公开(公告)号：US11823330B2

公开(公告)日：2023-11-21

申请号：US17634595

申请日：2019-08-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Masaaki Inoue ,  Hitoshi Niigaki ,  Yukihiro Goto ,  Shigehiro Matsuda ,  Toshiya Ohira ,  Ryuji Honda ,  Tomoya Shimizu ,  Hiroyuki Oshida

IPC: G06T17/20 ,  G06F30/18 ,  G01B11/00

CPC classification number: G06T17/20 ,  G01B11/002 ,  G06F30/18

Abstract: An object of the present disclosure is to provide a technique for creating a three-dimensional model of a line-like structure from a point cloud obtained using three-dimensional laser measuring equipment and detecting a three-dimensional model of a cable. A detection apparatus according to the disclosure includes a point cloud data input unit 12 that reads point cloud data where a structure that is present in a three-dimensional space is represented by a point cloud that is present in the three-dimensional space, a rule-based three-dimensional model generation unit 15 that combines linearly disposed point clouds into a group and generates a three-dimensional model of a line-like structure using a direction vector configured with point clouds included in the group, a machine learning-based three-dimensional model generation unit 14 that generates a three-dimensional model of a line-like structure based on a database that links point clouds and line-like structures, and a three-dimensional model merging unit that selects one of a plurality of three-dimensional models of line-like structures generated at an identical position in the three-dimensional space as a three-dimensional model of a line-like structure that is present in the three-dimensional space and merges three-dimensional models of the line-like structures that are present in the three-dimensional space.

公开(公告)号：US11719599B2

公开(公告)日：2023-08-08

申请号：US17762185

申请日：2019-10-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsushi Nakamura ,  Tomokazu Oda ,  Daisuke Iida ,  Hiroyuki Oshida ,  Yoshifumi Wakisaka

IPC: G01M11/00

CPC classification number: G01M11/39

Abstract: This disclosure describes inputting pulsated pump light in a fundamental mode or a first higher-order mode into one end of an optical fiber under test constructed by connecting two optical fibers in series; inputting probe light having an optical frequency difference within a Brillouin frequency shift range with respect to the pump light into the other end of the optical fiber under test in the fundamental mode or the first higher-order mode; measuring a Brillouin gain distribution related to a distance of transmitted light intensity of probe light output from the one end into which the pump light was input; and calculating each inter-modal coupling efficiency at the connection point of the optical fiber under test.

公开(公告)号：US20210255005A1

公开(公告)日：2021-08-19

申请号：US17275327

申请日：2019-09-12

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Tatsuya Okamoto ,  Daisuke Iida ,  Hiroyuki Oshida ,  Tetsuya Manabe

IPC: G01D5/353 ,  G01H9/00 ,  E02D29/14

Abstract: A manhole position identification method of the present invention includes: measuring, from an end of an optical fiber, a temporal variation in scattering light from the optical fiber when an impact blow is applied to a cover of a manhole located on a path of the optical fiber, so as to obtain temporal variations in a scattering light intensity distribution in a longitudinal direction of the optical fiber; determining an occurrence of vibration due to the impact blow based on the temporal variations at positions in the scattering light intensity distribution, so as to identify an impact blow position on the optical fiber; and associating the impact blow position on the optical fiber with a map position of the manhole whose cover has received the impact blow, so as to identify a position of the manhole expressed in terms of optical fiber length from the end.

公开(公告)号：US12135200B2

公开(公告)日：2024-11-05

申请号：US17635557

申请日：2019-08-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiya Ohira ,  Yukihiro Goto ,  Ryuji Honda ,  Hiroyuki Oshida

IPC: G01B11/02 ,  G01B1/00 ,  G01B11/00 ,  G01B11/03 ,  G01C3/00

Abstract: An object of the present invention is to provide an information processing apparatus, an information processing method, and a program, which are capable of determining an owner of an attachment attached to a facility using a solid model of a facility extracted from three-dimensional point group data. The present invention determines the owner of the attachment from a planar positional relationship between the solid model of a columnar structure and the solid model of the attachment in the solid model. For example, a distance between a utility pole and a center of a point (a center of a ground boundary) at which a branch line or a post reaches a ground is acquired, and whether the branch line or the post is owned by a communication company or an electric power company is determined based on whether the distance exists in a constant threshold determined by the communication company or the electric power company.

公开(公告)号：US12094153B2

公开(公告)日：2024-09-17

申请号：US17608963

申请日：2019-05-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hitoshi Niigaki ,  Yasuhiro Yao ,  Masaaki Inoue ,  Tomoya Shimizu ,  Yukihiro Goto ,  Shigehiro Matsuda ,  Ryuji Honda ,  Hiroyuki Oshida ,  Kana Kurata ,  Shingo Ando ,  Atsushi Sagata

IPC: G06T7/70 ,  G06T7/00

CPC classification number: G06T7/70 ,  G06T7/0002 ,  G06T2207/10028

Abstract: Provided is a point cloud analysis device that curbs a decrease in model estimation accuracy due to a laser measurement point cloud. A clustering unit (30) clusters a point cloud representing a three-dimensional point on an object obtained by a measurement unit mounted on a moving body and performing measurement while scanning a measurement position, within a scan line, to obtain a point cloud cluster. A central axis direction estimation unit (32) estimates a central axis direction based on the point cloud cluster. A direction-dependent local effective length estimation unit (34) estimates a local effective length based on an estimated central axis direction and an interval of scan lines, the local effective length being a length when a length of projection of the point cloud cluster in a central axis direction for each of the point cloud clusters is interpolated by an amount of a loss part of the point cloud.

