【作者】 陈晖；

【导师】 谭建平；

【作者基本信息】 中南大学 ， 机械工程， 2012， 博士

【摘要】 大型水压机是一个国家建立独立工业体系和强大国防所必须的大型战略性装备,其安全性可靠性至关重要。对大型水压机进行故障诊断及状态评估是实现大型水压机安全可靠运行和设备健康管理的关键,其研究意义重大。目前对大型水压机进行故障诊断及状态评估主要存在两方面的问题：一是缺乏从机理上研究大型水压机多类典型故障的产生原因及性能退化规律,从而影响了故障诊断及状态评估方法的有效性；二是设备结构复杂、工作环境恶劣,观测参数的随机扰动大,凭借传统单一传感器信息往往难以准确诊断系统故障。本文在国家“863”高技术研究发展计划项目“300MN模锻水压机状态监测及故障诊断研究”资助下,以大型水压机高压大流量水阀启闭故障和水压机立柱超常应力两类典型故障为例,采用多学科动态仿真技术分析了其故障机理,并将多源信息融合理论方法引入到其故障诊断与状态评估中,旨在探索提高大型水压机运行安全性、可靠性的技术方法和途径,为实现大型战略性水压装备更高层次的健康管理提供有效的技术支持。论文的主要研究内容包括：1.系统分析和研究了大型水压机强耦合条件下的系统动力学特性及典型故障产生机理问题。(1)采用多学科复合建模仿真技术,建立了大型水压机集流体动力、机械、控制于一体的复合动力学模型,系统分析了大型水压机强耦合条件下的系统动力学特性问题,研究揭示了大型水压机正常工况下的工作机理和工作特性,为大型水压机水路分配系统故障机理研究奠定了基础。(2)定性定量的分析了大型水压机复杂环境下高压大流量水阀启闭故障形成因素,通过故障仿真,研究了大型水压机强耦合条件下的高压大流量水阀启闭故障特性、演变规律及其影响模式,在此基础上,根据故障仿真结果对故障特征参数灵敏性进行了分析,这为大型水压机水路分配系统故障诊断及状态评估提供了理论依据。(3)采用现代CAE有限元建模仿真分析方法,研究了水压机大型活动横梁与立柱的接触力学行为,揭示了大型水压机立柱附加应力的产生机制、分布规律和参数影响规律,为大型水压机立柱应力状态评估及超限诊断奠定了基础。2.深入研究了基于多源信息融合的大型水压机故障诊断与运行状态评估方法(1)采用物理建模和数值模拟方法获取了大型水压机高压大流量水阀启闭故障条件下不同故障程度的特征参数基准值,在此基础上,提出了高压大流量水阀多参数融合故障诊断及运行状态评估的特征参数标准模式。(2)将灰色系统理论与方法引入到大型水压机水阀启闭故障的多源信息融合诊断中,采用灰色关联分析、灰色聚类评估等方法建立了大型水压机水阀启闭故障的多源信息融合诊断模型,利用300MN模锻水压机测试样本数据进行了验证。(3)提出了大型水压机立柱附加应力的计算方法、应力测试数据冗余校验及立柱应力状态的多源信息融合评估方法,利用300MN模锻水压机现场测试数据进行了验证。3.集成了大型水压机状态监测关键技术,设计实现了300MN模锻水压机状态监测与多源信息融合故障诊断系统。(1)针对大型大型水压机特殊的结构及工作环境,研究了大型水压机特殊环境下立柱应力、活动横梁空间位姿等非功能参数获取关键技术。(2)以300MN模锻水压机为对象,应用本文研究的理论和技术成果,设计实现了300MN模锻水压机状态监测与故障诊断系统。提高了300MN模锻水压机的运行安全性和可靠性。更多还原

