Adaptive hybrid global attitude tracking controller

In this paper, a quaternion-based attitude tracking controller is presented, which is robust to measurement noise and adaptable to modeling errors and external disturbances. By constructing the controller using the theory of hybrid systems and employing the backstepping technique an adaptive controller that globally asymptotically stabilizes the null tracking error set for the closed-loop system is obtained. Furthermore, two estimators are explicitly derived to account for slowly time-varying or constant disturbances and moment of inertia errors. All the stability and convergence properties are carefully proven using Lyapunov stability theory for hybrid systems. Simulation results are shown to assess the resulting closed-loop system performance.