Dynamic Model for a Flexible Space System Aiming at a Robust Control Design

Abstract

In this paper a generic model for a flexible space system consisting of an arbitrary numbers of flexible bodies connected to form a branched geometry is developed using a
Lagrangian formulation. This approach is then applied to derive the equations of motion of the US Space Station first assembly flight configuration, referred as MB-l, taking into
account the coupled rigid body flexible structural dynamic interaction. The frequency characterization of the MB-I model is determined, solving the eigenvalue problem, and the
potential problem for control structure interactions (CS1) is evaluated. The dynamic equations derived in physical coordinates are transformed into a set of decoupled equations
in modal state space form. It is shown that this procedure leads to computational advantages and facilitates to address issues such as model order reduction, truncation, and robustness with respect parameter variation and unmodelled dynamics in the context of the robust control design methodology, such as LQGIL TR, PRLQG and Hoo.