scholarly journals INVESTIGATION OF M2044 VOLTAMMETER ERRORS FOR PERSPECTIVE IMPROVEMENT OF CALIBRATION METHOD

2018 ◽  
pp. 25-29
Author(s):  
M. S. Titova ◽  
K. V. Epifantsev ◽  
T. P. Mishura
Keyword(s):  
Relative Error ◽  
Calibration Method ◽  
Main Design ◽  
Calibration Time

The method of checking voltmeters and ammeters involves checking certain intervals on the tool scale, which requires a sufficient amount of time from the verifier engineer. In the considered graphs, which revealed repeated dependences of the main calibration errors on the calibration time. Therefore, this study is important to verify that it is not. The main design of the study was to improve the scale of the voltmeter based on the meter readings during meter calibration at Techpribor during the testing lab from 2016 to 2018. When studying the calibration graphs, jumps in the segment in the range from 40 to 90 V. It is assumed that an increase in the relative error provided that it was used for various fields of technology to improve the verification procedure for analog instruments. The marked interval should be checked on each scale mark on each limit.

scholarly journals Cobot User Frame Calibration: Evaluation and Comparison between Positioning Repeatability Performances Achieved by Traditional and Vision-Based Methods

Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 45
Author(s):  
Roberto Pagani ◽  
Cristina Nuzzi ◽  
Marco Ghidelli ◽  
Alberto Borboni ◽  
Matteo Lancini ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Production Line ◽  
Calibration Method ◽  
Fiducial Marker ◽  
Positioning System ◽  
Local Calibration ◽  
Calibration Methods ◽  
Robot Positioning ◽  
Good Repeatability ◽  
Calibration Time

Since cobots are designed to be flexible, they are frequently repositioned to change the production line according to the needs; hence, their working area (user frame) needs to be often calibrated. Therefore, it is important to adopt a fast and intuitive user frame calibration method that allows even non-expert users to perform the procedure effectively, reducing the possible mistakes that may arise in such contexts. The aim of this work was to quantitatively assess the performance of different user frame calibration procedures in terms of accuracy, complexity, and calibration time, to allow a reliable choice of which calibration method to adopt and the number of calibration points to use, given the requirements of the specific application. This has been done by first analyzing the performances of a Rethink Robotics Sawyer robot built-in user frame calibration method (Robot Positioning System, RPS) based on the analysis of a fiducial marker distortion obtained from the image acquired by the wrist camera. This resulted in a quantitative analysis of the limitations of this approach that only computes local calibration planes, highlighting the reduction of performances observed. Hence, the analysis focused on the comparison between two traditional calibration methods involving rigid markers to determine the best number of calibration points to adopt to achieve good repeatability performances. The analysis shows that, among the three methods, the RPS one resulted in very poor repeatability performances (1.42 mm), while the three and five points calibration methods achieve lower values (0.33 mm and 0.12 mm, respectively) which are closer to the reference repeatability (0.08 mm). Moreover, comparing the overall calibration times achieved by the three methods, it is shown that, incrementing the number of calibration points to more than five, it is not suggested since it could lead to a plateau in the performances, while increasing the overall calibration time.

scholarly journals On-Site Calibration Method for Line-Structured Light Sensor-Based Railway Wheel Size Measurement System

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6717
Author(s):  
Yunfeng Ran ◽  
Qixin He ◽  
Qibo Feng ◽  
Jianying Cui
Keyword(s):  
Structured Light ◽  
Field Tests ◽  
Calibration Method ◽  
Field Application ◽  
Calibration Error ◽  
Epipolar Constraint ◽  
Calibration Process ◽  
Calibration Methods ◽  
Calibration Accuracy ◽  
Calibration Time

Line-structured light has been widely used in the field of railway measurement, owing to its high capability of anti-interference, fast scanning speed and high accuracy. Traditional calibration methods of line-structured light sensors have the disadvantages of long calibration time and complicated calibration process, which is not suitable for railway field application. In this paper, a fast calibration method based on a self-developed calibration device was proposed. Compared with traditional methods, the calibration process is simplified and the calibration time is greatly shortened. This method does not need to extract light strips; thus, the influence of ambient light on the measurement is reduced. In addition, the calibration error resulting from the misalignment was corrected by epipolar constraint, and the calibration accuracy was improved. Calibration experiments in laboratory and field tests were conducted to verify the effectiveness of this method, and the results showed that the proposed method can achieve a better calibration accuracy compared to a traditional calibration method based on Zhang’s method.

scholarly journals DEM PARAMETERS CALIBRATION OF MIXED BIOMASS SAWDUST MODEL WITH MULTI-RESPONSE INDICATORS

2021 ◽  
pp. 183-192
Author(s):  
Gong Xun ◽  
Bai XueWei ◽  
Huang HaiBo ◽  
Zhang FengYu ◽  
Gong YuanJuan ◽  
...  
Keyword(s):  
Relative Error ◽  
Calibration Method ◽  
Rolling Friction ◽  
Test Scheme ◽  
Related Factors ◽  
Recovery Coefficient ◽  
Densification Mechanism ◽  
Calibration Experiment ◽  
Mixed Biomass ◽  
Response Indicators

