We report a fiber Bragg grating（FBG）-based sensor for the simultaneous measurement of a train bearing’s vibration and temperature. A pre-stretched optical fiber with an FBG and a mass is designed for axial vibratio...We report a fiber Bragg grating（FBG）-based sensor for the simultaneous measurement of a train bearing’s vibration and temperature. A pre-stretched optical fiber with an FBG and a mass is designed for axial vibration sensing. Another multiplexed FBG is embedded in a selected copper-based alloy with a high thermal expansion to detect temperature. Experiments show that the sensor possesses a high resonant frequency of 970 Hz, an acceleration sensitivity of 27.28 pm/g, and a high temperature sensitivity of 35.165 pm/℃. A resonant excitation test is also carried out that demonstrates the robustness and reliability of the sensor.展开更多
A novel fiber temperature sensor based on multimode interference theory is proposed and experimentally demonstrated.The sensing head is formed by a fiber bragg grating(FBG)connected with single-mode-no core-single-mod...A novel fiber temperature sensor based on multimode interference theory is proposed and experimentally demonstrated.The sensing head is formed by a fiber bragg grating(FBG)connected with single-mode-no core-single-mode fiber(SNS)fiber structure which consists of two sections of single mode fiber and no-core fiber.Using such a structure,not only the reflective measurement can be realized,but also the need for a gold-plated film can be avoided at the end of the fiber to enhance the reflected light signal.More importantly,the sensitivity is increased by 4 times as compared with the conventional FBG temperature sensor according to the experimental results,and it also provides the development space for multi-parameters monitoring.展开更多
Wavelength division multiplex has obvious advantages when it is used in fiber Bragg grating(FBG) sensing for simultaneous measurement of various quantities, but the number of sensors is usually restricted by the bandw...Wavelength division multiplex has obvious advantages when it is used in fiber Bragg grating(FBG) sensing for simultaneous measurement of various quantities, but the number of sensors is usually restricted by the bandwidth of SLED and demodulator. The identical fiber Bragg grating is introduced for fire alarm system and the method of collecting signal of identical FBG sensors is described. The experiment result shows that with identical FBG sensing. The number of the sensors coupled in one fiber increases greatly and the precision can be ensured to meet the requirement for fire alarm system.展开更多
This study proposes a method for real-time monitoring of lithium-ion battery(LiB)internal temperatures through the temperature response of an embedded fiber Bragg grating(FBG)sensor.This approach overcomes the limitat...This study proposes a method for real-time monitoring of lithium-ion battery(LiB)internal temperatures through the temperature response of an embedded fiber Bragg grating(FBG)sensor.This approach overcomes the limitations of most methods that can only detect the external temperature at limited places by providing the advantages of sensing both the internal temperature and external temperature at multiple points simultaneously for precise condition monitoring.In addition,a numerical LiB cell model was developed to investigate the heat generation and temperature gradient using the finite element analysis method.The outcomes show that this model can be used to predict the temperature with less than 5%discrepancy(1.5°C)compared with experimental results.Thereby,this proposed method can be effectively used to monitor the safety and state of health of LiBs and other types of rechargeable batteries in real-time.展开更多
The digital monitoring principle and technologies for heavy duty mechanical equipment based on fiber Bragg grating (FBG) technology are introduced in this paper. The fundamentals of new-style FBG sensing technology, i...The digital monitoring principle and technologies for heavy duty mechanical equipment based on fiber Bragg grating (FBG) technology are introduced in this paper. The fundamentals of new-style FBG sensing technology, including the photorefractive effect of FBG, the physical formation, and the relation between optical properties and grating parameters, are investigated. The plaster, encapsulation and distribution planning of FBG sensor (FBGS), which is used to monitor heavy duty mechanical equipment under abominable environment and extreme conditions, are also studied. In addition, theoretical and experimental researches on the strain, temperature, displacement, and stress transmission characteristics between FBGS and detection interface are presented. The principle and method for temperature compensation in non-uniformity temperature field are described in detail as well. Comparing with the traditional sensing monitoring techniques, the application of FBGS technology on digital monitoring and diagnosis for heavy duty mechanical equipment has a number of significant technical advantages and will make a new breakthrough in this field.展开更多
基金supported in part by the National Natural Science Foundation of China(Nos.51605348 and 51605344)in part by the Natural Science Foundation of the Hubei Province(No.2016CFB116)in part by the Open Research Fund of the Hubei Digital Manufacturing Key Laboratory(No.SZ1801)
文摘We report a fiber Bragg grating（FBG）-based sensor for the simultaneous measurement of a train bearing’s vibration and temperature. A pre-stretched optical fiber with an FBG and a mass is designed for axial vibration sensing. Another multiplexed FBG is embedded in a selected copper-based alloy with a high thermal expansion to detect temperature. Experiments show that the sensor possesses a high resonant frequency of 970 Hz, an acceleration sensitivity of 27.28 pm/g, and a high temperature sensitivity of 35.165 pm/℃. A resonant excitation test is also carried out that demonstrates the robustness and reliability of the sensor.
