Abstract
Rhonrad is a gymnastic tool that is interesting in terms of dynamics and control. Prom the governing basic equations of a Rhonrad with a fixed gymnast mass, we analyzed the fundamental characteristic of a steady Spiral motion of Rhonrad. First, we obtained the condition for a steady Spiral motion. By examining the eigenvalues of the perturbed motion of the Rhonrad from a steady motion, we next obtained a stable region of Spiral motion against a small disturbance, and discussed a common rule of gymnast for a stable Spiral motion. We further analyzed a feasible region of the stable Spiral motion without slipage for a limited frictional coefficient.
