Research and Realization of Auto-Calibration Technique Based on Structured Grating 3D Measuring System

2007 ◽  
Vol 10-12 ◽  
pp. 594-598
Author(s):  
Jun Ting Cheng ◽  
C. Zhao ◽  
W.T. He
Keyword(s):  
Measuring System ◽  
Experimental Result ◽  
Calibration Technique ◽  
Multiple Targets ◽  
The World ◽  
Random Placement ◽  
Calibration Accuracy ◽  
Regular Number

This paper introduced present application in the world and some problems in the calibration technique of 3D measuring system. Auto-calibration technique of multiple targets tracking for detecting outline based on random placement and regular number is put forward. At the same time, the concrete algorithm is given. Then, according to the algorithm, the corresponding experimental result is obtained. Furthermore, the calibration accuracy is compared and analyzed. Finally, it comes to a conclusion that this algorithm can make the operation more simple and convenient. And the calibration accuracy is kept within 0.03mm.

An Experimental Study on Saturated Liquid Nitrogen’s Boiling Under Transient Pulsed Laser Irradiation

2004 ◽  
Author(s):  
Zhaoyi Dong ◽  
Xiulan Huai ◽  
G.-X. Wang
Keyword(s):  
Temperature Variation ◽  
High Speed ◽  
Short Pulse ◽  
Heating Surface ◽  
High Heat ◽  
Measuring System ◽  
Experimental Result ◽  
High Speed Photography ◽  
High Heat Flux ◽  
Explosive Boiling

Liquid nitrogen (LN2) was widely applied in many areas, but researches on the boiling behavior under the transient high heat flux have not been reported. In this paper, the high power short pulse duration laser was used to heat the saturated LN2 rapidly, and the high-speed photography aided by the spark light system was employed to take series of photos which displayed the process of LN2’s boiling behavior under such conditions. At the same time, a special temperature measuring system was applied to record the temperature variation of the heating surface. The experimental result disclosed that at the earlier stage of laser heating, an explosive boiling would happen within LN2. After the newly-defined changeover time, the conventional boiling behavior would follow. Therefore the changeover time became an important index to distinguish these two kinds of boiling behaviors. By analyzing the temperature variation of the heating surface, it is found that the latent heat released by the crack of bubbles in explosive boiling is an important factor that greatly influences the boiling heat transfer mechanism.

Eye-in-Hand Robotic Gripper Vision Fusion for Object Recognition and Tracking

2019 ◽  
Author(s):  
Shih-Wei Liu ◽  
Jen-Yuan (James) Chang
Keyword(s):  
Object Recognition ◽  
Human Resources ◽  
Production Line ◽  
Tracking System ◽  
Target Object ◽  
Experimental Result ◽  
World Economic Forum ◽  
The World ◽  
The Future ◽  
World Economic

Abstract With the development of Automation industry, a new industrial model has been born, and traditional human resources have gradually been replaced by machines. The World Economic Forum (WEF) pointed out in “The Future of Jobs Report 2018” that the world is experiencing a “workplace revolution”, which means that machine will play a more important role in the future. In response to this situation, in this paper, techniques for object recognition and tracking on a conveyor using eye-in-hand gripper are presented, which are useful in production line for automatic object classification. The eye-in-hand configuration is the most suitable for camera and gripper application because the camera coordinate is the same as the gripper coordinate. The main advantages of eye-in-hand configuration are as follow: (1) occlusion avoidance (2) intuitive teleoperation (3) image from different angles (4) simple calibration. The main difference with eye-on-hand configuration is that it may be out of view sight when the camera is too close to the object. The experimental result is using the eye-in-hand robotic gripper to establish a tracking system to chase the target object. Preliminary results show that the speed of the conveyor can be calculated and the moving distance between the robot and the object is very close after a period of time. It means that the tracking system is successful.

