Recipient organisationCranfield UniversitySource-published name: Cranfield University
Funding£1.4M
PeriodSept 2021 — Sept 2026
In plain English
AI plain-English summary
A single optical fibre, taped to a surface, can now track the three-dimensional shape of a structure as it bends and moves. This matters because measuring the dynamic shape of large structures—such as wind turbine blades, aircraft wings, and railway tracks—is currently difficult and indirect. Existing methods rely on strain gauges and complex models to infer shape from local measurements. The direct fibre optic shape sensing (DFOSS) approach developed at Cranfield University removes that step: the fibre itself reports its own path through space, so the shape is measured directly, without needing a model of the structure. The current system works on objects up to 5 metres long, but many real-world structures are far larger. If this research succeeds, it will extend DFOSS to objects up to 100 metres long, such as the wing of a Boeing 737 or a wind turbine blade. That would allow engineers to monitor blade bending during operation, detect damage, and measure tip displacement in real time. In aerospace, it could enable active load control on morphing wings. In wind energy, it could improve blade design and reduce maintenance costs. The technology uses low-cost telecoms components, so it could become practical for widespread deployment on bridges, aircraft, and turbines—systems that quietly keep infrastructure safe and efficient.
View original technical description
Shape conveys information about a structure that is easily visualized and interpreted, and its dynamic, absolute measurement has significance in applications that span medicine (tracking the movement of minimally invasive instruments during surgery), wind turbines (monitoring turbine blade shape for active load alleviation control), aerospace (monitoring morphing wings, hydraulic hoses and electric cable looms), civil engineering (health monitoring of onshore and offshore structures), rail (monitoring tracks and rolling stock) and the sports and gaming industries (kinematic motion measurements). Direct fibre optic shape sensing (DFOSS) is a disruptive technology that has the potential to have a transformative impact. DFOSS allows the fibre path, as well as the structure to which the fibre is attached, to be followed through space in three dimensions. A key advantage of DFOSS is that the shape is determined directly within the sensing fibre, removing the dependence on strain transfer from the structure and thus the requirement for a model of the structure. Simple surface mounting of the sensing fibre, for example using adhesive tape, is sufficient. The DFOSS approach proposed here is based on Fibre Segment Interferometry, an approach pioneered by Cranfield University, which employs a simple, cost-effective and robust interrogation system exploiting well-proven telecoms laser diodes, detectors and optical fibre components to offer highly sensitive high-speed dynamic curvature measurements. Our initial implementation of the approach is suitable for relative measurement of the shape of small structures (of length upto 5 m), with a sensing gauge length in the range 1cm to 1m and has been successfully trialled on a 5m helicopter rotor rotating at ~400rpm in a ground test on an Airbus H135 helicopter. This proposal aims to solve the scientific challenges involved in extending the capabilities of this DFOSS approach to undertake absolute measurements of shape on larger scale objects, wind turbine blades and aircraft wings (measurement lengths up to 100m, with spatial resolution of the order 1m and data rates of up to 1 kHz). The challenges introduced by the scale of the objects and the anticipated rates of change of shape will require significant innovation, driving a radical evolution of the measurement configuration while maintaining the low cost and robust nature of the approach. Innovation is also required in the processing of the long lengths of multicore optical fibre at the heart of the approach and in the means for its deployment with a known alignment. The design and development of the approach will be informed by real measurement challenges in wind energy and aerospace, with the aim to demonstrate its use on the wing of Boeing 737, for example measuring the response to the jacking of the wing, and on a wind turbine, measuring blade shape changes and blade tip displacement, undertaking vibration characterisation of the blade, and damage location identification on a faulty blade.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know