# US 10,768,197 B2 · Accelerometer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,768,197 B2 - Document ID: US10768197B2 - Status: Granted - Kind: B2 - Application number: 14/929,711 - Filed: 2015-11-02 - Published: 2016-05-05 - Granted: 2020-09-08 - Earliest claimed: 2014-11-03 - Assignees: Schlumberger Technology Corporation - Applicants: Schlumberger Technology Corporation - Inventors: Daniele Molteni - Web page: https://patentgrep.com/patent/US10768197B2 ## CPC - G01P 15/093: by photoelectric pick-up - G01D 5/353: influencing the transmission properties of an optical fibre - G01H 9/004: {using fibre optic sensors (light guides per se G02B6/00, acousto-optical devices specially adapted for gating or modulating in optical wave guides G02F1/125)} - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES ## Abstract An accelerometer device (100) comprises a former (118) and an optical fiber (120) wound around the former. The winding of optical fiber (120) has a sensing portion (126) that is free to move in relation to a direction of desired sensitivity (128). A movable element (106) is disposed opposite the sensing portion (126) of the optical fiber (120), the movable element (106) being translatable so as to urge against the sensing portion (126) of the optical fiber (120) from a position external to the winding of the optical fiber (120) in order to vary a length of the optical fiber (120). The variation in the length of the optical fiber (120) caused by the moveable element (106) is indicative of an acceleration in the direction of desired sensitivity (128). ## Claims ### Claim 1 An accelerometer device comprising: a former; an optical fiber wound around the former, the winding of optical fiber having a sensing portion having a first side and a second side opposite the first side, the second side being separated from the former by a gap; and a movable element disposed adjacent to the sensing portion of the optical fiber, the movable element being translatable so as to urge against the first side of the sensing portion of the optical fiber in order to vary a length of the optical fiber, the variation in the length of the optical fiber caused by the movable element being indicative of an acceleration in a direction of desired sensitivity, wherein the movable element is external to the winding of the optical fiber. ### Claim 2 (depends on 1) The device according to claim 1, further comprising: a protective stop configuration arranged to prevent translation of the movable element beyond a predetermined travel distance. ### Claim 3 (depends on 1) The device according to claim 1, further comprising: an interferometer operably coupled to or integrally formed with the optical fiber. ### Claim 4 (depends on 1) The device according to claim 1, further comprising: a coherent optical time domain reflectometer operably coupled to the optical fiber. ### Claim 5 (depends on 1) The device according to claim 1, wherein the movable element is coupled to the sensing portion of the optical fiber. ### Claim 6 (depends on 1) The device according to claim 1, wherein the sensing portion of the optical fiber is, when in use, deformable by the movable element. ### Claim 7 (depends on 1) The device according to claim 1, wherein the movable element is arranged to provide a conduit, a strand of the sensing portion of the optical fiber passing through the conduit. ### Claim 8 (depends on 1) The device according to claim 1, wherein the sensing portion of the optical fiber comprises a plurality of strands of optical fiber; the movable element comprises a plurality of conduits; and the plurality of strands respectively pass through the plurality of conduits, the plurality of conduits being spaced to preserve relative positions of the plurality of strands of optical fiber. ### Claim 9 (depends on 1) The device according to claim 1, wherein the movable element is arranged to provide a channel, a strand of the sensing portion of the optical fiber extending substantially within the channel. ### Claim 10 (depends on 1) The device according to claim 1, wherein the movable element comprises mass. ### Claim 11 (depends on 1) The device according to claim 1, further comprising: a biasing element coupled to the movable element and arranged to limit force applied by the movable element to the sensing portion of the optical fiber. ### Claim 12 (depends on 11) The device according to claim 11, further comprising: an anchoring member, the anchoring member being disposed in a fixed relation with respect to the sensing portion of the optical fiber, wherein the movable element is operably coupled to the anchoring member via the biasing element. ### Claim 13 (depends on 12) The device according to claim 12, further comprising: a housing, the housing comprising the anchoring member and houses the former, the optical fiber and the movable element. ### Claim 14 (depends on 12) The device according to claim 12, further comprising: a housing having an installation axis; wherein the anchoring member comprises a sloped surface inclined relative to the installation axis. ### Claim 15 (depends on 14) The device according to claim 14, wherein the former is shaped to define a former slope inclined relative to the installation axis, the sensing portion of the optical fiber wound around the former thereby following the former slope and extending at an incline relative to the installation axis; and the sloped surface extends substantially in parallel with the former slope followed by the sensing portion of the optical fiber wound around the former. ### Claim 16 (depends on 1) The device according to claim 1, further comprising: a housing having a longitudinal axis. ### Claim 17 (depends on 16) The device according to claim 16, wherein the former is fixed with respect to the housing. ### Claim 18 (depends on 1) The device according to claim 1, wherein the sensing portion of the optical fiber comprises a plurality of strands of optical fiber; the movable element comprises a plurality of guides; and the plurality of guides are arranged to receive the plurality of strands of optical fiber, and to preserve relative position of the plurality of strands of optical fiber. ### Claim 19 (depends on 18) The device according to claim 18, wherein the plurality of guides is a comb structure. ### Claim 20 (depends on 18) The device according to claim 18, wherein the plurality of guides is a plurality of channels; and the plurality of strands