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1 – 10 of over 3000Yongxing 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 measurement…
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.
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Shaoyi Xu, Fangfang Xing, Ruilin Wang, Wei Li, Yuqiao Wang and Xianghui Wang
At present, one of the key equipment in pillar industries is a large rotating machinery. Conducting regular health monitoring is important for ensuring safe operation of the large…
Abstract
Purpose
At present, one of the key equipment in pillar industries is a large rotating machinery. Conducting regular health monitoring is important for ensuring safe operation of the large rotating machinery. Because vibrations sensors play an important role in the workings of the rotating machinery, measuring its vibration signal is an important task in health monitoring. This paper aims to present these.
Design/methodology/approach
In this work, the contact vibration sensor and the non-contact vibration sensor have been discussed. These sensors consist of two types: the electric vibration sensor and the optical fiber vibration sensor. Their applications in the large rotating machinery for the purpose of health monitoring are summarized, and their advantages and disadvantages are also presented.
Findings
Compared with the electric vibration sensor, the optical fiber vibration sensor of large rotating machinery has unique advantages in health monitoring, such as provision of immunity against electromagnetic interference, requirement of less insulation and provision of long-distance signal transmission.
Originality/value
Both contact vibration sensor and non-contact vibration sensor have been discussed. Among them, the electric vibration sensor and the optical fiber vibration sensor are compared. Future research direction of the vibration sensors is presented.
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Keywords
Abstract
Purpose
The purpose of this paper is to extract the angle information of direct P wave within multidimensional vibration signals obtained through the sensor array, and to realize high precision shallow burst point localization based on direct of angle (DOA).
Design/methodology/approach
This paper presents a method which combines adaptive covariance matrix (ACM) algorithm with geometric constraint conditions for extracting the angle information of direct P wave by using its polarization characteristics. First, modify the obtained three-dimensional vibration data by using attitude rotation matrix and unify the coordinate system of vibration field. Next, construct the beam model of direct P wave by making use of ACM algorithm and extract its angle information. Finally, modify P wave beam model by taking advantage of the space geometric constraint relations between nodes.
Findings
The results of numerical simulation show that this method not only can extract the angle information of direct P wave arriving at each node effectively, but also can evaluate the quality of extracted angle information of direct P wave. Meanwhile, the results of underground shallow explosion experiment show that this method can extract the angle information of direct P wave of each node significantly and can realize underground shallow explosion source localization based on DOA by using this information, the location error can be limited less than 50 cm and satisfies the location requirements of shallow burst point.
Originality/value
This paper provides a method for various problems of underground localization based on the sensor array, such as directional demolition blasting, underground damage assessment, earth-penetrating projectile burst point positioning in weaponry industry testing plant, etc., and has definite value to engineering application in underground space positioning field.
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Milos Milovancevic and Edvard Tijan
The purpose of this research paper is to develop and analyze micro-electro-mechanical systems sensor for vibration monitoring of pumping aggregate.
Abstract
Purpose
The purpose of this research paper is to develop and analyze micro-electro-mechanical systems sensor for vibration monitoring of pumping aggregate.
Design/methodology/approach
The system is based on smart sensor and smart mobile phone.
Findings
The numerous measurements on a wide range of turbo aggregates were performed to establish the operating condition of pumping aggregates.
Originality/value
Afterwards, the influence of vibration at different positions on the output vibration of the pumping aggregate was analyzed by adaptive neuro fuzzy inference system method.
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Jinxue Sui, Xia Zhang, Li Yang, Zhilin Zhu and Zhang Xin
Vibration measurement is needed in many industrial production processes, such as equipment monitoring, fault diagnosis, and noise analysis and eliminating and so on. The purpose…
Abstract
Purpose
Vibration measurement is needed in many industrial production processes, such as equipment monitoring, fault diagnosis, and noise analysis and eliminating and so on. The purpose of this paper is to propose a simple vibration testing system which includes the laser, the string, position sensitive detector (PSD) and the corresponding signal processing circuit.
