US 12,264,960 B2
Sensor signal processing apparatus and sensor signal processing method
Tomoyuki Hino, Tokyo (JP); and Akihiro Tanaka, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Appl. No. 17/417,198
Filed by NEC Corporation, Tokyo (JP)
PCT Filed Mar. 5, 2019, PCT No. PCT/JP2019/008579
§ 371(c)(1), (2) Date Jun. 22, 2021,
PCT Pub. No. WO2020/178976, PCT Pub. Date Sep. 10, 2020.
Prior Publication US 2022/0057255 A1, Feb. 24, 2022
Int. Cl. G01H 9/00 (2006.01); G01D 5/353 (2006.01); H04B 10/2537 (2013.01)
CPC G01H 9/004 (2013.01) [G01D 5/35358 (2013.01); G01D 5/35361 (2013.01); H04B 10/2537 (2013.01)] 9 Claims
OG exemplary drawing
 
1. An optical fiber sensor apparatus, comprising:
a sensor signal processing apparatus comprising one or more memories storing instructions and one or more processors configured to execute the instructions to:
receive a sensor signal using scattered light of a light pulse propagating through an optical fiber, and calculate a variation of the sensor signal from a reference value; and
normalize the variation within a predetermined period time, and calculate a normalized variation;
a light sending circuit configured to generate the light pulse and send the light pulse to the optical fiber; and
a light reception processing circuit configured to receive the scattered light and generate the sensor signal, using the scattered light,
wherein the light sending circuit comprises a light coupler,
wherein the light coupler is configured to split the light pulse and to send, to the light reception processing circuit, a split light pulse of a part of the light pulse,
wherein the light reception processing circuit comprises:
a coherent light receiver configured to perform coherent detection on the scattered light by causing the scattered light to interfere with the split light pulse, and convert the scattered light into an analog electrical signal; and
a digital signal processing circuit configured to convert the analog electrical signal into a digital signal and generate the sensor signal.