Fiber Bragg Gratings in CYTOP Fibers Embedded in a 3D-Printed Flexible Support for Assessment of Human–Robot Interaction Forces

We developed a flexible support with embedded polymer optical fiber (POF) sensors for the assessment of human–robot interaction forces. The supports were fabricated with a three-dimensional (3D) printer, where an acrylonitrile butadiene styrene (ABS) rigid structure was used in the region of the support in which the exoskeleton was attached, whereas a thermoplastic polyurethane (TPU) flexible structure was printed in the region where the users placed their legs. In addition, fiber Bragg gratings (FBGs), inscribed in low-loss, cyclic, transparent, optical polymer (CYTOP) using the direct-write, plane-by-plane femtosecond laser inscription method, were embedded in the TPU structure. In this case, a 2-FBG array was embedded in two supports for human–robot interaction force assessment at two points on the users’ legs. Both FBG sensors were characterized with respect to temperature and force; additionally, the creep response of the polymer, where temperature influences the force sensitivity, was analyzed. Following the characterization, a compensation method for the creep and temperature influence was derived, showing relative errors below 4.5%. Such errors were lower than the ones obtained with similar sensors in previously published works. The instrumented support was attached to an exoskeleton for knee rehabilitation exercises, where the human–robot interaction forces were measured in flexion and extension cycles.

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Polymer optical fiber-embedded, 3D-printed instrumented support for microclimate and human-robot interaction forces assessment

Optics & Laser Technology ◽

10.1016/j.optlastec.2018.11.044 ◽

2019 ◽

Vol 112 ◽

pp. 323-331 ◽

Cited By ~ 4

Author(s):

Arnaldo G. Leal-Junior ◽

Camilo R. Díaz ◽

Maria José Pontes ◽

Carlos Marques ◽

Anselmo Frizera

Keyword(s):

Optical Fiber ◽

Human Robot Interaction ◽

Polymer Optical Fiber ◽

Robot Interaction ◽

Interaction Forces ◽

3D Printed

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Sensing small interaction forces through proprioception

Scientific Reports ◽

10.1038/s41598-021-01112-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Fazlur Rashid ◽

Devin Burns ◽

Yun Seong Song

Keyword(s):

Muscle Contraction ◽

Interaction Force ◽

Initial Position ◽

Human Robot Interaction ◽

Human Interaction ◽

Physical Interaction ◽

Robot Interaction ◽

Interaction Forces ◽

Force Direction ◽

Human Motor

AbstractUnderstanding the human motor control strategy during physical interaction tasks is crucial for developing future robots for physical human–robot interaction (pHRI). In physical human–human interaction (pHHI), small interaction forces are known to convey their intent between the partners for effective motor communication. The aim of this work is to investigate what affects the human’s sensitivity to the externally applied interaction forces. The hypothesis is that one way the small interaction forces are sensed is through the movement of the arm and the resulting proprioceptive signals. A pHRI setup was used to provide small interaction forces to the hand of seated participants in one of four directions, while the participants were asked to identify the direction of the push while blindfolded. The result shows that participants’ ability to correctly report the direction of the interaction force was lower with low interaction force as well as with high muscle contraction. The sensitivity to the interaction force direction increased with the radial displacement of the participant’s hand from the initial position: the further they moved the more correct their responses were. It was also observed that the estimated stiffness of the arm varies with the level of muscle contraction and robot interaction force.

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Polymer optical fiber strain gauge for human-robot interaction forces assessment on an active knee orthosis

Optical Fiber Technology ◽

10.1016/j.yofte.2018.02.001 ◽

2018 ◽

Vol 41 ◽

pp. 205-211 ◽

Cited By ~ 21

Author(s):

Arnaldo G. Leal-Junior ◽

Anselmo Frizera ◽

Carlos Marques ◽

Manuel R.A. Sánchez ◽

Thomaz R. Botelho ◽

...

