故障检测

In order to realize automatic testing and fault diagnosis for radio station , an automatic test system based on PXIbus was designed, also, the design of hardware, software and fault diagnosis were discussed in detail, and the method of classificatory testing about radio was introduced.

为了达到对通信系统电台的自动化测试和故障诊断的目的，设计了基于PXI总线的电台自动测试和故障诊断系统，详细说明了系统的硬件和软件组成以及故障诊断方法，并介绍了有关电台分级检测的方法，经验证此系统能够很好地完成电台的自动化测试与故障诊断并达到了设计要求；此系统的研制成功，充分说明了PXl总线系统在通信设备检测方面的巨大优势，为研制新一代的自动化测试系统指明了方向。

In this paper we begin with the electrical principle of the oxygen sensor, analyze the motive detecting method of the oxygen sensor in the LS400 car with the two-dimensional coordinator and explain the way to recognize the fault codes with oscillogram, finally illuminate the meaning of the different fault codes.

在修理发动机电控系统故障时，最想看到的就是发动机故障指示灯有规律地闪烁但有些故障需要在一定条件下，采用一定的方法才能检测到其故障代码，氧传感器的故障代码就属于这种代码通过对氧传感器的电路原理的分析，利用二维坐标图形论述了凌志LS400型轿车氧传感器的动态检测方法，并用波形图说明了该种车型的故障码识别方法，最后指出了不同故障码的意义。

Hence when it doesn't work normally we should make use of various examination means to diagnosis breakdown following reasonable steps so as to the repairmen can be carry out particularly.

希望通过本文，对自动变速器的性能检测与常见故障的诊断有一定的了解；对于修理人员在通过对自动变速器进行性能检测来检测故障诊断时能够起到一定的帮助。

In real flight, multiple sensors of aircraft engine control system may fault at a time. In order to solve this problem, a revised multiple-failure-hypothesis based testing is investigated. This approach uses multiple Kalman filters, and each of Kalman filter is designed based on a specific hypothesis for detecting specific sensors fault, and then uses WSSR (Weighted Sum of Squared Residual) to deal with Kalman filter residuals, and residual signals are compared with threshold in order to make fault detection decisions. The simulation results show that the proposed method can be used to detect multiple sensors soft failures fast and accurately.

一般认为两个以上传感器同时发生故障的概率较小，但实际上不能排除其发生的可能性；提出了一种改进的多重故障假设方法来解决航空发动机控制系统多传感器同时发生软故障的问题，这一方法采用一组卡尔曼滤波器，每个滤波器对应一个被检测传感器的故障模态；采用残差加权二乘方处理滤波残差并与门限值作比较来判断是否发生故障；仿真结果表明，所提出的方法能有效解决多传感器软故障的检测与隔离问题。

In doing back-up data, we followed the work to be done is to switch to a system running DOS, and DOS command line in the implementation of "fdisk / mbr" command string to try to repair the hard disk of soft failure occurred ; if such a repair method to try is invalid, then we can go online to download and install the hard drive Bad Track professional testing tool to double-check the local hard disk in the phenomenon of the existence of Bad Track, Bad Track If you can not find the hard disk, it can not detect hard drive through the phenomenon is likely to be caused by the logic of failure, when the only thing we can use the way is hard to find the logic of the corresponding brand Bad Track Repair Repair Tool to re-click the hard disk, I believe that case the hard disk will be able to detect the phenomenon can not be resolved the.

在做好数据的备份工作后，我们接下来要做的工作就是将系统切换到 DOS 运行状态，并在 DOS 命令行中执行" fdisk /mbr "字符串命令，来尝试修复硬盘中发生的软故障；要是这种修复方法尝试无效的话，我们可以到网上下载安装一些专业的硬盘坏道检测工具，来仔细检查本地硬盘中是否存在坏道现象，如果找不到硬盘坏道的话，那硬盘检测无法通过的现象很可能是逻辑故障引起的，此时我们唯一可以使用的办法就是找到对应品牌硬盘的逻辑坏道修复工具来重新修复一下硬盘，相信这么一来硬盘检测无法通过现象就能被解决了。

On the basis of electrical network characterization, Chapter 5 presents a new principle to detect PCB's fault first time. Three methods of online test for electrical network characterization are described in detail. Then, a hierarchical, combinatorial approach is firsfly presented. The test efficiency of this method is studied also. The experiment result shows that the new approach can greatly enhance the test efficiency of fixtureless tester under the requirement of 100% test for PCB's connections.

