Optimal ascent trajectory and guidance law for aerospace plane

Abstract

This paper proposes a real-time optimal guidance law for aerospace planes with air-breathing engines. First, the minimum fuel ascent trajectory is solved in order to obtain the knowledge for developing the guidance law. The optimal ascent trajectory shows that the aerospace plane flies along the maximum dynamic pressure using the air-breathing engines. The strategy for developing an optimal guidance law is that the guidance law controls the dynamic pressure using the PID controller to trace the maximum dynamic pressure. The results of flight simulation by the real-time optimal guidance law show that the guidance law is the optimal. Nomenclature C, : Drag Coefficient C L : Lift Coefficient CT : Thrust Control Throttle D : Aerodyhamic Drag g : Acceleration of Gravity g, : Acceleration of Gravity at Sea Level & : Feedback gain ‘of the dynamic pressure time integral h : Altitude & : Specie Impulse K, : Feedback gain ‘of the velocity K, : Feedback gain of the dynamic pressure L : Aerodynamic Lift m : Weight Mass q : Dynamic Pressure r : Radial Distance from Center of Earth S : Wing Reference Area S ATR : Reference Area of Air-Turbo Ram Jet Engine S SCR : Reference Area of Scram Jet Engine Copyright01 998 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved * Researcher., Non Member T Engineer, Non Member $ Engineer, Non Member t : Time T : Thrust u : Control Vector V : Inertial Velocity x : State Vector x, : Command state vector a : Angle of Attack y : Path Angle zz : Feedback gain of the dynamic pressure time derivative w : Angular Velocity of Earth