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Article
Publication date: 15 March 2019

Guangkai Sun, Yang Hu, Mingli Dong, Yanlin He, Mingxin Yu and Lianqing Zhu

Soft robotics is a burgeoning field owing to its high adaptability and safety in human–machine interaction and unstructured environments. However, the feedback control of…

Abstract

Purpose

Soft robotics is a burgeoning field owing to its high adaptability and safety in human–machine interaction and unstructured environments. However, the feedback control of soft actuators with flexible sensors is still a challenge.

Design/methodology/approach

To address this issue, this study proposes an optical fibre-based sensing membrane for the posture measurement of soft pneumatic bending actuators. The major contribution is the development of a flexible sensing membrane with a high sensitivity and repeatability for the feedback control of soft actuators. The characteristics of sensing membrane were analysed. The relationship between wavelength shift and bending curvature was derived. The curvatures of soft actuator were measured at four bending status, and the postures were reconstructed.

Findings

The results indicate that the measurement error is less than 2.1% of the actual bending curvature. The sensitivity is up to 212.8 pm/m−1, and the signal fluctuation in repeated measurements is negligible. This approach has broad application prospects in soft robotics, because it makes the optical fibre achieve more strength and compatible with soft actuators, thus improving the sensing accuracy, sensitivity and reliability of fibre sensors.

Originality/value

Different from previous approaches, an optical fibre with FBGs is embedded into a multilayered polyimide film to form a flexible sensing membrane, and the membrane is embedded into a soft pneumatic bending actuator as the smart strain limited layer which is able to measure the posture in real time. This approach makes the optical fibre stronger and compatible with the soft pneumatic bending actuator, and the sensing accuracy, sensitivity and reliability are improved. The proposed sensing configuration is effective for the feedback control of the soft pneumatic bending actuators.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 23 August 2021

Xiao Fang, Yajie Zeng, Feng Xiong, Jiang Chen and Fei Cheng

Seepage of the dam is an important safety problem, which may cause internal erosion of the structure. In the field of seepage monitoring in civil engineering, the…

Abstract

Purpose

Seepage of the dam is an important safety problem, which may cause internal erosion of the structure. In the field of seepage monitoring in civil engineering, the distributed optical fiber sensing technology based on the temperature tracing method has been paid more attention due to its unique advantages of high sensitivity, good stability and high resolution. The purpose of this paper is to make a review of the existing related research, so as to facilitate the later scholars to understand and further study more systematically.

Design/methodology/approach

In this paper, three kinds of commonly used distributed fiber temperature measurement technologies are introduced. Based on the working principle, monitoring system, theoretical analysis, experimental research and engineering application of the fiber seepage monitoring technology, the present situation of dam seepage monitoring based on distributed fiber is reviewed in detail and their advantages and disadvantages are compared.

Findings

The thermal monitoring technology of seepage measurement depends on the accuracy of optical fiber temperature measurement (including the accuracy of the system and the rationality of the discrimination method), the correct installation of optical fiber and the quantitative analysis of temperature data. The accuracy of the current monitoring system can basically meet the existing measurement requirements, but the correct installation of optical fiber and the calibration of temperature data need to be further studied for different discrimination methods, and this field has great research value.

Originality/value

At present, there are many applications and research studies of optical fiber sensing in the field of structural health monitoring, and there are also reviews of related aspects. However, there is little or no review only in the field of seepage monitoring. This paper summarizes the research and application of optical fiber sensing in the field of seepage monitoring. The possibility of the gradient method to find its new prospect with the development of monitoring systems and the improvement of temperature resolution is discussed. The idea of extending the seepage monitoring method based on distributed optical fiber thermal monitoring technology to other monitoring fields is also given in the paper.

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Article
Publication date: 20 March 2017

Lujun Cui, Huichao Shang, Yan-long Cao and Gao-feng Zhou

Long life and high hydrogen sensitivity are the crucial performance parameters for an optical fiber hydrogen sensing membrane, and these are the fundamental areas of study…

Abstract

Purpose

Long life and high hydrogen sensitivity are the crucial performance parameters for an optical fiber hydrogen sensing membrane, and these are the fundamental areas of study for an optical fiber hydrogen sensor. Considering that a traditional optical fiber hydrogen sensor based on pure palladium cannot meet the expectations for long life and rapid sensitivity simultaneously, the experiment in this paper designed a kind of reflective optical fiber bundle hydrogen gas sensor based on a Pd0.75–Ag0.25 alloy to achieve a hydrogen sensing system. This paper aims to discuss the issues with this system.

