scholarly journals Application Research of Frequency-Modulated Continuous-Wave Displacement Sensor Based on Zero-Crossing Phase Detecting Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Bin Sun ◽  
Junfang Song ◽  
Gang Zheng ◽  
Xiongxing Zhang
Keyword(s):  
Optical Fiber ◽  
Continuous Wave ◽  
Optical Measurement ◽  
Complex Surface ◽  
Detection Algorithm ◽  
Displacement Sensor ◽  
Phase Detection ◽  
Laser Interference ◽  
Zero Crossing ◽  
Technical Specifications

Frequency-modulated continuous-wave (FMCW) interference, as a new technology of laser interferometry, has the advantages of length traceability, large range, high accuracy, simple structure, and optical fiber transmission. Based on the formula of FMCW laser interference displacement, a zero-crossing phase detection algorithm is proposed, which can accurately calculate the initial phase of a cosine signal in a modulation period, and it is successfully applied to the contact laser interference displacement sensor. The experimental results show that the FMCW technology based on the zero-crossing phase detection algorithm can achieve the technical specifications of the contact displacement sensor with a measurement range greater than 15 mm and the standard deviation is less than 0.01 μm. The conversion of noncontact measurement to contact measurement can realize the direct measurement of workpieces with complex surface conditions on the production line, breaking through the limitation of optical measurement and expanding the application of optical fiber interferometry.

scholarly journals High-precision optical fiber pressure sensor using frequency-modulated continuous-wave laser interference

AIP Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 025038
Author(s):  
Lang Bai ◽  
Gang Zheng ◽  
Bin Sun ◽  
Xiongxing Zhang ◽  
Qiming Sheng ◽  
...  
Keyword(s):  
Optical Fiber ◽  
High Precision ◽  
Pressure Sensor ◽  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Laser Interference ◽  
Wave Laser

A phasor-distance based faulty phase detection and fault classification technique for parallel transmission lines

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Nishant Kothari ◽  
Bhavesh R. Bhalja ◽  
Vivek Pandya ◽  
Pushkar Tripathi ◽  
Soumitri Jena
Keyword(s):  
Transmission Lines ◽  
Power Flow ◽  
Detection Algorithm ◽  
Current Transformer ◽  
Operating Conditions ◽  
Fault Classification ◽  
Phase Detection ◽  
Parallel Transmission ◽  
Classification Technique ◽  
Computational Requirement

AbstractThis paper presents a phasor-distance based faulty phase detection and fault classification technique for parallel transmission lines. Detection and classification of faulty phase(s) have been carried out by deriving indices from the change in phasor values of current with a distance of one cycle. The derived indices have zero values during normal operating conditions whereas the index corresponding to the faulty phase exceeds the pre-defined threshold in case of occurrence of a fault. A separate ground detection algorithm has been utilized for the identification of involvement of ground in a faulty situation. The performance of the proposed technique has been evaluated for intra-circuit, inter-circuit and simultaneous faults with wide variations in system and fault conditions. The suggested technique has been evaluated for over 23,000 diversified simulated fault cases as well as 14 recorded real fault events. The performance of the proposed technique remains consistent under Current Transformer (CT) saturation as well as different amount and direction of power flow. Moreover, suitability to different power system network has also been studied. Also, faults having fault current less than pre-fault conditions have been detected accurately. The results obtained suggest that it is able to detect faulty phases as well as classify faults within quarter-cycle from the inception of fault with impeccable accuracy. Besides, as modern digital relays have been already equipped with phasor computation facility, phasor-based technique can be easily incorporated with relative ease. At last, a comparative evaluation suggests its superiority in terms of fault classification accuracy, fault detection time, diversify fault scenarios and computational requirement among other existing techniques.

An enlarge polymer optical fiber linear-displacement sensor based on constructive interference

2021 ◽  
Vol 63 ◽  
pp. 102481
Author(s):  
Abdul Ghaffar ◽  
Mujahid Mehdi ◽  
YanYun Hu ◽  
Arnaldo G. Leal-Junior ◽  
Abdul Basit ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Linear Displacement ◽  
Displacement Sensor ◽  
Polymer Optical Fiber ◽  
Constructive Interference

Continuous-wave short-cavity laser based on the Er- Yb-codoped phosphorosilicate optical fiber

2020 ◽  
Author(s):  
D. S. Lipatov ◽  
A. N. Guryanov ◽  
A. S. Lobanov ◽  
A. N. Abramov ◽  
A. A. Umnikov ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Continuous Wave ◽  
Cavity Laser

scholarly journals Gait Phase Detection Based on Muscle Deformation with Static Standing-Based Calibration

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1081
Author(s):  
Tamon Miyake ◽  
Shintaro Yamamoto ◽  
Satoshi Hosono ◽  
Satoshi Funabashi ◽  
Zhengxue Cheng ◽  
...  
Keyword(s):  
Learning Algorithm ◽  
Detection System ◽  
Calibration Method ◽  
Detection Algorithm ◽  
Video Data ◽  
Detection Accuracy ◽  
Phase Detection ◽  
Gait Phase ◽  
Logistic Regression Algorithm ◽  
Short Time

Gait phase detection, which detects foot-contact and foot-off states during walking, is important for various applications, such as synchronous robotic assistance and health monitoring. Gait phase detection systems have been proposed with various wearable devices, sensing inertial, electromyography, or force myography information. In this paper, we present a novel gait phase detection system with static standing-based calibration using muscle deformation information. The gait phase detection algorithm can be calibrated within a short time using muscle deformation data by standing in several postures; it is not necessary to collect data while walking for calibration. A logistic regression algorithm is used as the machine learning algorithm, and the probability output is adjusted based on the angular velocity of the sensor. An experiment is performed with 10 subjects, and the detection accuracy of foot-contact and foot-off states is evaluated using video data for each subject. The median accuracy is approximately 90% during walking based on calibration for 60 s, which shows the feasibility of the static standing-based calibration method using muscle deformation information for foot-contact and foot-off state detection.

Continuous-wave laser oscillation with an ultralong optical-fiber resonator

1982 ◽  
Vol 72 (10) ◽  
pp. 1338 ◽  
Author(s):  
Masataka Nakazawa ◽  
Masamitsu Tokuda ◽  
Naoya Uchida
Keyword(s):  
Optical Fiber ◽  
Continuous Wave ◽  
Laser Oscillation ◽  
Continuous Wave Laser ◽  
Wave Laser
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