具有未知死区输入的不确定非线性切换系统的模糊自适应控制

The majority of the practical engineering system is not only the switched nonlinear systems, and also affected by the dead-zone inputs. In control process, we not only need to consider compensating the unknown dead zone, also need to design the switching signal and subsystems controllers. Therefore, to explore the control problem for switched nonlinear systems with dead zone is of great significance. This project will focus on a class of uncertain strict-feedback switched nonlinear systems with unknown dead-zone inputs, and the corresponding pure-feedback switched nonlinear systems. On the basis of fuzzy logic systems to model the nonlinear uncertainties, this project will combine adaptive back-stepping design methods, dynamic surface control technique, alleviating computation algorithm, dwell time method, Lyapunov constructed functions approach and robust control theory, for the measurable and un-measurable stats, mainly discuss the adaptive state-feedback tracking control schemes, the fuzzy observer designing and output-feedback control algorithms. By using the Lyapunov stability analysis theory, the robustness and stability of the closed-loop systems and the related H∞ control ability will be studied. Aiming to simplify the controller design process and to improve the control efficiency, this project will get a high level of research results. The results proposed by this project will provide a new and effective intelligent analysis and design approaches for the switched nonlinear systems, which will provide theoretical control design study basis for dealing the complex industrial processes.

多数实际工程系统往往既是非线性切换系统, 又受未知死区输入的影响,在控制过程中, 不仅要考虑补偿死区,还要设计切换信号与子系统控制器.因此探讨带死区非线性切换系统的控制问题意义重大.本项目拟针对一类具有未知死区输入的不确定严格反馈以及纯反馈非线性切换系统; 将基于模糊逻辑系统作为函数逼近器,结合自适应Back-stepping技术、动态面控制方法、减少计算量算法、驻留时间法、Lyapunov 函数构造法和鲁棒控制理论; 重点研究这类系统的状态反馈跟踪控制, 以及状态不可测时的模糊观测器设计和输出反馈控制问题; 基于Lyapunov 稳定性理论,分析和证明闭环系统的稳定性、鲁棒性和 H∞控制性能等理论问题; 旨在简化控制器设计过程和提高控制效率,获得高水平的理论研究成果. 该项目的研究将为非线性切换系统控制提供一套新的、行之有效的智能分析与设计方法, 为研究复杂工业过程的控制提供理论依据.

具有非光滑死区输入的不确定非线性切换系统经常出现在实际工程控制中,本课题在非线性系统控制理论的统一框架下,旨在简化控制器设计过程,提高控制效率,基于反推设计技术, 结合自适应模糊控制技术、动态面控制技术以及减少计算量控制算法, Lyapunov稳定性理论对带未知死区的非线性切换系统进行了研究.首先探讨了状态可测时的严格反馈形式下的带死区非线性切换系统的自适应动态面模糊状态反馈控制,可以有效的避免传统非反推设计的计算膨胀问题;其次分析了带死区的非线性严格反馈切换系统在状态不可测时的基于模糊观测器的减少计算量输出反馈跟踪控制,可以实现自适应调节参数数目减少,在线计算量减少的目的; 紧接着实现了纯反馈结构下的带死区的非线性切换系统的在状态可测时的状态反馈动态面跟踪控制问题;最后研究了在状态不可测时的纯反馈结构带死区切换系统的输出反馈跟踪模糊控制. 这些结果可以克服现阶段关于非线性死区切换系统的控制器设计过程中的 ‘计算膨胀’问题及自适应调节参数过多等问题.这些均为带未知死区非线性不确定切换系统提供了一套行之有效的理论研究依据并为后续研究提供了可能性.