Design, analysis and experiments of a spatial universal rotating magnetic field system for capsule robot

For non-contact drive of capsule micro robot in bending intestine, we propose a technical scheme in which three axis orthogonal square Helmholtz coils are employed to generate a spatial universal outer rotating uniform magnetic field using magnetic field superposition principle. For their optimization design, electromagnetic mathematical model of the three axis Helmholtz coils system is derived to analyse the electromagnetic dynamic characteristics with respect to their structural parameters. Theoretical research and simulations show that the axial orientation of rotating magnetic field can be adjusted in response to currents applied to three axis Helmholtz coils, and superimposed magnetic field features good uniformity and directivity. Finally, the uniformity and directivity of magnetic field are verified through experiments, which can drive capsule robot forward inside bending pipe. The technology for generating spatial universal rotating magnetic field provides a possible solution for non-contact drive of capsule micro robot in bending intestine, which has a promising application prospect in medical engineering.