A method for acquiring high-frequency magnetic field intensity distribution

Abstract

This invention discloses a method for acquiring high-frequency magnetic field intensity distribution. First, the method calibrates the errors between the individual magnetic sensors on a magnetic sensor array. Then, the transmitting coil is activated for energy transmission. A signal light source is triggered periodically by a data box. Once the optical signal is received by the calibration node of the first group of magnetic sensor arrays, it triggers an optical fiber interruption signal for the magnetic sensors in the first group, initiating one data acquisition. Simultaneously, the optical signal is transmitted to the calibration node of the next group of magnetic sensor arrays, triggering the corresponding optical fiber interruption signal for data acquisition. Finally, interpolation is performed on the magnetic sensor intensities over two time intervals to obtain the magnetic field distribution of the entire array at a specific time. This invention uses a modulated optical signal as the transmitting end, leveraging light to trigger the synchronous acquisition of multiple magnetic sensors, effectively reducing the acquisition error of the magnetic field intensity.

Description

Technical Field

[0001] This invention belongs to the field of testing and signal processing, and specifically relates to a method for acquiring high-frequency magnetic field intensity distribution. Background Technology

[0002] Magnetic resonant coupling wireless power transfer technology is a key technology in the current field of wireless power transfer. The magnetic field, as the transmission medium, directly affects the system's transmission efficiency. Therefore, the study of spatial magnetic field distribution and the synchronous variation curve of the spatial magnetic field during wireless power transfer is crucial to this technology.

[0003] Existing discrete magnetic field sensing units mostly use electrical signals as synchronization signals, and for short distances, they often use level signals as trigger signals. Some also utilize optical fibers for synchronization trigger signals. These methods all require long cables for physical connections, limiting the acquisition environment (which must be wired). Synchronization via wireless networks or other radio frequency signals suffers from significant synchronization errors. If offline crystal oscillator synchronization is used, the crystal's ppm value is above 10, potentially leading to a CLOCK error exceeding 10µs. This is unsuitable for acquiring high-frequency changing magnetic fields over a wide spatial range. Furthermore, high-frequency magnetic fields change rapidly; for the same time difference, the change is greater with higher frequencies, demanding higher sampling time and accuracy. Summary of the Invention

[0004] To avoid the shortcomings of the traditional methods mentioned above and to achieve better magnetic field distribution acquisition, this invention proposes a high-frequency magnetic field intensity distribution acquisition method.

[0005] The technical solution of the present invention is as follows:

[0006] 1. Before starting data acquisition, calculate the acquisition time error between the individual magnetic sensors on the magnetic sensor array.

[0007] 1.1 Turn on the signal light source to output optical signals. The calibration node of the first set of magnetic sensor arrays receives the combined optical signals of R and G. At the same time, after receiving the optical signals, the calibration node starts counting and then emits optical signals to the corresponding calibration node of the second set of magnetic sensor arrays.

[0008] 1.2 When the calibration node of the second set of magnetic sensor arrays receives an optical signal, it transmits a laser signal to the calibration node of the first set of magnetic sensor arrays. When the calibration node of the first set of magnetic sensor arrays receives the laser signal from behind, it stops counting. The counting time T0 is obtained; then the error time Td = T0 / 2, which is the acquisition time error between the two sets of magnetic sensor arrays.

[0009] 2. The transmitting coil generates a high-frequency magnetic field for energy transmission. The data box triggers the signal light source to emit light signals for synchronous acquisition. After the light signal is received by the calibration node of the first group of magnetic sensor arrays, it triggers the fiber optic interruption signal of the first group of magnetic sensor arrays to perform one data acquisition. All magnetic sensors are connected to their own calibration nodes and are triggered for acquisition by the fiber optic interruption signal of the sensors.

[0010] 3. While the optical signal is being received at the first set of magnetic sensor array calibration nodes, it is transmitted to the second set of magnetic sensor array calibration nodes. At the same time, the calibration nodes trigger the corresponding magnetic sensor fiber optic interruption signal to collect data.

[0011] 4. When the optical signal pulse is a 10µs pulse signal, both the first and second magnetic sensor arrays record m sets of data every 10µs.

[0012] 5. When the sampling time of the first magnetic sensor array of the nth data is Tn1, the magnetic field strength collected by the Q magnetic sensors of the first magnetic sensor array is K1m0…K1mi…K1mQ, i∈[0,Q]. The sampling time of the second magnetic sensor array in the same sampling is Tn1+Td, and the magnetic field strength collected by the Q magnetic sensors of the second magnetic sensor array is K1n0…K1ni…K1nQ; where n≤m, and Q is a positive integer.

[0013] 6. Using the sampling time of the first set of magnetic sensor arrays as the reference time, data regression is performed using interpolation to obtain the magnetic field strength data of the second set of magnetic sensor arrays at time Tn1. The magnetic field strength of the i-th magnetic sensor position of the second set of magnetic sensor arrays at time Tn1 can be calculated as (Tn1-Tn0-Td) / (Tn1-Tn0)*K1ni.

