Certainty-equivalence based super-twisting control using continuous adaptation laws

摘要

The certainty-equivalence super-twisting controller (CESTA) combines approaches from variable structure and adaptive control. In this paper, an improved variant of this algorithm is presented that resorts to a recently introduced Lyapunov function for the super twisting algorithm, establishing a novel continuous adaptation law. These controllers are beneficial for systems that are affected by structured and unstructured uncertainties. It is demonstrated that the combination of sliding-mode and adaptive control methodologies allows to relax the boundedness condition, known from the super twisting algorithm. In comparison to earlier work, asymptotic stability of the system states may be shown while requiring relaxed conditions on the structured uncertainty. The effectiveness of the proposed algorithm is shown with a simulation example.