Alternate representation of butterfly robot

This paper focus on the challenging tasks of controlling underactuated systems. A well known example is the butterfly robot, where the task is to have continuous rotation of the plates without losing contact between ball and plates. The first step is to reduce the degrees of freedom of the dynamical model to facilitate the choice of holonomic constraint. The next step is trajectory planning with motion generation, and lastly the stabilization of this motion is required to obtain the desired trajectory