Systems with Time Delays
DOI link for Systems with Time Delays
Systems with Time Delays book
Mathematical models of systems with time delays were introduced in Section 2.2.2. If there is a time delay in a linear system, then its transfer function includes a term e −hs where h > 0 is the delay time. For this class of systems, transfer functions cannot be written as ratios of two polynomials of s. The discussion on Routh-Hurwitz and Kharitanov stability tests, and root locus techniques do not directly extend to systems with time delays. In order to be able to apply these methods, the delay element e −hs must be approximated by a rational function of s. For this purpose, Padé approximations of delay systems will be examined in this chapter.