국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	An Autonomous Onboard Targeting Algorithm Using Finite Thrust Maneuvers.
저자	Scarritt, Sara K.;; Marchand, Belinda G.;; Brown, Aaron J.;; Tracy, William H.;; Weeks, Michael W.
Keyword	ALGORITHMS;; AUTONOMY;; INJECTION GUIDANCE;; ORBITAL MECHANICS;; SPACECRAFT CONTROL;; THRUST;; TRANSEARTH INJECTION;; TRANSFER ORBITS
URL	http://hdl.handle.net/2060/20100036821
보고서번호	JSC-CN-21507
발행년도	2010
출처	NTRS (NASA Technical Report Server)
ABSTRACT	In earlier investigations, the adaptation and implementation of a modified two-level corrections (or targeting) process as the onboard targeting algorithm for the Trans-Earth Injection phase of Orion is presented. The objective of that targeting algorithm is to generate the times of ignition and magnitudes of the required maneuvers such that the desired state at entry interface is achieved. In an actual onboard flight software implementation, these times of ignition and maneuvers are relayed onto Flight Control for command and *****ution. Although this process works well when the burn durations or burn arcs are small, this might not be the case during a contingency situation when lower thrust engines are employed to perform the maneuvers. Therefore, a new model for the two-level corrections process is formulated here to accommodate finite burn arcs. This paper presents the development and formulation of the finite burn two-level corrector, used as an onboard targeting algorithm for the Trans-Earth Injection phase of Orion. A performance comparison between the impulsive and finite burn models is also presented. The present formulation ensures all entry constraints are met, without violating the available fuel budget, while allowing for low-thrust scenarios with long burn durations.