Adaptive Decoupling Control of Three-Axis Active Magnetic Compensation System Based on MSG Identification

Magnetic shielding room (MSR) and three-axis magnetic field compensation (TMFC) system are necessary for extremely weak magnetic field measurement. The TMFC system can effectively reduce the impact of magnetic field interference on the extremely weak magnetic field measurement in the MSR, but the coupling effect between different compensation axes reduces the compensation performance. This article proposes an adaptive decoupling control method based on online modified stochastic gradient (MSG) identification. The decoupler is designed to transform the TMFC system into three single-input-single-output (SISO) systems based on the interaction model structure established by frequency-domain identification and the parameters identified online using MSG algorithm. In addition, a feedback controller was designed to ensure that the SISO system has the satisfied dynamic performance and stability. Experimental results indicate that the proposed method realizes dynamic decoupling of TMFC system.