Counterexample to a Lyapunov Condition for Uniform Asymptotic Partial Stability

Jakub Orlowski (1) , Antoine Chaillet (1) , Mario Sigalotti (2, 3)

1 L2S - Laboratoire des signaux et systèmes
2 CaGE - Control And GEometry
3 LJLL (UMR_7598) - Laboratoire Jacques-Louis Lions

Partial stability characterizes dynamical systems for which only a part of the state variables exhibits a stable behavior. In his book on partial stability, Vorotnikov proposed a sufficient condition to establish this property through a Lyapunov-like function whose total derivative is upper-bounded by a negative definite function involving only the sub-state of interest. In this note, we show with a simple two-dimensional system that this statement is wrong in general. More precisely, we show that the convergence rate of the relevant state variables may not be uniform in the initial state. We also discuss the impact of this lack of uniformity on the connected issue of robustness with respect to exogenous disturbances.

Mots clés: Lyapunov methods; Stability of nonlinear systems

Domaines: Optimisation et contrôle [math.OC]

Jakub Orlowski, Antoine Chaillet, Mario Sigalotti. Counterexample to a Lyapunov Condition for Uniform Asymptotic Partial Stability. IEEE Control Systems Letters, 2020, 4 (2), pp.397-401. ⟨10.1109/LCSYS.2019.2939717⟩. ⟨hal-02291650⟩