Design and Control of a Three-Dimensional Electromagnetic Drive System for Micro-Robots

Three-dimensional electromagnetic field drive technology, as a cutting-edge remote wireless control method, is extensively utilized in the biomedical diagnosis and treatment of micro-robots. This paper presents the design of a three-dimensional electromagnetic drive system for micro-robots, leveraging a gradient magnetic field to achieve comprehensive automatic control in three axes. Firstly, we refine the iron core’s end structure to produce an uniform gradient magnetic field throughout the three-dimensional space. Following that, the parameters at the end of the iron core are fine-tuned to meet the specifications for magnetic field gradient, magnetic flux density, and effective workspace. Then a three-dimensional electromagnetic drive system with strong magnetic field gradient is established, achieving a remarkable maximum gradient of 1.70 T/m at the center of the workspace. Compared with other systems, the gradient is significantly enhanced. Subsequently, we carry out a three-dimensional drive experiment for a micro-robot, confirming the system’s driving efficacy. To enable precise path following for micro-robots within a three-dimensional space, we have formulated a control strategy rooted in micro-robot dynamics. The controller stability is guaranteed through the Lyapunov theory. Ultimately, a three-dimensional path following experiment is executed on the developed electromagnetic drive system. The experiment confirms the capability of our designed system which can achieve the three-dimensional closed-loop motion for the micro-robot.