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 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.

CALCULATION OF THE PARAMETERS OF THE WIND TURBINE ROTOR EDDY CURRENT SENSOR

2021 ◽  
Vol 118 (3) ◽  
pp. 134-141
Author(s):  
Аlina Fazylova
Keyword(s):  
Wind Turbine ◽  
Eddy Current ◽  
Turbine Rotor ◽  
Current Sensor ◽  
Eddy Current Sensor ◽  
Turbine Shaft ◽  
Current Sensors ◽  
Strong Winds ◽  
Hostile Environments ◽  
Wind Turbine Rotor

Eddy current sensors are used to measure shaft clearance in wind turbines and to check that there is a thin film of oil in the clearance. In this case, the oil is usually applied under pressure. Because the eddy current sensors are resistant to oil, pressure and temperature, this allows them to operate reliably in these hostile environments. When the gap becomes too large, a maintenance warning is generated. Eddy current sensors help detect axial and radial deflection of the turbine shaft. Radial movement occurs when the shaft is off-center. Axial movement indicates that the shaft is tilted relative to the central axis. Both cannot be eliminated completely. However, with significant deviations, increased bearing wear occurs. If such situations are detected, the turbine should be shut down as soon as possible for maintenance, even before an accident occurs. Finally, eddy current sensors are used to measure forces or torques applied to the nacelle. These influences can be caused by vibration, wind loads or other factors that, over time, can lead to the destruction of the entire structure. Eddy current sensors can also be used to measure axial, radial or tangential deflection of clutch discs, which ensure the safety of the rotor in the event of strong winds. This article provides a method for calculating an inductive sensor. This calculation will allow you to correctly develop a wind turbine eddy current sensor.

Rapid prototyping eddy current sensors using 3D printing

2018 ◽  
Vol 24 (1) ◽  
pp. 106-113 ◽  
Author(s):  
Bo Li ◽  
Lifan Meng ◽  
Hongyu Wang ◽  
Jing Li ◽  
Chunmei Liu
Keyword(s):  
3D Printing ◽  
Rapid Prototyping ◽  
Eddy Current ◽  
Fused Deposition Modeling ◽  
Current Sensor ◽  
Content Type ◽  
Fused Deposition ◽  
Eddy Current Sensor ◽  
3D Printed ◽  
Current Sensors

Purpose The purpose of this paper is to investigate the process of rapid prototyping eddy current sensors using 3D printing technology. Making full use of the advantages of 3D printing, the authors study on a new method for fabrication of an eddy current sensor. Design/methodology/approach In this paper, the authors establish a 3D model using SolidWorks. And the eddy current sensor is printed by the fused deposition modeling method. Findings Measurement results show that the 3D printing eddy current sensor has a wider linear measurement range and better linearity than the traditional manufacturing sensor. Compared to traditional eddy current sensor fabrication method, this 3D printed sensor can be fabricated at a lower cost, and the fabrication process is more convenient and faster. Practical implications This demonstrated 3D printing process can be applied to the 3D printing of sensors of more sophisticated structures that are difficult to fabricate using conventional techniques. Originality/value In this work, the process of rapid prototyping eddy current sensors using 3D printing is presented. Sensors fabricated with the 3D printing possess lots of merits than traditional manufactures. 3D printed sensors can be customized according to the configuration of the overall system, thus reducing the demand of sensor's rigid mounting interfaces. The 3D printing also reduce design costs as well as shortens the development cycle. This allows for quick translation of a design from concept to a useful device.

scholarly journals Design, Modeling, and Evaluation of the Eddy Current Sensor Deeply Implanted in the Human Body

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3888 ◽  
Author(s):  
Rajas Khokle ◽  
Karu Esselle ◽  
Desmond Bokor
Keyword(s):  
Human Body ◽  
Eddy Current ◽  
Orthopedic Implants ◽  
Current Sensor ◽  
Eddy Current Sensor ◽  
Curve Fit ◽  
Sensitivity Range ◽  
Present Context ◽  
Current Sensors

