含未知虚拟控制系数的非线性系统的自适应模糊控制

【作者】 王芳；

【导师】 陈兵；

【作者基本信息】 青岛大学 ， 系统理论， 2019， 硕士

【摘要】 本文主要针对一类状态不可测并含有未知虚拟控制系数的单输入单输出非线性系统的自适应模糊控制问题。基于模糊自适应控制方法、Backstepping设计技术和李雅普诺夫稳定性理论,本文提出了设计鲁棒观测器的思路,在所设计的鲁棒观测器基础上进一步给出自适应模糊输出反馈控制方案,并给出闭环系统的稳定性分析。具体的研究成果如下:1.针对一类状态变量不可测量并含有未知虚拟控制系数的严格反馈的非线性系统,使用凸组合方法解决未知虚拟控制系数对于观测器设计所造成的困难,构造出受控系统的模糊观测器。进而利用模糊自适应方法和Backstepping技术给出基于观测器的输出反馈控制方案,最后进行了闭环系统的稳定性分析,证明了闭环系统信号保持有界,同时系统输出能够会很好的跟踪给定的参考信号。通过数值仿真验证了所提出的控制方案的有效性。2.针对非严格反馈非线性系统,给出了鲁棒观测器的设计方案,进一步基于模糊控制方法和Backstepping设计技术构造出模糊自适应控制器。在控制器设计过程中,对非严格反馈部分运用Young不等式及模糊逻辑系统中基函数向量的性质,解决了非严格反馈结构对于Backstepping设计所带来的困难,在模糊自适应控制理论的框架下将Backstepping设计拓展到一类非严格反馈系统。最后进行了闭环系统的稳定性分析,证明了闭环系统信号保持有界,同时系统输出能够很好的跟踪给定的参考信号。并通过数值仿真验证了所提出的控制方案的有效性。3.针对带死区输入情况的非线性系统的控制问题。死区输入由两部分相加组成,分别是一个线性部分和一个有界非线性部分。而后设计出相应的观测器和控制器。最终,以一个实例仿真证明了理论结果的有效之处。更多还原

【Abstract】 This thesis mainly addresses a class of adaptive fuzzy control problems for single-input single-output nonlinear systems with unmeasurable state variables and unknown virtual control coefficients.Based on Adaptive fuzzy control method,Backstepping technique and Lyapunov stability theory,a robust observer design scheme is proposed,furthermore,an observer-based adaptive fuzzy output feedback control strategy is developed.The closed-loop stability analysis is also given.The specific research content is listed as follows:1.Consider adaptive fuzzy output feedback control for a class of strict-feedback nonlinear systems with the unmeasurable state variables,unknown virtual control coefficients.By using the convex combination method,the difficulty caused by the unknown virtual control coefficients for observer design is overcome.A robust fuzzy observer is constructed,furthermore,an observer-based adaptive fuzzy output feedback control scheme is proposed by Backstepping.The closed-loop stability is provided,it is shown that all the closed-loop signals are bounded and the systems output fellows the given reference signal well.At last,numerical simulation is utilized to test the effectiveness of the suggested control scheme.2.Consider adaptive fuzzy output feedback control for a class of non-strict feedback nonlinear systems.A robust fuzzy observer design scheme is presented by fuzzy control method and Backstepping technique.During the procedure of controller design,the Young inequality and the property of the norm of basis vector functions of fuzzy logic systems are used to overcome the difficulty caused by the structure of non-strict feedback.Thus,under the frame of adaptive fuzzy control theory Backstepping is extended to non-strict feedback nonlinear systems for control design.Finally,the stability analysis of the closed-loop system is carried out,which proves that the closed-loop system signal remains bounded,and the system output can track a given reference signal well.The effectiveness of the proposed control scheme is verified by numerical simulation.3.The control design is considered for nonlinear systems with dead zone input.The input dead zone is decomposed into the sum of two parts,which is a linear part and a bounded nonlinear part.The corresponding observer and controller designschemes are given next.Finally,an example simulation demonstrates the effectiveness of the theoretical results.更多还原