基于故障矩阵的贝叶斯故障定位方法

故障的准确诊断和定位是云计算系统提供持续服务的前提条件;为了提高系统故障诊断和定位的性能,文章提出了一种基于故障矩阵的贝叶斯故障定位方法;首先,对云计算系统的软件结构进行了抽象,对事物进行了定义,并描述了事务的执行路径;其次,将系统运行的多个执行路径表示为故障矩阵,并给出了组件健康状态的逻辑命题表达式;最后,应用贝叶斯概率分析了系统故障的概率;实验表明,文章提出的方法与其它相关方法相比,故障识别的准确性更高,所用的执行时间更短。

基于故障矩阵的配电网故障定位研究与实现

配电网络在矿井下的变电所馈出线路多,并且线路延伸很长,矿井下形成了复杂的供配电网络系统,配电网络出现接地或短路故障后,故障点的查找与定位十分困难。只有依靠人工逐条线路查找有明显的短路或接地故障点,才能切除故障线路确定准确的故障痕迹,不影响正常安全生产,给矿井迅速恢复供电带来了极大的困扰。为此,通过研究配电网拓扑结构,建立数学模型,提出基于此模型的故障矩阵定位算法,加快故障点的精确定位,提高检修效率,保证安全生产。

超声诊断仪无图像故障的快速诊断及应急维修方法

目的 由于超声诊断仪故障类型复杂多变,因其实时性使得获取准确故障数据困难较大,且仅通过人工诊断具有主观性,导致诊断效率不高。为了提高对超声诊断仪故障诊断的精准性,设计超声诊断仪无图像故障的快速诊断及应急维修方法。方法 利用实时监测环境监测超声诊断仪应用状态,计算超声诊断仪故障出现的时刻,获取故障数据,并对其进行初次特征提取;通过计算故障特征的权重值,进行二次特征提取,构建故障矩阵;利用故障诊断函数,诊断超声诊断仪故障;根据诊断结果,提出应急维修方案,完成超声诊断仪无图像故障的快速诊断及应急维修方法的设计。结果 在实验测试中,超声诊断仪无图像故障的快速诊断及应急维修方法诊断时间仅为0.89 ms,诊断效率更高。结论 通过设计快速诊断及应急维修方法,可以提高超声诊断仪的响应速度和诊断准确性,从而优化医疗服务质量,更好地为患者提供可靠的诊断结果。

基于专家思维的多维度故障诊断方法

针对目前专家系统诊断准确度不高的问题,提出一种基于专家故障诊断思维方式的多测点、多时间点、多敏感参数相融合的故障诊断方法。从故障诊断专家对设备异常进行分析诊断的思路出发,依据故障机理、故障响应特点及故障劣化规律,选择相关测点、多时间点的数据来构建敏感参数矩阵,并生成对应的故障矩阵和权重矩阵,对设备异常状态进行诊断。利用该方法对某石化一离心压缩机异常状态进行分析诊断,结论准确,且能避免不同时间点诊断结论冲突问题。

Web服务故障的分类方法

Web服务故障分类是实现故障诊断的基础。在分析了Web服务的故障管理流程的基础上,提出了Web服务类型和执行过程相结合的Web服务故障分类方法,构建了Web服务故障树,根据故障及其外部表现间的对应关系构造了Web服务故障矩阵,通过分析和验证说明Web服务分类方法能够有效支持快速、准确的Web服务故障诊断。

基于FCA的物理层故障定位方法

提出了一种基于故障关联算法(FCA)的物理层故障定位模型,依据故障之间的关联关系,运用图论和故障矩阵的方法求出根故障集,确定故障源,有效地起到故障过滤和定位的功能。

新型燃气轮机热参数故障诊断数学模型的研究和应用

介绍了一种新型燃气轮机热参数故障模型。与以往的热参数故障模型有所不同的是该模型对由故障导致的特性线移动所引起的性能变化及由部件匹配引起的性能变化进行了分离 ,提高了模型的准确性和精度。此外 。

基于站域保护的煤矿井下电网防越级技术研究

煤矿井下供电系统的防越级主要解决的问题是使离故障点最近的配电点出线跳闸,而各配电点采用单母线接线,使防越级系统成为二级通信网络,结构复杂,难以满足实时性要求。根据站域保护思想,提出了一种站域保护的井下防越级方案,该方案由站域保护装置和监控主机通过实时以太网构成的单级通信网络实现。站域保护装置的功能是采集井下供电系统配电点的电气信息,确定故障出线并上传故障信息;监控主机利用故障矩阵法确定故障线路所在的配电点,并向站域保护装置下发跳闸指令,使离故障点最近的断路器跳闸,而高性能实时以太网的应用,保证了防越级跳闸系统的实时性。实验结果表明,该方案可以使离故障点最近的断路器跳闸,且满足煤矿井下防越级的实时性要求,为解决煤矿井下越级跳闸问题提供了新的方法。

