| 摘要 |
PURPOSE:To attain a highly speedy pattern matching regardless of the value of a period N even when the N of a signal comes to be larger by executing the Fourier transformation of two signals to be pattern-matched, determining a shifting quantity to other signal of one side signal based on the inclination of the difference of the phase angle of both signals and executing the pattern matching. CONSTITUTION:Two periodical signals xi and yi are both Fourier-transformed, made into X(m) and Y(m) and next, a phase difference A(m) after Fourier- transformation is executed ranging from m=0 to n=1 or from m=0 to n/2-1 is obtained from an equation 1. Provided that Re( ) shows a real number part, Im( ) shows an imaginary number part, and when Arg.X(m), Arg.Y(m) and A(m) are shown in the figure, figures (a)-(c) are obtained. Here, an inclination DELTAA(m) of a phase difference A(m) is obtained by an equation 2 and the value DELTAA(m) is corrected so as to come to be 0<=DELTAA(m)<2pi. The average value of the inclination is obtained, made N-fold, made into B, the obtained B is divided by p, P(B/2pi), next, only by the P, the signal xi is shifted to the right and by the calculation of an equation 4, a pattern matching is executed. By the minimum value of dp, a similarity is decided. |
