Study On The Wireless Microrobots System In-pipe

A microrobot for the gastrointestinal diseases diagnosis and treatment is an ideal method of the non-invasive gastrointestinal detection and treatment. In our study, a novel tele-operation system for wireless in-pipe microrobots has been proposed, which will be used for the gastrointestinal diseases’ diagnosis and treating of human beings, as well as the micro-pipeline testing. Based on the external magnetic field driving principle, the motion state and motion position of the microrobot can be controlled by system wireless in real time. In the system, the external magnetic field models, the wireless in-pipe microrobots and the control panels have been analyzed and designed, in addition, we also have tested and evaluated the performance of them by experiments.Firstly, according to the motion mechanism of microrobots, the arched magnetic field model, rotation magnetic field model and 3-axes Helmholtz coil model have been designed, then we analyze the drive and control theory of the models. In addition, the magnetic field models have been established, and the properties calibration of models also have been evaluated.Secondly, according to the driving principle of external magnetic field, the microrobot with fin driven, the microrobot with symmetrical spiral structure and the microrobot with hybrid motion have been proposed and designed, then the movement mechanism analysis, structural modeling, simulation and experiments, control algorithm and performance evaluation have been done based on the different models of microrobot. In order to improve the kinematic characteristics of microrobots in the vertical direction, the gravity compensation mechanism has been proposed, which can make the microrobot realize the symmetrical dynamic performance.Based on a series of experiments, we have evaluated the performance of different microrobots. The experimental results indicate that the microrobot with fin driven can realize unidirectional movement in the arched magnetic field model, and the microrobot with symmetrical spiral structure and the microrobot with hybrid motion own the similar symmetrical dynamic performance based on gravity compensation mechanism, and in the rotation magnetic field model, they can achieve forward-backward motion in the horizontal direction and upward-downward motion in the vertical direction, they can also realize oblique upward-oblique downward motion at the inclined plane with 45 degree. In addition, the microrobot with symmetrical spiral structure or with hybrid motion can be stopped at any position in the pipe we needed, so they are suitable to the basic movement requirements in the practical application.Finally, according to the external magnetic field model, microrobot model and the experimental operation requirements, the power type portable control panel and tele-operation portable control panel have been proposed and designed. In order to improve the quality of rotation magnetic field, the control algorithm of 8-Steps rotation magnetic field has been proposed, and the effectiveness and efficiency of the control algorithm also has been verified by the experiments. At the same time, combined with the actual operation requirements, we have integrated the system and evaluated the performance of it. Then we analyzed and verified the dynamic performance effect of microrobots on the different input currents and different Reynolds numbers of the fluids based on the system.With the technology development of medical field in the future, the tele-operation system for wireless in-pipe microrobots will open a new way to the gastrointestinal diseases detection and treatment, and it will be widely used in the medical field and the industrial application.