Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical Fiber

Shape-sensing optical fibers have become increasingly important in applications requiring flexible navigation, spatial awareness, and deformation monitoring. Fiber Bragg Grating (FBG) sensors inscribed in multi-core optical fibers have been democratized over the years and nowadays offer a compact an...

Full description

Saved in:
Bibliographic Details
Main Authors: Georgios Violakis, Nikolaos Vardakis, Zhenyu Zhang, Martin Angelmahr, Panagiotis Polygerinos
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/25/14/4494
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849419081959079936
author Georgios Violakis
Nikolaos Vardakis
Zhenyu Zhang
Martin Angelmahr
Panagiotis Polygerinos
author_facet Georgios Violakis
Nikolaos Vardakis
Zhenyu Zhang
Martin Angelmahr
Panagiotis Polygerinos
author_sort Georgios Violakis
collection DOAJ
description Shape-sensing optical fibers have become increasingly important in applications requiring flexible navigation, spatial awareness, and deformation monitoring. Fiber Bragg Grating (FBG) sensors inscribed in multi-core optical fibers have been democratized over the years and nowadays offer a compact and robust platform for shape reconstruction. In this work, we propose a novel, computationally efficient method for determining the 3D tip position of a bent multi-core FBG-based optical fiber using a second-order polynomial approximation of the fiber’s shape. The method begins with a calibration procedure, where polynomial coefficients are fitted for known bend configurations and subsequently modeled as a function of curvature using exponential decay functions. This allows for real-time estimation of the fiber tip position from curvature measurements alone, with no need for iterative numerical solutions or high processing power. The method was validated using miniaturized test structures and achieved sub-millimeter accuracy (<0.1 mm) over a 4.5 mm displacement range. Its simplicity and accuracy make it suitable for embedded or edge-computing applications in confined navigation, structural inspection, and medical robotics.
format Article
id doaj-art-e9b9a48712e240e6a5c0bb2cd93aa87a
institution Kabale University
issn 1424-8220
language English
publishDate 2025-07-01
publisher MDPI AG
record_format Article
series Sensors
spelling doaj-art-e9b9a48712e240e6a5c0bb2cd93aa87a2025-08-20T03:32:15ZengMDPI AGSensors1424-82202025-07-012514449410.3390/s25144494Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical FiberGeorgios Violakis0Nikolaos Vardakis1Zhenyu Zhang2Martin Angelmahr3Panagiotis Polygerinos4School of Electrical and Computer Engineering, Hellenic Mediterranean University, Estavromenos, 71410 Heraklion, GreeceSchool of Electrical and Computer Engineering, Hellenic Mediterranean University, Estavromenos, 71410 Heraklion, GreeceDepartment of Fiber Optical Sensor Systems, Fraunhofer Heinrich Hertz Institute, Am Stollen 19H, 38640 Goslar, GermanyDepartment of Fiber Optical Sensor Systems, Fraunhofer Heinrich Hertz Institute, Am Stollen 19H, 38640 Goslar, GermanyControl Systems and Robotics Laboratory, Department of Mechanical Engineering, School of Engineering, Hellenic Mediterranean University, 71004 Heraklion, GreeceShape-sensing optical fibers have become increasingly important in applications requiring flexible navigation, spatial awareness, and deformation monitoring. Fiber Bragg Grating (FBG) sensors inscribed in multi-core optical fibers have been democratized over the years and nowadays offer a compact and robust platform for shape reconstruction. In this work, we propose a novel, computationally efficient method for determining the 3D tip position of a bent multi-core FBG-based optical fiber using a second-order polynomial approximation of the fiber’s shape. The method begins with a calibration procedure, where polynomial coefficients are fitted for known bend configurations and subsequently modeled as a function of curvature using exponential decay functions. This allows for real-time estimation of the fiber tip position from curvature measurements alone, with no need for iterative numerical solutions or high processing power. The method was validated using miniaturized test structures and achieved sub-millimeter accuracy (<0.1 mm) over a 4.5 mm displacement range. Its simplicity and accuracy make it suitable for embedded or edge-computing applications in confined navigation, structural inspection, and medical robotics.https://www.mdpi.com/1424-8220/25/14/4494optical fibersmulti-core optical fibersshape sensingshape reconstruction
spellingShingle Georgios Violakis
Nikolaos Vardakis
Zhenyu Zhang
Martin Angelmahr
Panagiotis Polygerinos
Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical Fiber
Sensors
optical fibers
multi-core optical fibers
shape sensing
shape reconstruction
title Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical Fiber
title_full Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical Fiber
title_fullStr Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical Fiber
title_full_unstemmed Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical Fiber
title_short Rapid and Accurate Shape-Sensing Method Using a Multi-Core Fiber Bragg Grating-Based Optical Fiber
title_sort rapid and accurate shape sensing method using a multi core fiber bragg grating based optical fiber
topic optical fibers
multi-core optical fibers
shape sensing
shape reconstruction
url https://www.mdpi.com/1424-8220/25/14/4494
work_keys_str_mv AT georgiosviolakis rapidandaccurateshapesensingmethodusingamulticorefiberbragggratingbasedopticalfiber
AT nikolaosvardakis rapidandaccurateshapesensingmethodusingamulticorefiberbragggratingbasedopticalfiber
AT zhenyuzhang rapidandaccurateshapesensingmethodusingamulticorefiberbragggratingbasedopticalfiber
AT martinangelmahr rapidandaccurateshapesensingmethodusingamulticorefiberbragggratingbasedopticalfiber
AT panagiotispolygerinos rapidandaccurateshapesensingmethodusingamulticorefiberbragggratingbasedopticalfiber