Design/methodology/approach

A reflective optical fiber bundle hydrogen sensor was made up of an optical fiber bundle and a Pd0.75–Ag0.25 alloy hydrogen membrane. A combination of optical fiber light intensity measurements and the reference calculation method were used to extract the hydrogen concentration information from within the optical fiber, and the relationship between the hydrogen concentration changes and the reflective light intensity in the optical fiber was established.

Findings

The reflective optical fiber bundle hydrogen gas sensor based on a Pd–Ag alloy membrane was shown to provide an effective way to detect hydrogen concentrations. The experimental results showed that a 20-30-nm-thick Pd0.75–Ag0.25 alloy membrane could reach high hydrogen absorption and sensitivity. Key preparation parameters which included sputtering time and substrate temperature were used to prepare the hydrogen membrane during the DC sputtering process, and the reflectivity of the Pd–Ag alloy membrane was enough to meet the requirements of long life and high hydrogen sensitivity for the optical fiber hydrogen sensor.

Originality/value

This paper seeks to establish a foundation for optimizing and testing the performance of the Pd–Ag alloy hydrogen sensing membrane for an optical fiber bundle hydrogen sensor. To this end, the optimal thickness and key preparation parameters for the Pd–Ag alloy hydrogen sensing membrane were discussed. The results of this research have proved that the reflective optical fiber hydrogen sensor based on a Pd0.75–Ag0.25 alloy is an effective approach and precisely enough for hydrogen gas monitoring in practical engineering measurements.

Details

Sensor Review, vol. 37 no. 2
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 1 February 1992

Radislav Potyrailo and Sergei Golubkov

Achievements in guided wave optics have had a great influence on many areas of technology for several years. Fibre optic communication links, sensors for various…

Abstract

Achievements in guided wave optics have had a great influence on many areas of technology for several years. Fibre optic communication links, sensors for various parameters, recently developed distributed temperature sensors, integrated optical switches, etc. are all applications that are commercially available. The field of analytical chemistry is no exception in this growing technology. In order to compete with well‐established chemical‐sensing instrumentation, optical waveguide chemical sensors (OWCSs) must show all the qualities of such instrumentation. OWCSs combine well‐known features of sensors, based on waveguide optics, with optical methods of chemical analysis and offer advantages over other types of chemical sensor. OWCSs are electrically passive, corrosion‐resistant, can respond to analytes for which other chemical sensors are not available, and referencing can be carried out optically. They allow multicomponent measurements at several wavelengths, have a common technology for fabrication of sensors for different chemical and physical parameters and are easily compatible with telemetry etc. Further, only OWCSs are capable of distributed sensing. However, interference from ambient light, temperature, long‐term instability, relatively slow response time, and limited dynamic range may be a problem for some types of OWCS. These disadvantages can be considerably reduced using various methods.

Details

Sensor Review, vol. 12 no. 2
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 11 February 2021

Yongxing Guo, Min Chen, Li Xiong, Xinglin Zhou and Cong Li

The purpose of this study is to present the state of the art for fiber Bragg grating (FBG) acceleration sensing technologies from two aspects: the principle of the…

Abstract

Purpose

The purpose of this study is to present the state of the art for fiber Bragg grating (FBG) acceleration sensing technologies from two aspects: the principle of the measurement dimension and the principle of the sensing configuration. Some commercial sensors have also been introduced and future work in this field has also been discussed. This paper could provide an important reference for the research community.

Design/methodology/approach

This review is to present the state of the art for FBG acceleration sensing technologies from two aspects: the principle of the measurement dimension (one-dimension and multi-dimension) and the principle of the sensing configuration (beam type, radial vibration type, axial vibration type and other composite structures).

Findings

The current research on developing FBG acceleration sensors is mainly focused on the sensing method, the construction and design of the elastic structure and the design of a new information detection method. This paper hypothesizes that in the future, the following research trends will be strengthened: common single-mode fiber grating of the low cost and high utilization rate; high sensitivity and strength special fiber grating; multi-core fiber grating for measuring single-parameter multi-dimensional information or multi-parameter information; demodulating equipment of low cost, small volume and high sampling frequency.

Originality/value

The principle of the measurement dimension and principle of the sensing configuration for FBG acceleration sensors have been introduced, which could provide an important reference for the research community.

Details

Sensor Review, vol. 41 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 1 March 1990

Elzbieta Marszalec and Janusz Marszalec

Integration of lasers and fibre optics into robotic systems provides new opportunities in sensing and material processing. Increased productivity and application of robots…

Abstract

Integration of lasers and fibre optics into robotic systems provides new opportunities in sensing and material processing. Increased productivity and application of robots in hostile environments are other possibilities.

