Differential magnetic localization method for the microrobot with two cylindrical permanent magnets

In order to find an effective method to control the wireless medical microrobot in vivo, such as the gastrointestinal tract and hemocoele, a specified kind of microrobot is proposed. It has two permanent magnets which are vertical each other, and is driven by the external rotating magnetic field. However obtaining the position and the orientation of the microrobot is the precondition of controlling it. So a differential localization method is developmental considering the strong background magnetic field. This method is based on magnetic dipoles model and nonlinear least square optimization algorithm. The numerical simulation results show the proposed method is effective.