On hyperexponential stabilization of a chain of integrators in continuous and discrete time subject to unmatched perturbations
Moussa Labbadi, Denis Efimov
TL;DR
This work generalizes hyperexponential stabilization from a double integrator to an arbitrary-order chain of integrators subject to unmatched perturbations by designing a recursive, time-varying feedback with increasing gains. In continuous time, the method yields hyperexponential convergence for $x_1$ while ensuring $x_2$ remains bounded and higher-order states are ISS through gain saturation; a corresponding implicit Euler discretization preserves these properties in discrete time. The authors provide explicit constructions for low-order cases, establish conditions on the gain sequence, and prove robustness to disturbances, including a coordinate transformation that isolates matched and mismatched effects. Numerical examples and simulations illustrate rapid convergence and bounded responses, highlighting practical applicability to fast stabilization under uncertainty. Overall, the approach offers a principled way to achieve accelerated stabilization of high-order systems with unmatched perturbations in both continuous and discrete domains.
Abstract
A recursive time-varying state feedback is presented for a chain of integrators with unmatched perturbations in continuous and discrete time. In continuous time, it is shown that hyperexponential convergence is achieved for the first state variable \(x_1\), while the second state \(x_2\) remains bounded. For the other states, we establish ISS {\cb property} by saturating the growing {\cb control} gain. In discrete time, we use implicit Euler discretization to {\cb preserve} hyperexponential convergence. The main results are demonstrated through several examples of the proposed control laws, illustrating the conditions established for both continuous and discrete-time systems.
