Stabilisation and improvement of performance by extension of universal formula in the presence of disturbance

Dept. of Electr. & Comput. Eng., Tehran Univ., Iran
IEE Proceedings - Control Theory and Applications (Impact Factor: 1.05). 04/2005; DOI: 10.1049/ip-cta:20041128
Source: IEEE Xplore

ABSTRACT Krstic-Sontag's formula proves constructively that the existence of a control Lyapunov function implies asymptotic stabilisability. A similar result can be obtained for systems subject to unknown disturbances by input-to-state stabilising control Lyapunov functions (ISS-CLFs) and the input-to-state analogue of Krstic-Sontag's formula. A generalisation of the ISS version of Krstic-Sontag's formula is provided by completely parameterising all continuous ISS control laws that can be generated from a known ISS-CLF. Given an ISS-CLF, the synthesis problem reduces to that of finding indexes b(x) and υ(x) that lead to desirable performance, i.e. convergence rate and performance index. A large family of ISS controls is shown that solve the inverse optimal gain assignment problem.

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