Correction of misalignment errors in the magnetic gradient tensor measurement system and its application in localization

¹ North University of China, State key Laboratory of Extreme Environment optoelectronic Dynamic Testing Technology and Instrument, 030051 No. 3 Xueyuan Road, Jiancaoping, Taiyuan, China
² North University of China, School of Instrumentation and Electronics, 030051 No. 3 Xueyuan Road, Jiancaoping, Taiyuan, China
³ Brunel University of London, Department of Mechanical and Aerospace Engineering, Kingston lane, Uxbridge UB8 3PH, UK

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The magnetic gradient tensor measurement system (MGTMS) is critical for detecting and localizing ferromagnetic targets. However, its localization accuracy is closely linked to measurement precision, which is often compromised by sensor misalignment errors. To mitigate these errors, this study proposes a practical calibration method using a standard magnetic source, achieving effective misalignment correction with minimal system alteration. The proposed method is validated through both simulations and localization experiments. Simulation results indicate that the root mean square error (RMSE) of the calibrated tensor values is reduced by three orders of magnitude compared to the uncalibrated state. Experimental results further demonstrate that the average localization error decreases from 0.040 m to 0.019 m after calibration, corresponding to a 52.5% improvement in positioning accuracy. These results highlight the potential of improving the accuracy of MGTMS-based target localization in practical applications.