I. Introduction
Prior studies have explored the tracking control problem of uncertain nonlinear systems with many applications related to motors, robots, and wind turbine systems [1]. A variety of constructive adaptive backstepping schemes have been proposed [2]. In particular, adaptive control design with fuzzy logic systems (FLSs) or neural networks (NNs) has generated an abundance of research results [3]–[12]. A common characteristic of the aforementioned algorithms is that they mainly focus on strict feedback systems. However, in practical applications, controlled systems generally have a non-strict feedback form. Thus, it is important to research the tracking control problem of non-strict feedback systems. In recent decades, many excellent studies on this problem have been produced [13]–[17].