An instability condition for uncertain systems toward robust bifurcation analysis

In this paper, we consider instability analysis of uncertain feedback systems. First, we present an instability counterpart of the small gain stability theorem. Based on the instability theorem, we solve the problem of instability analysis for systems with dynamic uncertainties. Then, we propose a novel concept of robust bifurcation analysis. An illustrative example is presented for bifurcation analysis of uncertain genetic network models.