An electric vehicle wireless charging positioning system and a positioning method thereof

Abstract

The application discloses a kind of electric vehicle wireless charging positioning system and its positioning method, including ground end module and car end module, ground end module includes ground end controller and ground end detection coil, ground end detection coil senses the position of car end transmitting coil in car end module, ground end controller calculates the position information of electric vehicle, and sends position information to car end module;The application can quickly position, provide coordinate information and offset angle information, and the vehicle can correct vehicle coordinates and offset angle according to the above information, so that the ground end module and the car end module are maximized. Align, make the wireless charging efficiency reach the best;Meanwhile, the application uses multiple position detection coils and multiple frequency magnetic induction signal switching, which detects the angle information of electric vehicle and expands the detection range, and the ground end detection coil only works in two frequency time-sharing mode in any period. It can save the port resources of ground end frequency drive and reduce the cost of processor.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology for electric vehicles, and specifically to a wireless charging positioning system and positioning method for electric vehicles. Background Technology

[0002] In recent years, with the rapid development of the global electric vehicle industry, achieving safe, convenient, and efficient charging for electric vehicles has become of great significance. The traditional method for charging electric vehicles involves directly obtaining power from the grid through charging stations. However, when charging electric vehicles via wired connections, the charging socket or cable often has exposed parts, which can easily generate electrical sparks and arcs during high-power charging, posing significant safety hazards. Simultaneously, with the application of new technologies such as autonomous driving and automatic parking, people expect a completely automated charging process for electric vehicles, leading to increasing calls for automation in electric vehicle charging.

[0003] To address the above issues, short-range wireless power transmission technology is typically used for wireless charging of electric vehicles. This technology usually involves installing a transmitter on the ground or underground and a receiver on the vehicle's chassis. The transmitter generates a magnetic field, which the receiver receives and induces a current. This current is then rectified into direct current (DC) to charge the vehicle's battery. Because it's a contactless charging method based on magnetic induction, the relative position of the vehicle to the transmitter directly affects the magnetic induction strength, which in turn directly impacts charging efficiency and can even lead to charging failure.

[0004] Therefore, how to design a wireless charging positioning system and method for electric vehicles that can quickly locate and provide vehicle coordinate information and offset angle information to electric vehicles is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] To address the aforementioned deficiencies in the existing technology, this invention proposes a wireless charging positioning system and positioning method for electric vehicles.

[0006] The technical solution adopted in this invention is to design a wireless charging and positioning system for electric vehicles, including a ground-mounted module and a vehicle-mounted module installed under the vehicle. The ground-mounted module includes a ground controller, a power transmitting coil 12, a ground detection coil W1, and a detection circuit. The power transmitting coil emits an electromagnetic field, and the ground detection coil is used to detect the magnetic induction signal emitted by the vehicle-mounted transmitting coil in the vehicle-mounted module. The detection circuit is used to convert the magnetic induction signal into a detection signal. The controller calculates the position information of the electric vehicle based on the detection signal and sends the position information to the vehicle-mounted module. The vehicle-mounted module includes a vehicle controller, a power receiving coil 22, and a vehicle transmitting coil W2. The power receiving coil is used to receive the electromagnetic field emitted by the power transmitting coil, and the vehicle controller controls the vehicle-mounted transmitting coil to emit the magnetic induction signal and communicates with the ground controller.

[0007] The ground module includes a ground chassis 11 stacked from bottom to top, a power transmitting coil 12, a ground magnetic core 13, a ground detection coil W1, and a ground panel 14; the vehicle module includes a vehicle chassis 21 stacked from top to bottom, a power receiving coil 22, a vehicle magnetic core 23, and a vehicle detection coil W2.

[0008] The ground detection coil W1 includes multiple position detection coils (W1-1, W1-2...W1-n), which are distributed on the upper surface of the ground module and connected to the ground controller respectively. When the vehicle-end transmitting coil W2 of the vehicle-end module falls into the range of the ground detection coil in the plumb line and emits a magnetic induction signal, the ground controller determines the position of the electric vehicle by comparing the strength of the magnetic induction signals induced on each position detection coil.