基金supported by the National Natural Science Foundation of China(No.U1537102)the Fund of Aeronautics Science(No.20152852036,20170252004)+2 种基金the Fundamental Research Funds for the Central Universities(NS2016004)the Shanghai Academy of Spaceflight Technology(No.SAST2015062)the State Key Laboratory of Mechanics and Control of Mechanical Structures(Nanjing University of Aeronautics and astronautics)(No.MCMS-0516K01)
文摘A novel fiber temperature sensor based on multimode interference theory is proposed and experimentally demonstrated.The sensing head is formed by a fiber bragg grating(FBG)connected with single-mode-no core-single-mode fiber(SNS)fiber structure which consists of two sections of single mode fiber and no-core fiber.Using such a structure,not only the reflective measurement can be realized,but also the need for a gold-plated film can be avoided at the end of the fiber to enhance the reflected light signal.More importantly,the sensitivity is increased by 4 times as compared with the conventional FBG temperature sensor according to the experimental results,and it also provides the development space for multi-parameters monitoring.
基金National Natural Science Foundation of China(60537050)
文摘Wavelength division multiplex has obvious advantages when it is used in fiber Bragg grating(FBG) sensing for simultaneous measurement of various quantities, but the number of sensors is usually restricted by the bandwidth of SLED and demodulator. The identical fiber Bragg grating is introduced for fire alarm system and the method of collecting signal of identical FBG sensors is described. The experiment result shows that with identical FBG sensing. The number of the sensors coupled in one fiber increases greatly and the precision can be ensured to meet the requirement for fire alarm system.
基金supported by the National Natural Science Foundation of China(Nos.62365013,62175097,and 62065013)the 03 Special Project and 5G Project of Jiangxi Province(No.20232ABC03A05).
文摘This study proposes a method for real-time monitoring of lithium-ion battery(LiB)internal temperatures through the temperature response of an embedded fiber Bragg grating(FBG)sensor.This approach overcomes the limitations of most methods that can only detect the external temperature at limited places by providing the advantages of sensing both the internal temperature and external temperature at multiple points simultaneously for precise condition monitoring.In addition,a numerical LiB cell model was developed to investigate the heat generation and temperature gradient using the finite element analysis method.The outcomes show that this model can be used to predict the temperature with less than 5%discrepancy(1.5°C)compared with experimental results.Thereby,this proposed method can be effectively used to monitor the safety and state of health of LiBs and other types of rechargeable batteries in real-time.
基金Supported by the National Natural Science Foundation of China (Grant Nos.50620130441 and 50775167)
文摘The digital monitoring principle and technologies for heavy duty mechanical equipment based on fiber Bragg grating (FBG) technology are introduced in this paper. The fundamentals of new-style FBG sensing technology, including the photorefractive effect of FBG, the physical formation, and the relation between optical properties and grating parameters, are investigated. The plaster, encapsulation and distribution planning of FBG sensor (FBGS), which is used to monitor heavy duty mechanical equipment under abominable environment and extreme conditions, are also studied. In addition, theoretical and experimental researches on the strain, temperature, displacement, and stress transmission characteristics between FBGS and detection interface are presented. The principle and method for temperature compensation in non-uniformity temperature field are described in detail as well. Comparing with the traditional sensing monitoring techniques, the application of FBGS technology on digital monitoring and diagnosis for heavy duty mechanical equipment has a number of significant technical advantages and will make a new breakthrough in this field.
