scholarly journals High-Accuracy Calibration Based on Linearity Adjustment for Eddy Current Displacement Sensor

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2842 ◽  
Author(s):  
Wei Liu ◽  
Bing Liang ◽  
Zhenyuan Jia ◽  
Di Feng ◽  
Xintong Jiang ◽  
...  
Keyword(s):  
Eddy Current ◽  
Measurement Accuracy ◽  
Characteristic Curve ◽  
Calibration Method ◽  
High Accuracy ◽  
Output Characteristic ◽  
Displacement Sensor ◽  
Support Vector ◽  
Displacement Sensors ◽  
Calibration Accuracy

High precision position control is essential in the process of parts manufacturing and assembling, where eddy current displacement sensors (ECDSs) are widely used owing to the advantages of non-contact sensing, compact volume, and resistance to harsh conditions. To solve the nonlinear characteristics of the sensors, a high-accuracy calibration method based on linearity adjustment is proposed for ECDSs in this paper, which markedly improves the calibration accuracy and then the measurement accuracy. After matching the displacement value and the output voltage of the sensors, firstly, the sensitivity is adjusted according to the specified output range. Then, the weighted support vector adjustment models with the optimal weight of the zero-scale, mid-scale and full-scale are established respectively to cyclically adjust the linearity of the output characteristic curve. Finally, the final linearity adjustment model is obtained, and both the calibration accuracy and precision are verified by the established calibration system. Experimental results show that the linearity of the output characteristic curve of ECDS adjusted by the calibration method reaches over 99.9%, increasing by 1.9–5.0% more than the one of the original. In addition, the measurement accuracy improves from 11–25 μ m to 1–10 μ m in the range of 6mm, which provides a reliable guarantee for high accuracy displacement measurement.

scholarly journals A calibration method of robot kinematic parameters by drawstring displacement sensor

2019 ◽  
Vol 16 (5) ◽  
pp. 172988141988307 ◽  
Author(s):  
Yahui Gan ◽  
Jinjun Duan ◽  
Xianzhong Dai
Keyword(s):  
Calibration Method ◽  
Industrial Robots ◽  
Displacement Sensor ◽  
Kinematic Parameters ◽  
Position Measurement ◽  
Positioning Accuracy ◽  
End Effector ◽  
Displacement Sensors ◽  
Absolute Positioning ◽  
The Absolute

Calibration of robot kinematic parameters can effectively improve the absolute positioning accuracy of the end-effector for industrial robots. This article proposes a calibration method for robot kinematic parameters based on the drawstring displacement sensor. Firstly, the kinematic error model for articulated robot is established. Based on such a model, the position measurement system consisting of four drawstring displacement sensors is used to measure the actual position of the robot end-effector. Then, the deviation of the kinematic parameters of the robot is identified by the least-squares method according to robot end-effector deviations. The Cartesian space compensation method is adopted to improve the absolute positioning accuracy of the robot end-effecter. By experiments on the EFORT ER3A robot, the absolute positioning accuracy of the robot is significantly improved after calibration, which shows the effectiveness of the proposed method.

scholarly journals Analytical Modeling for the Grating Eddy Current Displacement Sensors

2015 ◽  
Vol 15 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Chunfeng Lv ◽  
Wei Tao ◽  
Huaming Lei ◽  
Yingying Jiang ◽  
Hui Zhao
Keyword(s):  
Eddy Current ◽  
Analytical Modeling ◽  
Expansion Method ◽  
Displacement Sensor ◽  
Modeling Approach ◽  
Eigenfunction Expansion Method ◽  
Displacement Sensors ◽  
Wide Range ◽  
New Type ◽  
Cartesian Coordinate

Abstract As a new type of displacement sensor, grating eddy current displacement sensor (GECDS) combines traditional eddy current sensors and grating structure in one. The GECDS performs a wide range displacement measurement without precision reduction. This paper proposes an analytical modeling approach for the GECDS. The solution model is established in the Cartesian coordinate system, and the solving domain is limited to finite extents by using the truncated region eigenfunction expansion method. Based on the second order vector potential, expressions for the electromagnetic field as well as coil impedance related to the displacement can be expressed in closed-form. Theoretical results are then confirmed by experiments, which prove the suitability and effectiveness of the analytical modeling approach.

Wavelength Modulating Self-Mixing Interferometer

2017 ◽  
Vol 870 ◽  
pp. 15-20
Author(s):  
Dong Mei Guo ◽  
Hai Qing Jiang
Keyword(s):  
Laser Beam ◽  
Fourier Analysis ◽  
Laser Diode ◽  
Measurement Accuracy ◽  
High Accuracy ◽  
Displacement Sensor ◽  
Interference Signal ◽  
Wavelength Modulation ◽  
Analysis Method ◽  
Measurement Resolution

Self-mixing interference (SMI) was used to measure the displacement with a resolution of λ/2 by counting the interference signal peaks. In order to increase the measurement accuracy beyond λ/2, sinusoidal wavelength modulation (SWM) technique is introduced in SMI in this paper. Wavelength modulation of the laser beam is obtained by sinusoidal modulating the injection current of the laser diode. Fourier analysis method is proposed to demodulate the phase. Experimentally, the micro-movements of a high precision commercial PZT have been reconstructed, which can obtain a displacement measurement resolution of a few nanometers. It provides a potential displacement sensor with high accuracy and quite compact configuration.

scholarly journals Obtaining characteristics of FMM displacement sensor by applying a flick standard

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1041-1043
Author(s):  
Marta Wiśniewska ◽  
Sabina Żebrowska-Łucyk
Keyword(s):  
Calibration Method ◽  
Displacement Sensor ◽  
Characteristic Curves ◽  
Factors Affecting ◽  
The Core ◽  
Displacement Sensors ◽  
Calibration Uncertainty ◽  
Novel Method ◽  
Core Idea

A novel method for obtaining characteristics of displacement sensors applied to form measuring machines is presented. In order to find the characteristic curves of such sensors, flick standards are adopted. In the paper, besides the core idea of this calibration method, there is an influence of some of the most important factors affecting calibration uncertainty presented.

