Kybernetika 62 no. 4, 561-583, 2026

Disturbance observer-based robust control for a class of uncertain nonlinear systems

Chengcheng Wang, Xianglei Jia, Chengdi Xiang and Yingying HanDOI: 10.14736/kyb-2026-4-0561

Abstract:

This paper addresses the global output regulation problem for a class of strict-feedback systems subject to unknown nonlinearities and mismatched disturbances. A composite robust control strategy based on backstepping, high-gain scaling and disturbance observers is developed. In particular, unknown mismatched nonlinearities are suppressed by introducing high-gain scaling, and mismatched disturbances are compensated for by improved disturbance observers. Rigorous Lyapunov analysis guarantees the global stability of the closed-loop system and the achievement of output regulation. A key advantage of the proposed controller is that it does not rely on specific models of nonlinearities, thus ensuring strong robustness to model uncertainties. Finally, simulation results are provided to validate the effectiveness of the proposed method.

Keywords:

nonlinear systems, backstepping control, disturbance observers, high-gain scaling

Classification:

93C10, 93C73, 93D05

paper.pdf

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