Dynamic Modeling and Controller Design for a Spherical Rolling Robot Equipped With a Gyro

In this paper, we derive a dynamic model of a spherical rolling robot that has a new driving mechanism equipped with a gyro and design a controller to stabilize a desired translational motion of the robot. Due to the angular momentum of the gyro, nutation motion of the internal mechanism of the robot may be caused. A feedback controller is designed to achieve the stabilization to a straight motion of the robot and nutation damping in the internal mechanism simultaneously. The asymptotic stability is proved using a Lyapunov function, and the effectiveness of the controller is verified by experiments. The controller is also successfully applied to other translational motions such as a circular motion and a meandering motion.