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End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders

Soft continuum robots are compliant mechanisms that rely on a deformable structure in order to achieve a desired posture. One of the challenges in designing and controlling this type of robot is to obtain the necessary proprioceptive information without resorting to external sensors, like cameras or...

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Detalles Bibliográficos
Autores principales: Costa, Carlos F. R., Reis, João C. P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9921875/
https://www.ncbi.nlm.nih.gov/pubmed/36772685
http://dx.doi.org/10.3390/s23031647
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author Costa, Carlos F. R.
Reis, João C. P.
author_facet Costa, Carlos F. R.
Reis, João C. P.
author_sort Costa, Carlos F. R.
collection PubMed
description Soft continuum robots are compliant mechanisms that rely on a deformable structure in order to achieve a desired posture. One of the challenges in designing and controlling this type of robot is to obtain the necessary proprioceptive information without resorting to external sensors, like cameras or 3D positioning devices. This requires a reliable and repeatable sensor that can be embedded in the highly deformable structure, distributed along its length, without imposing a significant change to the overall stiffness. This paper presents design considerations and practical results of estimating the tip position of a soft continuum manipulator module using embedded linear magnetic encoders. Three flexible scales with incremental tracks and a magnetic pole pitch of 2 mm are embedded in the robot structure as passive tendons, and six pairs of Hall effect linear sensors are used to measure the relative displacement between points along the outer surface of the structure. The curvature and tip position are then estimated from these measurements. Results are compared with the ground truth measurement of the tip position provided by a commercial optical tracker system. Average error estimates lower than 2.0 mm, with 8.7 mm peak value, were obtained for a robot module with a motion span of approximately 100 mm.
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spelling pubmed-99218752023-02-12 End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders Costa, Carlos F. R. Reis, João C. P. Sensors (Basel) Article Soft continuum robots are compliant mechanisms that rely on a deformable structure in order to achieve a desired posture. One of the challenges in designing and controlling this type of robot is to obtain the necessary proprioceptive information without resorting to external sensors, like cameras or 3D positioning devices. This requires a reliable and repeatable sensor that can be embedded in the highly deformable structure, distributed along its length, without imposing a significant change to the overall stiffness. This paper presents design considerations and practical results of estimating the tip position of a soft continuum manipulator module using embedded linear magnetic encoders. Three flexible scales with incremental tracks and a magnetic pole pitch of 2 mm are embedded in the robot structure as passive tendons, and six pairs of Hall effect linear sensors are used to measure the relative displacement between points along the outer surface of the structure. The curvature and tip position are then estimated from these measurements. Results are compared with the ground truth measurement of the tip position provided by a commercial optical tracker system. Average error estimates lower than 2.0 mm, with 8.7 mm peak value, were obtained for a robot module with a motion span of approximately 100 mm. MDPI 2023-02-02 /pmc/articles/PMC9921875/ /pubmed/36772685 http://dx.doi.org/10.3390/s23031647 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Costa, Carlos F. R.
Reis, João C. P.
End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders
title End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders
title_full End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders
title_fullStr End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders
title_full_unstemmed End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders
title_short End-Point Position Estimation of a Soft Continuum Manipulator Using Embedded Linear Magnetic Encoders
title_sort end-point position estimation of a soft continuum manipulator using embedded linear magnetic encoders
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9921875/
https://www.ncbi.nlm.nih.gov/pubmed/36772685
http://dx.doi.org/10.3390/s23031647
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