Research on Bubble Diameter Measurement Technology of Transparent Potting Gel Based on Image Processing in Micro-rectangular Electrical Connector

Author(s):  
Li Ma ◽  
Kai Kai Han ◽  
Ying Jie Ding ◽  
Peng Hui Ding
2013 ◽  
Vol 303-306 ◽  
pp. 376-381
Author(s):  
Wang Biao ◽  
Xiao Fen Yu ◽  
Cong Yu Xu ◽  
Jia Wen Hu

Because of the large diameter’s big volume, heavy weight, high thermal capacity and bad measurement environment, the workpiece’s diameter can only be detected in the processing locale. Though the rolling-wheel method can realize the large diameter online measurement, it can not achieve the diameter high precision measurement influenced by rolling-wheel skidding, compression deformation and temperature distribution. Focusing on the above problem, a new multi function rolling-wheel large diameter measurement system is designed. The designed system mainly researches the main error resource’s distinguish and amendment methods, such as the round grating graduator error, rolling-wheel shape error, rolling-wheel compression deformation, skidding of rolling-wheel to measured axis workpiece and its non-uniform temperature etc. The system can obtain the measured axis’s diameter and roundness real time while getting the needed information of error amendment by integrating multi opto-electronic switch, round grating, reference grating, micro-displacement sensor, temperature sensor etc. The system can realize diameter measurement extended uncertainty 5Dμm(D:1m~10m) and roundness measurement extended uncertainty 1.5Dμm.


2021 ◽  
Vol 37 (4) ◽  
pp. 623-633
Author(s):  
Jiangtao Ji ◽  
Jingwei Sun ◽  
Xin Jin ◽  
Hao Ma ◽  
Xuefeng Zhu

Highlights A new background segmentation algorithm for depth image was developed. Cap diameter of white button mushroom was measured automatically. The average of diameter measurement error was 4.94%. This work can provide online decision support for selectively harvesting of Agaricus bisporus . Abstract. With the increase in the production and yield of white button mushrooms (Agaricus bisporus), efficient harvesting has become a challenge. Automatic selective harvesting has gradually become a solution. The diameter of the mushroom cap is an essential indicator of the harvesting standard. To provide guidance for selective harvesting, this article presents a method for target detection and measuring the diameter of mushroom caps by using depth image processing. According to the three-dimensional structure characteristics of the mushroom, a novel method is proposed to segment it from the compost it grows on. In this method, compost is regarded as the floor of the sea and mushrooms as standing islands. With the rise of sea level, the compost is gradually submerged, and the target of Agaricus bisporus is stable. These features were used to realize the background segmentation. After background segmentation, the pixel coordinates of the contour points of the mushroom caps are transformed into world coordinates, and the cap diameter is measured by Hough transform. In total, 380 mushrooms depicted in 25 depth images were used to test the developed algorithms. The results showed that 92.37% of the mushrooms were correctly detected. The missed detection rate was less than 8%, and the false detection rate was 1.96%. The average diameter measurement error was 4.94%, and the average process time to measure a single mushroom was approximately 0.50 s. The method proposed in this article can provide online decision support for automatic selective harvesting of Agaricus bisporus, which can improve the quality and efficiency of its production. Keywords: Background segmentation, Computer vision, Diameter measurement, Edible fungus, Hough transform.


Bubble sizes in bubble column affect transfer processes. Therefore, it’s important to calculate bubble size and interfacial area. Bubble size distribution (BSD) in a bubble column of rectangular cross section with dimensions 0.2m x 0.02m was measured using photographic method (400 fps) for air-water system. Gas holdup, Sauter-mean bubble diameter, aspect ratio and specific interfacial area were estimated from BSD. Effect of superficial gas velocity and static bed height on these parameters was investigated. The bubble size distribution exhibited mono-modal distribution showing the presence of non-uniform homogeneous bubbling regime. The frames of video were analysed using image processing steps to obtain major and minor axis of elliptical bubbles. Values of d32, , and ai were estimated from the data. The value of d32 increased with increasing Ug but is independent of Hs. The values of d32 were somewhat higher than the values reported by other investigators. The value of ai increases with increasing Ug and with decreasing Hs. Present values of compared well with the data reported in literature.


2011 ◽  
Vol 383-390 ◽  
pp. 4987-4993
Author(s):  
Zhi Qiang Ma ◽  
Shi Yu Sun ◽  
Yuan Zeng Cheng ◽  
Chun Ping Wang

At the closed-loop calibration research of anti-aircraft weapons systems, the miss distance between target and projectiles is difficult to obtain accurately. In order to solve this problem, this paper provided using the digital image processing technology to research the miss distance measurement methods, focusing on the image filtering technology, edge detection technology and target recognition technology. According to the simulation results, the paper selected the adaptive median filtering to remove image noise, adopted the edge detection method based on the iterative threshold to obtain target edge and used template matching technology to identify the target in the image. Finally, according to the principle of image measurement technique, using centroid tracking measurement technology to achieve the miss distance measurement. The application of digital image processing technology makes the miss distance measurement become simple, effective and convenient. This measurement method enables to save money, improve accuracy, get results in real time and have a high research value.


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