This paper studies the observer-based adaptive fuzzy tracking control problem for a general class of multi-input-single-output nonstrict-feedback systems subject to unmeasured states and actuator failures. For actuator failures, both cases of lock-in-place and loss of effectiveness are synchronously considered. To handle the unknown nonlinear functions, fuzzy logic systems are employed. By constructing a fuzzy observer and a serial-parallel estimation model, the unmeasured states are estimated and the accuracy of approximating the unknown functions is improved. Moreover, taking into account the prediction error between the fuzzy observer and the serial-parallel estimation model, a novel composite fuzzy output-feedback control scheme is developed. Unlike some existing control schemes for systems with actuator failures, the developed control scheme allows one to avoid the problem of “explosion of complexity” and improve the approximation performance. It is proved that all signals in the system are bounded and the tracking error converges to a small neighborhood of the origin by choosing appropriate parameters. Finally, the effectiveness of the proposed method is confirmed via simulation examples with actuator failures.

中文翻译：

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具有执行器故障的非严格反馈系统的基于观察者的复合自适应模糊控制

本文研究了一类多输入单输出非严格反馈系统的基于观测器的自适应模糊跟踪控制问题，该系统受不可测量状态和执行器故障的影响。对于执行器故障，同时考虑锁定到位和失效两种情况。为了处理未知的非线性函数，采用了模糊逻辑系统。通过构建模糊观测器和串并联估计模型，估计未测量状态，提高逼近未知函数的精度。此外，考虑到模糊观测器和串并联估计模型之间的预测误差，开发了一种新的复合模糊输出反馈控制方案。与一些现有的致动器故障系统的控制方案不同，所开发的控制方案可以避免“复杂度爆炸”的问题并提高逼近性能。证明了系统中的所有信号都是有界的，通过选择合适的参数，跟踪误差收敛到原点的一个小邻域。最后，通过执行器故障的仿真实例证实了所提出方法的有效性。