Adaptive fuzzy output feedback control for nonlinear systems based on event-triggered mechanism

Abstract

Approaches of considering event-triggered fuzzy control for nonlinear output feedback systems are restricted to a conservative result that only a tunable unknown tracking error is obtained. This work proposes a new fuzzy control strategy to remove this restriction. Technically, a new idea contributes to the design of the Lyapunov function, which is constructed with a series of smooth functions rather than chosen in a quadratic form as regular. With this idea, a new direct adaptive fuzzy controller is then developed to avoid the possible chattering phenomenon in addition to achieve the asymptotic stability. Besides the chattering-free property, the proposed scheme is performance-oriented in the sense that the relationship between the design parameters and tracking performance is established in an explicit way, which allows the users to make design decisions accordingly. Through Lyapunov analysis, it is proven that besides the system stability, the tracking error will ultimately approach to a user-defined interval. Simulation studies are performed to demonstrate the theoretical results.