【作者】 何洪；

【导师】 彭涛；

【作者基本信息】 湖南工业大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 基于观测器的故障检测方法一直是基于解析模型故障诊断方法研究的热点,它充分利用系统的数学模型,具有鲁棒性强、效率高和可靠性好等优点。但大多基于观测器的故障检测系统的设计都采用H∞优化技术,设计方法、算法复杂,为工程实践带来不便。本论文在介绍基于观测器的故障诊断原理的基础上,从开环和闭环两方面介绍了如何对故障系统建模,并对倒立摆系统、三容水箱系统、汽车横向动态系统三个应用实例详细分析了动态系统的故障建模。然后,针对线性时不变离散系统,结合观测器理论与等价空间方法,建立评价函数,并确定阈值,把传统的优化问题转化为对观测器和滤波器的优化设计来求解,简化了设计方法,并获得了较为满意的结果。数值仿真验证了方法的有效性。最后,针对线性时不变连续系统,构建输出观测器生成残差,通过添加后置滤波器来抑制残差中不感兴趣部分而加强其中反应故障的成分,以区分故障与模型不确定性等未知输入的影响,设计方法、算法简单。数值仿真和倒立摆系统、三容水箱系统、汽车横向动态系统三个应用实例仿真说明了有后置滤波器的残差检测效果要明显优于无后置滤波器的效果,验证了方法的有效性。更多还原

【Abstract】 The observer-based fault detection method, which is robust, strong, high efficiency and good reliability, has been a hot in the model-based fault diagnosis method. The mathematical model of the system was made full use of by the observer-based fault detection method. But the H_∞optimization technology was used in most of the observer-based fault detection systems, which was proved to be complex and inconvenient in engineering practice.The open-loop and closed-loop fault systems are introduced to explain how to model for the fault systems on the basis of introducing the observer-based fault diagnosis principle. The models of the inverted pendulum control system, the three tank system and the vehicle lateral dynamic system are analyzed minutely.For LTI discrete systems, combining the observer theory with the parity space, the evaluation function is established, and the threshold is confirmed. The traditional optimization problems are transformed into the design of the observer and filter, which are simplified, so the good results are obtained. Numerical simulation shows the effectiveness of the method.Finally, for LTI continuous system, the output observer is constructed to generate the residual. Curbing the disagreeable aspect and strengthening the needed aspect of the residual by adding a post-filter, which are aim to distinguish the influence of the fault and the model uncertainty, and the algorithm is simple. The detecting result of using post-filter is proved to be better than the detecting result of non post-filter by numerical simulations and the simulations of the inverted pendulum control system, the three tank system and the vehicle lateral dynamic system. Simulation examples show the effectiveness of the design method and the algorithm.更多还原