On the design of observers with specified eigenvalues

This correspondence considers the problem of designing an observer with specified distinct eigenvalues to estimate a set of linear state functionals for a linear multivariable system. The conditions given for the design of an
r
th-order observer, where
r \leq \nu_{0} - 1
(ν
0
is the observability index), represent an extension of the results of Murdoch [3] and Fortmann and Williamson [2]. The conditions are based on the assumption that the observer eigenvalues are distinct from those of the plant.