Research On Drive And Control Characteristics Of Micro Robot Driven By External Magnetic Field

Nowadays micro robot has been shown broad prospect for applying in nucleus industries, aeronautic and astronautics, military affairs, as it has low inertia, high resonance, short response time and so on. Practice proved that wireless drive on micro robot is a good way to enhance reliability and feasibility, therefore micro-robot controlled by magnetic field without cable might be applied in medical treatment firstly.Giant magnetostrictive material, as it has high magnetostrictive coefficient, high power density, quick response time and high output force, has a potential for applying in many prospects, such as precision location control, initiative vibration control, super-precision finishing and robot.In this paper, a micro in-pipe robot driven by outside magnetic field is proposed, whose principle is, to realize its driving, by means of the vibration of outside magnetic field converting magnetic power into mechanical one through the action of piezomagnetism and magneomechanical couple of its micro GMA, that it is driven in wireless way.Based on research on characteristics of magnetostrictive material, negative current feedback is adopted in controller, to decrease time constant of magnetic vibration circuit, resulting in high frequency increasing, lower distorting and bigger output displacement.Then robot system composing and working principle is introduced, magnetomechanical converting process of outside magnetic power is studied, magnetomechanical control model and robot dynamic moving model are established, thereafter simulation and optimization on the whole system is conducted, the results show that damping coefficient and eddy current affect the system much greatly.Based on dynamic friction characteristics of its elastic legs and drive characteristics of giant magnetostriction material (GMM), double direction controlling model for micro in-pipe robot is establish, in which its positive direction drive is carried out by utilizing the Multiple frequency phenomenon of GMM, while its adverse moving is implemented by applying direct current offset magnetic field to change the slant of its elastic legs, under magnetomechanical couple of GMA, converting vibrating magnetic power to that of mechanical power, as a result, double moving is realized.Finally, micro robot in medical application is explored, circle loop permanent magnet rotating magnetic field with frequency conversion, according to magnetic charge integral principle and rotating driving micro robot mathematic model is established.By analysis in experiment results, the experiments show this system is feasible, therefore, outside magnetic field drive and double direction control method without cable is realized.