Nonlinear dynamic inversion control of a miniature morphing aircraft

Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace EngineeringThis thesis investigates the feasibility of using Dynamic Inversion to develop control laws for time varying systems, specifically Miniature Morphing Air Vehicles. Two Linear Time Varying systems are investigated namely a pendulum of variable length and a miniature aircraft with the ability to change wing sweep. Simulations of the pendulum and the aircraft are provided with and without the control law in the loop. These simulations show the effectiveness of using dynamic inversion to control LTV systems. The aircraft model used in the simulations is a fourth order model which contains only the longitudinal dynamics. The stability and performance of the open and closed loop is investigated using a notion of LTV poles, that employ a time-varying Ricatti equation. This work also presents preliminary nonlinear aerodynamic model for a miniature aircraft which morphs through variable wing sweep. The estimation of the aerodynamics and the stability derivatives were conducted using Athena Vortex Lattice (AVL). Dynamic Inversion is used to design a control law using the nonlinear model of the aircrafts longitudinal dynamics. The nonlinear zero-dynamics are discussed and investigated for stability. The control law is validated by simulating the aircraft in a a pull up maneuver while simultaneously morphing