Research On Driving Method Of Macro Robot With Rotational Magnetic Field

Micro robot has small volume, quick response, and low energy consumption characters. Wireless driving method ought to be used to enhance the reliability and feasibility of micro robots. Lumen wireless micro robot can swim in body fluid in human's natural pipe, and it can diagnose, treat, operate and such other works in our bodies.This paper investigates a wireless driving method to actuate the micro capsule robot by using combined coils. Helmholtz coils can generate uniform magnetic field, so, according to vector addition, perpendicular cylindrical coil group is used to make uniform rotational magnetic field. By adjusting the amplitude, frequency and phase of current flowing into coils, the intensity, rotating velocity and direct of rotational plane can be controlled to drive micro robot.The flux density model is established to analyze laws that quality of magnetic field (flux density, uniformity and power loss) be affected by the size and configuration of coil, which provides the reference of coil optimum design. Double axial perpendicular helmholtz coils are designed. Magnetic field of each helmholtz coils is simulated with finite element analysis software ANSYS. Both the simulation result of each helmholtz and their contrast are consistent with the theory analysis, which proves the reliability of the model.Finally, the flux density of combined coils is calculated and the uniformity in space is analyzed. Analysis results show that combined magnetic field has a good uniformity. Additionally, the relationship of currents flowing into three axial perpendicular helmholtz coils is deduced in order to produce space rotational magnetic field with different directions at will. When both the amplitude and phase satisfy the condition concerned with the azimuth of micro robot locomotion, the rotational magnetic direct can be rectified according to the request.