Design/methodology/approach
PSD is an optical semiconductor sensor that can fast locate the luminous spot position precisely, which means that it can output different electric current according to the luminous spot at different position of its surface. Moreover, the experiment on PSD sensor using different vibration source and frequency had been carried out. Finally, the vibration waveform of the luminous spot on PSD photosurface was obtained.
Findings
According to the experimental results, each kind of vibration parameter with different vibration source, such as vibration frequency and amplitude can be calculated.
Originality/value
The experimental results agreed with the actual parameter, which showed PSD not only had its own good qualities in the position measurement, but also had the unique superiority in the vibration measurement.
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Li Hong, Yewei Wang, Zhongchao Qiu, Jianxian Cai, Zhenjing Yao and Zhitao Gao
The purpose of this paper is to solve the problem of weak low-frequency vibration measurement capability of FBG accelerometer, and propose a FBG accelerometer based on cross reed.
Abstract
Purpose
The purpose of this paper is to solve the problem of weak low-frequency vibration measurement capability of FBG accelerometer, and propose a FBG accelerometer based on cross reed.
Design/methodology/approach
This study proposed a new type FBG acceleration sensor based on cross reeds. When the sensor vibrates, the mass block in the new structure rotates around the center of the cross reeds, which could eliminate the impact of friction, reduce the natural frequency of the sensor and improve its sensitivity. This study theoretically analyzed the impact of several structural parameters on the sensitivity and natural frequency of the proposed sensor and used COMSOL to perform static stress analysis and modal simulation; in this study, a test system was built to test the performance of the proposed sensor.
Findings
The test results revealed that the proposed sensor had a natural frequency of 94 Hz; within a low-frequency range of 1–65 Hz, its sensitivity response was flat, the dynamic range was 81.89 dB, the sensitivity was 243.59 pm/g and the linearity was 99.97%. The cross reeds effectively strengthened the structural stability, the relative standard deviation of the repeatability of the sensor was 0.89% and the transverse crosstalk in the working frequency band was −26.97 dB.
Originality/value
This study innovatively proposes the structure of the two symmetrical cross reeds, which can improve sensitivity by eliminating the influence of friction, and the structure of cross reeds can effectively suppress the influence of lateral crosstalk. The proposed sensor can realize real-time accurate measurement of low-frequency weak vibration signals.
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Adli B. Haddad and Bassem O.F. Al-Bedoor
In this paper, a vibration measuring technique that relies on the use of piezoelectric material and is originally developed to measure the vibration of turbine blade is adopted to…
Abstract
Purpose
In this paper, a vibration measuring technique that relies on the use of piezoelectric material and is originally developed to measure the vibration of turbine blade is adopted to measure the vibration of cutting tool in turning. The piezoelectric material is embedded at the root of the cutting tool. The scope of this research is to investigate the feasibility of using this technique by first conducting ANSYS simulation to solve the coupled field equations that govern the piezoelectric phenomenon followed by experimental work to compare the measured data with those obtained by conventional method to have an insight into the effectiveness of the adopted technique. Both simulation and experimental results show that the use of an embedded PZT sensor at the root of cutting tool is very useful for measuring vibration and can be used for further cutting operation control. In addition, it has captured more information than conventional vibration measurement techniques.
Design/methodology/approach
Vibration measurement of root-embedded PZT material to convert the dynamic cutting forces into vibration signals that can be used in cutting process optimization and improvement of cutting quality.
Findings
PZT material is found to be very responsive to high-frequency vibrations such that it can catch Chatter phenomena and can be used in developing control strategies.
Research limitations/implications
Mainly used for turning cutting process in this research. Other manufacturing process like milling special tool holder designs.
Practical implications
Can be used as online monitoring systems for cutting tool holders.
Social implications
Engineer and technician aid in quality assurance and control.
