Modeling and Design of Automatic Landing Systems for Variable Span Morphing Wing UAV

This paper describes the modeling of the aerodynamics and dynamics of a variable-span morphing wing unmanned aerial vehicle (UAV). The mass inertia moment in relation to span length is measured using Computer-aided design(CAD), and each aerodynamic coefficient for the maximum and minimum span is derived using Digital DATCOM. Based on MATLAB/Simulink, a multidimensional aerodynamic database is constructed using previously calculated data. The dynamic characteristics of the maximum and minimum spans are then analyzed and the trim condition defined. A PID controller and sliding mode control are designed and compared with each other using simulations that follow altitude commands. After confirming the suitability of the sliding mode control, an automatic landing system is constructed using the controller. In the automatic landing system, we control the longitudinal axis glide slope and flare trajectory on the assumption that the lateral axis is stable and analyze the effect of span length deformation on automatic landings.