Robust Hybrid Attitude and Gyro-Bias Observer on Quaternions

Existing research has reported that the topological obstructions pose inherent difficulty to attitude estimation. This article copes with the problem of obtaining a good estimation of attitude and gyro-bias using inertial measurements. First, we propose a quaternion-based scheme for the design and stability analysis of nonlinear attitude observers. Under the scheme, we expose the potential pitfalls of traditional observers:
almost
global asymptotic stability (GAS) and slow convergence for a continuous state-feedback observer, nonrobustness to arbitrary small measurement noises for a discontinuous state-feedback observer. Second, to address these limitations, we develop a generic quaternion-based hybrid scheme with guaranteed GAS and robustness to measurement noises, in the sense that knowledge of a specific potential function suffices to design an attitude and gyro-bias observer with desired properties. Furthermore, we give a new observer within the scheme. Simulation and experimental results demonstrate the fast convergence and robustness of the proposed observer.