Originality/value
The new approach of embedding PZT material at the cutting tool root and the signals presentation and processing.
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Emine Ayaz, Ahmet Öztürk, Serhat Şeker and Belle R. Upadhyaya
The purpose of this paper is to extract features from vibration signals measured from induction motors subjected to accelerated aging of bearings by fluting tests.
Abstract
Purpose
The purpose of this paper is to extract features from vibration signals measured from induction motors subjected to accelerated aging of bearings by fluting tests.
Design/methodology/approach
Aging tests were performed according to IEEE test procedures. The data acquisition involved the measurement of vibration signals using accelerometers that were installed on the bearings and on the motor casing. In this application, only two accelerometers, which were placed near the process end of the motor bearing, are used for data analysis and feature extraction studies. After the data collection, information from the two sensors was combined using simple sensor fusion method under the linearity conditions, and then spectral analysis and time‐scale analysis were performed. The fused vibration signal is decomposed into several scales using continuous wavelet transform (CWT) and its first scale is used to indicate the bearing degradation.
Findings
Bearing damage characterization was determined between 2‐4 kHz and some specific frequencies were calculated as harmonics of the bearing characteristic frequencies.
Research limitations/implications
The bearing damage characteristics used in this study is occurred by the experimental study. In terms of the methodology, the use of the CWT shows the fault characteristics from the initial case.
Practical implications
The experimental study and data acquisition are based on the accelerated aging of the motor bearings. Hence, the real aging is represented by the accelerated one. But, this situation reflects same properties of the aging occurred in industrial environments. The methodology is also applicable to the hardware application.
Originality/value
There are two important aspects of this research: the experimental study and the application of CWT to get the potential defects, which will appear as a failure in future, from the healthy case of the motor bearings.
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Stylianos K. Georgantzinos, Georgios I. Giannopoulos and Nick K. Anifantis
The purpose of this paper is to examine the potential of single-walled carbon nanotubes as mass sensors by developing analytical expressions and then comparing the outcome with…
Abstract
Purpose
The purpose of this paper is to examine the potential of single-walled carbon nanotubes as mass sensors by developing analytical expressions and then comparing the outcome with structural mechanics corresponding predictions.
Design/methodology/approach
The carbon nanotube (CNT) resonators are assumed to be either single or double clamped. Analytical formulas capable of describing the vibrational behavior of such CNT-based nanoresonators with an attached mass at nanotube tip or various intermediate positions are developed by combining the Euler–Bernoulli theory and Krylov–Duncan functions.
Findings
The validity and the accuracy of these formulas are examined for a wide range of cases via comparisons with corresponding results arisen by spring- or beam-based structural mechanics predictions. Both structural mechanics approaches utilize three-dimensional nanoscale elements formulated according to the molecular theory. The results indicate that the new sensor equations may be utilized for the estimation of vibration response of CNT-based mass sensors with reasonable accuracy.
Originality/value
Simple analytical formulas are proved to approximate the mass sensing ability of CNTs adequately, the fact that may significantly contribute in the effort of developing new sensor devices.
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The purpose of this paper is to describe the techniques and technologies used in a selection of sensors which operate in extreme environments.
Abstract
Purpose
The purpose of this paper is to describe the techniques and technologies used in a selection of sensors which operate in extreme environments.
Design/methodology/approach
Following a short introduction, this paper discusses the technologies used in a range of sensors, principally accelerometers and pressure, temperature and displacement sensors, used in environments characterised by elevated temperatures, radiation and high shock and vibration levels.
Findings
The paper shows that a range of different strategies is employed to allow sensors to operate in extreme environments. These include specialised designs, novel sensing technologies and others which are inherently capable of withstanding extreme conditions and materials which can perform in, or which are resistant to, these environments. Several new technologies are under development which aim to extend sensor performance to new levels.
Originality/value
This paper provides details of the technologies used in a range of sensors aimed at applications in extreme environments.
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