Abnormality detection device, abnormality detection program, and abnormality detection method

An abnormality detection program for detecting an abnormality occurring in a wheel assembly, the abnormality detection program causing a computer to execute:

• sequentially acquiring signals representing a rotation speed of the wheel assembly, as pulses having a rise;
• calculating a first index representing a temporal variation of the rise of each of the pulses corresponding to one rotation of the wheel assembly, at each time point;
• performing frequency analysis on the first index at each time point to calculate a frequency spectrum of the first index for rotational orders from a first order to an mth order, in which m is an integer of 2 or more, for each time point;
• calculating a total of gains of predetermined multiple rotational order components of the frequency spectrum at each time point, as a total gain at each time point;
• and
• determining that an abnormality has occurred in the wheel assembly, if an increase rate of the total gain per predetermined time calculated from the total gain at each time point is equal to or greater than a predetermined reference increase rate.

An abnormality detection method, executed by a computer, for detecting an abnormality occurring in a wheel assembly, the abnormality detection method comprising:

• sequentially acquiring signals representing a rotation speed of the wheel assembly, as pulses having a rise;
• calculating a first index representing a temporal variation of the rise of each of the pulses corresponding to one rotation of the wheel assembly, at each time point;
• performing frequency analysis on the first index at each time point to calculate a frequency spectrum of the first index for rotational orders from a first order to an mth order, in which m is an integer of 2 or more, for each time point;
• calculating a total of gains of predetermined multiple rotational order components of the frequency spectrum at each time point, as a total gain at each time point;
• and
• determining that an abnormality has occurred in the wheel assembly, if an increase rate of the total gain per predetermined time calculated from the total gain at each time point is equal to or greater than a predetermined reference increase rate.