Stability robustness of linear feedback-controlled mechanical systems in the presence of a class of unmodelled flexibilities

The author considers a class of linear mechanical systems containing flexible elements and subject to linear, memoryless, output-feedback controllers. The damping and stiffness properties of some of the flexible elements are parameterized linearly in mu /sup -1/ and mu /sup -2/, respectively, where mu >0 and these components become more rigid as mu approaches zero. If a controller stabilizes a system model in which these components are assumed rigid, then it also stabilizes the model in which these components are flexible, provided mu is sufficiently small. The results are illustrated by an example.<
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