Design optimization of adjustable magnetic attraction device for track inspection robot

To ensure the effective operation of the underground track inspection robot in coal mines, this study proposes the design of an adjustable magnetic attraction device that can be installed on the robot. The paper analyzes the existing magnetic circuit structure and proposes a new model for the magnetic circuit structure, which is optimized for better performance. Mathematical models for magnetic induction intensity are established for strip and cylindrical permanent magnets, and finite element models are developed for single layer and three-layer adjustable magnetic attraction structures. The effects of the rotation angle of the cylindrical permanent magnet and various parameters of the yoke on the magnetic attraction are analyzed. The study also examines the influence of the thickness of both sides of the three-layer magnetic circuit structure model and the initial angle of the intermediate layer cylindrical permanent magnet on the magnetic attraction. The resulting magnetic attraction curve tends to linearize, with the best linearity achieved when the thickness ratio of the intermediate layer to both sides is 0.8, and the initial angle of the intermediate layer cylindrical permanent magnet is 52.5°. This linearity facilitates subsequent accurate control. Experimental verification shows that the theoretical calculations, simulation results, and experimental results are consistent, with errors within the allowable range. Overall, this study provides valuable insights into the design and optimization of the magnetic attraction device for underground track inspection robots in coal mines.