[0009] The vehicle-end transmitting coil W2 includes a front left transmitting coil W2a, a front right transmitting coil W2b, a rear left transmitting coil W2c, and a rear right transmitting coil W2d, which are respectively installed at the four corners of the vehicle-end module: front left, front right, rear left, and rear right.

[0010] This invention also designs a positioning method for a wireless charging positioning system for electric vehicles. The system adopts the aforementioned wireless charging positioning system for electric vehicles. The positioning method includes: the front left transmitting coil W2a, the front right transmitting coil W2b, the rear left transmitting coil W2c, and the rear right transmitting coil W2d respectively transmitting magnetic induction signals with frequencies of f4, f3, f2, and f1; the ground detection coil W1 confirms the position of the corresponding transmitting coil based on the magnetic induction signals of different frequencies, and then calculates the position information of the electric vehicle.

[0011] The location information includes coordinate information and offset angle information.

[0012] The ground detection coil has a rear coil oscillation frequency group and a front coil oscillation frequency group. The rear coil oscillation frequency group includes frequencies f2 and f1, and the front coil oscillation frequency group includes frequencies f4 and f3. When using the rear coil oscillation frequency group, the ground detection coil will alternately use frequencies f2 and f1. When using the front coil oscillation frequency group, the ground detection coil will alternately use frequencies f4 and f3. The detection coils at various positions couple and sense the changes in the strength of the magnetic induction signal. The detection circuit then converts the magnetic induction signal into a detection signal. The ground controller converts the detection signal into a corresponding vector value based on its strength, establishes a complex coordinate system, and obtains the coordinate information of the electric vehicle through calculation.

[0013] During the positioning and detection process, the rear left transmitting coil W2c and the rear right transmitting coil W2d of the vehicle-end module enter the area above the ground-end module. The detection coils at these positions couple and sense the changes in the strength of the magnetic induction signal. The magnetic induction signal is then converted into a detection signal by the detection circuit. The ground-end controller calculates the coordinates of the rear left and rear right transmitting coils based on the strength of the detection signal using the orthogonal principle. Then, it calculates the coordinate information of the center point of the vehicle-end module by combining the positional relationship between the rear left and rear right transmitting coils and the center point of the vehicle-end module. Finally, it calculates the offset angle information of the electric vehicle based on the coordinates of the rear left and rear right transmitting coils.

[0014] During the positioning and detection process, the front left transmitting coil W2a and the front right transmitting coil W2b of the vehicle-end module enter the area above the ground-end module. The detection coils at various positions couple and sense the changes in the strength of the magnetic induction signal. The magnetic induction signal is then converted into a detection signal by the detection circuit. The ground-end controller calculates the coordinates of the front left and front right transmitting coils based on the strength of the detection signal using the orthogonal principle. Then, it calculates the coordinate information of the center point of the vehicle-end module by combining the positional relationship between the front left and front right transmitting coils and the center point of the vehicle-end module. Finally, it calculates the offset angle information of the electric vehicle based on the coordinates of the front left and front right transmitting coils.

[0015] The positioning method includes the following specific steps:

[0016] Step 1: Start the vehicle-side module;

[0017] Step 2: Start the ground module. The ground detection coil W1 of the ground module adopts the rear coil oscillation frequency group.

[0018] Step 3: The ground module checks whether the vehicle module has issued a positioning command. If yes, proceed to step 4; otherwise, proceed to step 42.

[0019] Step 4: Turn on the vehicle-end transmitting coil W2. The front left transmitting coil W2a, the front right transmitting coil W2b, the rear left transmitting coil W2c, and the rear right transmitting coil W2d respectively transmit magnetic induction signals with frequencies of f4, f3, f2, and f1.

[0020] Step 5: The ground module detects whether the electric vehicle has entered the positioning area. If yes, proceed to step 6; otherwise, wait.

[0021] Step 6: The ground module detects the rear left transmitting coil W2c and the rear right transmitting coil W2d, then proceed to step 10;

[0022] The ground module detected the front left transmitting coil W2a and the front right transmitting coil W2b, but did not detect the rear left transmitting coil W2c and the rear right transmitting coil W2d. Proceed to step 20.