WMO questionnaire on recording precipitation gauges: state-of-the-art

2002 ◽  
Vol 45 (2) ◽  
pp. 139-145 ◽  
Author(s):  
B. Sevruk
Keyword(s):  
Data Transmission ◽  
State Of The Art ◽  
Precipitation Intensity ◽  
World Meteorological Organization ◽  
Measuring System ◽  
Orifice Area ◽  
The World ◽  
Precipitation Gauge ◽  
To Receive

To receive information on recording precipitation gauges used operationally by national meteorological services the World Meteorological Organization started a worldwide inquiry. This included the type of recording precipitation gauge (RPG), their manufacturer, measuring system applied, number of RPGs used, methods of recording and data transmission, orifice area size and installation heights, heating and windshield application as well as the question on the need to organising global intercomparisons of RPG measurements. The results of the 118 responses received (out of 180 countries) are presented and discussed. They show that there is a great variety in instruments and methods of observation of precipitation intensity used not only worldwide but also in the same country. This variety exceeds by far the variety in manual standard precipitation gauges.

Benchmarking the complex geometric profiles, dimensional accuracy and surface analysis of printed parts

2019 ◽  
Vol 26 (2) ◽  
pp. 319-329 ◽  
Author(s):  
Paridhi Subbaian Kaliamoorthy ◽  
Rajkumar Subbiah ◽  
Joseph Bensingh ◽  
Abdul Kader ◽  
Sanjay Nayak
Keyword(s):  
Surface Roughness ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Measuring System ◽  
Experimental Result ◽  
Complex Geometries ◽  
Thin Wall ◽  
Content Type ◽  
Metal Parts ◽  
Cooling Channels

Purpose Additive manufacturing has paved a way for geometrical freedom and mass customization of new and innovative products. However, it has a few limitations in printing complex geometries and sizes. The purpose of this paper is three-dimensional printing of metal parts using selective laser melting (SLM) has several intricacies. Design/methodology/approach To test the capabilities of SLM, the complex geometries of varying sizes, orientations, shapes such as square and cylindrical features, thin wall structures and holes were checked for dimensional accuracy and surface roughness. Findings The outcome of the study represents the capabilities of SLM and provide insight for solving the technological issues and processing constraint in the manufacture of metal parts from aluminum alloy. The analysis has proven that there is significant accuracy in dimension for large features in comparison with smaller one. The dimensional reproducibility was determined with the aid of an optical measuring system and the range of errors were calculated. These results show that the dimensional accuracy of the features in the printed part was within acceptable tolerance limits. This paper also investigated the significant contributing factors influencing printing of two and three-dimensional surface roughness based on the result of surface profilometer and it was observed that the surface was smoothened with the presence of overhangs and supports. Originality/value The ability of SLM to fabricate conformer cooling channels to support mould fabrication was tested. From the experimental result, it was observed that the quality of printing of conformal cooling channels depended on the diameter of channels with larger distortions in the channel having smaller diameter. The innovative aspect of the work was the study of build orientation combined with the investigated material.

Study on Evaporative Cooling Effect of Porous Decorative Layer Applied to Vertical Walls

2012 ◽  
Vol 193-194 ◽  
pp. 556-561 ◽  
Author(s):  
Yan Shan Feng ◽  
Lei Zhang ◽  
Qing Lin Meng
Keyword(s):  
Thermal Resistance ◽  
Surface Temperature ◽  
Porous Materials ◽  
Horizontal Plane ◽  
External Surface ◽  
Experimental Result ◽  
Temperature Peak ◽  
Inner Surface ◽  
The World ◽  
Vertical Walls

The porous materials are more and more popular throughout the world. However most of the resent researches focus on the porous materials applying to horizontal plane. In this paper an experiment was conducted to study the applicability of porous decorative layer applying to vertical walls. The Experimental result shows that the wet porous decorative layer has a good applicability to west-facing wall by reducing the external surface temperature at least 8°C and eliminating the temperature peak of inner surface. The equivalent thermal resistance of the porous decorative layer is 0.40 m2•K/W, when using the 4-day value of the measurement. In the summer of Guangzhou, the porous decorative layer on west-facing wall is recommended to supply water once a day at 13:00.

