Robust Control to Manipulate a Microparticle with Electromagnetic Coil System

Electromagnetic steering microrobots can be potentially used in various biomedical applications because these microrobots are minimally invasive and accessible in intricate microenvironments. In this paper, a robust feedback control approach is presented to precisely conduct the 3-D manipulation of a microparticle actuated by a self-constructed electromagnetic coil system. A nonlinear high-gain observer is designed to estimate the velocity of the controlled microparticle and to eliminate the measurement noise amplified by the high observer gain. Theoretical analysis indicated that the designed controller allows the entire system to maintain input-to-state stability in presence of perturbations. Simulations and experiments are performed to demonstrate the effectiveness of the proposed control approach.