FMEA等工具在电源模块项目开发中的应用

如何提高电源模块产品的质量并加快项目开发过程是所有的项目管理者都共同关注的问题,讨论了FMEA、Failure Matrix和Checklist几种工具在电源模块项目开发过程中的应用;解释了3种工具的内容;然后结合实例,给出了项目设计、设计验证、可靠性测试和量产测试几个关键环节中如何实施、使用这些工具的方法,并分析了几种工具综合使用对项目的影响和提升。通过分析发现,这些工具的应用可以极大地提升所开发产品的质量,节约成本。

可诊断系统的最优设计

本文提出了一个自诊断系统最优设计的方法,以Preparata和Barsi模型为例,把一步t可测试和顺序t可测试的最优设计问题统一归结为最小覆盖问题。此外,本文还提出了全局最优设计和局部最优设计的思想。考虑到计算机网络的连线费用,本文还给出了带权最优设计的方法。这方法还可用于除Preparata和Barsi模型以外的其它系统诊断模型。

ANALYSIS AND SIMULATION OF CONTROL MIXER CONCEPT FOR A CONTROL RECONFIGURABLE AIRCRAFT

In today's aircraft,the hardware redundancy is driven by the critical surfaces resulting in single point-failures.Reconfiguration technology remoVes the single surface criticality by employing control surfaces with aerodynamic redundancy.This paper studies a control reconfiguration scheme based on Control Mixer Concept.A technique for the design of a control mixer for an aircraft with damaged surfaces/actuators using the pseudo-inverse is developed and applied.This paper discusses its applications and limitations based on linear analysis and computer simulation.

An LMI Method to Robust Iterative Learning Fault-tolerant Guaranteed Cost Control for Batch Processes

Based on an equivalent two-dimensional Fornasini-Marchsini model for a batch process in industry, a closed-loop robust iterative learning fault-tolerant guaranteed cost control scheme is proposed for batch processes with actuator failures. This paper introduces relevant concepts of the fault-tolerant guaranteed cost control and formulates the robust iterative learning reliable guaranteed cost controller (ILRGCC). A significant advantage is that the proposed ILRGCC design method can be used for on-line optimization against batch-to-batch process uncertainties to realize robust tracking of set-point trajectory in time and batch-to-batch sequences. For the convenience of implementation, only measured output errors of current and previous cycles are used to design a synthetic controller for iterative learning control, consisting of dynamic output feedback plus feed-forward control. The proposed controller can not only guarantee the closed-loop convergency along time and cycle sequences but also satisfy the H∞performance level and a cost function with upper bounds for all admissible uncertainties and any actuator failures. Sufficient conditions for the controller solution are derived in terms of linear matrix inequalities (LMIs), and design procedures, which formulate a convex optimization problem with LMI constraints, are presented. An example of injection molding is given to illustrate the effectiveness and advantages of the ILRGCC design approach.

ROBUST RELIABLE CONTROLLER DESIGN FOR A CLASS OF TIME-VARYING UNCERTAIN SYSTEMS

The normal H ∞ control design deals with both plant modeling uncertainties and exogenous signal uncertainties by constructing a controller which stabilizes uncertain li near systems while satisfying an H ∞ norm bound constraint on disturbance attenuation for all admissible uncertainties. However, the control design may result in unsatisfactory performances or even instabilities in the event of sensor failures in practical plants. This paper focuses on the problem of the design of robust reliable H ∞ control for a class of time varying uncertainty system with sensor failures. The paper presents a novel technique which deal with this problem by solving three linear matrix inequalities (LMIs). The strict proof guarantees the feasibility of this approach.

Short-circuit fault analysis and isolation strategy for matrix converters

The behavior of matrix converter(MC) drive systems under the condition of MC short-circuit faults is comprehensively investigated. Two isolation strategies using semiconductors and high speed fuses(HSFs) for MC short-circuit faults are examined and their performances are compared. The behavior of MC drive systems during the fuse action time under different operating conditions is explored. The feasibility of fault-tolerant operation during the fuse action time is also studied. The basic selection laws for the HSFs and the requirements for the passive components of the MC drive system from the point view of short-circuit faults are also discussed. Simulation results are used to demonstrate the feasibility of the proposed isolation strategies.

A Novel Approach to Design Robust Fault Detection Filter for Networked Control Systems

In this paper, an approach for designing robust fault detection filter (RFDF) of networked control systems (NCSs) with unknown inputs is studied. The design aims at implementing the optimal trade-off between robustness of unknown inputs (including the item produced by networked-induced delay) and sensitivity of fault. The key design issue is to introduce an optimal fault detection filter based on NCSs with the control law compensation as the reference residual model of NCSs and to formulate the RFDF design as a model-matching problem. By applying H∞ optimization technique, linear matrix inequality (LMI) approach is given to solve the model-matching problem. The validity of the proposed approach is shown by a numerical example.