obtained through the vision-guided camera, and the multi-dimensional moving platform is moved by a controller. With the help of a coupling coefficient optimization algorithm between the transmitting and receiving coils, the transmitting and receiving coils of the wireless charging system are precisely aligned and tightly fitted. Even if the receiving and transmitting coils are offset, the coupling coefficient between the receiving and transmitting coils remains basically unchanged, thus completing automatic charging.

[0061] As a preferred embodiment of the above, the multi-dimensional moving platform realizes the three-coordinate movement and angle adjustment of the transmitting coil.

[0062] As a preferred embodiment of the above, the transmitting coil is flipped by controlling the multi-dimensional moving platform, so that the foreign object on the transmitting coil slides off, thereby achieving the purpose of removing the foreign object.

[0063] As a preferred embodiment of the above, the visual guidance camera and the transmitting coil are mounted on a multi-dimensional mobile platform.

[0064] Specifically, such as Figure 1 As shown, an automatic charging system for automobiles based on strongly coupled wireless charging technology includes a power grid, a PWM rectifier, a high-frequency inverter, a transmitter-side compensation network, and a transmitter coil.

[0065] The on-board device for electric vehicles includes: a receiving-side compensation network, a receiving coil, a rectifier circuit, and a battery pack;

[0066] A multi-dimensional mobile platform, equipped with a transmitting coil and a visual guidance camera.

[0067] The structure of the multi-dimensional mobile platform is not limited to any form. Its main functions include the ability to move the transmitting coil in three coordinates and adjust the angle. It can be in the form of a robotic arm, such as a three-coordinate robotic arm or a six-axis robotic arm, or it can be in the form of a platform structure.

[0068] like Figure 1 As shown, the multi-dimensional mobile platform can employ a mobile platform driven by servo motors or stepper motors, achieving precise linear motion through a precision transmission mechanism (such as ball screws, linear guides, etc.). The control system can be programmed as needed to achieve automated movement and positioning tasks.

[0069] In this embodiment, the multi-dimensional moving platform includes: X-axis motor 1, Y-axis motor 2, Z-axis motor 3, lifting mechanism 4, first angle adjustment motor 5, and second angle adjustment motor 6.

[0070] X-axis motor 1 drives the lifting mechanism 4 to move laterally, Y-axis motor 2 drives the lifting mechanism 4 to move up and down, and Z-axis motor 3 drives the lifting mechanism 4 to move longitudinally. The lifting mechanism 4 is not limited to any form and can be a fork-type lifting frame structure. At the end of the lifting mechanism 4, the transmitting coil is flipped laterally by the first angle adjustment motor 5 and the transmitting coil is flipped longitudinally by the second angle adjustment motor 6.

[0071] A transmitting coil and a visual guidance camera 7 are installed at the output end of the multi-dimensional mobile platform.

[0072] As a preferred embodiment of the above embodiments, the coupling coefficient optimization algorithm includes the following steps:

[0073] S1, Establish the transmitting coil to receiving coil model: consisting of a transmitting coil and a receiving coil with a size larger than the transmitting coil, with the receiving coil parallel to the transmitting coil;

[0074] S2, set the main parameters: including the diameter of the copper wire, the resonant frequency, and the distance between the transmitting coil and the receiving coil;

[0075] S3, Set specification constraints: Set constraints according to actual application and design requirements; including the range of inner length of the transmitting coil, the range of inner width of the transmitting coil, the range of number of turns of the transmitting coil, the range of inner length of the receiving coil, the range of inner width of the receiving coil, the range of number of turns of the receiving coil, and the step size;

[0076] S4, calculate the mutual inductance and self-inductance values ​​of the transmitting coil and the receiving coil;

[0077] S5, set the coupling coefficient k and the coupling coefficient volatility requirements: set the coupling coefficient k≥0.12; when offset laterally by 3cm, the coupling coefficient volatility ≤5%; when offset longitudinally by 3cm, the coupling coefficient volatility ≤5%.

