IMPROVEDγ – δ ROUTH APPROXIMATION OF INTERVAL SYSTEMS USING INTERVAL ARITHMETIC

In γ – δ Routh approximation of interval systems, interval Routh approximant may not be robustly stable even if the original interval system is robustly stable. Thus, in this paper an improvement is proposed to the γ – δ Routh approximation for interval systems using Kharitonov polynomials such that the resulting interval Routh approximant is always robustly stable. A numerical example illustrates the procedure.