Ultimate stability of nonlinear time-varying systems with multiple delays

The ultimate stability of nonlinear time-varying systems with multiple delays and bounded disturbances are investigated in this paper. Based on some comparison techniques via differential inequalities, explicit delay-independent conditions are derived for determining an ultimate bound such that all state trajectories of the system converge exponentially within that bound. The obtained results also guarantee exponential stability of the system when the input disturbance vector is ignored. Numerical simulations are given to illustrate the effectiveness of the obtained results.