Robust Control Design Techniques Using Differential Evolution Algorithms Applied to the PVTOL

Abstract

In this paper, we present a strategy to stabilize the attitude of a planar vertical take off and landing (PVTOL) vehicle with variable pitch propeller (VPP) rotors. In the VPP configuration, the thrust is obtained with the propeller pitch angle, instead of changing the rotor speed, and this concept adds maneuverability to the vehicle. The PVTOL used in this paper is highly unstable in its natural hovering flight state, therefore the main goal is to achieve a stable attitude. First of all, a simplified dynamic model that includes the VPP dynamics is obtained. Then, a methodology to select the parameters of a nonlinear controller using Differential Evolution algorithms (DEA) will be presented. The controller's parameters are selected with two purposes: to guarantee the asymptotic stability of the closed-loop system while taking into account the uncertainty, and to improve its robustness margin. And finally, The results are validated with real-time experiments.