Fixed-Time Stabilizing Control for Nonlinear Systems With Uncontrollable Linearization and Unmodeled Dynamics

This paper addresses the problem of fixed-time stabilization for a class of nonlinear systems.Unlike existing results in the literature, the studied system accounts for uncontrollable unstable linearization and unmodeled dynamics, which may represent a broader class of nonlinear systems. Thanks to the changing supply rates for fixed-time input-to-state stability (FxT-ISS) system and the adding-one-power-integrator (AOPI) techniques, we propose a partial-state feedback control scheme that ensures system states converge to zero in fixed time. The settling time under this fixed-time control scheme depends solely on the control design parameters, independent of the initial conditions. Finally, numerical simulations validate the effectiveness of the proposed method.