[0078] S6, calculate the coupling coefficient and the volatility of the coupling coefficient;

[0079] S7, Determine whether the coupling coefficient and coupling coefficient volatility meet the requirements: Compare the current coupling coefficient and coupling coefficient volatility with the set values. If they meet the requirements, save the parameters that meet the conditions; if they do not meet the requirements, further adjust the device parameters.

[0080] S8. Repeat steps S3 to S7 until all parameters reach their upper limits.

[0081] As a preferred embodiment of the above, in S4, the self-inductance of the transmitting coil and the receiving coil is calculated according to the formula 1 for calculating the self-inductance of a rectangular coil;

[0082] Formula 1 is:

[0083]

[0084] Among them: B 4z It is magnetic flux density, D is T x and R x The transmission distance between them is μ0, which is the vacuum permeability, a1 and a2 are the length and width of the transmitting coil, ξ and η are the double Fourier transform parameters, I is the excitation current added to the transmitting coil, and t represents time.

[0085] As a preferred embodiment of the above embodiments

[0086] Under different coil offsets, the mutual inductance between single-turn rectangular coils is calculated according to Formula 2.

[0087] Formula 2 is:

[0088]

[0089] Where: B is the magnetic flux density, I is the excitation current added to the transmitting coil, and b 1d and b 2d Let b1 and b2 be the length and width of Coil2, respectively, and ξ and η be the double Fourier transform parameters. S2 is the vertical distance between the receiving coil and the ground. iz and C ix The intermediate variable is represented by the specific expressions shown in formulas (3) and (4).

[0090] Formula (3) is:

[0091]

[0092] C iz It represents a complex number related to the geometry of the coil, the excitation current, the spatial frequency, and the distance between the coil and the ground. It takes into account the influence of the vertical direction of the coil when calculating mutual inductance.

[0093] Formula (4) is:

[0094]

[0095] C ix It represents another complex number related to the geometry of the coil, the excitation current, the spatial frequency, and the distance between the coil and the ground. It takes into account the influence of the horizontal direction of the coil when calculating mutual inductance and includes an imaginary unit j, which is usually related to phase or time changes.

[0096] in: μ0 is the permeability in vacuum, I is the excitation current added to the transmitting coil, and Z0 is the vertical distance between the transmitting coil and the ground. The term is an exponential term, representing the attenuation of electromagnetic waves as they propagate through space.

[0097] These two intermediate variables C iz and C ix Used to calculate the mutual inductance M between two coils 11 They are combined through integral expressions to account for the spatial relationships and electromagnetic interactions between coils.

[0098] As a preferred embodiment of the above, the total mutual inductance value is calculated according to Formula 3 for mutual inductance calculation between multi-turn coils;

[0099] Formula 3 is:

[0100] Where: N1 and N2 are the number of turns of the transmitting coil and the receiving coil, respectively; m is the m-th turn of the transmitting coil; and n is the n-th turn of the receiving coil.

[0101] The following is a specific embodiment that details the implementation process of the entire technical solution.

[0102] 1 System Composition

[0103] This system includes a grid-side rectifier, an inverter, a transmitting coil, a receiving coil, a multi-dimensional moving platform, and a vision-guided camera. The multi-dimensional moving platform is responsible for adjusting the position and angle of the transmitting coil to achieve precise alignment with the receiving coil.

[0104] 2 System Parameter Settings

[0105] Copper wire diameter: 4mm

[0106] Resonant frequency: 85kHz

[0107] Initial distance between transmitting and receiving coils: 15cm

[0108] 3. Implementation of Coupling Coefficient Optimization Algorithm

[0109] S1. Establishing the Model

[0110] Create a model of a transmitting coil and a receiving coil that is larger than the transmitting coil, with the receiving coil parallel to the transmitting coil.

[0111] S2. Set main parameters

[0112] Based on the parameters above, we perform the following calculations:

[0113] Self-induction calculation (Formula 1):

[0114]

[0115] Where μ0 is the free permeability (4π×10⁻⁶). -7H / m), a1 and a2 are the length and width of the transmitting coil (0.6m and 0.6m respectively), and I is the excitation current (10A).

