Rotation measurement system based on linear active disturbance rejection and quasi-proportional resonant control

Magnetic measurement of cells is crucial in medical research. However, the extremely weak magnetic signals of cells and their susceptibility to environmental magnetic interference, conventional measurement methods are insufficient. This study proposes a novel method for extracting and measuring ultra-weak magnetic fields based on cell rotation and develops a magnetic shielding box (MSB) with a differential transmission structure. By driving precise differential rotation of cells within the MSB via an external motor, the proposed approach enhances the extraction of target magnetic signals. To effectively suppress low-frequency and specific-frequency magnetic interference inside the MSB, a dynamic compensation controller is designed by innovatively combining linear active disturbance rejection control with quasi-proportional resonant control, which drives biplanar coils to generate dynamic compensation fields. Experimental results verify the advantages of the proposed method in noise suppression and magnetic signal extraction. This study provides new ideas for the precise measurement of extremely weak biomagnetic signals.