MRA-TESO-Based High-Precision Active Magnetic Compensation Method

Active magnetic compensation (AMC) is of significant importance in enhancing the signal-to-noise ratio of cardiac magnetic signals. However, in practical environments, multiple magnetic disturbances exist and need to be suppressed to ensure the accuracy of magnetocardiography (MCG) measurements. This paper proposes a model reference adaptive extended state observer with tracking filter (MRA-TESO) based high-precision active magnetic compensation method. It addresses the model errors in the AMC system and the insufficient capability of a typical extended state observer (ESO) in estimating complex disturbances. In the MRA-TESO framework, a tracking filter is employed to increase the system type of the equivalent open-loop transfer function for improved disturbance observation. Additionally, a model reference adaptive law is introduced to reduce internal system disturbances, providing more accurate model information and thereby lowering the bandwidth required for disturbance estimation. Experimental results demonstrate that the proposed method achieves satisfactory disturbance rejection performance.