Stability Analysis of an Adaptive Guidance and Control System applied to a Winged Re-Entry Vehicle

Abstract

The design and analysis of a Model Reference Adaptive Guidance and Control system to control the motion of a winged re -entry vehicle during hypersonic bank reversals is discussed. This design makes use of Simple Adaptive Control theory, which aims at tra cking the output of a reference model. The reference model is a linearized state -space representation of the non -linear re -entry vehicle, stabilized by an output feedback controller. A stepwise approach is followed, beginning with separating the translatio nal and rotational motion. Linearized state -space systems are used to study the open -loop stability and to define sufficient conditions for application of Direct Adaptive Control theory, which are later on repeated for the non -linear, time -varying system. Subsequently, the linearized systems are applied as reference model and used to tune the adaptive gains. The design of guidance system and attitude controller is done separately, after which both systems are integrated into a combined GNC system. Non -linea r simulations, finally, show the robust performance of the integrated system.