Research on Magnetic Anisotropy Detection Method and System Based on Time-Frequency Analysis Enhancement

To achieve high-precision detection of magnetic anisotropy in ferromagnetic materials, this paper develops a magnetic anisotropy detection system based on enhanced time–frequency analysis. The hardware platform mainly consists of an excitation board, a power amplifier, a data acquisition card, sensors, and a host PC. The software is developed on the LabVIEW platform and integrates data acquisition, real-time signal processing, and feature analysis into a unified measurement and control system. Through frequency-sweep and amplitude-sweep experiments, the optimal operating parameter range of the sensor is determined, and the system repeatability is evaluated using the coefficient of variation of the measured data. The results demonstrate that the system exhibits good repeatability for 21 characteristic parameters, satisfying the requirements for high-precision detection. On this basis, the short-time Fourier transform is introduced into the anisotropy analysis of magnetic Barkhausen noise, and a multidimensional feature parameter system is established. Experimental comparisons between 30QG130 grain-oriented silicon steel and X70 pipeline steel indicate that the proposed time–frequency domain method exhibits higher sensitivity in quantifying the degree of magnetic anisotropy and identifying the rolling direction of materials than conventional time-domain methods. The anisotropy coefficient k reaches its maximum value in the critical magnetization region. Further experimental results show that different anisotropic mechanisms exhibit distinct response patterns in the time and frequency domains. Time–frequency analysis can directly reveal the magnetic domain magnetization dynamics by simultaneously observing time-domain evolution and frequency-domain energy distribution, thereby providing a novel and effective approach for decoupling complex magnetic anisotropy coupling mechanisms.