Morges, Switzerland
Morges, Switzerland

Time filter

Source Type

Patent
Omnisens | Date: 2014-06-26

A method of determining deformation in a structure around which a sensing optical fiber is helically wound, includes performing a distributed measurement at a point along the fiber, to obtain a frequency gain spectrum at that point. Performing a distributed measurement includes, adjusting a pulse width of a pulse pump signal to achieve a predefined spatial resolution and providing the pulse pump signal with adjusted pulse width in the fiber to generate scattering, which is used to obtain the frequency gain spectrum. Identifying at least two curves which, when added together, best fit the frequency gain spectrum. Identifying the frequency at which peaks of the curves occur. Determining deformation in the structure by determining deformation in the fiber at the point using a frequency at which a peak of an identified curve occurs. The amount of deformation in the fiber corresponds to the amount of deformation in the structure.


Patent
Omnisens | Date: 2017-05-03

According to the present invention there is provided a method of determining deformation in a structure around which at least one sensing optical fiber is helically wound, the method comprising the steps of: (a) performing a distributed measurement at a point along the at least one sensing optical fiber, to obtain a frequency gain spectrum at that point, wherein the step of performing a distributed measurement comprises, adjusting a pulse width of a pulse pump signal so as to achieve a predefined spatial resolution for the detection of deformation, and providing the pulse pump signal with adjusted pulse width in the sensing optical fiber to generate scattering which is used to obtain said frequency gain spectrum, wherein said predefined spatial resolution for the detection of deformation is a value which is within the range (pitch of the helical wound sensing optical fiber) - (50% of the pitch of the helical wound sensing optical fiber) - (pitch of the helical wound sensing optical fiber) + (50% of the pitch of the helical wound sensing optical fiber); (b) identifying at least two curves which, when added together, best fit the frequency gain spectrum; (c) identifying the frequency at which peaks of the at least two curves occur; (d) determining deformation in the structure by determining deformation in the at least one sensing optical fiber, at said point at which the distributed measurement was performed, using a frequency at which a peak of an identified curve occurs, wherein the amount of deformation in the sensing optical fiber corresponds to the amount of deformation in the structure.


The invention relates to a device (17) for monitoring a structure, comprising: a first cable (7A) comprising a first measuring optical fibre and a first carrier element (10A, 11A); a second cable (7B) comprising a second measuring optical fibre and a second carrier element (10B, 11B); and a connection housing (18) comprising a compartment (25) inside of which the first carrier element (10A, 11A) and the second carrier element (10B, 11B) extend and an adhesive composition (47) filling the compartment (25), the first carrier element (10A, 11A) and the second carrier element (10B, 11B) being embedded in the adhesive composition (47) so as to securely fasten the carrier elements (10A, 11A, 10B, 11B) to one another.


Grant
Agency: European Commission | Branch: FP7 | Program: BSG-SME | Phase: SME-2012-1 | Award Amount: 1.60M | Year: 2012

Most European offshore wind farms are currently installed within 20 km of the coast in shallow water depths up to 20m. The next generation will be developed at distances of 40 km in sea depths up to 80m. These new locations present technical challenges for engineering and the possibility of new synergies between all marine renewable energy resources including wave, tide and wind. Inspection and maintenance at depth is difficult and the raising of transmission voltages to keep cable sizes manageable is urgently required as the technical difficulty of hauling heavy cables is significantly increased. The availability of self-monitoring connectors to eliminate routine maintenance at greater depths is seen as a potential step-change improvement in infrastructure management and the development of ROV-installable wet-mate connectors as an alternative to dry-mated cable is a dominant industry objective. We will deliver a prototype 33kV hybrid wet-mate connector with a connectivity monitoring system and future-proof features for higher voltage connector technologies. This will lead to efficient power transmission, reduced installation and maintenance costs and precision remote monitoring that reduces routine maintenance and intervention by divers, benefitting health, safety and affordability.


A Brillouin optical distributed sensing device and method includes a structure for generating an optical pulsed signal and an optical probe signal. Includes is a circulation component for directing the optical pulsed signal to a sensing optical fiber and for directing an optical measurement signal with Brillouin scattering information arising from the sensing optical fiber toward a detection apparatus. Also included is an optical routing component for configuring the device to allow generating: (i) according to a first configuration, an optical measurement signal with stimulated Brillouin scattering information resulting from the interaction of the optical pulsed signal, and an optical probe signal propagating in the sensing optical fiber in a direction opposite to the optical pulsed signal, or (ii) according to a second configuration, an optical measurement signal with spontaneous Brillouin scattering information resulting from the propagation of the optical pulsed signal in the sensing optical fiber.


Patent
Omnisens | Date: 2013-12-20

A sensing cable including one or more optical fibers and a coating which is provided on the one or more optical fibers. The coating is configured so that pressure applied to the sensing cable, along one or more axes, induces less lateral compression on the one or more optical fibers than pressure applied to the sensing cable along one or more other axes so as to change birefringence in the one or more optical fibers.


Patent
Omnisens | Date: 2014-02-06

According to the present invention there is provided a method for installing a sensing cable along a pipeline, comprising the steps of, attaching one or more conduits to an outer-surface of a pipe which is to be installed in a bore hole to form a pipeline assembly; moving the pipeline assembly into the bore hole; moving an fiber optic sensing cable into one or more of the conduit after the pipeline assembly has been moved into the bore hole or before the pipeline assembly has been moved into the bore hole. There is further provided a corresponding pipeline assembly, and a attachment head which can facilitate attachment of a pulling line to a pipeline assembly.


Methods of performing a distributing sensing measurement included the steps of, modulating the frequency of one or more light signals output from one or more light sources, using one or more multi-level sequence of bits so that the one or more light signals are frequency modulated; using the one or more frequency modulated light signals to provide a pump signal and a probe signal; propagating the pump and probe signals along an optical fiber; using interactions between the pump and probe signal to perform a distributed sensing measurement. There is further provided corresponding sensing systems.


Patent
Omnisens | Date: 2014-12-10

A sensing cable designed for distributed pressure sensing includes one or more optical fibres which have a continuous weak fiber Bragg grating permanently written inside a core of the optical fiber. The sensing cable is configured so that pressure applied to the sensing cable changes birefringence in the one or more optical fibers.


A method for detecting a structural fault in a structure includes the steps of, (a) performing a Brillouin measurement at a point along a sensing optical fiber which operably cooperates with the structure, to obtain a Brillouin gain spectrum at that point; (b) identifying at least two curves which, when added together, best fit the Brillouin gain spectrum; (c) identifying if peaks of the least two curves occur at different frequencies so as to determine if the structure has a structural fault. There is further provided a corresponding apparatus for detecting a structural fault in a structure.

Loading Omnisens collaborators
Loading Omnisens collaborators