Sensitivity models of canonical form delay-differential systems

In the study of adaptive control problems and design of low sensitivity systems, it is often required to evaluate the sensitivity of systems to parameter variations. This correspondence presents a method for obtaining low-order sensitivity models for canonical form single-input linear constant delay differential systems. Total symmetry and complete simultaneity (TSACS) properties of the first-order sensitivity functions are provided. They subsume and reduce to the results of Wilkie and Perkins [7] in the absence of delay.