Details

Industrial Robot: An International Journal, vol. 17 no. 3
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 28 March 2008

S. O'Keeffe, C. Fitzpatrick, E. Lewis and A.I. Al‐Shamma'a

The purpose of this paper is to provide a detailed review of radiation dosimetry techniques based on optical fibre dosimeters. It presents a comprehensive bibliography of…

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Abstract

Purpose

The purpose of this paper is to provide a detailed review of radiation dosimetry techniques based on optical fibre dosimeters. It presents a comprehensive bibliography of the current research activities in the area.

Design/methodology/approach

A range of published work on optical fibre radiation dosimeters are presented, with the merits and limitations discussed. Each radiation dosimetry technique is discussed in turn, providing examples of dosimeters using such techniques reviewed. The main focus is on gamma radiation although other radiation dosimeters are considered.

Findings

This paper provides information on the wide range of research activity into radiation dosimeters. The dose ranges of these dosimeters are presented, along with the advantages and disadvantages of different dosimetry techniques.

Originality/value

A comprehensive review of published research in the area of solid radiation dosimetry is presented in this paper. It provides an individual with a review of the various techniques used and most recent research in that field.

Details

Sensor Review, vol. 28 no. 2
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 1 March 2005

José Mireles

Owing to the technology growth, especially in Microsystems technology and Nanotechnology, new products will provide new ways to sense variables that are crucial for…

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1557

Abstract

Purpose

Owing to the technology growth, especially in Microsystems technology and Nanotechnology, new products will provide new ways to sense variables that are crucial for product improvement and system reliability. A big concern of the scientific community is the measurement of low level flow measurements, especially for the biomedical and/or systems on a chip approaches.Design/methodology/approach – A new flow meter concept design consists of a surface micromachined sensor having an optical high reflective mirror made of gold, which is attached to unique cantilever designs that bend due to the drag force of mass flow. The bending of the cantilevers produces the mirror to approach/depart from an optical fiber end‐tip. The reflective light to fiber is modulated using a Fabry‐Perot interferometry technique to determine the mirror separation to the fiber, which corresponds to the mass flow.Findings – The new concept design shows a big potential approach to measure low flow measurements for air, gas and liquids of low viscosity. The results of this concept, through finite element analysis, show that the material used to build the sensor, makes them excellent candidates for fabrication. The stresses of the materials and allowable (readable) bending are among the tolerances of such materials/construction‐design. The sensor is not affected by electromagnetic interference and does not require electrical currents to sense, i.e. it is perfectly suited for biomedical and low mass‐flow sensing such as lab‐on‐chip applications.Originality/value – Among all approaches to sense low flow measurements, most of them need either “big” turbine approaches (dimensions over 1 cm diameter), or the need of an electrical approach needed in the end measurement sensor. This work proposes a non‐electrical approach.

Details

Sensor Review, vol. 25 no. 1
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 1 April 1996

Z. Keresztes‐Nagy

The majority of methods for the optical monitoring of gases can be divided into two main groups. In the first, the intrinsicoptical properties of the gas are exploited to…

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167

Abstract

The majority of methods for the optical monitoring of gases can be divided into two main groups. In the first, the intrinsic optical properties of the gas are exploited to sense it. In the second group, an indicator is used to transduce the gas concentration into a measurable optical parameter. Most gas sensors are usually sensitive to only one parameter of the monitored gas. This paper contains a description of a gas multisensor that is suitable for measuring gas concentration and pressure at the same time. It needs a special sensor construction that can measure the mentioned properties in parallel. The essence of this sensor is the double rle of the diaphragm. This means that the diaphragm itself is for sensing the pressure and suitable layer with an immobilised reagent is applied on top of the diaphragm for sensing the concentration of the gas. The sensing method is a fibre guided incident light beam to the diaphragm's surface. The incident beam passes through the concentration‐sensitive layer twice as the diaphragm's surface reflects it. The properties of the reflected beam contain the required information — pressure and concentration — about the measured gas. At the output of the system the reflected light intensity is proportional to pressure and the spectrum is promotional to concentration of gas. The paper describes the design and results in detail.

Details

Microelectronics International, vol. 13 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 1 June 2000

L. Everall, A. Gallon and D. Roberts

This paper describes state‐of‐the‐art optical technology, employing Bragg gratings, which has been used to develop an Optical Fibre Strain Sensing System. This system is…

Abstract

This paper describes state‐of‐the‐art optical technology, employing Bragg gratings, which has been used to develop an Optical Fibre Strain Sensing System. This system is capable of providing actual strain and temperature information for new and existing structures. The sensors, written into the core of standard single mode optical fibre, are embedded into the composite material, or surface bonded on to the structure for load monitoring. The system can be used as a design tool for engineers, for composite cure‐monitoring, setting up of rigs etc., or can be used as a health monitoring tool to periodically monitor loading of bridges, buildings and pipelines.

Details

Sensor Review, vol. 20 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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