本文第5章利用集成电路的输出特性，首次提出了一种新的印刷电路板连接故障的检测原理，给出了三种印刷电路板电气网络输出特性的在线测试方法；在此基础上，首次提出并实现了基于飞针式在线测试仪的层式组合测试思想，研究了这种方法的检测效率；应用实例表明这种方法在不降低对印刷电路板连接故障100％测试的要求下，可以有效地提高飞针式在线测试仪的检测效率。

In this paper Ⅰ successfully applied these methods to fault diagnosis, and presenting some new innovative machinery fault diagnosis method; First Ⅰ present a new gear wornout fault diagnosis method, this method use the vibration signal's time-frequency attribute and instantaneous phase undulation to accurately detect gear's fault, and by comparing with the traditional frequency domain analysis method, this method reveals that many nonlinear and nonstationary characteristic exist in gear's vibration, this tell us that if we use frequency domain analysis method without pay attention to the signal's characteristic, we could get wrong diagnostic result; Then Ⅰ present a new bearing fault diagnosis method, this method use ATVFD and Hilbert transform to do envelop demodulation,Ⅰ analyze the envelop with time-frequency method and find out that this method is more accurate then traditional method.Ⅰ also explain that the modulation of the fault to the carrier wave may also be non-stationary and nonlinear; Finally Ⅰ present a cylinder pressure measurement method of diesel engine by means of vibration, cylinder pressure is an important parameter of diesel engine fault diagnosis, the pressure measuring is simplified a lot by this method,Ⅰ also use the ATVFD and time-frequency analysis to realize it.

本文中将上述理论方法成功地应用到故障诊断中去，提出了几点创新性的诊断方法；提出了一种齿轮磨损故障诊断的新方法，该方法利用振动信号能量的时频域分布特征与瞬时相位波动特征可以进行精确的齿轮故障诊断，并通过与传统的频域诊断方法的比较，揭示出齿轮振动中存在的明显的非线性与非平稳特征，说明了不加选择地利用频域分析方法进行齿轮故障诊断很可能会得到错误的诊断结果；提出了一种轴承故障诊断的新方法，该方法利用ATVFD分解与Hilbert变换进行包络解调，并对解调得到的包络信号进行时频域分析，可以实现更加准确轴承故障诊断，说明了故障对载波信号的调制往往也是非平稳与非线性的；提出了一种利用振动信号进行柴油机汽缸内压力检测的新方法，柴油机汽缸压力的变化是柴油机故障诊断的重要参数，利用振动方法可大大简化汽缸压力的检测过程，该方法也是综合利用ATVFD分解与时频域分析方法实现的。

So proposing the motor vehicle therefore the original is aimed at this problem examines that string block is diagnosed together with the recovering scheme , the diagnosis expert system therefore establishing,the installation carries on the inline diagnosis to the examination ,therefore moreover to the block carries on the online resumeing,the loss that creates reduces up the minimal in an attempt to obstructing because of affairs ,at the same time,therefore also is diagnosing research going a step further to the block against the recovering means.

本文针对此问题提出了汽车检测线的故障诊断与恢复方案，建立了故障诊断专家系统，对检测设备进行在线诊断，并对故障进行在线恢复，以求把因故障造成的损失减到最小，同时，也是对故障诊断与恢复方法的更进一步的研究。

The testability of program is a prediction of its ability to reveal faults and it is an important characteristic of software.

软件的可测试性表示软件中故障检测的难易程度，是重要的软件质量特性之一。

It is a significant approach to derive Analytical Redundancy Relations for fault detection and isolation based on ARR.

利用解析冗余关系方法进行故障检测和隔离的关键就是系统解析冗余关系的建立。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。