Abstract: This paper proposed a virtual-real fusion simulation method of magnetic lines suitable for middle school experiments, and explored a set of algorithms applicable to the properties of magnetic lines in 3D space. It was applied to the multi-modal natural interactive augmented reality (AR) experiment system. This algorithm employed RK4 to generate magnetic induction lines and adopted the minimum energy method to revise them when necessary. The AR system utilized augmented reality based on physical kits and the multi-camera cooperative AR three-dimensional registration to overcome the traditional problem of two-dimensional MARK tracking failure. Finally, an electro-magnetic experiment commonly conducted in middle school teaching was taken as an example to test this magnetic induction line generation algorithm. Tests results show that these magnetic induction lines conform to the laws of physics and can better facilitate the electromagnetics-related physical experiments, which is of practical significance. By magnifying the phenomenon of the experiment, it is conducive to students’ understanding of physical concepts. 

Key words: magnetic lines, simulation, MARK, Runge Kutta method, revise