scholarly journals Displacement Sensing of an Active String Actuator by an Optical Fiber

2021 ◽  
Vol 10 (1) ◽  
pp. 35
Author(s):  
Weihang Tian ◽  
Shuichi Wakimoto ◽  
Kazuya Nagaoka ◽  
Yorifumi Yoshimoto ◽  
Takefumi Kanda ◽  
...  

We have fabricated a string-shaped actuator called “Active string” that has high contractile displacement/force by accumulating thin pneumatic artificial muscles using the string production process. However, displacement control of the active string is challenging because general bulky and rigid displacement sensors are not suitable for the sensor element of the active string. Therefore, in this report, a flexible optical fiber sensor is combined with the active string to enable sensing of its displacement. As the active string contracts, the radius of curvature of the optical fiber decreases, and light intensity propagating in the optical fiber decreases due to bending loss. The experimental results showed that the optical fiber sensor value changed with corresponding to the displacement of the active string. It shows the possibility that it is possible to make a displacement estimation of the displacement of the active string using an optical fiber sensor.

2021 ◽  
Vol 22 ◽  
pp. 48
Author(s):  
Yujie Li ◽  
Ming Zhang ◽  
Yu Zhu

This paper proposes a POI displacement estimation method based on the functional optical fiber sensor and the phase modulation principle to improve the POI displacement estimation accuracy. First, the relation between the object deformation and the optic fiber lightwave phase is explained; the measurement principle of functional optical fiber sensor based on the heterodyne interference principle and its layout optimization method is proposed, and a POI displacement estimation model is presented based on the data approach. Secondly, a beam is taken as the simulation object, the optimal position and length of the optical fiber sensor are determined based on its simulation data. Finally, the experimental device is designed to verify the effectiveness of the POI displacement estimation method based on the optic fiber sensors. The frequency-domain plot of the signals shows that the optical fiber sensors can express the flexible deformation of the analyzed object well. The POI displacement estimation model with the fiber optic sensor signals as one of the inputs is constructed. Through estimating the test data, the error using the optical fiber sensor-based POI displacement estimation method proposed in this paper reduces by more than 61% compared to the rigid body-based assumption estimation method.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Jianchun Qiu ◽  
Dongjian Zheng ◽  
Kai Zhu ◽  
Bin Fang ◽  
Lin Cheng

Considering the differential settlement in the junction between the structure perpendicular to the dike and the body and foundation of dike (called the earth-rock junction in this paper) during runtime, an experimental investigation of optical fiber sensor monitoring was conducted. Based on the sensing mechanism of single-mode optical fiber bending loss, the experiment focused on the influence of the bending radius of an optical fiber on the bending loss. In view of the characteristics of the differential settlement in the earth-rock junction, we designed a butterfly-type optical fiber sensor and composite optical fiber sensor for monitoring device in monitoring the differential settlement to enlarge the monitoring range and improve the sensibility of optical fiber sensor. Based on the research on the working principle and bending properties of the composite optical fiber monitoring device, we conducted experiments on the bending of the composite optical fiber sensor monitoring device and the use of the device for monitoring the differential settlement. These experiments verified the feasibility of the composite optical fiber sensor monitoring device at monitoring the differential settlement in the earth-rock junction.


Author(s):  
Dakuan Yu ◽  
Xueguang Qiao ◽  
Xiangyu Wang ◽  
Lisong Zhang

The optical fiber sensor for oriented bending based on eccentric UV exposure is fabricated. With the eccentric UV exposure on the ready-made Michelson interference fiber structure, the optical sensor gives the oriented bending characteristics by changing the radial circular symmetry of fiber cladding refractive indexes. The principle of the asymmetric process of the eccentric exposure to cladding mode are analyzed. The bending loss of the excited cladding mode in different radial directions is detected. The experimental results show that the Michelson interference has some oriented bending characteristics in the eccentric UV exposure process. There are different bending sensitivity in different radial directions. Furthermore, the bending sensitivity is higher on the exposed side and the curvature sensitivity is 5.5 dB·m. On the opposite side, the bending sensitivity is lower and the curvature sensitivity is -1.31 dB·m. With these oriented bending characteristics, the optical sensor can be applied to oil and gas exploration and development and to oriented seismic wave vector detection.


2018 ◽  
Vol 56 (1) ◽  
pp. 94-99
Author(s):  
N. Sogabe ◽  
S. Nakaue ◽  
K. Chikiri ◽  
M. Hayakawa

2019 ◽  
Vol 5 (0) ◽  
pp. 19-00095-19-00095
Author(s):  
Shogo FUJIMOTO ◽  
Suguru UEMURA ◽  
Nobuyuki IMANISHI ◽  
Shuichiro HIRAI

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1166
Author(s):  
Bin Liu ◽  
Jianping He ◽  
Shihai Zhang ◽  
Yinping Zhang ◽  
Jianan Yu ◽  
...  

Brillouin frequency shift (BFS) of distributed optical fiber sensor is extracted from the Brillouin gain spectrum (BGS), which is often characterized by Lorenz type. However, in the case of complex stress and optical fiber self damage, the BGS will deviate from Lorenz type and be asymmetric, which leads to the extraction error of BFS. In order to enhance the extraction accuracy of BFS, the Lorenz local single peak fitting algorithm was developed to fit the Brillouin gain spectrum curve, which can make the BSG symmetrical with respect to the Brillouin center frequency shift. One temperature test of a fiber-reinforced polymer (FRP) packaged sensor whose BSG curve is asymmetric was conducted to verify the idea. The results show that the local region curve of BSG processed by the developed algorithm has good symmetry, and the temperature measurement accuracy obtained by the developed algorithm is higher than that directly measured by demodulation equipment. Comparison with the reference temperature, the relative measurement error measured by the developed algorithm and BOTDA are within 4% and 8%, respectively.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hyeong-Min Kim ◽  
Dae Hong Jeong ◽  
Ho-Young Lee ◽  
Jae-Hyoung Park ◽  
Seung-Ki Lee

AbstractA simple optical fiber sensor based on localized surface plasmon resonance was constructed for direct and rapid measurement of thyroglobulin (Tg). Specific tests for Tg in patients that have undergone thyroidectomy are limited because of insufficient sensitivity, complicated procedures, and in some cases, a long time to yield a result. A sensitive, fast, and simple method is necessary to relieve the psychological and physical burden of the patient. Various concentrations of Tg were measured in a microfluidic channel using an optical fiber sensor with gold nanoparticles. The sensor chip has a detection limit of 93.11 fg/mL with no specificity for other antigens. The potential applicability of the Tg sensing system was evaluated using arbitrary samples containing specific concentrations of Tg. Finally, the sensor can be employed to detect Tg in the patient’s serum, with a good correlation when compared with the commercial kit.


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