Output feedback tracking control for lower‐triangular nonlinear time‐delay systems with asymmetric input saturation

Abstract

In this paper, the problem of output feedback tracking control is investigated for lower-triangular nonlinear time-delay systems in the presence of asymmetric input saturation. A novel design program based on a dynamic high gain design approach is proposed to construct an output feedback tracking controller. The innovation here is that the problem of constructing tracking controller can be transformed into the problem of constructing two dynamic equations, with one being utilized to deal with the nonlinear terms and the other one being applied to analyze the influence of asymmetric input saturation. It is proved by an appropriate Lyapunov-Krasovskii functional that the proposed tracking controller subject to saturation can ensure that all the signals of the closed-loop system are globally bounded and the tracking error is prescribed sufficiently small when time is long enough. A practical example is given to illustrate the effectiveness of the proposed method. K E Y W O R D Sdynamic gain controller, input saturation, nonlinear systems, output feedbackInt J Robust Nonlinear Control. 2020;30:3471-3483. wileyonlinelibrary.com/journal/rnc

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