Adaptive Fuzzy Output Feedback Tracking Backstepping Control of Strict-Feedback Nonlinear Systems With Unknown Dead Zones
Adaptive Fuzzy Output Feedback Tracking Backstepping Control of Strict-Feedback Nonlinear Systems With Unknown Dead Zones
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DOI：
10.1109/tfuzz.2011.2171189
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发表时间：
2012-02
影响因子：
11.9
通讯作者：
Shaocheng Tong;Yong-ming Li
中科院分区：
文献类型：
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作者：
Shaocheng Tong;Yong-ming Li
本文针对一类具有未知函数、未知死区和不可测状态的非线性严格反馈系统，考虑了一种自适应模糊反步控制方法。利用模糊逻辑系统来逼近未知的非线性函数，并设计模糊滤波器状态观测器来估计不可测状态。通过使用自适应反步递归设计技术并构造死区逆，提出了一种新的自适应模糊反步输出反馈控制方法。数学证明了所得到的闭环自适应控制系统的所有信号都是半全局一致最终有界的，并且通过适当选择设计参数，跟踪误差收敛到原点的一个小邻域。所提出的方法不仅解决了死区问题，而且取消了先前文献中状态都可用于测量的限制性假设。提供了两个仿真示例来显示所提出方法的有效性。
In this paper, an adaptive fuzzy backstepping control approach is considered for a class of nonlinear strict-feedback systems with unknown functions, unknown dead zones, and immeasurable states. Fuzzy logic systems are utilized to approximate the unknown nonlinear functions, and a fuzzy filters state observer is designed to estimate the immeasurable states. By using the adaptive backstepping recursive design technique and constructing the dead-zone inverse, a new adaptive fuzzy backstepping output-feedback control approach is developed. It is mathematically proved that all the signals of the resulting closed-loop adaptive control system are semiglobally uniformly ultimately bounded, and the tracking error converges to a small neighborhood of the origin by appropriate choice of design parameters. The proposed approach cannot only solve the problem of the dead zones but also cancel the restrictive assumption in the previous literature that the states are all available for measurement. Two simulation examples are provided to show the effectiveness of the proposed approach.