Global practical tracking via disturbance rejection control for uncertain nonlinear systems with quantized input and output

Global regulation of large‐scale nonlinear systems via decentralized output‐feedback switching control

“…Before starting, we estimate the upper bound of V(t m ), m = 1, 2, … . From (18), we have that, for t ∈ [t m , t m+1 ),…”

“…Remark If $$$ {c}_{k,1} $$$, $$$ {c}_{k,2} $$$ are known constants and $$$ {d}_k^{\ast }=0 $$$, a static/constant gain 15,18 or a bounded time‐varying gain 19 is usually enough to make $$$ V $$$ nonincreasing. However, the serious uncertainties here arising from the unknown growth rate and unknown external disturbances have become an obstacle to subsequent analysis.…”

“…• In terms of control method: Different from existing LSNSs design methods, including backstepping design method, [5][6][7][8] forwarding and saturation design method, [9][10][11] static/constant gain scaling method, 15,18 time-varying gain scaling method, 4,19,20 and dynamic gain scaling method, 14,16,17,21 a novel decentralized output-feedback switching control method is proposed for the first time in this article. Owing to the introduction of the switching mechanism, the logic unit can detect and supervise the system behavior in real time, which endows this method with strong adaptive capability and disturbance tolerance.…”

“…In Reference 17, the adaptive output‐feedback control problem of upper‐triangular LSNSs is solved by using the dynamic gain scaling method. When the system uncertainties, arising from system parameters and/or system nonlinearities, are essentially minor, such as a known constant growth rate, a static/constant gain 18 or a bounded time‐varying gain 19 is usually enough to achieve the control objective. However, once serious uncertainties occur in the system, an unbounded time‐varying gain 20 or a dynamic gain 21 is usually introduced to counteract adverse effects.…”

“…Inspired by the above discussions, we aim to investigate the global regulation problem for a class of LSNSs subject to unknown growth rate and unknown external disturbances. The main contributions of this article are summarized as follows: In terms of control method : Different from existing LSNSs design methods, including backstepping design method, 5‐8 forwarding and saturation design method, 9‐11 static/constant gain scaling method, 15,18 time‐varying gain scaling method, 4,19,20 and dynamic gain scaling method, 14,16,17,21 a novel decentralized output‐feedback switching control method is proposed for the first time in this article. Owing to the introduction of the switching mechanism, the logic unit can detect and supervise the system behavior in real time, which endows this method with strong adaptive capability and disturbance tolerance. In terms of controller structure : By avoiding the use of the iterative design step in References 5‐11 and the gain derivative information in References 4,13,14,16, and 17, the decentralized output‐feedback switching controller designed in this article has a concise linear‐like form and low complexity.…”