BAKRI AlaeddineENCA/ BOUKHALFAAbdelouaheb2025-07-162025-07-162025-06-30ELC/22/25https://repository.univ-msila.dz/handle/123456789/47249This thesis addresses the design of Higher Order Sliding Mode (HOSM) controllers with optimal reaching properties for nonlinear systems with known relative degree. A robust extension of the classical Fuller’s problem—termed the Robust Fuller’s Problem—is introduced to derive control laws that ensure finite-time convergence to the sliding manifold while maintaining robustness against uncertainties. The proposed approach provides a systematic parameter tuning method and unifies various existing HOSM algorithms within a generalized theoretical framework. Simulation results validate the superior performance of the developed controllers in terms of convergence speed, chattering reduction, and disturbance rejection.enThesis