With the ongoing development of artificial intelligence, the intelligent control of nontriangular nonlinear systems has become increasingly relevant across numerous fields. However, the results for nontriangular nonlinear systems with unknown control directions are not common, and how to ensure the fixed-time stability is a worthy research direction. In addition, owing to the limited network communication resources, it is challenging to design a fixed-time control scheme that considers both system performance and data transmission. In this article, we skillfully employ the property of the fuzzy logic system to address nontriangular structure uncertainties. Moreover, by introducing the Nussbaum gain technique into the fixed-time command filtered backstepping design procedure, an event-triggered fixed-time adaptive fuzzy controller is constructed to guarantee the system is practically fixed-time stable and relieve transmission burden. Eventually, the practicability and superiority of the...

This article focuses on the problem of fixed-time adaptive fuzzy control for a class of nontriangular nonlinear systems with unknown control directions under the event-triggered framework. To tackle the algebraic loop issue arising from the nontriangular structure, the property of the fuzzy logic system is employed. The command filter and the error compensation signals, which have the feature of fixed-time convergence, are constructed to eliminate the “explosion of complexity” phenomenon and the effect of filtered error, respectively. By integrating the Nussbaum gain technique into the relative threshold-based event-triggered mechanism, a singularity-free fixed-time adaptive fuzzy control scheme is devised to ensure that the closed-loop system is practically fixed-time stable, and the tracking error converges to a small region near the origin in a fixed time. Finally, simulation examples are presented to demonstrate the effectiveness and superiority of the proposed fixed-time control a...