In order to investigate the rolling-forward law of a spherical underwater vehicle and the influence of mass distribution on its motion, this study carries out the innovative design and analysis of its mechanical mechanism.

First, a dynamic model of the rolling-forward motion is established using the Newton-Euler method. The influence of mass distribution on its motion is then analyzed through the ground test and underwater hydrodynamics theory. Finally, by building a simulation environment and virtual prototype, the rolling dynamics of the vehicle underwater and on land are compared and analyzed.

The results show that when the built-in driving unit rotates constantly, the speed of the vehicle fluctuates and the swing angle of the built-in driving unit also alters periodically. When the driving weight is increased, the period and amplitude of swing angle become smaller, and the rolling-forward motion becomes more stable.

The results of this paper can provide guidance for the further optimization of spherical underwater vehicles.