Uncertainty and Disturbance Estimation for Quadrotor Control Using Extended High-Gain Observers: Experimental Implementation

This paper presents a complete experimental implementation of an Extended High-Gain Observer (EHGO) based disturbance and uncertainty estimator for use in quadrotor control. The system is designed as a multi-time-scale system to deal with mechanical underactuation and to ensure convergence of EHGO estimates for use in the output feedback control. The lumped, estimated disturbance is passed into the rotational dynamic inversion based control, and the feedback linearization based translational control to cancel the estimated disturbances. This results in a feedback control scheme that is robust to external disturbances as well as model uncertainties, such as an uncertain air-frame mass and rotational inertial matrix. The control is verified through simulation and experimental results.