[0023] Step 10: The ground detection coil W1 adopts the rear coil oscillation frequency group. Based on the strength of the magnetic induction signal received by the detection coils at various positions, the coordinates of the rear left and rear right transmitting coils are calculated using the orthogonal principle. Then, combined with the positional relationship between the rear left and rear right transmitting coils and the center point of the vehicle-end module, the coordinate information of the center point of the vehicle-end module is calculated. Finally, based on the coordinates of the rear left and rear right transmitting coils, the offset angle information of the electric vehicle is calculated. Proceed to step 40.

[0024] Step 20: The ground detection coil W1 adopts the front coil oscillation frequency group. Based on the strength of the magnetic induction signal received by the detection coils at various positions, the coordinates of the front left and front right transmitting coils are calculated using the orthogonal principle. Then, combined with the positional relationship between the front left and front right transmitting coils and the center point of the vehicle-end module, the coordinate information of the center point of the vehicle-end module is calculated. Finally, based on the coordinates of the front left and front right transmitting coils, the offset angle information of the electric vehicle is calculated. Proceed to step 40.

[0025] Step 40: The ground module transmits the coordinate information and offset angle information to the vehicle module;

[0026] Step 41: Check if the electric vehicle has left the positioning area. If yes, proceed to step 42; otherwise, proceed to step 5.

[0027] Step 42: The vehicle-side module shuts down the positioning command, shuts down the vehicle-side transmitting coil W2, and shuts down the ground module.

[0028] The beneficial effects of the technical solution provided by this invention are:

[0029] This invention enables rapid positioning, providing electric vehicles with vehicle coordinate and offset angle information. Manually driven or automatically parked vehicles can then correct their coordinates and offset angles based on this information, maximizing the alignment between the ground module and the vehicle module and optimizing wireless charging efficiency. Furthermore, this invention employs multiple position detection coils and switching between multiple frequency magnetic induction signals, detecting both the electric vehicle's angle information and expanding the detection range. The ground detection coils utilize two sets of oscillation frequencies, each containing two frequencies that operate in a time-division manner. This saves port resources on the processor responsible for frequency driving on the ground side, reducing processor costs. Attached Figure Description

[0030] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0031] Figure 1 This is a schematic side sectional view of a preferred embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the vehicle end from below, representing a preferred embodiment of the present invention.

[0033] Figure 3 This is a bottom view of the ground module;

[0034] Figure 4 This is a top view of the ground module;

[0035] Figure 5 This is a control flowchart of a preferred embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0037] This invention discloses a wireless charging positioning system for electric vehicles, see below. Figure 1 The overall side sectional view shown includes a ground-end module mounted on the ground and a vehicle-end module mounted on the underside of the electric vehicle. Figure 3 and Figure 4The bottom and top views of the ground module are shown respectively. The ground module includes a ground controller, a power transmitting coil 12, a ground detection coil W1, and a detection circuit. The power transmitting coil emits an electromagnetic field, and the ground detection coil couples the magnetic induction signal emitted by the vehicle-end transmitting coil in the magnetic induction vehicle module. After identification, amplification, and filtering, the signal is converted into a detection signal. The controller calculates the electric vehicle's position information based on the detection signal and sends the position information to the vehicle-end module. The vehicle-end module includes a vehicle-end controller, a power receiving coil 22, and a vehicle-end transmitting coil W2. The power receiving coil receives the electromagnetic field emitted by the power transmitting coil, and the vehicle-end controller controls the vehicle-end transmitting coil to emit the magnetic induction signal and communicates with the ground controller.

[0038] Combination Figure 1 , 3 In the preferred embodiment shown in Figure 4, the ground module includes a ground chassis 11 stacked from bottom to top, a power transmitting coil 12, a ground magnetic core 13, a ground detection coil W1, and a ground panel 14; the vehicle module includes a vehicle chassis 21 stacked from top to bottom, a power receiving coil 22, a vehicle magnetic core 23, and a vehicle detection coil W2.

[0039] See Figure 4 The ground detection coil W1 includes multiple position detection coils (W1-1, W1-2...W1-n), which are distributed on the upper surface of the ground module and connected to the ground controller respectively. When the vehicle-end transmitting coil W2 of the vehicle-end module falls into the range of the ground detection coil in the plumb direction and emits a magnetic induction signal, the ground controller determines the position of the electric vehicle by comparing the strength of the magnetic induction signals induced on each position detection coil.