[0014] 7. Similarly, calculate the magnetic field strength of all calibration nodes of the second set of magnetic sensor arrays at sampling time Tn1, and obtain the magnetic field strength distribution of the entire array of the second set of magnetic sensor arrays at sampling time Tn1.

[0015] The beneficial effects of this invention are as follows: This invention uses a modulated optical signal as the transmitter, and within the reach of the optical path, it utilizes light to trigger the synchronous acquisition of multiple magnetic sensors. With a default light speed of 3 * 10^8 meters per second, the error per meter in the distance difference between sensors is: 1 / (3 * 10^8) = 3.3 ns. This distance error can be compensated by using laser ranging beforehand, where the obtained distance measurement value is used to back into the acquired data. When the laser ranging is accurate to the millimeter level, the synchronization error of each sensor will be less than 3.3 ps. Attached Figure Description

[0016] Figure 1This is an overall diagram of the data acquisition device;

[0017] Figure 2 This is a front view of the data acquisition box;

[0018] Figure 3 This is a side view of the data acquisition box;

[0019] Figure 4 This is a schematic diagram of the receiving device;

[0020] Figure 5 This is a schematic diagram of the transmitter device. Detailed Implementation

[0021] The acquisition device involved in the method of this invention is as follows: Figure 1 and Figure 2 As shown, it includes a signal light source, a transmitting coil, a data acquisition box, and a receiving coil. The transmitting coil is an electromagnetic generator used to produce high-frequency changing electromagnetic signals and form a high-frequency magnetic field. The receiving coil is a device used to receive electromagnetic signals. Figure 2 This is a front view of the data acquisition box and the magnetic sensor array, which is a schematic diagram of the magnetic sensor array. Each magnetic sensor array contains 17 calibration nodes and 17 magnetic sensors corresponding to each calibration node. In the figure, 1 to 17 correspond to the distribution positions of the 17 magnetic sensors. Figure 3 This is a side view of the data acquisition box and the magnetic sensor array, which shows the spatial relationship between the 17 calibration nodes.

[0022] 1. Before starting data acquisition, it is necessary to calculate the acquisition time error between the various magnetic sensors on the magnetic sensor array. Differences in the light source signals received by different points due to misalignment of the center or tilt of the array will manifest as acquisition time error.

[0023] 1.1 Turn on the signal light source to output optical signals. The 17th calibration node of the first group of magnetic sensor arrays receives the combined optical signal of R and G. At the same time, after receiving the optical signal at the 17th node, it starts counting and then transmits the optical signal to the 17th calibration node of the second group of magnetic sensor arrays.

[0024] This embodiment is primarily based on the speed of optical signals. To eliminate the influence of ambient light on the acquisition and measurement, the transmitting end, i.e., the signal light source, emits light composed of R-light and G-light at set wavelengths. The calibration node, i.e., the receiving end, collects all three types of light. Figure 5 As shown, the transmitting end includes R-component optical transmitter 1 and G-component optical transmitter 2. The receiving end, which is also the calibration node, is as follows: Figure 4As shown, it includes ambient light inlet 1, R-component light inlet 2, and G-component light inlet 3. After installation, the calibration node first collects the ambient light data of the original interface for subsequent comparison, using the ratio of R-component to G-component to eliminate potential interference. Here, R represents the red light signal, and G represents the green light signal.

[0025] 1.2 When calibration node 17 of the second magnetic sensor array receives a signal, it transmits a laser signal to calibration node 17 of the first magnetic sensor array. Counting stops when calibration node 17 of the first magnetic sensor array receives the laser signal. The counting time T0 is obtained, and the error time Td = T0 / 2 represents the acquisition time error between the two magnetic sensor arrays.

[0026] 2. When starting work, the transmitting coil generates a high-frequency magnetic field of 100k-300mhz for energy transmission. The data box triggers the signal light source to emit light signals for synchronous acquisition. After the light signal is received by the 17th calibration node of the first group of magnetic sensor arrays, it triggers the fiber optic interruption signal of the first group of array magnetic sensors to perform one data acquisition. All magnetic sensors are connected to their own calibration nodes and are triggered for acquisition by the fiber optic interruption signal of the sensors.

[0027] 3. While the optical signal is received at calibration node 17 of the first set of magnetic sensor arrays, the optical signal is transmitted to calibration node 17 of the second set of magnetic sensor arrays. At the same time, calibration node 17 triggers the corresponding magnetic sensor fiber optic interruption signal to collect data.

[0028] 4. When performing data time correction and interpolation curves, the acquisition time error Td is required. When the optical signal pulse is a 10us pulse signal, both the first and second magnetic sensor arrays record m sets of data every 10us.

[0029] 5. When the sampling time of the first group of magnetic sensor arrays for the nth data is Tn1, n≤m, the magnetic field strengths collected by the 17 magnetic sensors are K1m0, K1m1…K1m16. The sampling time of the second group of magnetic sensor arrays for the same sampling is Tn1+Td, and the magnetic field strengths collected by the 17 magnetic sensors are K1n0, K1n1…K1n16.