Joint replacement surgeries have enabled motion for millions of people suffering from arthritis or grave injuries. However, over 10% of these surgeries are revision surgeries. We have first analyzed the data from the worldwide orthopedic registers and concluded that the micromotion of orthopedic implants is the major reason for revisions. Then, we propose the use of inductive eddy current sensors for in vivo micromotion detection of the order of tens of μ m. To design and evaluate its characteristics, we have developed efficient strategies for the accurate numerical simulation of eddy current sensors implanted in the human body. We present the response of the eddy current sensor as a function of its frequency and position based on the robust curve fit analysis. Sensitivity and Sensitivity Range parameters are defined for the present context and are evaluated. The proposed sensors are fabricated and tested in the bovine leg.

scholarly journals A New Method for Measuring the Rotational Angles of a Precision Spherical Joint Using Eddy Current Sensors

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4020 ◽  
Author(s):  
Penghao Hu ◽  
Linchao Zhao ◽  
Chuxin Tang ◽  
Shanlin Liu ◽  
Xueming Dang ◽  
...  
Keyword(s):  
Eddy Current ◽  
Output Signal ◽  
Sensor Array ◽  
Mechanical Performance ◽  
Model Simulation ◽  
Current Sensor ◽  
Parallel Mechanisms ◽  
Spherical Joint ◽  
Eddy Current Sensor ◽  
Current Sensors

Precision spherical joint is a spherical motion pair that can realize rotation with three degrees of freedom. This joint is widely used in robots, parallel mechanisms, and high-end medical equipment, as well as in aerospace and other fields. However, the rotation orientation and angle cannot be determined when the joint is in passive motion. The real-time determination of the rotation orientation and angle is crucial to the improvement of the motion control accuracy of the equipment where the joint is installed in. In this study, a new measurement method that utilizes eddy current sensors is proposed to identify the special features of the joint ball and realize angle measurements indirectly. The basic idea is to manufacture the specific shape features on the ball without affecting its movement accuracy and mechanical performance. An eddy current sensor array is distributed in the ball socket. When the ball head rotates, the features on the ball opposite to the sensor, as well as the output signal of every eddy current sensor, change. The measurement model that establishes the relationship between the output signal of the eddy current sensor array and the rotation direction and angle of the ball head is constructed by learning and training an artificial neural network. A prototype is developed using the proposed scheme, and the model simulation and feasibility experiment are subsequently performed. Results show that the root mean square angular error of a single axis within a range of ±14° is approximately 20 min, which suggests the feasibility of the proposed method.

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 Simulating eddy current sensor outputs for blade tip timing

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774802 ◽  
Author(s):  
Nidhal Jamia ◽  
Michael I Friswell ◽  
Sami El-Borgi ◽  
Ralston Fernandes
Keyword(s):  
Eddy Current ◽  
Tip Clearance ◽  
Vibration Measurement ◽  
Current Sensor ◽  
Contactless Method ◽  
Diagnostic Features ◽  
Blade Vibration ◽  
Eddy Current Sensor ◽  
Blade Tip ◽  
Current Sensors

Blade tip timing is a contactless method used to monitor the vibration of blades in rotating machinery. Blade vibration and clearance are important diagnostic features for condition monitoring, including the detection of blade cracks. Eddy current sensors are a practical choice for blade tip timing and have been used extensively. As the data requirements from the timing measurement become more stringent and the systems become more complicated, including the use of multiple sensors, the ability to fully understand and optimize the measurement system becomes more important. This requires detailed modeling of eddy current sensors in the blade tip timing application; the current approaches often rely on experimental trials. Existing simulations for eddy current sensors have not considered the particular case of a blade rotating past the sensor. Hence, the novel aspect of this article is the development of a detailed quasi-static finite element model of the electro-magnetic field to simulate the integrated measured output of the sensor. This model is demonstrated by simulating the effect of tip clearance, blade geometry, and blade velocity on the output of the eddy current sensor. This allows an understanding of the sources of error in the blade time of arrival estimate and hence insight into the accuracy of the blade vibration measurement.

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 %.

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
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