[0040] The ground controller transmits complex signals of different frequencies to the detection coils through a data update trigger control method, thereby achieving the purpose of timely receiving complex signals of different frequencies and expanding the ground positioning area. Due to the use of coil frequency switching, the size of the vehicle positioning area is expanded. Angle information can also be calculated from the position information of multiple coils to indicate the vehicle's deviation direction and correct the vehicle's driving direction. All of the above features do not require additional hardware costs, reduce the number of detection coils, lower the hardware requirements of the ground controller, and reduce the chip port resources that the software depends on.

[0041] See Figure 2The diagram shown is a top-view view of the vehicle-side module, which is mounted on the bottom of the electric vehicle. The vehicle-side transmitting coil W2 includes a front left transmitting coil W2a, a front right transmitting coil W2b, a rear left transmitting coil W2c, and a rear right transmitting coil W2d, which are respectively mounted at the four corners of the vehicle-side module: front left, front right, rear left, and rear right. In a preferred embodiment, the front left transmitting coil Wa, the front right transmitting coil Wb, the rear left transmitting coil Wc, and the rear right transmitting coil Wd are arranged in a square on a horizontal plane, and the center of this square overlaps with the center of the power receiving coil.

[0042] This invention also discloses a positioning method for a wireless charging positioning system for electric vehicles. The system adopts the aforementioned wireless charging positioning system for electric vehicles. The positioning method includes: the front left transmitting coil W2a, the front right transmitting coil W2b, the rear left transmitting coil W2c, and the rear right transmitting coil W2d respectively transmitting magnetic induction signals with frequencies of f4, f3, f2, and f1; the ground detection coil W1 confirms the position of the corresponding transmitting coil based on the magnetic induction signals of different frequencies, and then calculates the position information of the electric vehicle.

[0043] In a preferred embodiment, the position information includes coordinate information and offset angle information.

[0044] In a preferred embodiment, the ground detection coil W1 has a rear coil oscillation frequency group and a front coil oscillation frequency group. The rear coil oscillation frequency group includes frequencies f2 and f1, and the front coil oscillation frequency group includes frequencies f4 and f3. When using the rear coil oscillation frequency group, the ground detection coil W1 alternates between frequencies f2 and f1; when using the front coil oscillation frequency group, the ground detection coil W1 alternates between frequencies f4 and f3. The position detection coils couple and sense changes in the strength of the magnetic induction signal. The detection circuit then converts the magnetic induction signal into a detection signal, which is a numerical signal. The strength of the induction signal is converted into a numerical value. The ground controller converts the magnitude of the detection signal into a corresponding vector value, establishes a complex coordinate system, and obtains the coordinate information of the electric vehicle through calculation. It should be noted that the ground detection coil uses two oscillation frequency groups, each of which includes two frequencies. These two frequencies operate in a time-sharing manner, which saves port resources of the processor responsible for frequency driving on the ground side, reducing the processor cost.

[0045] In the positioning detection process, the default and common scenario is that the rear of the electric vehicle reverses into the area above the ground module. The rear left transmitting coil W2c and the rear right transmitting coil W2d of the vehicle module then enter the area above the ground module. The ground detection coil W1 will alternately use frequency f2 and frequency f1. The position detection coils couple and sense the changes in the strength of the magnetic induction signal. The detection circuit then converts the magnetic induction signal into a detection signal. The ground controller calculates the coordinates of the rear left and rear right transmitting coils based on the strength of the detection signal using the orthogonal principle. Then, it calculates the coordinate information of the center point of the vehicle module by combining the positional relationship between the rear left and rear right transmitting coils and the center point of the vehicle module. Finally, it calculates the offset angle information of the electric vehicle based on the coordinates of the rear left and rear right transmitting coils.

[0046] If the vehicle reverses too far, the two coils W2c and W2d at the rear of the electric vehicle will move away from above the ground module. The front left transmitting coil W2a and the front right transmitting coil W2b of the vehicle-end module will then enter above the ground module. The ground detection coil W1 will use alternating frequencies f4 and f3 to detect changes in the strength of the magnetic induction signal. The detection circuit will then convert the magnetic induction signal into a detection signal. The ground controller will calculate the coordinates of the front left and front right transmitting coils based on the strength of the detection signal using the orthogonal principle. It will then combine the positional relationship between the front left and front right transmitting coils and the center point of the vehicle-end module to calculate the coordinate information of the center point of the vehicle-end module. Finally, it will calculate the offset angle information of the electric vehicle based on the coordinates of the front left and front right transmitting coils.