[0116] Mutual inductance calculation (Formula 2):

[0117]

[0118] Where b1 and b2 are the length and width of the receiving coil (0.26m and 0.26m respectively), d is the distance between the coils (0.15m), and C iz and C ix It is an intermediate variable.

[0119] Calculation of intermediate variables (Formulas 3 and 4):

[0120]

[0121]

[0122] Parameter explanation:

[0123]

[0124] μ0: Permeability in vacuum

[0125] I: Excitation current added to the transmitting coil

[0126] z0: Vertical distance between the transmitting coil and the ground

[0127] The term is the exponential term, representing the attenuation of electromagnetic waves as they propagate through space.

[0128] Total mutual inductance calculation (Formula 5):

[0129]

[0130] Where N1 and N2 are the number of turns of the transmitting coil and the receiving coil, respectively.

[0131] S3. Set specification constraints

[0132] Based on practical applications and design requirements, the optimization range of the coil is set as shown in Table 1 below.

[0133] Table 1 Optimization range of coil parameters

[0134]

[0135] S4. Calculate mutual inductance and self-inductance values.

[0136] Use the above formula to calculate the mutual inductance and self-inductance values ​​of the transmitting and receiving coils.

[0137] S5. Set the coupling coefficient k and the coupling coefficient volatility requirement.

[0138] Set the coupling coefficient k ≥ 0.10; when offset laterally by 3 cm, the volatility of the coupling coefficient is ≤ 5%; when offset longitudinally by 3 cm, the volatility of the coupling coefficient is ≤ 5%.

[0139] S6. Calculate the coupling coefficient and its volatility.

[0140] Based on the calculation results, the coupling coefficient and the coupling coefficient volatility are obtained.

[0141] S7. Determine whether the coupling coefficient and coupling coefficient volatility meet the requirements.

[0142] The current coupling coefficient and coupling coefficient volatility are compared with the set values. If the requirements are met, the parameters that meet the conditions are saved; if the requirements are not met, the device parameters are further adjusted.

[0143] S8. Repeat the above steps.

[0144] Repeat steps S3 to S7 until all parameters reach their upper limits.

[0145] 2.4 Implementation Results

[0146] Through the above embodiments, we obtained the self-inductance, mutual inductance, and coupling coefficient of the transmitting and receiving coils. Through optimization algorithms, we ensured that the coupling coefficient remained essentially constant even when the transmitting and receiving coils were offset. Specific values ​​are shown in Tables 2 and 3 below:

[0147] Table 2 Coupling coefficients and errors during lateral offset.

[0148]

[0149] Table 3 Coupling coefficient and error when offset along the longitudinal direction.

[0150]

[0151] As can be seen from the table above, the coupling coefficients are all greater than 0.10, the error of the coupling coefficient when shifted laterally is 0.39%, and the error of the coupling coefficient when shifted laterally is 0.19%, all less than 5%. These data demonstrate that the present invention has the corresponding technical effect, that is, when the transmitting coil and the receiving coil are shifted, the coupling coefficient remains basically unchanged, thereby achieving efficient and stable wireless charging.

[0152] like Figure 2 As shown, an automatic charging method for automobiles based on strongly coupled wireless charging technology, used in an automatic charging system for automobiles, includes the following steps:

[0153] S1, Set the X, Y, Z axis coordinate error and angle rotation error requirements: Set the error between the actual coordinate and the set coordinate in the X direction to be less than 3cm; set the error between the actual coordinate and the set coordinate in the Y direction to be less than 3cm; set the error between the actual coordinate and the set coordinate in the Z direction to be less than 0.1cm;

[0154] S2, after the electric vehicle arrives at the parking area, the visual guidance camera searches for the location of the receiving coil on the electric vehicle and obtains the coordinate position and deflection angle of the receiving coil.

