Abstract: The Equipment abnormal degree detection problem is studied. How to detect the abnormal degree of equipment rapidly without fault samples has become an important problem of state inspection, so a new information matching detection method called variable threshold information detector (VTI-detector) is presented. On the basis of the disperse increment theory and proposed concept of amicable limited information density, matching threshold of each normal training sample compared to itself (normal samples) is calculated. Furthermore, vector including the information of matching threshold, namely VTI-detector, is built. At last, based on the VTI-detector and amicable limited information density concept, an abnormal degree formula is proposed. To take the Iris data sets of UCI for an example, the VTI-detector method shows a better detection performance by comparison with other three kinds of commonly used anomaly detection methods. Through the calculation of abnormal degree formula, the abnormal degree of normal and abnormal bearings can be displayed in the form of real-time curves. The result shows that this method has an obvious effect, which proves it has a good application prospect.

Key words: Abnormal degree, Amicable limited information density, Variable threshold information detector