Image-Guided Corridor-Based Motion Planning and Magnetic Control of Microrotor in Dynamic Environments

The in vivo manipulation of magnetic microrobots has attracted considerable attention because of its advantages of noninvasiveness and high precision in the targeted delivery. This article presents an automated control scheme for a magnetic microrotor (an anchor-like microrobot), which has the potential for microsurgery and delivery under the guidance of optical coherence tomography imaging in real time. A front-end optimal path planner that considers both the path length and the path clearance based on the particle swarm optimization, as well as a back-end dense corridor-based trajectory generator, is designed to ensure the collision avoidance of the microrotor navigation in blood vessels. In addition, to achieve robust and safe trajectory tracking of the microrotor, a model-predictive controller based on the extended state observer is used to compensate for the unmodeled dynamics and unknown disturbance while further restricting the state space. Simulations are performed to tune the parameters and validate the proposed approach. Experiments of navigating the microrotor in dynamic environment with different flow rates are performed to demonstrate the effectiveness of the proposed approach.