  Based on the double pendulum and Lagrange equation, the moving particles are
captured by a binocular three-dimensional capture camera. Two trajectory models
of Astrojax and the relationship between trajectory empirical formula and
parameters are established. Through research, the calculated trajectory of this
formula and related parameters fit well with the actual measured trajectory,
and can accurately predict and change the trajectory of the model. The
equipment and materials required in the experiment are simple and easy to
obtain, and the experimental theme is relatively interesting and novel, which
can be applied as an extended experiment in college physics experiment course,
so that students can understand the motion characteristics of the double
pendulum and learn physics from life. The designing experiment can not only
improve students' interest in learning, but also broaden their knowledge and
cultivate their practical ability.
