Magnetic Modeling And Motion Control Of Active Capsule Endoscopy Guided By Dextrous Robots

Compared with the traditional gastrointestinal examination, the new wirelesscapsule endoscopy is tolerated, noninvasive and easy to operate. However, it takespictures randomly, and its pos and position cannot be controlled. So, there is anobvious and urgent need to achieve the controllability of the capsule. Nevertheless,for the methods of Inchworm-like microrobot, Capsular locomotive microrobot, andlegged capsule and so on, the common defects are that the driving parts occupy lotsof space and consume much more power, and cannot ensure the safety of the capsule.Besides, the ways of magnetic control are also described as inconvenient operation,limited working space, not full degree of freedom, and requirement of special shape.For overcoming the drawback of active control schemes proposed, a newmethod based on dextrous robot and magnetic control is put forward in this thesis.Because there is no usable model at the present time, first the3D analytical modelof the magnetic flux density distribution of a cuboidal permanent magnet is builtbased on molecular current theory. Then the analytical magnetic force andmagnetic torque model of a permanent magnet in an extern magnetic field is got forone permanent magnet and two permanent magnets based on the magnetic dipoletheory, and the ANSYS data gives a successful verification. Then, the thesis buildsthe model of forward kinematics and inverse kinematics for the dextrous robot withthe method of product of exponential formula, and chooses the optimal solution inaccordance with shortest distance rule. Next, the thesis builds the statics forcemodels for the capsule respectively in2D and3D space. In order to avoid noanalytical solution for one permanent magnet driving model, the thesis turns staticsforce model into the optimal problem. And according to the requirement of artificialnavigation based on multi degrees of freedom of joystick and autonomous imageaided navigation, active control is realized.At last, the experimental platform is built to perform artificial navigationexperiment based on multi degrees of freedom of joystick and autonomous imageaided navigation experiment. The experimental analysis show the capsule can bedriven effectively and dexterity in the intestine model and its velocity reachabove10mm/s, which can shorten the whole examination time from68hdownto15min, and finally verify its feasibility and effectiveness.