scholarly journals ATMOSPHERIC ENVIRONMENT DETECTION METHOD BASED ON MULTI-ROTOR UAV PLATFORM

2018 ◽  
Vol XLII-3/W5 ◽  
pp. 67-71
Author(s):  
A. Shen ◽  
S. Zhou ◽  
S. Peng
Keyword(s):  
Detection Method ◽  
Center Of Gravity ◽  
Atmospheric Environment ◽  
Detection Accuracy ◽  
Flight Safety ◽  
Rotor Speed ◽  
Gradual Process ◽  
The Stability ◽  
Environment Detection ◽  
Improve Stability

<p><strong>Abstract.</strong> For the method of atmospheric detection based on multi-rotor UAV, the effects of flight safety and airflow on detection accuracy are analyzed. The detector mounted on the multi-rotor drone should be highly symmetrical and the center of gravity should be on the same vertical line as the center of gravity of the drone. Mounting the detector above the drone's fuselage will reduce the stability of the drone, and lowering it will improve stability, but for models with high stability, placing it below will affect the maneuverability of the drone. The airflow interference in the area where the detector can be placed near the fuselage is related to the drone: the faster the rotor speed, and the closer the rotor is to the fuselage, the stronger the airflow interference. At the same time, the influence of airflow disturbance on temperature and humidity has a gradual process. Waiting for a period of time after starting the drone can change the error into a fixed error for post-processing. This method was used to detect a pollution process and achieved good results.</p>

Detection method for stability of microcontroller accessories based on biosensor

2021 ◽  
pp. 1-14
Author(s):  
Yan Ren ◽  
Jiayong Liu
Keyword(s):  
Process Design ◽  
Detection Method ◽  
Detection Accuracy ◽  
Stability Testing ◽  
Term Operation ◽  
Existing Problems ◽  
Testing Method ◽  
And Performance ◽  
The Stability

In order to solve the problem of poor accuracy of traditional microcontroller attachment stability testing method, a microcontroller attachment stability testing method based on biosensor was designed to solve the existing problems. The reliability test index of the microcontroller is established, then the interference of the microcontroller accessory is detected and responded, and the interference detection signal of the microcontroller accessory is selected. The process design of stability detection of microcontroller accessories based on biosensor is completed. The experimental results show that the stability detection method based on biosensor designed in this paper can ensure the stability detection accuracy of microcontroller accessories above 80%, which is more accurate than traditional methods. It can be used to evaluate the stability, reliability and performance of microcontroller accessories in long-term operation.

scholarly journals Straightness Detection Method and Accuracy Analysis of Guide Rail Parts

2021 ◽  
Vol 2133 (1) ◽  
pp. 012020
Author(s):  
Xiaoying Wang
Keyword(s):  
Machine Tools ◽  
Detection Method ◽  
Detection Methods ◽  
Detection Accuracy ◽  
Accuracy Analysis ◽  
Geometric Accuracy ◽  
Guide Rail ◽  
The Common ◽  
The Stability

Abstract Guide rail is widely used in various machine tools. It mainly plays the role of guidance and support. The geometric accuracy of the guide rail, especially the straightness accuracy, directly affects the stability of the machine tool and the accuracy of the workpiece. By analyzing the common detection methods, application scope and detection accuracy of straightness of guide rail parts, the application occasions and detection accuracy of each detection method are clarified. It provides a theoretical basis and guidance for testers to detect straightness and deal with errors.

scholarly journals Large area dynamic detection method for remote communication fault of power consumption information acquisition terminal

2021 ◽  
Vol 252 ◽  
pp. 01025
Author(s):  
Yiqun Zhu ◽  
Jijun Zheng ◽  
Zhen Li ◽  
Xiaolei Liu
Keyword(s):  
Information Acquisition ◽  
Detection Method ◽  
Experimental Comparison ◽  
Detection Accuracy ◽  
Power Equipment ◽  
Remote Communication ◽  
Long Distance ◽  
Equipment Operation ◽  
Dynamic Detection ◽  
The Stability

With the rapid development of power system technology, the requirements for the stability of power equipment operation are higher and higher. In order to ensure the stability of power equipment operation, this paper puts forward the dynamic detection method of long-distance communication fault of power information acquisition terminal. Through the collection of remote communication fault dynamic information, data preprocessing. And the fault area is accurately located to determine the fault location. Through the power information acquisition terminal to determine the abnormal value, the detection effect of communication fault can be realized. According to the experimental comparison, it can be seen that compared with the traditional fault detection methods, the large interval dynamic detection method of power information acquisition terminal remote communication fault has higher detection accuracy and significant advantages.

