Event-Triggered Adaptive Fuzzy Output-Feedback Control for Nonstrict-Feedback Nonlinear Systems With Asymmetric Output Constraint

作者：Wang, Anqing; Liu, Lu; Qiu, Jianbin^*; Feng, Gang

来源：IEEE Transactions on Cybernetics, 2022, 52(1): 712-722.

DOI：10.1109/TCYB.2020.2974775

• Nonlinear systems
• Fuzzy logic
• Adaptive systems
• Observers
• Control systems
• Symmetric matrices
• Time-varying systems
• Adaptive fuzzy control
• barrier Lyapunov BLF)
• event-triggered control
• nonstrict-feedback nonlinear systems

This article addresses the event-triggered adaptive fuzzy output-feedback control problem for a class of nonstrict-feedback nonlinear systems with asymmetric and time-varying output constraints, as well as unknown nonlinear functions. By designing a linear observer to estimate the unmeasurable states, a novel event-triggered adaptive fuzzy output-feedback control scheme is proposed. The barrier Lyapunov BLF) and the error transformation technique are used to handle the output constraint under a completely unknown initial tracking condition. It is shown that with the proposed control scheme, all the solutions of the closed-loop system are semiglobally bounded, and the tracking error converges to a small set near zero, while the output constraint is satisfied within a predetermined finite time, even when the constraint condition is violated initially. Moreover, with the proposed event-triggering mechanism (ETM), the Zeno behavior can be strictly ruled out. An example is finally provided to demonstrate the effectiveness of the proposed control method.