The design of 3-D space electromagnetic control system for high-precision and fast-response control of capsule robot with 5-DOF

In view of the shortcomings of traditional gastroscopy and capsule robot in human stomach detection, a new 6-square coil electromagnetic control device for capsule robot attitude control was proposed in this paper. The device can not only generate uniform magnetic field in arbitrary direction and wide range of three-dimensional space to control the capsule to revolve, but also generate magnetic field with a certain gradient to provide propulsion for the capsule. Compared with the traditional electromagnetic device consisting of Helmholtz coil and Maxwell wire, it is easier to assemble, has higher coil utilization rate and more diverse driving signals. At the same time, it has a pair of movable coils, which can adjust the coil spacing according to the demand and produce different magnetic field configuration. Firstly, the appropriate device parameters were chosen by modeling and simulation, and illustrate the advantages of the system in generating magnetic field. After that, the feasibility of the device to control the capsule robot was proved by experiments such as fixed-point three-dimensional rotation scanning and two-dimensional planar locomotion. The moving distance in plane point motion of the capsule robot can be adjusted by adjusting the signal type, amplitude and frequency of the driving coil, so as to improve the control accuracy reasonably. It can achieve a maximum accuracy of 1 mm in plane point motion, and the angle control accuracy in three-dimensional scanning motion can reach up to 10°.