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US 12,560,509 B2Granted
Optical fiber sensor for structural acoustic abnormality monitoring
AssigneeNEC Corporation
InventorsYuma Matsuda, Tomoyuki Hino
Life of this patent
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Abstract
Provided is an optical fiber sensor that is capable of highly accurately detecting an abnormality in a structure from vibration information. This optical fiber sensor includes an optical fiber that is laid in the vicinity of a structure, a light source for introducing pulsed light of a specific period into the optical fiber, and an optical sensor for detecting return light that has been obtained as a result of the introduction of the pulsed light into the optical fiber. The structure is determined to have an abnormality if the spectral centroid of vibration information exceeds a threshold.
Claims12
A detection method comprising:
- collecting vibration information on a structure having a solid surface, occurring when an object passes by the structure and the object is any one of a gaseous body, a liquid body, and a solid body;
- deriving a spectrum centroid from the vibration information being collected;
- and
- detecting an abnormality of the structure when the spectrum centroid exceeds a threshold value;
- collecting, using an optical fiber and a light source that introduces pulsed light with a specific cycle to the optical fiber, the vibration information occurring when the object passes near the structure, in a form of return light associated to the pulsed light being introduced from the light source to the optical fiber, the optical fiber running in a vicinity of the structure, and
- setting a plurality of observation points away from one another in the optical fiber running in the vicinity of the structure, the plurality of observation points comprising at least a first observation point, a second observation point, and a third observation point, wherein the second observation point and the third observation point are both in a vicinity of the first observation point;
- and
- detecting the abnormality of the structure based on determining that the spectrum centroid exceeds a certain threshold value at least both at the first observation point and also at any of the second observation point and the third observation point.
5 more elements
A detection method comprising:
- collecting vibration information on a structure having a solid surface, occurring when an object passes by the structure and the object is any one of a gaseous body, a liquid body, and a solid body;
- deriving a spectrum centroid from the vibration information being collected;
- and
- detecting an abnormality of the structure when the spectrum centroid exceeds a threshold value;
- collecting, using an optical fiber and a light source that introduces pulsed light with a specific cycle to the optical fiber, the vibration information occurring when the object passes near the structure, in a form of return light associated to the pulsed light being introduced from the light source to the optical fiber, the optical fiber running in a vicinity of the structure, and
- setting a plurality of observation points away from one another in the optical fiber running in the vicinity of the structure, the plurality of observation points comprising at least a first observation point, a second observation point, and a third observation point, wherein the second observation point and the third observation point are both away from the first observation point;
- and
- detecting the abnormality of the structure based on determining both that the abnormality of the structure is indicated at least both at the first observation point and also at any of the second observation point and the third observation point.
5 more elements
An optical fiber sensor comprising:
- an optical fiber running in a vicinity of a structure having a solid surface;
- a light source configured to introduce pulsed light with a specific cycle to the optical fiber;
- an optical sensor configured to detect return light acquired by introducing the pulsed light to the optical fiber, and the optical fiber sensor is configured to determine that the structure has an abnormality when a spectrum centroid in vibration information exceeds a threshold value;
- and
- an abnormality determination circuit configured to detect the abnormality of the structure based on determining both that the abnormality of the structure is indicated at least both at a first observation point and also at any of a second observation point and a third observation point, wherein the second observation point and the third observation point are both away from the first observation point by at least a predetermined amount of space.
2 more elements
Dependencies are inferred from the claim text.