Uncertainty Characterization in Integrated Modeling
Scott A. Uebelhart, David C. Miller, Carl A. Blaurock · 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference · 2005
Integrated modeling of structures, disturbances, optics and controls is becoming an important tool in the analysis of space telescopes which, due to their large size or limitations of the testing environment can not be fully system tested prior to launch. Characterizing the uncertainty in these models is an important aspect in validating the design but is complicated not only by large numbers of uncertain parameters and non-parametric uncertainties, but also by the changing nature of uncertainty analyses as the design process progresses. The changing role of an uncertainty analysis is described at key stages in the design lifecycle, from the start of conceptual design with simple \stick models, through the critical design with testbed data available. Each stage is examined with emphasis on the information or data required at the start of an analysis, and ways in which results at one stage motivate the analysis in the next. Next, the role of uncertainty analysis in the early stages of a design is demonstrated using an integrated model of a proposed space telescope. Key parametric uncertainties are identifled using Design of Experiments techniques applied to computer simulations. Intuition-based model uncertainty factors are applied to the model and the results compared to an uncertainty analysis using worst-case bounds. Finally, methods of improving early-stage model uncertainty factors using analysis results are suggested.