[0155] S3, the controller obtains the coordinate position of the receiving coil, drives the multi-dimensional moving platform to move, and adjusts the position of the transmitting coil so that the transmitting coil is basically aligned with the receiving coil;

[0156] S4, by controlling the flipping of the transmitting coil through a multi-dimensional moving platform, causes foreign objects on the surface to slide off, thereby clearing the foreign object target from the transmitting coil, and then resets it;

[0157] S5, and then the transmitting coil and receiving coil are gradually brought into close contact through the multi-dimensional mobile platform control;

[0158] S6. Repeat steps S2 to S5 until all coordinate position parameters reach the set target.

[0159] The working principle of this invention is as follows:

[0160] After the electric vehicle stops, the visual guidance camera on the transmitting coil side captures the position information of the receiving coil, and then transmits the position information to the multi-dimensional mobile platform. The multi-dimensional mobile platform adjusts the position of the transmitting coil in real time so that the transmitting coil and the receiving coil are aligned and closely fitted.

[0161] Based on the wireless charging system, a visually guided camera positioning device and a multi-dimensional moving platform are used to ensure that the transmitting coil and receiving coil are precisely aligned and closely fitted. With the coupling coefficient optimization algorithm of the transmitting and receiving coils, even if the receiving coil and transmitting coil of the wireless charging system are offset within a large range, the coupling coefficient between the receiving coil and the transmitting coil remains basically unchanged, thus completing automatic charging.

[0162] By using a multi-dimensional moving platform to rotate the transmitting coil 90 degrees, foreign objects can slide off, achieving the goal of removing metallic foreign objects from the transmitting coil.

[0163] Preferred embodiments of the invention are described herein, including the known best modes by which the inventors carry out the invention. Variations of the preferred embodiments will be apparent to those skilled in the art upon reading the foregoing description. The inventors expect those skilled in the art to reasonably apply such variations, and the inventors believe that applications different from those explicitly described herein can also implement the invention. Therefore, the invention includes all modifications and equivalents to the spirit referenced in the appended claims, which are permitted under applicable law. Furthermore, any combination of all possible variations of the foregoing elements is also included in the invention, unless otherwise indicated herein or clearly contradicted in the context.

[0164] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0165] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. An automatic charging system for automobiles based on strongly coupled wireless charging technology, comprising a grid-side rectifier, an inverter, a transmitting coil, and a receiving coil, characterized in that, It also includes a multi-dimensional mobile platform and a visual guidance camera; the position of the receiving coil is obtained through the visual guidance camera, and the multi-dimensional mobile platform is moved by the controller. With the coupling coefficient optimization algorithm of the transmitting coil and the receiving coil, the transmitting coil and the receiving coil of the wireless charging system are precisely aligned and closely fitted. Even if the receiving coil and the transmitting coil are offset, the coupling coefficient between the receiving coil and the transmitting coil can remain basically unchanged, and automatic charging can be completed. The coupling coefficient optimization algorithm includes the following steps: S1, Establish the transmitting coil to receiving coil model: consisting of a transmitting coil and a receiving coil with a size larger than the transmitting coil, with the receiving coil parallel to the transmitting coil; S2, set the main parameters: including the diameter of the copper wire, the resonant frequency, and the distance between the transmitting coil and the receiving coil; S3, Set specification constraints: Set constraints according to actual application and design requirements; including the range of inner length of the transmitting coil, the range of inner width of the transmitting coil, the range of number of turns of the transmitting coil, the range of inner length of the receiving coil, the range of inner width of the receiving coil, the range of number of turns of the receiving coil, and the step size; S4, calculate the mutual inductance and self-inductance values ​​of the transmitting coil and the receiving coil; S5, set the coupling coefficient k and the coupling coefficient volatility requirements: set the coupling coefficient k≥0.12; when offset laterally by 3cm, the coupling coefficient volatility ≤5%; when offset longitudinally by 3cm, the coupling coefficient volatility ≤5%. S6, calculate the coupling coefficient and the volatility of the coupling coefficient; S7, Determine whether the coupling coefficient and coupling coefficient volatility meet the requirements: Compare the current coupling coefficient and coupling coefficient volatility with the set values. If they meet the requirements, save the parameters that meet the conditions; if they do not meet the requirements, further adjust the device parameters. S8. Repeat steps S3 to S7 until all parameters reach their upper limits.

