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Further study of spectral controllability of systems with multiple commensurate delays in state variables. (English) Zbl 0545.93011
This is the third paper in a series of four by the author et al. on algebraic methods for the study of spectral controllability and finite spectrum assignability for delay systems with finitely many commensurate delays and scalar control [see the author, M. Ito and M. Kaneko, ibid. 38, 913-926 (1983; Zbl 0528.93037); the author and M. Ito, ibid. 39, 363-374 (1984; Zbl 0531.93014) (not ibid. 38 (1983), 621, as it appears in the references of the paper under review); the author, M. Ito and M. Kaneko, ibid. 39, 1073-1082 (1984; Zbl 0534.93045)]. The present paper proves necessity of a condition for spectral controllability in terms of finite Laplace transforms. Sufficiency has been proved earlier.
Reviewer: F.Colonius
34K35Functional-differential equations connected with control problems
93B25Algebraic theory of control systems
44A10Laplace transform
93B55Pole and zero placement problems
93C05Linear control systems
93C99Control systems, guided systems