串级系统主动容错控制设计

【作者】 冯冲；

【导师】 宋彤；

【作者基本信息】 大连理工大学 ， 检测技术与自动化装置， 2004， 硕士

【摘要】 容错控制技术的提出和应用对于提高工业系统的可靠性和安全性具有非常现实的意义。本文在讨论了过程系统容错控制技术应用基础上，阐述了基于故障诊断技术、神经网络系统辨识技术及控制律重构技术的主动容错控制的基本思想和方法。并以串级控制系统为对象完成了针对系统传感器故障的主动容错控制系统设计。首先，根据主动容错控制需要故障诊断单元的要求，采用基于信号处理的故障诊断方式，应用小波分析方法对传感器信号进行分析，并据此建立了串级控制系统的故障诊断单元模块。其次，应用神经网络实现对被控对象的特性模型辨识；并根据状态反馈控制律重构思想推导了串级系统的容错控制律重构规则。系统运行中，容错控制系统根据故障诊断单元所发出的控制律重构指令，采用推导出的串级系统重构规则进行系统控制律重构，使被控对象在新的控制律作用下平稳运行。 仿真实验充分表明了小波分析对于非平稳信号分析的优势，较好地实现了对传感器故障诊断的任务，为串级系统容错控制功能的实现打下基础；仿真曲线同样显示出控制律重构后的被控对象运行稳定，并且，重构后串级系统运行特性，与原系统的运行特性近似，说明该设计是可行。更多还原

【Abstract】 The bringing forward and application of fault tolerant control technology has obvious operation significance to increase reliability and security of industry system. This paper introduces basic idea and method of active fault tolerant control, which is based on malfunction diagnosis, neural network, system identification and control law reconstruction, after discussion about application of process system fault tolerant control technology, and completes an active fault tolerant control system design of a cascaded control system aiming at sensor malfunction. First, the malfunction diagnosis unit of sensor signal is built based on wavelet analysis method. Then, model of the controlled object is identified using neural network and reconstruction rules of the fault tolerant control law of the cascaded system are deducted according to state feedback control law reconstruction theory. While operating, fault tolerant control system reconstructs system control law according to instructions from malfunction diagnosis unit so that the controlled system runs stably. Simulation shows the sufficient advantage of wavelet in analyzing unstable signal. The task of sensor malfunction diagnosis is well completed using this method which provides a good base for succedent work.. The stable running of the controlled system under the reconstructed control law is also indicated in the simulation curves. The feasibility of the design is proved by the similarity of the operating characteristic between the reconstructed system and the original one.更多还原