US 12,146,776 B2
Propagation time measurement device
Naoki Yoshitake, Kyoto (JP); Yui Ishida, Kyoto (JP); Takeshi Fujiwara, Kyoto (JP); Yoshitaka Tsurukame, Kyoto (JP); and Masaki Yawata, Kyoto (JP)
Assigned to OMRON CORPORATION, Kyoto (JP)
Appl. No. 17/769,888
Filed by OMRON Corporation, Kyoto (JP)
PCT Filed Sep. 25, 2020, PCT No. PCT/JP2020/036323
§ 371(c)(1), (2) Date Apr. 18, 2022,
PCT Pub. No. WO2021/084985, PCT Pub. Date May 6, 2021.
Claims priority of application No. 2019-196256 (JP), filed on Oct. 29, 2019.
Prior Publication US 2022/0291026 A1, Sep. 15, 2022
Int. Cl. G01F 1/667 (2022.01)
CPC G01F 1/667 (2013.01) 18 Claims
OG exemplary drawing
 
1. A propagation time measurement device, comprising:
a plurality of vibrators at different positions relative to a pipe in which a fluid flows, the plurality of vibrators including at least a first vibrator configured to convert a transmission signal being an electric signal to an acoustic signal and a second vibrator configured to receive the acoustic signal transmitted from the first vibrator and propagating through the fluid in the pipe and convert the acoustic signal to a reception signal being an electric signal;
a setting function configured to estimate a propagation time of the acoustic signal between the first vibrator and the second vibrator with the first and second vibrators positioned on the pipe and to set a maximum value of a duration of the transmission signal to be shorter than the estimated propagation time;
a transmission signal generator configured to generate the transmission signal for measurement; and
a signal processor configured to determine a propagation time of the acoustic signal from the first vibrator to the second vibrator through cross-correlation analysis between the transmission signal and the reception signal,
wherein the transmission signal generator generates the transmission signal to satisfy the conditions of:
a ratio of a height of a peak other than a maximum peak in an autocorrelation function of the transmission signal to a height of the maximum peak being 0.8 or less;
a duration of the transmission signal being at least five times a shortest period of the transmission signal or at least 20 times a half width at half maximum of the autocorrelation function of the transmission signal; and
the duration of the transmission signal being shorter than or equal to the maximum value set by the setting function.