Report
Teaser, summary, work performed and final results
Periodic Reporting for period 1 - PULSe (Pervasive Ubiquitous Lightwave SEnsor)
Teaser
OutlineBrillouin Distributed Optical Fibre Sensing is a powerful lightwave technology for measuring and mapping temperatures, deformations and pressures in thousands of industrial, civil and environmental applications using a sensing fibre cable installed along the asset to be...
Summary
Outline
Brillouin Distributed Optical Fibre Sensing is a powerful lightwave technology for measuring and mapping temperatures, deformations and pressures in thousands of industrial, civil and environmental applications using a sensing fibre cable installed along the asset to be monitored and an interrogator equipment to sweep a “virtual sensor†and measure temperature (strain) individually at any cable point.
PULSe (Pervasive Ubiquitous Lightwave Sensor) is a research project funded by the European commission under the Horizon 2020 Framework Programme.
Brillouin can be an ideal pervasive sensor for long-range distributed sensing (simultaneous individual measurements at different locations) using inexpensive fibres; it can be also an ideal ubiquitous solution because of its intrinsic safety (no sparks in explosion/fire risk areas), immunity to high-voltage and interferences, resistance to moisture and corrosion, bio-compatibility and miniaturization.
The first generations of novel Brillouin equipment could not match the price reduction expectations for a wider ‘mass-scale’ market. The synergy of cost-effective equipment, easy-to-apply sensors, processing software and accessible know-how could boost the diffusion of Brillouin sensing in a range of different markets with well-established and new application domains.
Goals
PULSe main goals are to optimize, industriale and secure the market uptake of a Brillouin distributed sensing solution based on a synergy of innovative interrogator equipment, strain sensing cable, data processing software and open-access support tools.
PULSe partners covers the full value chain of development, manufacturing, commercialization and service. PULSe partners have established experience on Brillouin and project management, a captive market ready for immediate exploitation of the project results and a global expansion strategy in cooperation with already established external foreign support partners geographically consistent with the market segmentation.
BOTDA sensing
The physical principles underlying the PULSe project sensor system are based on stimulated Brillouin scattering effect along single-mode optical fibers, and the sensing system exploits a technology called Brillouin optical time-domain analysis (BOTDA) for the interrogator equipment.
A Brillouin sensing solution comprises a sensing fibre cable, that has to be installed or displaced along the asset to be monitored, and a sensor interrogator equipment that creates the “virtual sensor†that is swept along the cable length to measure the distribution of deformation, temperature or pressure along its whole length.
The technology is based on the Brillouin effect, an interaction between lightwaves and mechanical vibrations in which the striction induced by the electrical field of the lightwave excites mechanical waves (phonons) inside the fibre at the expense of the wavelength of the light that is interacting, with a linear dependence from the temperature and strain in the fibre. By analysing the wavelength of the Brillouin scattered light point-by-point along the fibre, the deformation or temperature is continuously measured just as if a “virtual†sensor would have been swept along the whole fibre length [1].
State-of-the-art of this technology are Brillouin Optical Time-Domain Analyser (BOTDA) based on Stimulated Brillouin Scattering (SBS). The basic working scheme of a BOTDA is presented in Figure 1 and works as follows: (1) a pulse of “pump†light is injected at a first end of the sensing fibre and creates a travelling virtual sensor that moves along its length, while at the opposite end of the fibre (2) the “probe†light having a specific wavelength is continuously injected. When the “travelling†sensor (3) sweeps a region of the sensor that has the temperature (or strain) characteristics tested by the specific “probe†wavelength in use, the probe light results perturbed by stimulated Brillo
Work performed
PULSe project activities started on 1st January 2017, and will run until 30th June 2019, with an expected duration of 30 months.
During the first project period, the technical activities have been were focused mainly in the development of the interrogator equipment, in the development and test of sensing cable and of the data management platform, while the management, dissemination and exploitation activities have been focused on the project start-up, in the creation of project website, in the market uptake support web platform, in devising the exploitation an dissemination plan, in promotion activities and in involvement of external exploitation partners as expected by the description of actions.
Final results
PULSe’s innovation content is especially relevant for the interrogator equipment, the strain sensing cable and data management platform. A new sensing system can be significantly cheaper, more efficient and more stable than present ones, and is in course of being developed. The innovations will be accompanied by increase of industrial replication capabilities, market uptake support tools and standardisation.
PULSe interrogator is based on a novel patented BRL system in which part of the pump light sourced by a master laser is injected into a ring circuit in counter-propagation with some Brillouin-shifted light initially produced by spontaneous scattering and successively by self-sustained stimulated scattering. Re-circulating Stokes scattering is amplified and part of it is picked up to be used as probe in the sensor.
Moreover, bare optical fibre is generally unsuitable for strain sensing in industrial applications because of no protection, handling issues and non-uniform stress transfer, and a fiber cable must be used with optical fiber sensors. Most strain sensing cables reported in literature show low market availability, high price and large Minimum Order Quantity (MOQ). To sense strain, the optical fibre must be tightly glued to the cable sheath but this makes the cable difficult to handle because any bending can damage the fibre. In the specialty cable under development with PULSe project, the fibre coupling is loose until the product is installed on the final application and during the installation a heat driven loose-to-tight coupling transition can make it sensitive to strain.
The synergy of cost-effective equipment, easy-to-apply sensors, processing software platform and accessible know-how will help boosting the diffusion of PULSe solution in a market of already validated applications and with wider cross-sector impact in environmental protection, CO2 and greenhouse gas reduction, social costs and public health.
Website & more info
More info: http://www.pulse-h2020.eu.