A low-power magnetic levitation capsule robot system based on permanent magnets-electromagnetic coils array

Magnetic levitation capsule robots show great promise for gastric disease diagnosis due to their non-invasive nature and low infection risk. To reduce electromagnetic coils’ power consumption and minimize the device size, this study proposes a modified magnetic levitation capsule robot system based on a commercial magnetic levitation device. Symmetrically distributed permanent magnets array provide the main levitation force, while electromagnetic coils’ array only provide horizontal restoring forces, significantly reducing power consumption. Through a bottom-mounted design, the entire apparatus is positioned beneath the hospital bed, improving clinical safety and convenience. Addressing the weakened Hall sensor signals caused by the reduced size of the capsule robot (levitating permanent magnet), we established an accurate magnetic field model, analyzed the interaction forces between the stator and capsule robot, developed a magnetic field-displacement measurement platform to precisely determine the relationship between effective signals detected by Hall sensors and capsule robot displacement, and quantified electromagnetic coils’ interference on position detection. Based on the research above, a prototype has been developed. Experimental results demonstrate that the system achieves ±0.2 mm static levitation accuracy and ±0.35 mm dynamic tracking accuracy at a movement speed of 2.7 mm/s while maintaining power consumption below 0.2 A, providing a new technical solution for low-power, miniaturized, and clinically friendly magnetic levitation capsule robots.