2. The vehicle automatic charging system based on strongly coupled wireless charging technology according to claim 1, characterized in that, The multi-dimensional moving platform enables the three-coordinate movement and angle adjustment of the transmitting coil.

3. The vehicle automatic charging system based on strongly coupled wireless charging technology according to claim 1, characterized in that, By controlling the flipping of the transmitting coil through a multi-dimensional moving platform, foreign objects on the transmitting coil can slide off, thereby achieving the purpose of removing foreign objects.

4. The vehicle automatic charging system based on strongly coupled wireless charging technology according to claim 1, characterized in that, The vision-guided camera and transmitting coil are mounted on a multi-dimensional mobile platform.

5. The vehicle automatic charging system based on strongly coupled wireless charging technology according to claim 1, characterized in that, In S4, the self-inductance of the transmitting coil and the receiving coil is calculated according to the formula (1) for calculating the self-inductance of a rectangular coil; Formula (1) is: Among them: B 4z It is magnetic flux density, D is T x and R x The transmission distance between them is μ0, which is the vacuum permeability, a1 and a2 are the length and width of the transmitting coil, ξ and η are the double Fourier transform parameters, I is the excitation current added to the transmitting coil, and t represents time.

6. The vehicle automatic charging system based on strongly coupled wireless charging technology according to claim 5, characterized in that, Under different coil offsets, the mutual inductance between single-turn rectangular coils is calculated according to the mutual inductance formula (2) between single-turn rectangular coils; Formula (2) is: Where: B is the magnetic flux density, I is the excitation current added to the transmitting coil, and b 1d and b 2d Let b1 and b2 be the length and width of Coil2, respectively, and ξ and η be the double Fourier transform parameters. S2 is the vertical distance between the receiving coil and the ground. iz and C ix As an intermediate variable, the specific expressions are shown in formulas (3) and (4): Formula (3) is: Formula (4) is: Where: j is the imaginary unit, representing the square root of -1. μ0 is the permeability in vacuum, I is the excitation current added to the transmitting coil, and Z0 is the vertical distance between the transmitting coil and the ground. The term is an exponential term, representing the attenuation of electromagnetic waves as they propagate through space.

7. The vehicle automatic charging system based on strongly coupled wireless charging technology according to claim 6, characterized in that, The total mutual inductance value is calculated according to the formula (5) for mutual inductance between multi-turn coils; Formula (5) is: Where: N1 and N2 are the number of turns of the transmitting coil and the receiving coil, respectively; m is the m-th turn of the transmitting coil; and n is the n-th turn of the receiving coil.

8. A method for automatic charging of an automobile based on strongly coupled wireless charging technology, used in the automatic charging system for automobiles according to any one of claims 1-4, characterized in that, Includes the following steps: S1, Set the X, Y, Z axis coordinate error and angle rotation error requirements: Set the error between the actual coordinate and the set coordinate in the X direction to be less than 3cm; set the error between the actual coordinate and the set coordinate in the Y direction to be less than 3cm; set the error between the actual coordinate and the set coordinate in the Z direction to be less than 0.1cm; S2, after the electric vehicle arrives at the parking area, the visual guidance camera searches for the location of the receiving coil on the electric vehicle and obtains the coordinate position and deflection angle of the receiving coil. S3, the controller obtains the coordinate position of the receiving coil, drives the multi-dimensional moving platform to move, and adjusts the position of the transmitting coil so that the transmitting coil is basically aligned with the receiving coil; S4, by controlling the flipping of the transmitting coil through a multi-dimensional moving platform, causes foreign objects on the surface to slide off, thereby clearing the foreign object target from the transmitting coil, and then resets it; S5, and then the transmitting coil and receiving coil are gradually brought into close contact through the multi-dimensional mobile platform control; S6. Repeat steps S2 to S5 until all coordinate position parameters reach the set target.

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