Robust Hurwitz and Schur stability test for interval matrices

By relying on a 2D face test, we obtain a necessary and sufficient condition for the robust Hurwitz and Schur stability of interval matrices. We reveal that it is impossible that there are some isolated unstable points in the parameter space of the matrix family, so the stability of exposed 2D faces of an interval matrix guarantees stability of the matrix family. Examples are given to demonstrate the applicability of our robust stability test of interval matrices.