简介:Anewquantitativeconceptisintroducedinthispaper,whichmaybeusedtofacilitatethemeasurementofthecontrollabilityofasubspace~subspacecontrollabilitydegree.Thentheconcreteformofthesubspacecontrollabilitydegreeofaflexiblestructureisderived,andtheerrorsofsubspacecontrollabilitydegreeanddynamicalresponsecausedbythesubstitutionofarepeatedmodesubspaceforacloselyspacedmodesubspacearediscussed.Alltheresultsshowthatthissubstitutionisrationalundersomeconditions.