| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique by which an inspection of an operation sound can be performed even in a very noisy environment.SOLUTION: A step is performed, in which a dispersion value is calculated for extracted values of frequencies for each time. If the dispersion value is a threshold value (for example, 1000) or less, a determination step is performed that an operation sound is blown. By the above method, a presence of the operation sound can be inspected even in an assembly line full of background noise and noises generated by workers. The dispersion value is calculated by squaring a difference in order to emphasize a degree of vibration. For example, when the threshold value is set to a dispersion of 1000, a dispersion value within a range of Ttime (blowing time of the operation sound) becomes much lower than the threshold value, and a dispersion value other than the range of Ttime (non-blowing time of the operation sound) becomes much higher than the threshold value, allowing the blowing time and the non-blowing time to be more clearly distinguished from each other. |
