A safe implementation for finite spectrum assignment: robustness analysis

In this paper we introduce a distributed delay control law that assigns a finite closed-loop spectrum and whose implementation with a sum of point-wise delays is safe. The resulting closed-loop characteristic quasipolynomial is of retarded type, and not of neutral type, which was shown to be a cause of instability in previous schemes. Robustness properties of the new scheme with respect to delay and parameter uncertainty are analyzed and an illustrative example is given.