US 12,467,805 B2
Apparatus and methods for calculating the behavior of linear structures
Takashi Matsui, Musashino (JP); Kazuhide Nakajima, Musashino (JP); Nobutomo Hanzawa, Musashino (JP); Ryota Wada, Tokyo (JP); and Hideaki Murayama, Tokyo (JP)
Assigned to NTT, Inc., Tokyo (JP)
Appl. No. 18/034,899
Filed by NTT, Inc., Tokyo (JP); and THE UNIVERSITY OF TOKYO, Tokyo (JP)
PCT Filed Oct. 18, 2021, PCT No. PCT/JP2021/038481
§ 371(c)(1), (2) Date May 2, 2023,
PCT Pub. No. WO2022/097466, PCT Pub. Date May 12, 2022.
Claims priority of application No. 2020-185198 (JP), filed on Nov. 5, 2020.
Prior Publication US 2024/0019323 A1, Jan. 18, 2024
Int. Cl. G01L 1/24 (2006.01); G01B 11/24 (2006.01)
CPC G01L 1/242 (2013.01) [G01B 11/24 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An apparatus comprising:
an optical fiber sensor in which an optical fiber is arranged along a linear structure and configured to detect strain of the optical fiber; and
a processor configured to:
express at least one parameter in a plurality of discrete values for each predetermined length of the linear structure, and forecast behavior of the linear structure by using each of the discrete values;
acquire behavior of the linear structure detected using the optical fiber;
calculate a likelihood between the forecasted behavior of the linear structure and the acquired behavior of the linear structure;
update at least one of the plurality of discrete values on the basis of the likelihood; and
calculate behavior of the linear structure by using the updated plurality of discrete values,
wherein the likelihood is calculated based on an infinite product of a probability density function defined by an average value of a displacement in a rotation direction of the linear structure derived for each predetermined length, and a standard deviation of an observation error of the behavior of the linear structure detected by using the optical fiber,
wherein the behavior of the linear structure is acquired by calculating a deflection angle with respect to each unit length of the linear structure, on the basis of the strain detected by the optical fiber sensor.