Adaptive output feedback stabilization for a class of nonlinear systems with inherent nonlinearities and uncertainties

Abstract

SUMMARYThis paper investigates the problem of adaptive stabilization by output feedback for a class of uncertain nonlinear systems. The distinguishing feature of such a class of systems is the presence of uncertain control coefficient and unmeasured states dependent growth with growth rate of polynomial-of-output multiplying an unknown constant. First, new high-gain K-filters with two dynamic gains are introduced, and an appropriate state observer is constructed based on the K-filters. Then, motivated by the universal control idea, the backstepping scheme is successfully developed for the adaptive output feedback control design. By appropriate choice of the design parameters, the global stability of the closed-loop system can be guaranteed. Finally, numerical simulations are provided to illustrate the correctness of the theoretical results.

Global adaptive regulation of feedforward nonlinear time‐delay systems by output feedback

“…Clearly, these uncertain or nonlinear output functions satisfy Assumption . On the other hand, system with Assumption also covers a class of nonlinear systems with unknown control coefficients , for example, the system can be transformed into by and . In the case of output feedback control for feedforward nonlinear time‐delay systems, the existing results allow usually the growth rate only including either an unknown constant or input functions c ( u ) and , for example, .…”

Global state regulation by output feedback for feedforward systems with input and output dependent incremental rate

“…Unlike the control scheme proposed by [6], universal adaptive high-gain observers were introduced to achieve global output feedback stabilization in [7,8]. For a larger class of nonlinear systems with unknown control coefficients, the global state regulation problem was investigated by output feedback in [9][10][11]. Furthermore, a universal adaptive output feedback controller was constructed for a class of nonlinear systems with unknown time delays and output function in [12], and an output feedback controller was proposed by introducing double dynamic gains in [13].…”

“…Thus, it is necessary to impose some extra restrictive conditions on nonlinear terms to obtain global output feedback controller. In the case when uncertain nonlinear systems dominated by a lower-triangular system with linear growth in unmeasured states, the problems of global output feedback stabilization or regulation have been addressed in [2][3][4][6][7][8][9][10][11][12][13]. Specifically, using a feedback domination design method, the global exponential stabilizer was constructed under the linear growth condition with known growth rate in [2].…”

Output feedback regulation for large-scale uncertain nonlinear systems with time delays

“…In the last decade, the problem of global output feedback control of nonlinear systems with linear unmeasurable states multiplying by the various growth functions has received considerable attention and still remains as an active research topic (see e. g., [1,2,9,10,11,12,13,15,16,18,22,23,24,25,26]). For example, a time-varying output feedback controller has been proposed for the global regulation of nonlinear uncertain systems DOI: 10.14736/kyb-2015- with an unbounded time-varying delay in the input in [9].…”