| 摘要 |
[Problem] To make it possible to detect the peak frequency of a signal wave at a desired frequency resolution and in a desired time window length while avoiding a conflicting relationship between the frequency resolution (f0) and the time window length (T0). [Solution] A peak frequency detection device that detects a peak frequency at which the maximum power spectrum is achieved in a predetermined frequency band (fcl to fch), said peak frequency detection device being provided with: an n multiplication unit that multiplies each element of a digital data string by n (n is an integer of 2 or more); an FFT unit that derives, as a virtual peak frequency, a frequency that corresponds to the maximum value of a power spectrum that is obtained by performing a fast Fourier transform of a digital data string of N (N is an integer of a power of 2 and is determined in accordance with a sampling frequency (fs), a sampling resolution (ftg), and a time window length (Ttg)) sample frequencies (fs) that are multiplied by n; and a 1/n multiplication unit that outputs the value of the virtual peak frequency multiplied by 1/n as the peak frequency of the digital data string. The peak frequency detection device satisfies n ≥ 1/(ftg×Ttg), fs/(n×ftg) ≤ N ≤ fs×Ttg, and fs > 2×n×fch. |
