The effect of small time-delays on the closed-loop stability of boundary control systems (Q2563992)

This paper presents instability resulting from the introduction of small time-delays in boundary control systems with in-span controls. The approach combines input-output methods and modal analysis. Destabilization results for systems with ill-posed open-loop transfer functions are presented. A large class of PDE systems for which robustness results of spectral stability translate to robustness results of modal stability is identified.