The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 27, 2022
Filed:
Nov. 01, 2019
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Tadashi Minotani, Musashino, JP;
Eri Matsunaga, Musashino, JP;
Masahito Nakamura, Musashino, JP;
Masayuki Tsuda, Musashino, JP;
NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo, JP;
Abstract
A crack detection device includes: a sensor unit that has a three-layer structure of conductor-insulator-conductor and is attached to a structure; a frequency characteristics acquisition unit that sweeps a predetermined frequency range to acquire a plurality of frequencies at which the impedance of the sensor unit is maximum or minimum; a crack presence/absence determination unit that determines the presence or absence of a crack based on a nonuniformity of the plurality of frequencies; a crack position table in which a relationship between crack positions and frequency shift directions is recorded; and a crack position detection unit that, when the crack presence/absence determination unit determines that there is a crack, takes a difference between two frequencies acquired by the frequency characteristics acquisition unit to determine a sign, and then refers to the crack position table in accordance with the sign to detect a crack position.