Robust attitude stabilization on exponential coordinates of SO(3) group for quadrotor under inertia perturbation

The attitude control of quadrotors is commonly realized using Euler angle parameterization. However, this approach is prone to singularities, particularly when the pitch angle reaches 90 degrees, which restricts the achievable rotational range. Furthermore, when quadrotors carry payloads, inertia disturbances arise, affecting system dynamics and degrading stability. To address these issues, this paper proposes a PD controller designed directly on the exponential coordinates of the SO(3). This approach is global in nature and free from the limitations and singularities of local parameterizations. In addition, a compensator is introduced to mitigate the effects of inertia perturbations. The proposed control system is theoretically proven to be stable via Lyapunov analysis. Simulation results demonstrate that the exponential coordinate-based controller remains singularity-free under large-angle rotations, while the compensator effectively suppresses inertia perturbations and ensures convergence of the state variables to the origin.