scholarly journals Determination of Surface Crack Orientation Based on Thin-Skin Regime Using Triple-Coil Drive–Pickup Eddy-Current Sensor

2021 ◽  
Vol 70 ◽  
pp. 1-9
Author(s):  
Mingyang Lu ◽  
Xiaobai Meng ◽  
Ruochen Huang ◽  
Liming Chen ◽  
Zezhi Tang ◽  
...  
Keyword(s):  
Eddy Current ◽  
Surface Crack ◽  
Current Sensor ◽  
Crack Orientation ◽  
Eddy Current Sensor ◽  
Thin Skin

scholarly journals Determination of Surface Crack Orientation Based on Thin-Skin Regime Using Triple-Coil Drive-Pickup Eddy-Current Sensor

2020 ◽  
Author(s):  
Mingyang Lu ◽  
Xiaobai Meng ◽  
Ruochen Huang ◽  
Liming Chen ◽  
Zezhi Tang ◽  
...  
Keyword(s):  
Eddy Current ◽  
Surface Crack ◽  
Surface Defects ◽  
Current Sensor ◽  
Voltage Measurement ◽  
Small Surface ◽  
Eddy Current Sensor ◽  
Voltage Change ◽  
Excitation Coil ◽  
Thin Skin

Electromagnetic sensors have been used for inspecting small surface defects of metals. Based on the eddy-current thin-skin regime, a revised algorithm is proposed for a triple-coil drive-pickup eddy-current sensor scanning over long surface crack slots (10 mm) with different rotary angles. The method is validated by the voltage measurement of the designed EC sensor scanning over a benchmark (ferromagnetic) steel with surface defects of different depths and rotary angles. With an additional sensing coil for the designed EC sensor, the defect angle (or orientation) can be measured without spatially and coaxially rotating the excitation coil. By referring to the voltage change (due to the defect) diagram (voltage sum versus voltage different) of two sensing pairs, the rotary angle of the surface crack is retrieved with a maximum residual deviation of 3.5 %.

scholarly journals Analysis of Tilt Effect on Notch Depth Profiling Using Thin-Skin Regime of Driver-Pickup Eddy-Current Sensor

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5536
Author(s):  
Mingyang Lu ◽  
Xiaobai Meng ◽  
Ruochen Huang ◽  
Anthony Peyton ◽  
Wuliang Yin
Keyword(s):  
Eddy Current ◽  
Tilt Angle ◽  
Depth Profiling ◽  
Current Sensor ◽  
Notch Depth ◽  
Measured Voltage ◽  
Eddy Current Sensor ◽  
Thin Skin ◽  
Different Depths ◽  
Current Sensors

Electromagnetic eddy current sensors are commonly used to identify and quantify the surface notches of metals. However, the unintentional tilt of eddy current sensors affects results of size profiling, particularly for the depth profiling. In this paper, based on the eddy current thin-skin regime, a revised algorithm has been proposed for the analytical voltage or impedance of a tilted driver–pickup eddy current sensor scanning across a long ideal notch. Considering the resolution of the measurement, the bespoke driver–pickup, also termed as transmitter–receiver (T-R) sensor is designed with a small mean radius of 1 mm. In addition, the T-R sensor is connected to the electromagnetic instrument and controlled by a scanning stage with high spatial travel resolution, with a limit of 0.2 μm and selected as 0.25 mm. Experiments were conducted for imaging of an aluminium sheet with seven machined long notches of different depths using T-R sensor under different tilt angles. By fitting the measured voltage (both real and imaginary part) with proposed analytical algorithms, the depth profiling of notches is less affected by the tilt angle of sensors. From the results, the depth of notches can be retrieved within a deviation of 10% for tilt angles up to 60 degrees.

scholarly journals Inversion of Distance and Magnetic Permeability Based on Material-Independent and Lift-off Insensitive Algorithms Using Eddy Current Sensor

2020 ◽  
Author(s):  
Mingyang Lu ◽  
Xiaobai Meng ◽  
Ruochen Huang ◽  
Liming Chen ◽  
Anthony Peyton ◽  
...  
Keyword(s):  
Eddy Current ◽  
Magnetic Permeability ◽  
Skin Effect ◽  
Maximum Error ◽  
Current Sensor ◽  
Dual Frequency ◽  
Eddy Current Sensor ◽  
Thin Skin ◽  
Lift Off ◽  
Effect Experiment

Eddy current sensors can be used to test the characteristics and measure the parameters of the conductive samples. As the main obstacle of the multi-frequency eddy current sensor, the lift-off distance affects the effectiveness and accuracy of the measurement. In this paper, a material-independent algorithm has been proposed for the restoration of the lift-off distance when using the multi-frequency eddy current sensor, which is based on the approximation under the thin-skin effect. Experiment testing on the performance of the proposed method is presented. Results show that from the dual-frequency inductance, the lift-off distance could be restored with a maximum error of 0.24 mm for the distance up to 12 mm. Besides, the derived lift-off distance is used for the inversion of the magnetic permeability. Based on a lift-off insensitive inductance (LII) feature, the magnetic permeability of steels can be inversed in an iterative manner, with an error of less than 0.6 % for the lift-off distance up to 12 mm.

scholarly journals Analysis of Tilt Effect on Notch Depth Profiling Using Thin-Skin Regime of Driver-Pickup Eddy-Current Sensor

