Trajectory Planning and Control for Robotic Magnetic Manipulation

TL;DR

This paper introduces a novel trajectory planning and control framework for robotic magnetic manipulation, enabling precise and robust control of internal magnets using external magnets, with applications in minimally invasive gastrointestinal procedures.

Contribution

It presents a unified constrained trajectory optimization method that considers the dynamics of the internal magnet and external manipulator, advancing magnetic manipulation control techniques.

Findings

Maximum mean error of 0.18 cm in experiments

Robustness to external disturbances demonstrated

Effective in complex navigation scenarios

Abstract

Robotic magnetic manipulation offers a minimally invasive approach to gastrointestinal examinations through capsule endoscopy. However, controlling such systems using external permanent magnets (EPM) is challenging due to nonlinear magnetic interactions, especially when there are complex navigation requirements such as avoidance of sensitive tissues. In this work, we present a novel trajectory planning and control method incorporating dynamics and navigation requirements, using a single EPM fixed to a robotic arm to manipulate an internal permanent magnet (IPM). Our approach employs a constrained iterative linear quadratic regulator that considers the dynamics of the IPM to generate optimal trajectories for both the EPM and IPM. Extensive simulations and real-world experiments, motivated by capsule endoscopy operations, demonstrate the robustness of the method, showcasing resilience to external disturbances and precise control under varying conditions. The experimental results show that the IPM reaches the goal position with a maximum mean error of 0.18 cm and a standard deviation of 0.21 cm. This work introduces a unified framework for constrained trajectory optimization in magnetic manipulation, directly incorporating both the IPM's dynamics and the EPM's manipulability.