scholarly journals Stability Analysis of Different Regulation Modes of Hydropower Units

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1933
Author(s):  
Xinran Guo ◽  
Yuanchu Cheng ◽  
Jiada Wei ◽  
Yitian Luo
Keyword(s):  
Stable Operation ◽  
Rotor Speed ◽  
Frequency Range ◽  
Power Regulation ◽  
Normal Frequency ◽  
Dynamic Performances ◽  
Negative Damping ◽  
The Stability ◽  
Regulation Mode ◽  
Water Inertia

The dynamic characteristics of hydropower unit governing systems considerably influence the stability of hydropower units and the connected power system. The dynamic performances of hydropower units with power regulation mode (PRM) and opening regulation mode (ORM) are different. This paper establishes a detailed linear model of a hydropower unit based on the Phillips–Heffron model. The damping characteristic and stability of two regulation modes with different water inertia time constants TW were analyzed. ORM tended to provide negative damping, while PRM often provided positive damping in the major parts of the frequency range within the normal frequency oscillations when TW was large. Eigenvalue analysis illustrated that PRM has better stability than ORM. To validate the analysis, a simulation under two typical faults WAS conducted based on a nonlinear model of a hydropower unit. The simulation results illustrated that the responses of units with PRM are more stable in terms of important operating parameters, such as output power, rotor speed, and power angles. For hydropower units facing challenges in stable operation, PRM is recommended to obtain good dynamic stability.

scholarly journals An Automatic Concrete Crack-Detection Method Fusing Point Clouds and Images Based on Improved Otsu’s Algorithm

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1581
Author(s):  
Xiaolong Chen ◽  
Jian Li ◽  
Shuowen Huang ◽  
Hao Cui ◽  
Peirong Liu ◽  
...  
Keyword(s):  
Crack Detection ◽  
Detection Method ◽  
Multiple Scales ◽  
Point Clouds ◽  
Depth Image ◽  
Detection Accuracy ◽  
Detection Techniques ◽  
Concrete Crack ◽  
3D Point Clouds ◽  
2D Images

Cracks are one of the main distresses that occur on concrete surfaces. Traditional methods for detecting cracks based on two-dimensional (2D) images can be hampered by stains, shadows, and other artifacts, while various three-dimensional (3D) crack-detection techniques, using point clouds, are less affected in this regard but are limited by the measurement accuracy of the 3D laser scanner. In this study, we propose an automatic crack-detection method that fuses 3D point clouds and 2D images based on an improved Otsu algorithm, which consists of the following four major procedures. First, a high-precision registration of a depth image projected from 3D point clouds and 2D images is performed. Second, pixel-level image fusion is performed, which fuses the depth and gray information. Third, a rough crack image is obtained from the fusion image using the improved Otsu method. Finally, the connected domain labeling and morphological methods are used to finely extract the cracks. Experimentally, the proposed method was tested at multiple scales and with various types of concrete crack. The results demonstrate that the proposed method can achieve an average precision of 89.0%, recall of 84.8%, and F1 score of 86.7%, performing significantly better than the single image (average F1 score of 67.6%) and single point cloud (average F1 score of 76.0%) methods. Accordingly, the proposed method has high detection accuracy and universality, indicating its wide potential application as an automatic method for concrete-crack detection.

scholarly journals Examination of Abnormal Behavior Detection Based on Improved YOLOv3

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 197
Author(s):  
Meng-ting Fang ◽  
Zhong-ju Chen ◽  
Krzysztof Przystupa ◽  
Tao Li ◽  
Michal Majka ◽  
...  
Keyword(s):  
Detection Method ◽  
Abnormal Behavior ◽  
Detection Accuracy ◽  
Average Precision ◽  
Research Results ◽  
Behavior Detection ◽  
Abnormal Behavior Detection ◽  
The Mean ◽  
Examination Room ◽  
Detection Speed

Examination is a way to select talents, and a perfect invigilation strategy can improve the fairness of the examination. To realize the automatic detection of abnormal behavior in the examination room, the method based on the improved YOLOv3 (The third version of the You Only Look Once algorithm) algorithm is proposed. The YOLOv3 algorithm is improved by using the K-Means algorithm, GIoUloss, focal loss, and Darknet32. In addition, the frame-alternate dual-thread method is used to optimize the detection process. The research results show that the improved YOLOv3 algorithm can improve both the detection accuracy and detection speed. The frame-alternate dual-thread method can greatly increase the detection speed. The mean Average Precision (mAP) of the improved YOLOv3 algorithm on the test set reached 88.53%, and the detection speed reached 42 Frames Per Second (FPS) in the frame-alternate dual-thread detection method. The research results provide a certain reference for automated invigilation.

