This paper considers the asymptotic adaptive tracking control issues for the nonstrict feedback nonlinear systems. By adding the negative exponential function to the Lyapunov function, the exponentially asymptotic convergence is realised for the first time. In addition, the prior knowledge of the lower and upper bounds of unknown nonlinear functions have been removed in this article. The unknown nonlinear functions and uncertain external disturbance are solved by using fuzzy logical systems (FLS) and the bound-estimation method. It is shown that the tracking error can converge to zero at an exponential rate and the whole signals of the controlled system are bounded. Finally, simulation examples have been presented to prove the effectiveness of the raised scheme.

本文考虑了非严格反馈非线性系统的渐近自适应跟踪控制问题。通过在Lyapunov函数中加入负指数函数，首次实现了指数渐近收敛。此外，本文去除了未知非线性函数上下界的先验知识。采用模糊逻辑系统（FLS）和界估计法求解未知的非线性函数和不确定的外部干扰。结果表明，跟踪误差可以以指数速率收敛到零，并且受控系统的整个信号是有界的。最后通过仿真实例验证了所提方案的有效性。