Vision-based Crack Identification on the Concrete Slab Surface using Fuzzy Reasoning Rules and Self-Organizing

2016 ◽  
Vol 6 (4) ◽  
pp. 1577
Author(s):  
Kwang Baek Kim ◽  
Hyun Jun Park ◽  
Doo Heon Song
Keyword(s):  
Concrete Slab ◽  
Ground Truth ◽  
Noise Removal ◽  
Measuring System ◽  
Experimental Result ◽  
Crack Identification ◽  
Structure Stability ◽  
Self Organizing Map ◽  
Color Channel ◽  
Self Organizing

Identifying cracks on the surface of concrete slab structure is important for structure stability maintenance. In order to avoid subjective visual inspection, it is necessary to develop an automated identification and measuring system by vision based method. Although there have been some intelligent computerized inspection methods, they are sensitive to noise due to the brightness contrast and objects such as forms and joints of certain size often falsely classified as cracks. In this paper, we propose a new fuzzy logic based image processing method that extracts cracks from concrete slab structure including small cracks that were often neglected as noise. We extract candidate crack areas by applying fuzzy method with three color channel values of concrete slab structure. Then further refinement processes are performed with Self Organizing Map algorithm and density based noise removal process to obtain basic crack characteristic attributes for further analysis. Experimental result verifies that the proposed method is sufficiently identified cracks with various sizes with high accuracy (97.3%) among 1319 ground truth cracks from 30 images.

scholarly journals NEOLIBERALISM AS AN APPROACH IN POSTMODERN PUBLIC ADMINISTRATION

2019 ◽  
Vol 4 (44) ◽  
pp. 31-39
Author(s):  
Oleksandr Ghromadetskyi
Keyword(s):  
Public Administration ◽  
Public Management ◽  
Management Practices ◽  
Measuring System ◽  
Incentive System ◽  
The Public ◽  
The World ◽  
Application Potential ◽  
Main Ideas ◽  
Modern Orthodox

The article revises the neo-liberal postmodern approach to public administration within the scientific paradigm by Ch. Fox and H. Miller. Within the framework of the relevant scientific construct, the researchers identified three leading approaches (neo-liberalism, constitutionalism and communitarianism) designed to replace the outdated model of the modern (orthodox) government. The justification for the postmodern public administration could contribute to the modernization of public management practices in the world in general and in Ukraine in particular. The systematization of the imperatives of the neoliberal approach to public administration is one of the stages of the above-mentioned justification.  The purpose of the paper is to reveal the content and application potential of the neoliberal approach within postmodern public administration, to research its main ideas and tools. Methodological basis of the study consists of logical methods (synthesis, analysis, induction, etc.), as well as special ones (historical, systemic, comparative). As a result of the study, it was found that the content of the neoliberal approach to public administration deals with marketization of the public sector in order to conduct de-bureaucratization and efficiency improvements. The main tools in the process are performance evaluation and audit, contracting out, privatization, implementation of incentive system, and management. Compared with the orthodox model of public administration, the neoliberal counterpart has certain advantages, in particular, the refusal to prevail standardized rules and regulations in favor of outcomes. Nevertheless, at the same time, the neoliberal approach remains faithful to the rational traditions of reality perception. Despite significant practical results, the shortcomings of the neo-liberal postmodern model of public administration (opportunities for corruption and overestimation of the efficiency measuring system) were described.

scholarly journals A New Joint Denoising Algorithm for High-G Calibration of MEMS Accelerometer Based on VMD-PE-Wavelet Threshold

2021 ◽  
Vol 2021 ◽  
pp. 1-16 ◽  
Author(s):  
Huiliang Cao ◽  
Zekai Zhang ◽  
Yu Zheng ◽  
Hao Guo ◽  
Rui Zhao ◽  
...  
Keyword(s):  
Peak Amplitude ◽  
Measuring System ◽  
Permutation Entropy ◽  
Complex Signal ◽  
Signal Distortion ◽  
Denoising Method ◽  
Mems Accelerometer ◽  
Dynamic Part ◽  
Calibration Accuracy ◽  
The Imf

