Pole placement under structural constraints

The spectral assignability properties of the linear map A+BF are exploited under the structural constraints that a given controlled invariant complement of the imaginary part of B are both (A+BF) invariants. Correlations with previous results are established, and the duality is performed with conditioned invariants. Direct applications are found in the linear geometric theory of many reduced-order syntheses, e.g. those of observers, regulators, etc.<
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