A note on the extension of Rosenbrock's Nyquist array techniques to a larger class of transfer function matrices
Jeffrey C. Kantor, Ronald P. Andres · International Journal of Control · 1979
A natural extension of the multivariable Nyquist array methodologies of Rosenbrock and co-workers to systems having other than diagonally dominant transfer function matrices is proposed. Stability theorems based on the concept of a set of ‘ normalized ’ Gershgorin bands are given. These theorems incorporate results of several recent investigations (Araki and Nwokah 1975, Nwokah 1975, Mee 1976, and Owens 1978). A ‘ normalized ’ form of the Ostrowski bands and a decomposition technique for reducible transfer function matrices are also presented.