Taking hybrid biomass sawdust as the material, carry out the simulation calibration experiment with JKR contact model based on DEM principle. The Plackett-Burman factorial experiment is carried out by Design-Expert for 10 related factors. Combined with the steepest climbing test scheme, according to the Box-Behnken experiment, the parameter calibration of the multi-response Indicators is completed. The results are as follows: the Poisson's ratio of hybrid sawdust is 0.30, the density is 399.22kg·m-3, the recovery coefficient between sawdust particles is 0.47, the rolling friction coefficient between sawdust particles is 0.39, and the parameter of surface energy density between sawdust particles (JKR) is 0.29J·m-2. Through the comparative verification experiment, it can be seen that the relative error of the repose angle is 3.41%, and the relative error of the stress-time response curve is less than 6.36%, which verifies the reliability of the calibration method, and provides a theoretical reference for the study of the constitutive characteristics of biomass materials and the densification mechanism.

Sphere-Based Geometrical Calibration Method for Structured Light Surface Measurement Systems

2012 ◽  
Vol 571 ◽  
pp. 433-438 ◽  
Author(s):  
Jules Douet ◽  
Jing Xu ◽  
Ken Chen
Keyword(s):  
Structured Light ◽  
Calibration Method ◽  
Ease Of Use ◽  
Translation Method ◽  
Surface Measurement ◽  
Measurement Systems ◽  
Light System ◽  
Light Surface ◽  
Calibration Time ◽  
Structured Light System

This paper proposes a sphere-based calibration method for the structured light system with unconstrained one projector & one camera, regardless of pattern codification. A 1-pose example of such a method is also proposed and tested. In comparison with a traditional plane translation method of 15 poses, we note an increase in the consistency of more than 10% while the calibration time shrinks to 6% and the calibration accessory is reduced to the size of a flash-light. This method suits well for applications where mobility, speed and ease-of-use are important criteria.

Difference between calibration and practical force proving instruments

2021 ◽  
Vol 26 (1) ◽  
pp. 67-77
Author(s):  
Seif M. Osman ◽  
Gouda M. Mahmoud ◽  
Abdulelah A. Binown ◽  
Hamad Alghamdi
Keyword(s):  
Relative Error ◽  
Uncertainty Estimation ◽  
Load Cell ◽  
Expanded Uncertainty ◽  
Cell Capacity ◽  
Repeatability Error ◽  
Load Cells ◽  
Repeatability And Reproducibility ◽  
The Difference ◽  
Calibration Time

This is an experimental work on seventy load cells which aims to highlight the difference between results out of force, proving instruments calibration according to ISO 376:2011 and its practical use. It spots on the difference between the relative error of repeatability and reproducibility and their contributions on load cells classifications, uncertainty estimation and calibration time. Results show that there is no significant effect for relative error of repeatability on load cell classification, ignoring the relative repeatability error in estimating the relative expanded uncertainty lead to decrease with values between 1 ppm and 270 ppm in the range from 20 % to 50 % of load cell capacity and by values between 1 ppm and 183 ppm in the range from 50 % to 100 % of the load cell capacity. It is concluded that performing measurements to calculate the relative error of repeatability is not effective in the normal calibration process for the examined seventy load cells, further measurements over subsequent years are recommended to ensure results reproducibility aiming to generalize the conclusion and recommend measurements for the relative repeatability error for load cell conformity assessment after manufacturing.

Improvement of the passive efficiency calibration of the segmented gamma scanner

Kerntechnik ◽  
2021 ◽  
Vol 86 (1) ◽  
pp. 70-77
Author(s):  
S. Hou ◽  
J. Luo ◽  
C. Yang ◽  
W. Zhang
Keyword(s):  
Detection Efficiency ◽  
Calibration Method ◽  
Rapid Analysis ◽  
Efficiency Calibration ◽  
Radioactive Material ◽  
Transmission Measurement ◽  
Emission Measurement ◽  
Actual Measurement ◽  
Analysis System ◽  
Calibration Time

Abstract The Segmented Gamma Scanner(SGS) technology is specially used for type identification and activity quantitative analysis of radioactive material in sealed containers, which mainly divided into the transmission measurement and the emission measurement. In actual measurement process, it cannot meet the need for rapid analysis because the efficiency calibration time takes up more than 60% of the whole detect time in the data analysis. Whereas most previous research have focused on theory or specific applications, this research groups aim to different aspects of the SGS technique and direct it at an audience with interests in the need for rapid analysis. The Monte Carlo simulation calculation models were established by the passive efficiency calibration method, and then the detection efficiency database was carried out based on the experimental verification. Lots of work was used to analysis the influence of crosstalk between layers and interpolation step. Furthermore, the database was implanted into the control and analysis system to complete the measurement experiments. The results show the measuring time of single waste drums is about 30 min, and the average relative deviation is less than 10%, so the problem that the time taken to calibrate the detection efficiency is too long has been solved effectively. The efficiency in the use of SGS technology has been increased.