[0047] See Figure 5 The positioning method includes the following specific steps:

[0048] Step 1: Start the vehicle-end module (the vehicle-end module is working, but the vehicle-end transmitting coil W2 does not emit a magnetic induction signal. Except during positioning detection, the vehicle-end transmitting coil is in a stopped state, thereby saving energy and extending the service life of the equipment).

[0049] Step 2: Start the ground terminal module. The ground terminal detection coil W1 of the ground terminal module uses the rear coil oscillation frequency group (entering the ready detection state; the default method is for the rear of the electric vehicle to reverse into the area above the ground terminal module, so the default oscillation frequency for detection is frequency f2 and frequency f1).

[0050] Step 3: The ground module checks whether the vehicle module has issued a positioning command (the vehicle and ground controllers communicate to transmit the positioning command). If yes, proceed to step 4 (perform positioning detection); otherwise, proceed to step 42 (do not perform positioning detection).

[0051] Step 4: Turn on the vehicle-end transmitting coil W2. The front left transmitting coil W2a, the front right transmitting coil W2b, the rear left transmitting coil W2c, and the rear right transmitting coil W2d respectively transmit magnetic induction signals with frequencies of f4, f3, f2, and f1 (i.e., four frequency signals, each representing one of the four transmitting coils).

[0052] Step 5: The ground module detects whether the electric vehicle has entered the positioning area. If yes, proceed to step 6; otherwise, wait (when the electric vehicle enters the positioning area, the ground detection coil W1 can detect the magnetic induction signal to determine whether the electric vehicle has entered the positioning area).

[0053] Step 6: The ground module detects the rear left transmitting coil W2c and the rear right transmitting coil W2d, and proceeds to step 10 (in this case, the rear of the electric vehicle reverses into the area above the ground module).

[0054] The ground module detects the front left transmitting coil W2a and the front right transmitting coil W2b, but does not detect the rear left transmitting coil W2c and the rear right transmitting coil W2d, so proceed to step 20 (this is the case where the vehicle reverses too far and the two coils W2c and W2d at the rear of the electric vehicle move away from above the ground module).

[0055] Step 10 (the two rear transmitting coils are located above the ground detection coil W1): The ground detection coil W1 uses the rear coil oscillation frequency group. Based on the strength of the magnetic induction signal received by the detection coils at various positions, the coordinates of the rear left and rear right transmitting coils are calculated using the orthogonal principle. Then, combined with the positional relationship between the rear left and rear right transmitting coils and the center point of the vehicle-end module, the coordinate information of the center point of the vehicle-end module is calculated. Finally, based on the coordinates of the rear left and rear right transmitting coils, the offset angle information of the electric vehicle is calculated, and then proceed to step 40. It should be noted that, in a preferred embodiment, the rear left transmitting coil W2c and the rear right transmitting coil W2d form an inverted right triangle with the center point of the vehicle-end module. The coordinates of the center point of the vehicle-end module can be calculated using the geometric formula of trigonometric functions.

[0056] Step 20 (the two front transmitting coils are located above the ground detection coil W1): The ground detection coil W1 uses the front coil oscillation frequency group. Based on the strength of the magnetic induction signal received by the detection coils at various positions, the coordinates of the front left and front right transmitting coils are calculated using the orthogonal principle. Then, combined with the positional relationship between the front left and front right transmitting coils and the center point of the vehicle module, the coordinate information of the center point of the vehicle module is calculated. Finally, based on the coordinates of the front left and front right transmitting coils, the offset angle information of the electric vehicle is calculated, and then proceed to step 40. It should be noted that, in a preferred embodiment, the front left transmitting coil W2a and the front right transmitting coil W2b form an inverted right triangle with the center point of the vehicle module. The coordinates of the center point of the vehicle module can be calculated using the geometric formula of trigonometric functions.

[0057] Step 40: The ground module transmits the coordinate information and offset angle information to the vehicle module;

[0058] Step 41: Check if the electric vehicle has left the positioning area. If yes, proceed to step 42; otherwise, proceed to step 5.

