Research On Driving And Swimming Characteristic Of A Capsule Micro Robot

Micro robot features with small volume, quick response, and low energy consumption, which has extensive application. Such as wireless micro in-pipe swimming robot controlled by external magnetic field has a widespread prospect for applying in medical engineering, it has the characteristic of minor injury, painless and low treatment cost.This paper proposes a wireless driving method to actuate the capsule micro robot to swim by using a permanent magnetic hollow cylinder of NdFeB magnetized in the radial direction as the exterior driver, which is rotated by a frequency conversion govern motor that produces a rotating external magnetic field, the micro robot has a spiral structure and a permanent magnetic inner driver of NdFeB embedded in it, the inner driver has the same magnetic structure with the exterior driver.On the basis of expatiating on the driving and the swimming theory of the micro robot, The paper firstly establishes the mathematics model of the magnetic driving torque and the axial magnetic force acted on the micro robot by the external magnetic field, makes a lot of calculations and analysis on the driving characteristic of the external magnetic field, and optimizes the pole number of the inner and the exterior driver.Thereafter, the paper establishes the mathematical model of the axial thrust force, the load torque and the swimming velocity of the micro robot when it is swimming in the viscous fluid, and also establishes the simulative dynamic swimming model under the MATLAB environment of the micro robot. On the basis of theses models, the paper makes a lot of calculations, simulations and analysis on the stationary state and the transition state characteristic of the micro robot, and also optimizes the spiral angle of the micro robot.Finally, A lot of experiments on the driving and swimming characteristic were done. The results shows that the external rotating magnetic field produced by the NdFeB exterior driver could act a large magnetic drive torque on the micro robot, and drive it to double swim in the pipe full of viscous fluid with a quick velocity, the swimming velocity could be adjusted easily in a wide range by changing the driving frequency. The experimental results catch the theoretical results well, the driving method the paper proposes is feasible, and provides the basis for micro robot applying in medical engineering.