Anti‐unwinding adaptive spacecraft attitude tracking control based on similar skew‐symmetric structures

This article addresses the adaptive attitude tracking control based on similar skew‐symmetric structure. Based on the structure, a novel adaptive backstepping scheme is proposed to design the attitude controller. To avoid unwinding, a rotation matrix rather than a quaternion is used to describe the attitude. Correspondingly, the application of similar skew‐symmetric structure is extended from euclidean space to noneuclidean space, for which the stability is proved by combining the Lyapunov function and the Morse–Lyapunov function. In addition, the smooth projection function is adopted to design the adaptive law for the unknown parameters. And the input‐to‐state stable property of the closed‐loop system is proved when considering the unmodeled disturbance. Finally, numerical simulations are carried out to illustrate the effectiveness of the proposed controllers.