2021 ◽  
Author(s):  
Mingyang Lu ◽  
Xiaobai Meng ◽  
Ruochen Huang ◽  
Anthony Peyton ◽  
Wuliang Yin
Keyword(s):  
Eddy Current ◽  
Depth Profiling ◽  
Current Sensor ◽  
Notch Depth ◽  
Voltage Imaging ◽  
Measured Voltage ◽  
Eddy Current Sensor ◽  
Thin Skin ◽  
Different Depths ◽  
Current Sensors

Electromagnetic eddy current sensors are commonly used to identify and quantify the surface notches of metals. However, the unintentional tilt of eddy current sensors affects results of size profiling, particularly for the depth profiling. In this paper, based on the eddy current thin-skin regime, a revised algorithm has been proposed for the analytical voltage or impedance of a tilted driver–pickup eddy current sensor scanning across a long ideal notch. Considering the resolution of the measurement, the bespoke driver–pickup, also termed as transmitter-receiver (T-R) sensor is designed with a small mean radius of 1 mm. Besides, the T-R sensor is connected to the electromagnetic instrument and controlled by a scanning stage with high spatial travel resolution , with a limit of 0.2 μm and selected as 0.25 mm. Experiments have been out on the voltage imaging of an aluminium sheet with 7 machined long notches of different depths using T-R sensor under different tilt angles. By fitting the measured voltage (both real and imaginary part) with proposed analytical algorithms, the depth profiling of notches is less affected by the tilt angle of sensors. From the results, the depth of notches can be retrieved within a deviation of 10 % for tilt angles up to 60 degrees.

Inspection of Surface Rolled Sintered Gears using Eddy-Current Sensor

2013 ◽  
Vol 133 (5) ◽  
pp. 300-306
Author(s):  
Tsutomu Mizuno ◽  
Yuichi Asato ◽  
Sho Goto ◽  
Takashi Watanabe ◽  
Teruie Takemasu ◽  
...  
Keyword(s):  
Eddy Current ◽  
Current Sensor ◽  
Eddy Current Sensor

scholarly journals Eddy Current Sensor System for Tilting Independent In-Process Measurement of Magnetic Anisotropy

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2652
Author(s):  
Frank Wendler ◽  
Rohan Munjal ◽  
Muhammad Waqas ◽  
Robert Laue ◽  
Sebastian Härtel ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Eddy Current ◽  
Digital Signal ◽  
Production Equipment ◽  
Sensor System ◽  
Current Sensor ◽  
Cold Forming ◽  
Eddy Current Sensor ◽  
Two Samples ◽  
Internal Mechanical Stress

Modern production equipment is based on the results of quality control as well as process parameters. The magnetic anisotropy of materials is closely connected to internal mechanical stress by the Villari effect, and also to hardening effects due to plastic deformations, and could therefore provide an interesting basis for process control. Nevertheless, the analysis of anisotropic properties is extremely sensitive to sensor and workpiece misalignments, such as tilting. In this work, a novel eddy current sensor system is introduced, performing a non-contact measurement of the magnetic anisotropy of a workpiece and realizing a separation and correction of tilting effects. The measurement principle is demonstrated with the example of two samples with different magnetic anisotropy values induced by cold forming. Both samples are analyzed under different tilt angles between the sensor axis and the surface of the workpiece. In this work, digital signal processing is demonstrated on the acquired raw data in order to differentiate the effects of tilt and of anisotropy, with the use of preliminary results as an example of two prepared samples.

Design and Implement of High-Accuracy On-Line Metal Thickness Measuring Instrument Based on NiosII Processor

2013 ◽  
Vol 834-836 ◽  
pp. 930-934
Author(s):  
Shou Liang Yang ◽  
Bao Liang Yang
Keyword(s):  
Eddy Current ◽  
Low Cost ◽  
High Accuracy ◽  
Resolving Power ◽  
Current Sensor ◽  
Measuring Instrument ◽  
Precision Data ◽  
Eddy Current Sensor ◽  
Metal Thickness ◽  
On Line

The paper proposes a new design of high-accuracy On-line Metal Thickness Measuring Instrument, which was based on EP2C20 series FPGA chip, through adding NiosII soft processor and other interfaces to FPGA, equipped with high precision data collection system and TFT LCD module and so on. The key hardware blocks schematics and components of the RC Oscillation Circuit,eddy current sensor Circuit,rectifier and filter Circuit,A/D converting circuit,FPGA Circuit are described,software flow charts and sample codes are given. According to practice, The measurement range of this system is 1~100 mm and the resolving power is 0.1 μm. degree of linearity is 1%, The system has many features including small volume of hardware, low cost, high detecting precision, convenient operating, high intelligent and so on, leading to broad and bright future. Key words: NiosII processor; eddy current sensor; metal thickness

A Generalized Approach for Failure Detection on Steel Products with the Use of an Eddy-Current Sensor

1989 ◽  
Vol 22 (6) ◽  
pp. 351-355
Author(s):  
T. Cecchin ◽  
D. Sauter ◽  
J. Merckle ◽  
F. Arroyo ◽  
M. Aubrun
Keyword(s):  
Eddy Current ◽  
Failure Detection ◽  
Current Sensor ◽  
Eddy Current Sensor
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