US 12,282,074 B1
Method and apparatus for measuring magnetic field intensity in high-temperature superconducting maglev transportation systems
Rong Chen, Chengdu (CN); Ping Wang, Chengdu (CN); Tao Lv, Chengdu (CN); Jingmang Xu, Chengdu (CN); Zhou Xu, Chengdu (CN); Kai Liu, Chengdu (CN); and Min Xue, Chengdu (CN)
Assigned to Southwest Jiaotong University, Chengdu (CN)
Appl. No. 18/838,852
Filed by Southwest Jiaotong University, Chengdu (CN)
PCT Filed Apr. 25, 2024, PCT No. PCT/CN2024/089770
§ 371(c)(1), (2) Date Aug. 15, 2024,
.
Claims priority of application No. 202311677088.6 (CN), filed on Dec. 8, 2023.
Int. Cl. G01R 33/00 (2006.01); B60L 13/04 (2006.01); B61B 13/08 (2006.01); B61D 15/08 (2006.01); G01R 33/07 (2006.01); G01R 33/10 (2006.01)
CPC G01R 33/0094 (2013.01) [B60L 13/04 (2013.01); B61B 13/08 (2013.01); B61D 15/08 (2013.01); G01R 33/07 (2013.01); G01R 33/10 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A magnetic field intensity measurement method for high-temperature superconducting maglev transportation systems, characterized by comprising the following steps:
S1. Establishing the top surface of the permanent magnet guideway (PMG) as the reference datum for magnetic field intensity measurements;
S2. Developing a chord-based multi-point measurement system to detect surface irregularities of the PMG, with system parameters including sampling interval, system order, and chord measurement configuration;
S3. Computing chord measurement values for multiple intermediate points using data from the multi-point chord measurement system, and constructing an inversion model for the measurement system employing the least squares method; the inversion model is used to reconstruct the original track irregularity waveform from chord-based measurements, where the reconstructed track irregularity represents the vertical displacement of the chord baseline;
S4. Determining gap sensor positions based on the optimal chord measurement configuration of the multi-point chord system, and deploying an array of Hall effect sensors along the direction of magnetic field intensity measurement;
S5. Adjusting the reference datum position using the vertical displacement of the chord baseline, and calculating the magnetic field intensity distribution at any height above the reference datum using interpolation techniques based on Hall effect sensor readings;
In step S3, the formula for calculating chord measurement values for multiple intermediate measurement points based on the multi-point chord measurement system data is expressed as:
G=H·Zz
In which G denotes the chord measurement value matrix, H denotes the measurement matrix, and Zz denotes the irregularity vector matrix of the PMG;
The chord measurement value matrix G is represented as:

OG Complex Work Unit Math
Where G(i) denotes all chord values of measurement points when the chord baseline begins at measurement point i, and gn−1,i denotes the chord value of measurement point n−1 when the chord baseline begins at measurement point i;
The fully configured measurement matrix H for the chord baseline is presented as:

OG Complex Work Unit Math
The measurement matrix H contains n−1 rows and n+1 columns, with the number of rows corresponding to the number of measurement points in the full configuration, and the number of columns matching the dimension of the irregularity vector covered by the chord baseline, including endpoints; hn−1[k] is the convolution kernel for measurement point n−1, with elements in the 1st and n+1 columns corresponding to the split ratios γi and γi of measurement point i, while the middle columns from the 2nd to the n form an identity matrix of dimension n−1;
The PMG irregularity vector matrix Zz corresponding to each column of the chord measurement value matrix G is expressed as:

OG Complex Work Unit Math
Where Zi represents the irregularity vector corresponding to the chord baseline position i.