ENHANCED STALL AND RECOVERY CONTROL SYSTEM (ESARCS) : A NONLINEAR MODEL-BASED FLIGHT CONTROL SYSTEM FOR UNINHABITED AIRBORNE VEHICLES (UAV)

A nonlinear model-based flight control system called ESARCS (Enhanced Stall And Recovery Control System) is presented for autonomous air-breathing vehicles such as Uninhabited (Unmanned) Airborne Vehicles (UAV). ESARCS technology allows UAV to operate, in a controlled flight, through wing and fin stall flight regimes, i.e., near stall and post stall flight regions. Near stall and post-stall flight is attained by ESARCS’s coupled 6-degree-Of-Freedom (6-DOF) model-based controller, the use of the vehicle’s complete nonlinear aerodynamic database, and the development of nonlinear time varying and state dependent control gains. Linear control techniques cannot provide this capability since wing and/or fin stall is a nonlinear phenomenon that linearization assumption neglect in the control design process. ESARCS has the potential for improving threat evasion and second shot capability (reducing turn radius), permitting shorter take off and landing distance (low dynamic pressure operation), allowing for larger payload capability, enhancing flight formation patterns, and reducing production costs associated with UAV. A more detailed explanation of these benefits is provided in the “Benefits of ESARCS to UAV” section.