A real time detection method for abnormal strapping of steel coil based on CCD active imaging

2021 ◽  
Author(s):  
Chuan Ye ◽  
Liming Zhao ◽  
Qiyan Wang ◽  
Bo Pan ◽  
Youchun Xie ◽  
...  
Keyword(s):  
Maximum Entropy ◽  
Detection Method ◽  
Saliency Detection ◽  
Automatic Segmentation ◽  
Engineering Application ◽  
Detection Accuracy ◽  
Steel Coil ◽  
Detection Model ◽  
Laser Stripe ◽  
Active Imaging

Abstract In order to accurately detect the abnormal looseness of strapping in the process of steel coil hoisting, an accurate detection method of strapping abnormality based on CCD structured light active imaging is proposed. Firstly, a maximum entropy laser stripe automatic segmentation model integrating multi-scale saliency features is constructed. With the help of saliency detection model, the purpose is to reduce the interference of the environment to the laser stripe and highlight the distinguishability between the stripe and the background. Then, the maximum entropy is used to segment the fused saliency features and accurately extract the stripe contour. Finally, the stripe normal field is obtained by calculating the stripe gradient vector, the stripe center line is extracted based on the stripe distribution normal direction, and the abnormal strapping is recognized online according to the stripe center. Experiments show that the proposed method is effective in terms of detection accuracy and time efficiency, and has certain engineering application value.

New Methodology for the Determination of the Vertical Center of Gravity of In-Service Semisubmersibles: Proposal and Numerical Assessment

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Ivan N. Porciuncula ◽  
Claudio A. Rodríguez ◽  
Paulo T. T. Esperança
Keyword(s):  
Accurate Determination ◽  
Center Of Gravity ◽  
Practical Implementation ◽  
Numerical Assessment ◽  
Neutral Equilibrium ◽  
Inclination Angles ◽  
Numerical Tools ◽  
The Stability ◽  
Metacentric Height

Along its lifetime, an offshore unit is subjected to several equipment interventions. These modifications may include large conversions in loco that usually are not adequately documented. Hence, the accurate determination of the platform's center of gravity (KG) is not possible. For vessels with low metacentric height (GM), such as semisubmersibles, Classification Societies penalize the platform's KG, inhibiting the installation of new equipment until an accurate measurement of KG is provided, i.e., until an updated inclining test is performed. For an operating semisubmersible, the execution of this type of test is not an alternative because it implies in removing the vessel from its in-service location to sheltered waters. Relatively recently, some methods have been proposed for the estimation of KG for in-service vessels. However, as all of the methods depend on accurate measurements of inclination angles and, eventually, on numerical tools for the simulation of vessel dynamics onboard, they are not straightforward for practical implementation. The objective of the paper is to present a practical methodology for the experimental determination of KG, without the need of accurate measurements of inclinations and/or complex numerical simulations, but based on actual operations that can be performed onboard. Indeed, the proposed methodology relies on the search, identification, and execution of a neutral equilibrium condition where, for instance, KG = KM. The method is exemplified using actual data of a typical semisubmersible. The paper also numerically explores and discusses the stability of the platform under various conditions with unstable initial GM, as well as the effect of mooring and risers.

The Study on High Precision 3D Detection Method of Steel Plate Surface Based on Structured Light

2012 ◽  
Vol 572 ◽  
pp. 338-342 ◽  
Author(s):  
Zhi Guo Liang ◽  
Quan Yang ◽  
Ke Xu ◽  
Fei He ◽  
Xiao Chen Wang ◽  
...  
Keyword(s):  
Surface Quality ◽  
Steel Plate ◽  
Detection Method ◽  
Structured Light ◽  
Detection Methods ◽  
Measurement Technology ◽  
Detection Accuracy ◽  
Plate Surface ◽  
Factors Affecting

Structured light 3D measurement technology with its simple structure, non-contact measurement, fast measurement speed and other advantages, has been widely used. Steel plate surface quality detection is not confined to the two-dimensional feature of gray detection, and local topography measurement for surface quality of steel plate detection becomes increasingly important. In this paper, steel plate surface 3D detection method based on structured light and the factors affecting the measurement accuracy are analyzed. Several effective methods of improving 3D detection accuracy are put forward. Compared with the traditional structured light 3D detection methods, the detection accuracy of new methods is remarkably improved, thus possessing better application values.

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