【Abstract】 Large hydraulic press is a strategical equipment of independent industrial system construction and national defence, its safety and reliability is crucial. As an import supporting technology of ensuring that the large hydraulic press operate safely and reliably and its maintenance actives are organized by the scientific and reasonable manners, research on the fault diaguosis and state assessment are of quite significance.The present research on large hydraulic press fault diaguosis and state assessment has two main issues that are not satisfactorily solved. One is the mechanisam and degradation laws of typical faults, which are important for fault diaguosis and state assessment is seldom investigated. The other is the shortage of diagnositic technologies. For example, it is quite difficult to carry out the missions of fault diagnosis and state assessment accurately using traditional single sensor imformation because of a series of special characteristics of large hydraulic press including complicated structures, poor operational environments and large disturbance of observation parameters.Supported by the projects "Research on condition monitoring and fault diaguosis of300MN hydraulic press", which belong to national high technolgoty research and development program of China (NHTRDPC,863Program), the opening/closing fault of high pressure and large flow capacity water valve and extraordinary column stress in large hydraulic press are taken as research objects in this paper. The mechanisams of the faults are investigated systematically using multidisciplinary complex simulation technique. Then based on previous work, the technology of fault diaguosis and state assessment based on multi-source information fusion are studied. The main purpose of the research work is to investigate the new approaches to deal with the problems of fault identification and state assessment accurately for large hydraulic press. At the same time, also aims at providing valid technical support for health management of large hydraulic press. The detailed contents and innovatie works are shown is the following sections.1. The system dynamic characteristic and mechanism of typical fault under the condition of serious coupling in large hydraulic press are analyzed systematically(1) A complex system dynamics model integration of fluid power, machinery and control is build using multidisciplinary complex simulation technique. The system dynamic characteristics under condition of serious coupling in large hydraulic press are analyzed systematically. The working mechanism and characteristic of large hydraulic press in normal working condition which provides a theoretical basis for fault diagnosis and condition assessment are revealed.(2)Factors for opening/closing fault formation under complex environment in high pressure and large flow capacity water valve are analyzed qualitatively and quantitatively. Fault characteristics, evolution law and how the faults influence the large hydraulic press in condition of serious coupling in large hydraulic pressare are analyzed systematically through fault simulation. Then based on these research works, the sensitivity of fault characteristic parameters which are important for fault diaguosis and state recognition are analyzed.(3)Using modern CAE finit element modeling simulation analysis method, the contact mechanics hehaviour between moving beam and column in large hydraulic press is analyzed. The mechanism, distribution and parameter influence of additional column stress are revealed. A calculation method for additional column stress calculation which is important for column stress state assessment and transfinite diagnosis is put forward.2. The technology of fault diaguosis and codition assessment in large hydraulic press based on multi-source information fusion are studied deeply.(1)The reference value of fault feature parameters under different opening/closing fault conditions in high pressure and large flow capacity water valve are obtainted through physical modeling and numerical simulation. Then based on these research works, a feature parameter standard model of opening/closing fault in high pressure and large flow capacity water valve is put forward.(2) The grey system theory and method is applied in multi-source information fusion fault diagnosis and codition assessment in high pressure and large flow water valve. A quantitative detection approach for opening/closing fault in high pressure and large flow capacity water valve is put forward, and a state assessment method for high pressure and large flow capacity water valve based on grey clustering is put forward. The methods are applied effectively in300MN die hydraulic press which demonstrates the effectiveness of the methods.(3)Based on data redundancy and complmentarity, a detecting data redundancy check method and a state assessment method for column stress are put forward. Experiment study is made which demonstrates the effectiveness of the methods.3. The key technologies of condition monitoring in large hydraulic press are studied and integrated. A condition monitoring and fault diagnosis based on multi-source information fusion is designed and applied in300MN die forging hydraulic press.(1)In view of the special structure and and working environment in large hydraulic press, the key technologies of non-functional parameter detecting methods such as column stress and crossbeam offset in non-working directions are studied.(2)300MN forging hydraulic press is taken as the object, a condition monitioring and fault diagnosis based on multi-source information fusion is designed using the theory and technology studied in this paper. The successful apply of the system improve the safety and reliability of300MN die forging dydraulic press.更多还原