A Mixed Signal DC Offset Cancellation for VGA of Zero-IF Receiver

2016 ◽  
Vol 26 (03) ◽  
pp. 1750047
Author(s):  
Yiqiang Zhao ◽  
Jingshuai Wang ◽  
Yun Sheng
Keyword(s):  
Calibration Method ◽  
Compensation Voltage ◽  
Digital Logic ◽  
Cmos Process ◽  
Mixed Signal ◽  
Offset Cancellation ◽  
Dc Offset ◽  
Measurement Results ◽  
Calibration Time

This paper proposes a mixed signal DC offset cancellation (DCOC) which does not cause the near-DC rejection for zero-IF receiver. To achieve low output offset efficiently, the DCOC consisting of a comparator, a digital logic controller and compensation voltage generators is used. It utilizes current sources arrays that are controlled by thermometer code to generate the compensation voltage. The proposed DCOC is implemented in GF 0.18 [Formula: see text]m CMOS process. The measurement results show that the proposed calibration method can reduce the offset residue to less than 80 mV and the total calibration time is less than 13 [Formula: see text]s. It only drains 60 [Formula: see text]A from a 3.3 V supply.

scholarly journals Calibration-Free Robot-Sensor Calibration approach based on Second-Order Cone Programming

2018 ◽  
Vol 173 ◽  
pp. 02005 ◽  
Author(s):  
Li Wei ◽  
LU Naiguang ◽  
Dong Mingli ◽  
Lou Xiaoping
Keyword(s):  
Relative Error ◽  
Calibration Method ◽  
Second Order ◽  
Sensor Calibration ◽  
Camera Motion ◽  
Calibration Target ◽  
Cone Programming ◽  
Second Order Cone Programming ◽  
Second Order Cone ◽  
Calibration Free

In order to overcome the restrictions of traditional robot-sensor calibration method which solve the tool-camera transformation and robot-world transformation rely on calibration target, a calibration-free approach that solve the robot-sensor calibration problem of the form AX = YB based on Second-Order Cone Programming is proposed. First, a Structure-From-Motion approach was used to recover the camera motion matrix up to scaling. Then rotation and translation matrix in calibration equation were parameterized by dual quaternion theory. Finally, the Second-Order Cone Programming method was used to simultaneously solve the optimal solution of camera motion matrix scale factor, the robot-world and hand-eye relation. The experimental results indicate that the calibration precision of rotation relative error is 3.998% and the translation relative error is 0.117% in defect of calibration target as 3D benchmark. Compared with similar methods, the proposed method can effectively improve the calibration accuracy of the robot-world and hand-eye relation, and extend the application field of robot-sensor calibration method.

scholarly journals A Fast Calibration Method for Phased Arrays by Using the Graph Coloring Theory

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4315 ◽  
Author(s):  
Lijie Yang ◽  
Ruirui Dang ◽  
Min Li ◽  
Kailong Zhao ◽  
Chunyi Song ◽  
...  
Keyword(s):  
Graph Coloring ◽  
Large Scale ◽  
Phased Array ◽  
Phased Arrays ◽  
Calibration Method ◽  
Omnidirectional Antenna ◽  
Phase Errors ◽  
Calibration Problem ◽  
Calibration Methods ◽  
Calibration Time

Phased array radars are able to provide highly accurate airplane surveillance and tracking performance if they are properly calibrated. However, the ambient temperature variation and device aging could greatly deteriorate their performance. Currently, performing a calibration over a large-scale phased array with thousands of antennas is time-consuming. To facilitate the process, we propose a fast calibration method for phased arrays with omnidirectional radiation patterns based on the graph coloring theory. This method transforms the calibration problem into a coloring problem that aims at minimizing the number of used colors. By reusing the calibration time slots spatially, more than one omnidirectional antenna can perform calibration simultaneously. The simulation proves this method can prominently reduce total calibration time and recover the radiation pattern from amplitude and phase errors and noise. It is worth noting that the total calibration time consumed by the proposed method remains constant and is negligible compared with other calibration methods.

A new calibration method for gravity meters

Geophysics ◽  
1991 ◽  
Vol 56 (5) ◽  
pp. 701-704 ◽  
Author(s):  
Lucien LaCoste
Keyword(s):  
Calibration Curve ◽  
Calibration Method ◽  
New Method ◽  
Micrometer Screw ◽  
Calibration Methods ◽  
Calibration Time ◽  
Calibration Interval

Current calibration methods give gravity meter accuracies of 3 to 5 μGal [Formula: see text] over 10 mGal intervals. The new calibration method should extend the accuracies to 100 mGal intervals. The new method nulls with both a micrometer screw and an electrostatic feedback nuller. The screw is calibrated and used only at discrete points and the electrostatic nuller completes the nulling to obtain gravity readings. Determining the calibration curve itself rather than measuring and integrating calibration (interval) factors avoids approximations. Circular errors (periods of the order of a turn of the screw) are completely taken into account at the discrete points. Calibration only at discrete points makes calibration time reasonable.

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