故障诊断动态阈值生成算法研究

Research on Dynamic Generating Algorithm of Threshold for Fault Detection

阈值的确定是基于模型的故障检测过程中重要的一环,文中利用具有不确定性双线性系统作为误差系统来生成残数.将该残数与设定的阈值进行比较,该阈值由具有未知不确定上界作为参数的线性系统生成.而这些未知不确定性上界可由某些设计参数替代.基于这一观点,提出了一种算法来选择设计参数值,以使无故障时选定的阈值大于残数值.应用实例表明动态生成阈值可以极大减少故障的误报率,从而验证了该参数设计算法的有效性.

It is an important step to determine a threshold in model-based fault detection. An error system of bilinear with uncertainties is employed to generate the residual in this paper. The residual is compared to a threshold which is generated by a linear system with unknown uncertainty upper bounds as parameters. These unknown uncertainty upper bounds can be substituted by design parameters. From this point, an algorithm is proposed to choose design parameter values so that the threshold is larger than the residual when no fault is present. An application example is given to demonstrate this parameter design algorithm which can reduce the number of fault misreporting greatly.