Parametric Robust Stability Analysis for Attitude Control of a Four-rotor mini-rotorcraft

This paper presents new results to compute the robustness margin of an attitude control system of a four-rotor mini-rotorcraft. The maximum parametric uncertainty is computed when a multivariable PD control is used to stabilize the attitude of the aerial vehicle. This work is based on the value set characterization of the mathematical model for the control system. This mathematical model is represented by an interval plant with time delay. The zero exclusion principle is used to compute the robustness margin of the closed loop control system. This approach transforms the original robust stability problem into simple graphic inspection problem where we only need to verify if a graph on the complex plane contains the origin or not. Furthermore, real-time experiments are presented which show the satisfactory performance of the proposed control strategy