Patent ID: 11892377
Assignee: SEIKO EPSON CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 2:
3. The time point acquisition method according to claim 1, wherein
the vibration component is removed by performing low-pass filter processing on the time-series data,
high-pass filter processing is performed on the time-series data on which the low-pass filter processing was performed,
a first peak and a second peak of the time-series data on which the high-pass filter processing was performed are acquired, and a first interval before the first peak, a second interval between the first peak and the second peak, and a third interval after the second peak are acquired,
in the first interval, a correction curve of the first interval is acquired by inverting a sign of the time-series data on which the high-pass filter processing was performed,
in the second interval,
in an interval less than a product of a first coefficient and a value obtained by inverting a sign of an amplitude of the first peak, a first straight line which is an approximate straight line of a correction curve of the first interval is acquired,
a second straight line which is a straight line obtained by multiplying a straight line passing through the first peak and the second peak by a second coefficient is acquired,
in an interval less than a product of a third coefficient and a value obtained by inverting a sign of an amplitude of the second peak, a third straight line which is an approximate straight line of a correction curve of the third interval is acquired,
a first intersection point, which is an intersection point of the first straight line and the second straight line, and a second intersection point, which is an intersection point of the second straight line and the third straight line, are acquired,
in the second interval, a correction curve of the second interval is acquired by setting a portion before the first intersection point as the first straight line, setting a portion from the first intersection point to the second intersection point as the second straight line, and setting a portion after the second intersection point as the third straight line,
in the third interval, a correction curve of the third interval is acquired by inverting a sign of the time-series data on which the high-pass filter processing was performed,
correction data is acquired by adding the correction curve of the first interval, the correction curve of the second interval, and the correction curve of the third interval, and
the entry time point and the exit time point are acquired by performing, for each of the entry time point and the exit time point, processing of acquiring a time point within a period after one time point and before another time point of two time points corresponding to two consecutive pieces of data between which a predetermined threshold is, the two consecutive pieces of data being included in a sum of the time-series data on which the high-pass filter processing was performed and the correction data.