Time-Varying Input and State Delay Compensation for Uncertain Nonlinear Systems

Kamalapurkar R., Fischer N., OBUZ S., Dixon W. E.

IEEE TRANSACTIONS ON AUTOMATIC CONTROL, vol.61, no.3, pp.834-839, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 61 Issue: 3
  • Publication Date: 2016
  • Doi Number: 10.1109/tac.2015.2451472
  • Journal Name: IEEE TRANSACTIONS ON AUTOMATIC CONTROL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.834-839
  • Eskisehir Osmangazi University Affiliated: No

Abstract

A robust controller is developed for uncertain, second-order nonlinear systems subject to simultaneous unknown, time-varying state delays and known, sufficiently small time-varying input delays in addition to additive, sufficiently smooth disturbances. An integral term composed of previous control values facilitates a delay-free open-loop error system and the development of the feedback control structure. A stability analysis based on Lyapunov-Krasovskii (LK) functionals guarantees uniformly ultimately bounded tracking under the assumption that the delays are bounded and slowly varying. Numerical simulations illustrate robustness of the developed method to various combinations of simultaneous input and state delays.