respectively extend substantially within the plurality of channels, the plurality of channels being spaced to preserve relative position of the plurality of strands of optical fiber. ### Claim 21 (depends on 1) The device according to claim 1, further comprising: a housing having a longitudinal installation axis; wherein the sensing portion of the optical fiber is inclined relative to the installation axis. ### Claim 22 (depends on 21) The device according to claim 21, wherein the former is shaped to define a former slope inclined relative to the installation axis, the sensing portion of the optical fiber around the former thereby following the former slope and extending at an incline relative to the installation axis. ### Claim 23 (depends on 21) The device according to claim 21, wherein the movable element is arranged in sloping relation to the installation axis. ### Claim 24 (depends on 21) The device according to claim 21, wherein a contact surface of the movable element slopes relative to the installation axis. ### Claim 25 (depends on 1) The device according to claim 1, the direction of desired sensitivity extending from the movable element, through the gap, and toward the former. ### Claim 26 (depends on 25) The device according to claim 25, wherein varying a length of the optical fiber by the acceleration in the direction of desired sensitivity is configured to deform the sensing portion across the gap. ### Claim 27 (depends on 1) A cable comprising a first accelerometer device according to claim 1. ### Claim 28 (depends on 27) The cable according to claim 27, further comprising: a second accelerometer device; and a peripheral wall defining a conduit having a cable longitudinal axis; wherein: the second accelerometer device comprises: a former; an optical fiber wound around the former, the winding of optical fiber having a sensing portion that is free to move in relation to a direction of desired sensitivity; and a movable element disposed opposite the sensing portion of the optical fiber, the movable element being translatable so as to urge against the sensing portion of the optical fiber from a position external to the winding of the optical fiber in order to vary a length of the optical fiber, the variation in the length of the optical fiber caused by the movable element being indicative of an acceleration in the direction of desired sensitivity; the first accelerometer device is oriented within the conduit so that the direction of desired sensitivity of the first accelerometer is a first direction relative to the cable longitudinal axis; the second accelerometer device is oriented within the conduit so that the direction of desired sensitivity of the second accelerometer is a second direction relative to the cable longitudinal axis; and the first direction is different from the second direction. ### Claim 29 (depends on 28) The cable according to claim 28, wherein the first direction is substantially perpendicular to the second direction. ### Claim 30 (depends on 28) The cable according to claim 28, wherein the first and second directions are substantially perpendicular to the cable longitudinal axis. ### Claim 31 (depends on 27) A seismic streamer comprising the cable according to claim 27. ### Claim 32 (depends on 27) An ocean bottom cable comprising the cable according to claim 27. ### Claim 33 (depends on 21) A cable comprising: a first accelerometer device according to claim 21; a second accelerometer device according to claim 21; a peripheral wall defining a conduit having a cable longitudinal axis; wherein the first accelerometer device is oriented within the conduit so that a first component of the direction of desired sensitivity of the first accelerometer device is a first direction relative to the cable longitudinal axis, a second component of the direction of desired sensitivity of the first accelerometer device is a second direction relative to the cable longitudinal axis and a third component of the direction of desired sensitivity of the first accelerometer is a third direction relative to the cable longitudinal axis; and the second accelerometer device is oriented within the conduit so that a first component of the direction of desired sensitivity of the second accelerometer device is a fourth direction relative to the cable longitudinal axis, a second component of the direction of desired sensitivity of the second accelerometer device is substantially the second direction relative to the cable longitudinal axis, and a third component of the direction of desired sensitivity of the second accelerometer device is a fifth direction relative to the cable longitudinal axis. ### Claim 34 (depends on 33) The cable according to claim 33, wherein the first direction is substantially parallel with the cable longitudinal axis. ### Claim 35 (depends on 34) The cable according to claim 34, wherein the second and third directions are substantially perpendicular with respect to each other and the cable longitudinal axis. ### Claim 36 (depends on 33) A seismic streamer comprising the cable according to claim 33. ### Claim 37 (depends on 33) An ocean bottom cable comprising the cable according to claim 33. ### Claim 38 A method of sensing acceleration, the method comprising: providing a winding of optical fiber around a frame, the optical fiber having a sensing portion that bridges a gap formed between the optical fiber and the frame; disposing a movable element adjacent to the sensing portion of the optical fiber and external to the winding of the optical fiber; moving a movable element in response to an acceleration event in order to vary contact between the movable element and the sensing portion of the optical fiber, thereby varying a length of the optical fiber, the variation in the length of the optical fiber being indicative of an acceleration in a direction of desired sensitivity. ### Claim 39 (depends on 38) The method according to claim 38, further comprising: providing a housing having a longitudinal installation axis; wherein inclining the sensing portion of the optical fiber relative to the installation axis. ### Claim 40 (depends on 38) The method of claim 38, the direction of desired sensitivity extending from the movable element, through the gap, and toward the frame. ### Claim 41 (depends on 40) The method according to claim 40, wherein moving the movable element in response to the acceleration deforms the sensing portion across the gap.