Uncertainty Evaluation for Parameterized Spacecraft Architectures in Conceptual Design
Scott A. Uebelhart, David Miller · 48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference · 2007
A conceptual design methodology combining uncertainty source identification and analysis methods with a parameterized spacecraft modeling framework is proposed. The parameterized model generates complete finite element and integrated dynamic models given a set of key design variables. The approach to uncertainty combines this modeling tool with Design of Experiments techniques in order to investigate the uncertainty space. Experimental design matrices and analysis of variance are used to identify the parameters which may contribute most to the uncertainty of model outputs. Given a reduced set of critical parameters, a bounded uncertainty analysis is run across the tradespace, and competing designs are compared based on their robustness to parametric uncertainty. The methodology is applied to an example large, flexible space telescope. The fully parameterized spacecraft model allows key substructures to be swapped and overall spacecraft dimensions to be changed based on the input variables. Given a sample range of design variables, nearly 1300 nominal design realizations are analyzed. The parameter identification and uncertainty analysis techniques are then applied to those designs that have superior nominal performance in order to determine the performance under uncertainty. The resulting uncertainty bounds are further used to identify which design variables are practical “knobs” for moving through the design space given the presence of uncertainty.