Variable structure attitude control for a rolling aerial vehicle via extended state observer

A novel attitude control scheme is proposed for a rolling aerial vehicle (RAV) with large uncertainties. Firstly, the RAV highly coupled nonlinear system is separated into attitude loop and angular loop via backstepping technique. The nominal states are calculated based on the procedure of trajectory linearization control (TLC). Then, extended state observers (ESO) are applied to estimate the uncertainties in the RAV system. Meanwhile, a feedback linearization-based controller is synthesized for the attitude loop using the estimated uncertainties, and an ESO-based sliding mode controller is synthesized for the angular rate loop. The stability of the closed-loop system is studied. Simulation results with comparisons are presented to demonstrate the feasibility of the proposed control scheme.