[0059] Step 42: The vehicle-side module shuts down the positioning command, shuts down the vehicle-side transmitting coil W2, and shuts down the ground module.

[0060] This positioning method can be adapted to vehicles of different heights without requiring any additional circuit modifications. The ground controller will automatically switch detection values ​​based on different signal strengths and filter out irrelevant signals.

[0061] This positioning method has high real-time performance, does not require wireless communication signal transmission, and switches coils through magnetic induction, so there is no "hysteresis" in the positioning coordinates.

[0062] The above embodiments are merely illustrative and not intended to be limiting. Any equivalent modifications or alterations made without departing from the spirit and scope of this application should be included within the scope of the claims of this application.

Claims

1. A wireless charging positioning system for electric vehicles, comprising a ground-mounted module and a vehicle-mounted module installed under the vehicle, characterized in that, The ground module includes a ground controller, a power transmitting coil (12), a ground detection coil (W1), and a detection circuit. The power transmitting coil emits an electromagnetic field, the ground detection coil is used to transmit the magnetic induction signal emitted by the vehicle-end transmitting coil in the magnetic induction vehicle-end module, and the detection circuit is used to convert the magnetic induction signal into a detection signal. The controller calculates the position information of the electric vehicle based on the detection signal and sends the position information to the vehicle-end module. The vehicle-end module includes a vehicle-end controller, a power receiving coil (22), and a vehicle-end transmitting coil (W2). The power receiving coil is used to receive the electromagnetic field emitted by the power transmitting coil. The vehicle-end controller controls the vehicle-end transmitting coil to emit the magnetic induction signal and communicates with the ground-end controller. The vehicle-end transmitting coil (W2) includes a front left transmitting coil (W2a), a front right transmitting coil (W2b), a rear left transmitting coil (W2c), and a rear right transmitting coil (W2d), which are respectively installed at the four corners of the vehicle-end module: front left, front right, rear left, and rear right. The front left transmitting coil (W2a), front right transmitting coil (W2b), rear left transmitting coil (W2c), and rear right transmitting coil (W2d) transmit magnetic induction signals with frequencies of f4, f3, f2, and f1, respectively. The ground detection coil (W1) determines the position of the corresponding transmitting coil based on the magnetic induction signals of different frequencies, and then calculates the position information of the electric vehicle. The ground detection coil (W1) has a rear coil oscillation frequency group and a front coil oscillation frequency group. The rear coil oscillation frequency group includes frequencies f2 and f1, and the front coil oscillation frequency group includes frequencies f4 and f3. When using the rear coil oscillation frequency group, the ground detection coil (W1) will alternately use frequencies f2 and f1. When using the front coil oscillation frequency group, the ground detection coil (W1) will alternately use frequencies f4 and f3. The ground detection coil (W1) includes multiple position detection coils (W1-1, W1-2...W1-n), which are distributed on the upper surface of the ground module and connected to the ground controller respectively. The position detection coils couple and sense the changes in the strength of the magnetic induction signal, and then the detection circuit converts the magnetic induction signal into a detection signal. The ground controller converts the detection signal into a corresponding vector value according to the strength of the detection signal, establishes a complex coordinate, and obtains the coordinate information of the electric vehicle through calculation.

2. The wireless charging positioning system for electric vehicles as described in claim 1, characterized in that, The ground module includes a ground chassis (11) stacked from bottom to top, a power transmitting coil (12), a ground magnetic core (13), a ground detection coil (W1), and a ground panel (14); the vehicle module includes a vehicle chassis (21) stacked from top to bottom, a power receiving coil (22), a vehicle magnetic core (23), and a vehicle transmitting coil (W2).

3. The wireless charging positioning system for electric vehicles as described in claim 1, characterized in that, When the vehicle-end transmitting coil (W2) of the vehicle-end module falls into the range of the ground-end detection coil in the direction of the plumb bob and emits a magnetic induction signal, the ground-end controller determines the position of the electric vehicle by comparing the strength of the magnetic induction signals induced on the detection coils at each position.

4. The wireless charging positioning system for electric vehicles as described in claim 3, characterized in that, The location information includes coordinate information and offset angle information.

