To reduce erroneous detection due to noise and to quickly and accurately detect the peak time of an inputted signal.
This device is provided with a product-sum operating part 24 which performs a product-sum operation (wavelet transformation) of an inputted time series signal with a function of complex variable with an imaginary part whose phase is shifted as much as π/2 with respect to a real part as the base of integration, a phase operating part 26 which operates a phase θfrom the ratio of the real part to the imaginary part of the results of the product-sum operation and a peak time detecting part 28 which detects a time when the operated phase θ changes from 2π to zero as a peak time. The wavelet transformation can quickly the peak time because of using a basic wavelet function that is localized in both temporal and frequency manners. It is also possible to prevent erroneous detection due to noise, etc., due to not performing a differential operation but the product-sum operation.
IYODA NORIBUMI
OSHIMA MASUJI
TOYOTA CENTRAL RES & DEV