Eddy Current Detection for Weld Defect and Automatic Separating System for Defective HFW Pipe

2013 ◽  
Vol 457-458 ◽  
pp. 344-349
Author(s):  
Xiao Qin Shen ◽  
Fu Sheng Yu ◽  
Ying Bao

An eddy current detection and automatic separating system is developed to defect the weld defects in HFW pipe and separate the defective pipe. Application of phase sensitive detector, the pure signal of the weld defect is obtained through a low-pass filter. The information of the weld defect signal, the displacement of flying saw and the welding speed of welded pipe are fused together. The mathematical model is established for unfixed length truncation of the defective welded pipe. An automatic separating system is designed to cut and separate the defective welded pipes in the production line. The practice shows that this system can accurately detect the weld defect, cut the welded pipe in the perfect position and maximumly reserve the welded pipe without defect. This detection and separating system can improve the quality of the welded pipes and avoid the waste.

2012 ◽  
Vol 433-440 ◽  
pp. 5714-5721
Author(s):  
Jin Shan Gao ◽  
Shi Jie Wang

Application of FPAA (field programmable analog array) for the construction of phase-sensitive detector is described. The working principle of the phase sensitive detector is introduced. With software called Anadigmdesigner2, a signal selection circuit, a inverting circuit, a rectifier and a low pass filter circuit are achieved. The simulation of the phase-sensitive detector circuit designed is made. Phase rang from 75º to 115 º, phase errors detected are below ±0.392%.


2013 ◽  
Vol 389 ◽  
pp. 489-493
Author(s):  
Yong Lv ◽  
Chun Hui Niu ◽  
Yue Qiang Li ◽  
Qing Shan Chen ◽  
Xiao Ying Li ◽  
...  

In order to detect the weak signal deeply buried in the noise, a weak signal detection system based on lock-in amplifier is proposed. The system includes the preamplifier circuit, active low pass filter circuit, AC amplifying circuit and phase sensitive demodulation circuit. Test results show that it can greatly increase the signal-to-noise ratio (SNR) up to 12.7db.


10.12737/7905 ◽  
2015 ◽  
Vol 7 (4) ◽  
pp. 35-38
Author(s):  
Табаков ◽  
Yu. Tabakov ◽  
Лавлинский ◽  
V. Lavlinskiy

The article includes a block diagram and the mathematical model for low pass filter designed for processing low frequency signal with a frequency of 10-40 Hz in order of eliminate various noises and interference.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 945
Author(s):  
Peng Guo ◽  
Jiayu Zhang ◽  
Lihui Feng ◽  
Jianmin Cui ◽  
Chaoyang Xing

In order to quantitatively study the interfered output of the accelerometer under an acoustic injection attack, a mathematical model for fitting and predicting the accelerometer output was proposed. With ADXL103 as an example, an acoustic injection attack experiment with amplitude sweeping and frequency sweeping was performed. In the mathematical model, the R-squared coefficient was R2 = 0.9990 in the acoustic injection attack experiment with amplitude sweeping, and R2 = 0.9888 with frequency sweeping. Based on the mathematical model, the dual frequency acoustic injection attack mode was proposed. The difference frequency signal caused by the nonlinear effect was not filtered by the low-pass filter. At a 115 dB sound pressure level, the maximum acceleration bias of the output was 4.4 m/s2 and the maximum amplitude of fluctuation was 4.97 m/s2. Two kinds of methods of prevention against acoustic injection attack were proposed, including changing the damping ratio of the accelerometer and adding a preposition low-pass filter.


2017 ◽  
Vol E100.C (10) ◽  
pp. 858-865 ◽  
Author(s):  
Yohei MORISHITA ◽  
Koichi MIZUNO ◽  
Junji SATO ◽  
Koji TAKINAMI ◽  
Kazuaki TAKAHASHI

2016 ◽  
Vol 15 (12) ◽  
pp. 2579-2586
Author(s):  
Adina Racasan ◽  
Calin Munteanu ◽  
Vasile Topa ◽  
Claudia Pacurar ◽  
Claudia Hebedean

Sign in / Sign up

Export Citation Format

Share Document