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利用现代化仪器设备和计算机系统等技术,来检查和识别机械设备及零、部件的实时状态与故障诊断,正在为企业带来巨大的经济效益.但在故障诊断过程中.敏感因子的确定是相当重要的,确定的好就能及时、准确地发现故障,能取得较好的诊断效果;相反就可能使故障诊断滞后,分析失败,不能取得满意的效果.敏感因子就是从系统动态的各个故障诊断的特征参数中筛选出的最敏感的特征参数,它能灵敏地反映系统(机器)故障状态的某些特征,当系统(机器)的故障状态发生微小变化时,对应这个特征参数指标会发生较大的变化.它可以是一个特征参数,也可以是几个参数的复合.复合敏感因子的诊断效果一般更好.一、敏感因子确定方法敏感因子的确定可以是理论推导,也可以在实验中寻找.1.从理论推导寻找敏感因子从表征系统动态特征的方程式中求微分,得出几个不同特征参数的导数值,某一个特征参数在无故障点的导数值最大,则它的敏感性就最高,这个特征参数就是要寻找的敏感因子.在实际工作中,同一台设备所处的工作状态会发生变化.例如,同一台造纸机可能生产白板纸,也可能生产瓦楞纸,甚至其它类型的纸.这样在不同类型纸的生产中,这台造纸机所处的正常运行状态发生了变化,此时其敏感因子也会发生变化.由图1可见,设备工作状态对应两个特征
The use of modern equipment and computer systems and other technologies to check and identify the real-time status of mechanical equipment and zero, components and fault diagnosis, is bringing huge economic benefits to the enterprise.But in the fault diagnosis process, the determination of the sensitivity factor is quite Important, well-defined will be able to timely and accurately find fault, can achieve better diagnostic results; the opposite may make fault diagnosis lag, failure analysis, can not obtain satisfactory results. Sensitive factor is the system from the dynamic diagnosis of each fault The most sensitive characteristic parameter selected from the characteristic parameters of the system can sensitively reflect some characteristics of the system (machine) fault state. When the fault state of the system (machine) changes slightly, the index corresponding to the characteristic parameter will occur Large changes. It can be a characteristic parameter, it can be a combination of several parameters. Composite sensitivity factor diagnosis is generally better. First, the determination of sensitive factors Sensitivity can be determined by theoretical deduction, but also in the experiment Finding .1. Deriving the Theoretical Sensitivity Looking for Sensitive Factors Deriving from the equation characterizing the dynamic characteristics of the system, we derive a few differences The derivative value of the parameter, the maximum derivative of a characteristic parameter at the point of no-fault, then it is the highest sensitivity, the characteristic parameter is to find the sensitive factor.In the actual work, the same device in which the working state For example, the same paper machine may produce white paper, it may also produce corrugated paper, or even other types of paper, so that the normal operation of the paper machine in the production of different types of paper has changed, this When its sensitivity factor will change.From Figure 1 shows that the working state of the device corresponds to two characteristics