Recently, the High-G MEMS accelerometer (HGMA) has been used in navigation, mechanical property detection, consumer electronics, and other fields widely. As the core component of a measuring system, it is very crucial to enhance the calibration accuracy of the accelerometer. In order to remove the noises in the accelerometer output signals to enhance its calibration accuracy, a combined denoising method which combines variational mode decomposition (VMD) with permutation entropy (PE) and wavelet threshold is given in this article. For the sake of overcoming the defect of signal distortion caused by the traditional denoising methods, this joint denoising method combines the good decomposition characteristics of VMD and the good denoising ability of wavelet threshold and introduces PE as a judgment criterion to achieve a good balance between denoising effect and signal fidelity. The combination of PE and VMD not only avoids the phenomenon of mode aliasing but also improves the ability to identify the noise components, which makes the wavelet threshold denoising more specific. Firstly, some intrinsic mode functions (IMFs) are obtained by using VMD to decompose the complex signal containing noise which is outputted from the accelerometer. Secondly, the IMF components can be divided into noise IMF components, mixed IMF components, and useful IMF components by PE algorithm. Thirdly, the noise IMF components can be discarded directly, and then the mixed IMF components can be denoised by wavelet threshold to obtain the noiseless IMF components; in addition, the useful IMF components need to be retained. Finally, the final denoising signal can be obtained by reconstructing the IMF components which have been denoised by the wavelet threshold and the useful IMF components retained before denoising. The experimental results prove that the combined denoising algorithm combines the merits of VMD, PE, and wavelet threshold, and this new algorithm has a good performance in the calibration denoising of accelerometer. Compared with the serious signal distortion caused by using only EMD or wavelet threshold, this method not only has a good denoising effect (the noises in the static part are eliminated by 99.97% and the SNR of the dynamic part is raised to 18.56) but also can maintain a good signal fidelity (the error of shock peak amplitude is 3.4%, the error of vibration peak amplitude is 0.4%, and the correlation coefficient between the denoising signals and dynamic part is as high as 0.982).

Nano-Displacement Measurement with Grating Interference

2011 ◽  
Vol 103 ◽  
pp. 35-40 ◽  
Author(s):  
Min Lan Jiang ◽  
Fu Peng Li ◽  
Xiao Dong Wang
Keyword(s):  
Measurement Accuracy ◽  
Laser Interferometer ◽  
Measuring System ◽  
Experimental Result ◽  
High Signal ◽  
Measurement Technology ◽  
Compact Structure ◽  
Signal Contrast ◽  
Grating Interferometer ◽  
Laser Light Source

Nano-Grating measurement technology has been made great development in our country, for its unique advantage which isn’t available in laser interferometer. This paper presents a Nano-grating interferometer displacement measuring system based on double diffraction grating and Semiconductor laser light source, analyzes the error origin of the system in detail and uses error correction and compensation method to improve the measurement accuracy. The experimental result indicated that the system does have stable interferometer, high signal contrast, and easy adjusted optical path, further more the system with a strong environmental adaptability and compact structure. Under 20mm range and 50mm/sec measurement speed, the system’s measuring repeatability is below 30nm.

scholarly journals Real-Time Implementation of AI-Based Face Mask Detection and Social Distancing Measuring System for COVID-19 Prevention

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Safa Teboulbi ◽  
Seifeddine Messaoud ◽  
Mohamed Ali Hajjaji ◽  
Abdellatif Mtibaa
Keyword(s):  
Real Time ◽  
Vision System ◽  
Close Contact ◽  
Public Health Problem ◽  
Confidence Score ◽  
Face Mask ◽  
Physical Distance ◽  
Measuring System ◽  
Social Distancing ◽  
The World

Since the infectious coronavirus disease (COVID-19) was first reported in Wuhan, it has become a public health problem in China and even around the world. This pandemic is having devastating effects on societies and economies around the world. The increase in the number of COVID-19 tests gives more information about the epidemic spread, which may lead to the possibility of surrounding it to prevent further infections. However, wearing a face mask that prevents the transmission of droplets in the air and maintaining an appropriate physical distance between people, and reducing close contact with each other can still be beneficial in combating this pandemic. Therefore, this research paper focuses on implementing a Face Mask and Social Distancing Detection model as an embedded vision system. The pretrained models such as the MobileNet, ResNet Classifier, and VGG are used in our context. People violating social distancing or not wearing masks were detected. After implementing and deploying the models, the selected one achieved a confidence score of 100%. This paper also provides a comparative study of different face detection and face mask classification models. The system performance is evaluated in terms of precision, recall, F1-score, support, sensitivity, specificity, and accuracy that demonstrate the practical applicability. The system performs with F1-score of 99%, sensitivity of 99%, specificity of 99%, and an accuracy of 100%. Hence, this solution tracks the people with or without masks in a real-time scenario and ensures social distancing by generating an alarm if there is a violation in the scene or in public places. This can be used with the existing embedded camera infrastructure to enable these analytics which can be applied to various verticals, as well as in an office building or at airport terminals/gates.

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