A High-Accuracy Calibration Method Using Sensor Sensitivity Difference for Piezoelectric Dynamometer

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Jun Zhang ◽  
Jun Shao ◽  
Zongjin Ren ◽  
Jing Yu ◽  
Xinyang Li ◽  
...  
Keyword(s):  
Piezoelectric Sensor ◽  
Calibration Method ◽  
Sensitivity Coefficient ◽  
High Accuracy ◽  
Test Accuracy ◽  
Real Time Control ◽  
Accuracy Measurement ◽  
Time Control ◽  
Sensor Sensitivity ◽  
Calibration Accuracy

Abstract High-accuracy measurement of force affects real-time control and process adjustment of industrial production. Piezoelectric sensor can be applied to measure force with the characteristics of high frequency and stiffness, great dynamic response and resistance to harsh conditions. As an important part of test, calibration determines sensitivity coefficient which directly affects test accuracy. To improve the calibration accuracy of offset loading force for multisensor piezoelectric dynamometer, a novel calibration method using sensor sensitivity difference is proposed in this paper. The calibration experiments of four sensors are performed to obtain the axial sensitivities and the force-to-electricity conversion coefficients. The multiple loading-point (MLP) calibration experiments of dynamometer are carried out, and the calibration results prove that the sensitivity difference of four sensors is the main reason affecting the calibration accuracy. The sensitivity difference calibration method (SDCM) is applied to the MLP calibration experiments, and the results show that the average resultant force deviations are reduced from 418.79 N (8.38% full scare (FS) to 24.16 N (0.61% FS) under a loading force of 5000 N, which proves high accuracy and reliability of SDCM. The calibration method will provide guidance for improving the calibration accuracy of dynamometer.

Output Voltage Characteristics of Eddy Current Displacement Sensor for Various Heat Treatments of Measuring Objects

2008 ◽  
Vol 128 (4) ◽  
pp. 289-297 ◽  
Author(s):  
Tsutomu Mizuno ◽  
Shigemi Enoki ◽  
Takashi Asahina ◽  
Takayuki Suzuki ◽  
Hiroyuki Maeda ◽  
...  
Keyword(s):  
Eddy Current ◽  
Output Voltage ◽  
Heat Treatments ◽  
Displacement Sensor

Temperature Invariant Phenomenon in Dual Coil Eddy Current Displacement Sensor: Investigation, Verification and Application

2019 ◽  
Vol 19 (21) ◽  
pp. 9680-9687 ◽  
Author(s):  
Yating Yu ◽  
Hanchao Li ◽  
Ke Xue ◽  
Dahuan Liu ◽  
Geng Gao
Keyword(s):  
Eddy Current ◽  
Displacement Sensor

scholarly journals Predicting Risk of Antenatal Depression and Anxiety Using Multi-Layer Perceptrons and Support Vector Machines

2021 ◽  
Vol 11 (3) ◽  
pp. 199
Author(s):  
Fajar Javed ◽  
Syed Omer Gilani ◽  
Seemab Latif ◽  
Asim Waris ◽  
Mohsin Jamil ◽  
...  
Keyword(s):  
Low Income ◽  
Operating Characteristic ◽  
Mental Health Problems ◽  
Characteristic Curve ◽  
Antenatal Depression ◽  
Low Income Countries ◽  
Support Vector ◽  
Depression And Anxiety ◽  
Gynecology And Obstetrics ◽  
Operating Characteristic Curve

Perinatal depression and anxiety are defined to be the mental health problems a woman faces during pregnancy, around childbirth, and after child delivery. While this often occurs in women and affects all family members including the infant, it can easily go undetected and underdiagnosed. The prevalence rates of antenatal depression and anxiety worldwide, especially in low-income countries, are extremely high. The wide majority suffers from mild to moderate depression with the risk of leading to impaired child–mother relationship and infant health, few women end up taking their own lives. Owing to high costs and non-availability of resources, it is almost impossible to diagnose every pregnant woman for depression/anxiety whereas under-detection can have a lasting impact on mother and child’s health. This work proposes a multi-layer perceptron based neural network (MLP-NN) classifier to predict the risk of depression and anxiety in pregnant women. We trained and evaluated our proposed system on a Pakistani dataset of 500 women in their antenatal period. ReliefF was used for feature selection before classifier training. Evaluation metrics such as accuracy, sensitivity, specificity, precision, F1 score, and area under the receiver operating characteristic curve were used to evaluate the performance of the trained model. Multilayer perceptron and support vector classifier achieved an area under the receiving operating characteristic curve of 88% and 80% for antenatal depression and 85% and 77% for antenatal anxiety, respectively. The system can be used as a facilitator for screening women during their routine visits in the hospital’s gynecology and obstetrics departments.

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