5. The wireless charging positioning system for electric vehicles as described in claim 4, characterized in that, During the positioning and detection process, the rear left transmitting coil (W2c) and rear right transmitting coil (W2d) of the vehicle-end module enter the area above the ground-end module. The detection coils at these positions couple and sense the changes in the strength of the magnetic induction signal. The magnetic induction signal is then converted into a detection signal by the detection circuit. The ground-end controller calculates the coordinates of the rear left and rear right transmitting coils based on the strength of the detection signal using the orthogonal principle. Then, it calculates the coordinate information of the center point of the vehicle-end module by combining the positional relationship between the rear left and rear right transmitting coils and the center point of the vehicle-end module. Finally, it calculates the offset angle information of the electric vehicle based on the coordinates of the rear left and rear right transmitting coils.

6. The wireless charging positioning system for electric vehicles as described in claim 5, characterized in that, During the positioning and detection process, the front left transmitting coil (W2a) and front right transmitting coil (W2b) of the vehicle-end module enter the area above the ground module. The detection coils at various positions couple and sense the changes in the strength of the magnetic induction signal. The magnetic induction signal is then converted into a detection signal by the detection circuit. The ground controller calculates the coordinates of the front left and front right transmitting coils based on the strength of the detection signal using the orthogonal principle. Then, it calculates the coordinate information of the center point of the vehicle-end module by combining the positional relationship between the front left and front right transmitting coils and the center point of the vehicle-end module. Finally, it calculates the offset angle information of the electric vehicle based on the coordinates of the front left and front right transmitting coils.

7. A positioning method for a wireless charging positioning system for electric vehicles, characterized in that, The electric vehicle wireless charging positioning system adopts the electric vehicle wireless charging positioning system according to any one of claims 1 to 6, and the positioning method includes the following specific steps: Step 1: Start the vehicle-side module; Step 2: Start the ground module. The ground detection coil (W1) of the ground module adopts the rear coil oscillation frequency group. Step 3: The ground module checks whether the vehicle module has issued a positioning command. If yes, proceed to step 4; otherwise, proceed to step 42. Step 4: Turn on the vehicle-end transmitting coil (W2). The front left transmitting coil (W2a), front right transmitting coil (W2b), rear left transmitting coil (W2c), and rear right transmitting coil (W2d) respectively transmit magnetic induction signals with frequencies of f4, f3, f2, and f1. Step 5: The ground module detects whether the electric vehicle has entered the positioning area. If yes, proceed to step 6; otherwise, wait. Step 6: The ground module detects the rear left transmitting coil (W2c) and the rear right transmitting coil (W2d), then proceed to step 10; If the ground module detects the front left transmitting coil (W2a) and the front right transmitting coil (W2b), but does not detect the rear left transmitting coil (W2c) and the rear right transmitting coil (W2d), proceed to step 20; Step 10: The ground detection coil (W1) adopts the rear coil oscillation frequency group. Based on the strength of the magnetic induction signal received by the detection coils at various positions, the coordinates of the rear left and rear right transmitting coils are calculated using the orthogonal principle. Then, combined with the positional relationship between the rear left and rear right transmitting coils and the center point of the vehicle-end module, the coordinate information of the center point of the vehicle-end module is calculated. Finally, based on the coordinates of the rear left and rear right transmitting coils, the offset angle information of the electric vehicle is calculated. Proceed to step 40. Step 20: The ground detection coil (W1) adopts the front coil oscillation frequency group. Based on the strength of the magnetic induction signal received by the detection coils at various positions, the coordinates of the front left and front right transmitting coils are calculated using the orthogonal principle. Then, combined with the positional relationship between the front left and front right transmitting coils and the center point of the vehicle-end module, the coordinate information of the center point of the vehicle-end module is calculated. Finally, based on the coordinates of the front left and front right transmitting coils, the offset angle information of the electric vehicle is calculated. Proceed to step 40. Step 40: The ground module transmits the coordinate information and offset angle information to the vehicle module; Step 41: Check if the electric vehicle has left the positioning area. If yes, proceed to step 42; otherwise, proceed to step 5. Step 42: The vehicle-side module shuts down the positioning command, shuts down the vehicle-side transmitting coil (W2), and shuts down the ground module.

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