An alternative characterization of robust stability and stability radius for linear time delay systems

This paper considers the problems of robust stability and stability radius pertaining to certain linear time delay systems. The aim is to establish the connection between recently published results on robust stability of time-delay systems based on matrix inequalities and computation of stability radius. As a result of this connection, an alternative formula to compute the real stability radius of time-delay systems with structured uncertainties is provided. We also report on explicit formulas for stability radius of special classes of time-delay systems.