Computer program for abnormality detection, abnormality detecting device and abnormality detecting method

摘要

To provide an abnormality detection computer program that can identify a frequency corresponding to a period of a sound generated by rotation on the basis of an audio signal even when a periodical noise exists.SOLUTION: An abnormality detection computer program includes instructions that cause a computer to perform: detecting an envelope of an audio signal representing a periodical sound generated from a rotation body having a predetermined number of blades and a periodical sound generated from other object; calculating a frequency spectrum of the audio signal for each frame from the envelope; detecting a candidate of a frequency corresponding to a period of the sound generated from the rotation body in the frame for each frame; obtaining duration in which variation of power is less than or equal to a certain value for the power of a frequency spectrum component in a candidate obtained for the frame for each frame; and identifying the candidate having the longest duration as the frequency corresponding to the period of the sound generated from the rotation body.SELECTED DRAWING: Figure 11