Stability and Stabilisation Through Envelopes for Retarded and Neutral Time-Delay Systems

Abstract : This paper deals with a new approach to develop an envelope that engulfs all poles of a time-delay system. Through LMIs we are able to determine envelopes for retarded and neutral time-delay systems. The envelopes proposed are not only tighter than the ones in the literature but, with our procedure, they can also be applied to verify the stability of the system and design state-feedback controllers which cope with design requirements regarding alpha stability.