Document Type

Article

Publication Date

2014

Publication Title

Journal of Guidance, Control, and Dynamics

Abstract

A generalized approach to the allocation of redundant thrust vector slew commands for multi-actuated launch vehicles is presented, where deflection constraints are expressed as omniaxial or elliptical deflection limits in gimbal axes. More importantly than in the aircraft control allocation problem, linear allocators (pseudoinverses) are preferred for large booster applications to facilitate accurate prediction of the control-structure interaction resulting from thrust vectoring effects. However, strictly linear transformations for the allocation of redundant controls cannot, in general, access all of the attainable moments for which there is a set of control effector positions thatsatisfles the constraints. In this paper, the control allocation efficiency ora certain class of linear allocators subject to multiple quadratic constraints is analyzed, and a novel single-pass control allocation scheme is proposed that augments the pseudolnverse near the boundary of the attainable set. The controls are determined over a substantial volume of lhe attainable set using only a linear transformation; as such, the algorithm maintains compatibility with frequencydomain approaches to the analysis of the vehicle closed-loop elastic stability. Numerical results using a model of a winged reusable booster system illustrate the proposed technique's ability to access a larger Fraction of the attainable set than a pseudoinverse alone.

Volume

37

Issue

2

First Page

374

Last Page

382

Comments

Originally published in the Journal of Guidance, Control, and Dynamics, Vol. 37, No. 2 (2014), pp. 374-382.

http://arc.aiaa.org/loi/jgcd

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