[0030] 6. Using the sampling time of the first set of magnetic sensor arrays as the reference time, data regression is performed using interpolation to obtain the data on the second set of magnetic sensor arrays at sampling time Tn1. The magnetic field strength at the position of magnetic sensor 17 in the second set of magnetic sensor arrays at sampling time Tn1 can be calculated as (Tn1-Tn0-Td) / (Tn1-Tn0)*K1n0.

[0031] 7. Similarly, calculate the magnetic field strength of the remaining 16 sensors of the second set of magnetic sensor arrays at sampling time Tn1, and obtain the magnetic field strength distribution of the entire array at sampling time Tn1.

Claims

1. A method for acquiring high-frequency magnetic field intensity distribution, characterized in that... The method includes the following steps: S1. Calculate the acquisition time error Td between the individual magnetic sensors on the magnetic sensor array; S2. The transmitting coil generates a high-frequency magnetic field for energy transmission. The data box triggers the signal light source to emit light signals for synchronous acquisition at regular intervals. After the light signal is received by the calibration node of the first set of magnetic sensor arrays, it triggers the fiber optic interruption signal of the magnetic sensor of the first set of magnetic sensor arrays to perform one data acquisition. S3. While the optical signal is obtained at the first set of magnetic sensor array calibration nodes, the optical signal is transmitted to the second set of magnetic sensor array calibration nodes. At the same time, the calibration nodes trigger the corresponding magnetic sensor fiber optic interruption signal to collect data. S4. When the optical signal pulse is a 10us pulse signal, both the first group of magnetic sensor arrays and the second group of magnetic sensor arrays record m sets of data every 10us. S5. When the sampling time of the first magnetic sensor array of the nth data is Tn1, the magnetic field strength collected by the Q magnetic sensors of the first magnetic sensor array is K1m0…K1mi…K1mQ, i∈[0,Q]. The sampling time of the second magnetic sensor array in the same sampling is Tn1+Td, and the magnetic field strength collected by the Q magnetic sensors of the second magnetic sensor array is K1n0…K1ni…K1nQ; where n≤m, Q is a positive integer. S6. Using the sampling time of the first group of magnetic sensor arrays as the reference time, perform data regression by interpolation to obtain the magnetic field strength at the position of the i-th magnetic sensor on the second group of magnetic sensor arrays at sampling time Tn1. S7. Similarly, calculate the magnetic field strength of all calibration nodes of the second set of magnetic sensor arrays at sampling time Tn1, and obtain the magnetic field strength distribution of the entire array of the second set of magnetic sensor arrays at sampling time Tn1.

2. The method for acquiring high-frequency magnetic field intensity distribution according to claim 1, characterized in that: The specific process for calculating the acquisition time error Td between the various magnetic sensors on the magnetic sensor array in step S1 is as follows: S1-1 turns on the signal light source to output optical signals. The calibration node of the first set of magnetic sensor arrays receives the combined optical signals of R and G. At the same time, after receiving the optical signals, the calibration node starts counting and emits optical signals to the corresponding calibration node of the second set of magnetic sensor arrays. Here, R represents red light signal and G represents green light signal. When the calibration node of the second set of magnetic sensor arrays receives the optical signal, it transmits a laser signal to the calibration node of the first set of magnetic sensor arrays. When the calibration node of the first set of magnetic sensor arrays receives the laser signal from behind, it stops counting and obtains the counting time T0. Then the error time Td = T0 / 2 is the acquisition time error between the two sets of magnetic sensor arrays.

3. The high-frequency magnetic field intensity distribution acquisition method according to claim 2, characterized in that: The combined R and G optical signal is emitted from a signal light source and is composed of selected wavelengths of R and G light.

4. A method for acquiring high-frequency magnetic field intensity distribution according to claim 1 or 2, characterized in that: The calibration node mentioned in step S1 includes an ambient light inlet, an R-component light inlet, and a G-component light inlet. After installation, the calibration node first collects the ambient light data of the original interface for subsequent comparison, and uses the R-light and G-light component ratio to eliminate potential interference.

5. A method for acquiring high-frequency magnetic field intensity distribution according to claim 1 or 2, characterized in that: The magnetic sensors described in step S1 are all connected to their own calibration nodes and are triggered by the fiber optic interruption signal of the magnetic sensors.

6. The method for acquiring high-frequency magnetic field intensity distribution according to claim 1, characterized in that: The magnetic sensor array described in step S2 contains 17 calibration nodes and 17 magnetic sensors corresponding to each calibration node, i.e., Q=17.

7. The method for acquiring high-frequency magnetic field intensity distribution according to claim 1, characterized in that: In step S6, the magnetic field strength at the position of the i-th magnetic sensor on the second magnetic sensor array at sampling time Tn1 is (Tn1-Tn0-Td) / (Tn1-Tn0)*K1ni.

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