Section: New Results

Stability analysis of (fractional) delay systems of neutral type

Participants : Catherine Bonnet, André Fioravanti [UNICAMP] , Le Ha Vy Nguyen.

The $H_{\infty }$-stability analysis of (fractional) delay systems of neutral type has been studied in [14] . It was shown that the chains of poles are asymptotic to vertical axes which position depend on the roots of a certain polynomial (easily determined from the given transfer function). In [14] the case of roots of multiplicity one was completely treated whereas the case of roots of multiplicity greater than one was considered only in the particularc case of neutral systems whose transfer function is a product of transfer functions of neutral systems with one delay. This year, we have studied more deeply the case of roots of multiplicity greater than one for both, standard and fractional delay systems.