Abstract: A control strategy of discrete approximation is proposed to realize non-contact steering swimming of capsule robot in curved pipe filled with viscous liquid. Based on Résal coordinate system attached to the robot for determining the posture of robot, the model of spatial magnetic moment generated by the coupling between external spatial rotating magnetic field and inner actuator embedded in robot and the fluid moment model relevant to liquid inside curved pipe in response to steering motion of robot are derived. The dynamic response characteristics of magnetic driving moment and fluid moment during steering in curved pipe are analyzed and simulated. Results show that the follow-up effect occurs while robot veering by external rotational magnetic field, and the fact that fluid moment can rapidly damp robot’s vibration caused by magnetic driving moment is beneficial to non-contact drive of robot inside curved pipe.

Key words: Capsule robot, Fluid moment, Follow-up effect, Magnetic driving moment, Spatial rotating magnetic field