Adaptive attitude control of the spherical drone on SO(3)

Abstract

We propose an adaptive attitude control for a spherical drone, having one propeller and four control surfaces mounted on orthogonal discs. The attitude motions are produced due to deflections of the flaps, in the slip stream of the propeller induced airflow. A coordinate-free (geometric) control law is developed to eliminate configurational singularities in control design, thereby enhancing the agility of the drone. The control law is directly on the nonlinear manifold, i.e., SO(3), without any Euclidean parametrization. A dynamic compensator is incorporated into the geometric control law; this enables the system to adapt to the uncertain parameters while achieving the original control objective. Simulations of the proposed control law are presented and discussed.