融合诊断中信息容错性的证据重构方法

Evidence reconstruction for information fault-tolerance in fusion diagnosis

在基于证据理论的故障融合诊断过程中,错误的待融合信息会引起故障的漏诊.针对此类容错性问题,提出了一种证据重构方法,在已有的故障诊断识别框架的基础上,利用多传感器信号的方差计算信号的相对可靠程度,构造新的信度函数,对待融合证据进行了重新分配,以减少出错信息对融合结果的影响,同时对该方法中可调参数的选取原则进行了理论分析.融合诊断实验在隔振器硬件实验平台上进行,诊断对象为振动发散故障,针对的信息容错性问题为基础加速度信号断路情况.对比性实验及结果分析表明,采用该方法能够在单路信号传输出错的情况下及时诊断振动发散故障,增加了融合诊断系统的容错性.

In the fusion fault diagnosis based on evidence theory,the abnormal information may cause missed diagnosis of faults.To solve the fault-tolerance problem,we propose an evidence reconstruction method.On the basis of the existing frame of fault diagnosis discernment,the variances of multisensor signals are employed to calculate the signal relative reliability,from which new basic probability assignment functions are formed accordingly.The fused evidences are redis-tributed and the effect of abnormal information is reduced.Principles for selecting the adjustable parameter in this method are theoretically analyzed.Experiments have been carried out on a hardware experimental platform for vibration isolator.The vibration divergence fault is diagnosed by the fusion diagnosis system.Disconnection of the major acceleration signal is considered as the fault-tolerance problem.Finally,result analysis of the comparative experiment shows that the vibration divergence fault can be diagnosed in time in the occurrence of one-channel abnormal signal.The fault-tolerance of the fusion diagnosis system is improved.