Keyword(s):

Optical Fiber ◽

Strain Gauge ◽

Human Robot Interaction ◽

Polymer Optical Fiber ◽

Robot Interaction ◽

Interaction Forces ◽

Knee Orthosis

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Numerical Analysis of Thermal Dependence of the Spectral Response of Polymer Optical Fiber Bragg Gratings

Iraqi Journal for Electrical And Electronic Engineering ◽

10.33762/eeej.2016.110678 ◽

2016 ◽

Vol 12 (1) ◽

pp. 85-95 ◽

Cited By ~ 1

Author(s):

Hisham K. Hisham

Keyword(s):

Numerical Analysis ◽

Optical Fiber ◽

Spectral Response ◽

Fiber Bragg Gratings ◽

Bragg Gratings ◽

Polymer Optical Fiber ◽

Thermal Dependence

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A Quasi-Static Model for Studying Physical Interaction Between a Soft Robotic Digit and a Human Finger

Volume 5A: 42nd Mechanisms and Robotics Conference ◽

10.1115/detc2018-85629 ◽

2018 ◽

Cited By ~ 1

Author(s):

Mahdi Haghshenas-Jaryani ◽

Muthu B. J. Wijesundara

Keyword(s):

Human Performance ◽

Theoretical Models ◽

Element Model ◽

Human Robot Interaction ◽

Physical Interaction ◽

Robotic Hand ◽

Robot Interaction ◽

Interaction Forces ◽

Comparison Of The Results ◽

Human Finger

This paper presents the development of a framework based on a quasi-statics concept for modeling and analyzing the physical human-robot interaction in soft robotic hand exoskeletons used for rehabilitation and human performance augmentation. This framework provides both forward and inverse quasi-static formulations for the interaction between a soft robotic digit and a human finger which can be used for the calculation of angular motions, interaction forces, actuation torques, and stiffness at human joints. This is achieved by decoupling the dynamics of the soft robotic digit and the human finger with similar interaction forces acting on both sides. The presented theoretical models were validated by a series of numerical simulations based on a finite element model which replicates similar human-robot interaction. The comparison of the results obtained for the angular motion, interaction forces, and the estimated stiffness at the joints indicates the accuracy and effectiveness of the quasi-static models for predicting the human-robot interaction.

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Adaptive Estimation of Human-Robot Interaction Force for Lower Limb Rehabilitation

Communications in Computer and Information Science - Neural Information Processing ◽

10.1007/978-3-030-36808-1_59 ◽

2019 ◽

pp. 540-547

Author(s):

Xu Liang ◽

Weiqun Wang ◽

Zengguang Hou ◽

Shixin Ren ◽

Jiaxing Wang ◽

...

Keyword(s):

Lower Limb ◽

Adaptive Estimation ◽

Interaction Force ◽

Human Robot Interaction ◽

Robot Interaction ◽

Limb Rehabilitation ◽

Lower Limb Rehabilitation

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Numerical Analysis of Thermal Dependence of the Spectral Response of Polymer Optical Fiber Bragg Gratings

Iraqi Journal for Electrical And Electronic Engineering ◽

10.37917/ijeee.12.1.9 ◽

2016 ◽

Vol 12 (1) ◽

pp. 85-95 ◽

Cited By ~ 1

Author(s):

Hisham Hisham

Keyword(s):

Optical Fiber ◽

High Stability ◽

Spectral Response ◽

Fiber Bragg Gratings ◽

Bragg Gratings ◽

Bragg Reflector ◽

Polymer Optical Fiber ◽

Thermal Dependence ◽

Silica Optical Fiber ◽

Index Modulation

The thermal dependence of the spectral response (i.e. transmission, reflection and time delay ( r) responses) of uniform polymer optical fiber (POF) Bragg gratings has been investigated. In addition to the temperature dependence, the effects of grating strength (kLg) and fiber index modulation ( n) have been investigated. Besides high capability of tunable wavelength due to the unique large and negative thermo-optic coefficient of POF, the spectral response for POF Bragg gratings show high stability and larger spectrum bandwidth with temperature variation compare with the silica optical fiber (SOF) Bragg gratings, especially with the increase of the kLg value. It was found that by increasing kLg, the peak reflectance value increases and the bandwidth of the Bragg reflector become narrower. Also it’s shown by increasing the kLg value, r deceasing significantly and reach its minimum value at the designed wavelength ( B). Furthermore, the r for POF Bragg gratings is less than that for SOF Bragg gratings at the same value of kLg. Also it’s found that the peak reflectivity value increases to around 60% when the n value increases from 1*10-4 to 5*10-4.

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