【作者】 尚启英；

【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， 2008， 硕士

【摘要】 随着现代工业控制系统复杂程度的增加和人们对系统性能指标要求的提高,系统的可靠性,可维护性和容错性受到了人们越来越多的重视。由此,故障检测及容错控制方法在近二十年一直作为控制界的研究热点,取得了显著的成果。本文从研究间歇式反应釜釜内温度控制出发,对于采用串级控制方式控制反应釜的釜内温度在主传感器失效的情况下,对其进行了深入的故障诊断及容错控制的研究,主要进行了以下几方面的研究工作。1)进行了利用人工神经网络建立反应釜控制回路的故障诊断系统的研究。为了保证网络训练数据的完备性,本文从求取对象系统故障树最小割集入手,通过系统故障模式获取训练样本。另外,考虑到复杂大型神经网络教师数据整理困难,学习精度和学习效率低下等问题。本文采用了复合模糊神经网络技术建立了反应釜的故障诊断系统。2)提出了一种基于辅助模型的最小二乘算法,对反应釜进行数学建模研究.论文根据对象的特点确定了模型结构,利用辅助模型来估算冷却水温度、冷却水流量和夹套温度对釜温的影响,最后利用最小二乘法进行参数辨识完成了对象系统的模型建立。该方法克服了标准最小二乘法由于无法辨识模型中未知中间变量而无法进行建模的困难,经Matlab对系统模型进行仿真,模型输出基本与实际输出符合,为对系统进行进一步的容错控制垫定了基础。3)利用所得的数学模型采用信号重构的方式设计了对象反应釜在控制系统主传感器失效时控制重构的容错控制方案。在故障检测单元激励下,利用数学模型估算的输出值取代主传感器的输出反馈回控制器,保证系统仍然可以正常运行。并利Matlab对设计的容错控制系统进行了仿真试验研究,仿真实验结果表明了,所设计的容错控制系统可以保证系统的稳定运行。更多还原

【Abstract】 With complexity of modern control systems increasing and the requirement of higher performance of the system, reliability, maintainability and fault-tolerant capacity have attracted more and more attention of the world. For two decade, fault detection and tolerant control have made great improvement, and many remarkable results have been obtained.Starting with temperature control of the Vessel proceeding Batch Reactor, this paper makes a further studying on fault detection and tolerant control in condition of using cascade control to the reactor temperature as the master sensor fails to work, the main research work on it is done as follows:1) In this paper, for the use of artificial neural network to build the reactor control circuit fault diagnosis system. In order to ensure a complete network of training data, this article start from striking a system fault tree minimal cut , through the system failure mode to obtain training samples. In addition, taking into account the complicated and large-scale neural network will be faced with hard data collated teachers, low learning precision and low learning efficiency. In this paper, the composite fuzzy neural network technology was used to build the reactor’s fault diagnosis system.2) An identification algorithm based on auxiliary models and least squares is developed and used to model the Batch Reactor. According to the characteristic of the reactor, the paper determines the model structure, and using auxiliary models to estimate Jacket temperature, cooling water temperature and the cooling water flow impact on the reactor temperature, and then, using least squares principle to produce the parameters. This method overcome the difficulties that standard least square does not work when the inner variables are unmeasurable. The simulated result shows that the algorithms proposed are effective and provides the basis for fault tolerant control.3) Using signal reconstruction to achieve a cascade control as sensor fails to work in the main control with proceeds mathematical mode. In the stimulation from fault detection unit, the feedback controller, with the inputs from the mathematical model estimates instead of the inputs from the master sensor, can make the systems in the normal operation. Finally, the simulation results show that, when the measurement of certain components in the system fails to work, leading to the lost of control signal, the assumptions to realize the system Fault Tolerant Control through the use of results calculated by the system model is totally feasible.更多还原