公开(公告)号：US11906387B2

公开(公告)日：2024-02-20

申请号：US17636930

申请日：2019-09-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsushi Nakamura ,  Daisuke Iida ,  Hiroyuki Oshida

IPC: G01M11/02 ,  G01M11/00

CPC classification number: G01M11/02 ,  G01M11/33

Abstract: The purpose of the present disclosure is to provide a mode field diameter test method and test device that enable acquisition of a mode field diameter for an arbitrary higher-order mode. The present disclosure is a mode field diameter test method including: a test light incidence procedure for selectively causing test light to be incident in a mode subject to measurement, on one end of an optical fiber 10 under test; a far-field pattern measurement procedure for measuring a far-field pattern of the mode subject to measurement, with respect to a divergence angle θ at the other end of the optical fiber under test, by a far-field scanning technique; and a mode field diameter calculation procedure for calculating, using an equation, a mode field diameter from information about incident mode orders in the test light incidence procedure and the far-field pattern measured in the far-field pattern measurement procedure.

公开(公告)号：US11879803B2

公开(公告)日：2024-01-23

申请号：US17926655

申请日：2020-06-03

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tomokazu Oda ,  Hiroyuki Oshida ,  Daisuke Iida ,  Atsushi Nakamura ,  Yuto Sagae

IPC: G01M11/00

CPC classification number: G01M11/39

Abstract: An optical fiber testing method is presented for measuring the change amount for the wave number k of a Brillouin Frequency Shift ν in stimulated Brillouin scattering generated in the same acoustic mode with respect to each target propagation mode. In this way, the ratio of the change amount measured at each propagation mode is acquired as the group delay ratio between the modes.

公开(公告)号：US11788928B2

公开(公告)日：2023-10-17

申请号：US17622977

申请日：2019-07-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tomokazu Oda ,  Yoshifumi Wakisaka ,  Daisuke Iida ,  Hiroyuki Oshida

IPC: G01M11/00 ,  G01M11/02 ,  H04B10/073

CPC classification number: G01M11/0285 ,  G01M11/39 ,  H04B10/073

Abstract: A light intensity distribution measurement apparatus is presented that is capable of accurately measuring the intensity of light in each mode at each position of an optical fiber through which light is propagated in a plurality of modes. With the light intensity distribution measurement apparatus, a gain coefficient matrix is acquired in advance, which is constituted by Brillouin gain coefficients of propagation modes with predetermined optical frequency differences measured using a reference optical fiber that exhibits the same properties as a measurement-target optical fiber and that does not cause mode coupling, and the intensity distribution of light in each propagation mode in a lengthwise direction of the measurement-target optical fiber is calculated based on the gain coefficient matrix and a difference in light intensity before and after Brillouin amplification of the probe light emitted in a predetermined propagation mode at a predetermined optical frequency difference measured using the measurement-target optical fiber.

公开(公告)号：US11754465B2

公开(公告)日：2023-09-12

申请号：US17426631

申请日：2019-09-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsushi Nakamura ,  Nazuki Honda ,  Daisuke Iida ,  Hiroyuki Oshida ,  Keiji Okamoto

IPC: G01M11/00

CPC classification number: G01M11/3127 ,  G01M11/3145 ,  G01M11/3154

Abstract: An object of the present invention is to provide an optical pulse test apparatus and an optical pulse test method that are capable of determining a change in state of an optical fiber connection portion without the need for reference and without being affected by changes in gap interval before and after the change in state. The optical pulse test apparatus according to the present invention is configured to perform an OTDR measurement by using test optical pulses having spectral widths of from several nm to several hundred nm arranged at intervals of several ten nm to several hundred nm, calculate a reflection peak value caused by the Fresnel reflection at the connection portion from the obtained OTDR waveform, and determine a state such as water immersion of the optical fiber connection portion based on the value.

公开(公告)号：US11747294B2

公开(公告)日：2023-09-05

申请号：US17798299

申请日：2020-02-13

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kazutaka Noto ,  Nazuki Honda ,  Hiroyuki Oshida

IPC: G01N25/68 ,  G01K11/322

CPC classification number: G01N25/68 ,  G01K11/322

Abstract: An object of the present disclosure is to realize water immersion detection that does not require a replacement module, and does not cause any optical loss. The present disclosure relates to a device configured to measure guided acoustic wave Brillouin scattering in a measurement target optical fiber, and detect water immersion of the measurement target optical fiber based on a characteristic around a peak of the guided acoustic wave Brillouin scattering.