Author: Sarah Nicole D'SouzaPublisher:
ISBN: 9781303538094
Category :
Languages : en
Pages :
Book Description
In order to address a gap in modeling flight feasible trajectories for vehicle shape optimization, a novel guidance algorithm was developed for this application. The baseline geometry and trajectory profile for guidance testing was based on an Orion like vehicle flying a skip entry upon lunar return. The reference trajectory generator for this guidance algorithm numerically solves the three degree of freedom Rotating, Spherical Planet equations of motion using a predictor- corrector and analytical functions, that represent the reference bank profile, to drive the solution. The automation of transition event determination provides the guidance initialization loads and a framework for adaptability. The initialization loads include the guidance activation/termination condition, the entry bank angle, and the linear transition velocity. The targeting scheme for this guidance algorithm leverage's the optimal control equations from Energy State Approximation methods to find a single control point that is blended to the reference trajectory to guide out the range excursion, caused by various dispersions. The set of dispersion used in this work simulate the change in aerodynamics that occur in a vehicle optimization study. The preliminary targeting formulation exhibits the potential guide out aerodynamic dispersions, expanding the range of aerodynamic dispersions -43% as compared to -20% for the Apollo Derived Final Phase Guidance.
