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Penetration Estimation of GMA Backing Welding Based on Weld Pool Geometry Parameters

Chinese Journal of Mechanical Engineering 2019年第3期32卷 134-144页

作者： junfen huang Long Xue Jiqiang huang Yong Zou Ke Ma Opto-Mechatronic Equipment Technology Beijing Area Major Laboratory Beijing Institute of Petrochemical Technology

Penetration estimation is a prerequisite of the automation of backing welding based on vision sensing technology. However, the arc interference in welding process leads to the difficulties of extracting the weld pool characteristic information, which brings great challenges to the penetration estimation. At present, most researches focus on the extraction of weld pool geometry parameters, and the visual sensing systems are complex in structure and complicated in the image processing algorithms. The research of penetration estimation based on weld pool geometry parameters is still in the exploratory stage. The purpose of this paper is to research the relationship between the weld pool geometry parameters and the penetration during backing welding and to estimate penetration using the weld pool geometry parameters. A passive vision sensing test system for gas metal arc (GMA) backing welding was established. An image processing algorithm was developed to extract the weld pool geometry parameters, namely, the area, maximum width and length, half-length, length-width ratio and advancing contact angle (simplified as AWP, MWWP, MLWP, HLWP, LWR and ACA, respectively). The corresponding relationships between the weld pool geometry parameters and the penetration state were explored by analysing their changes with the welding current and speed. The distribution of the weld pool geometry parameters corresponding to penetration was determined. When the AWP of the weld pool is within a certain range and the values of LWR and ACA are close to their maximum and minimum respectively, the penetration is in good condition. A mathematical model with the weld pool geometry parameters as independent variables and the back-bead width (the indicator of the penetration state) as a dependent variable was established based on multivariable linear regression analysis, and relevant statistical tests were carried out. Multivariable linear regression equations for the weld pool geometry parameter

关键词： Welding automation Passive vision sensing Weld pool geometry parameters Penetration state Mathematical model

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Welding Polarity Effects on Weld Spatters and Bead Geometry of Hyperbaric Dry GMAW

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 351-356页

作者： XUE Long WU Jinming huang junfen huang Jiqiang ZOU Yong LIU Jian Opto-Mechatronic Equipment Technology Beijing Area Major Laboratory Beijing Institute of Petrochemical Technology

Welding polarity has influence on welding stability to some extent, but the specific relationship between welding polarity and weld quality has not been found, especially under the hyperbaric environment. Based on a hyperbaric dry welding experiment system, gas metal arc welding（GMAW） experiments with direct current electrode positive（DCEP） and direct current electrode negative（DCEN） operations are carried out under the ambient pressures of 0.1 MPa, 0.4 MPa, 0.7 MPa and 1.0 MPa to find the influence rule of different welding polarities on welding spatters and weld bead geometry. The effects of welding polarities on the weld bead geometry such as the reinforcement, the weld width and the penetration are discussed. The experimental results show that the welding spatters gradually grow in quantity and size for GMAW with DCEP, while GMAW with DCEN can produce fewer spatters comparatively with the increase of the ambient pressure. Compared with DCEP, the welding current and arc voltage waveforms for DCEN is more stable and the distribution of welding current probability density for DCEN is more concentrated under the hyperbaric environment. When the ambient pressure is increased from 0.1 MPa to 1.0 MPa, the effects of welding polarities on the reinforcement, the weld width and the penetration are as follows： an increase of 0.8 mm for the weld reinforcement is produced by GMAW with DCEN and 1.3 mm by GMAW with DCEP, a decrease of 7.2 mm for the weld width is produced by DCEN and 6.1 mm by DCEP; and an increase of 3.9 mm for the penetration is produced by DCEN and 1.9 mm by DCEP. The proposed research indicates that the desirable stability in the welding procedure can be achieved by GMAW with DCEN operation under the hyperbaric environment.

关键词： welding polarity hyperbaric welding gas metal arc welding(GMAW) weld bead geometry spatter

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Constant Speed Control for Complex Cross-section Welding Using Robot Based on Angle Self-Test

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 260-268页

作者： XUE Long ZOU Yong huang Jiqiang huang junfen TAO Xinghua HU Yanfeng Opto-Mechatronic Equipment Technology Beijing Area Major Laboratory Beijing Institute of Petrochemical Technology School of Automation Science and Electrical Engineering Beihang University SINOPEC Research Institute of Petroleum Engineering

Expandable profile liner（EPL） is a promising new oil well casing cementing technique, and welding is a major EPLs connection technology. Connection of EPL is still in the stage of manual welding so far, automatic welding technology is a hotspot of EPL which is one of the key technologies to be solved. A robot for automatic welding of＂8＂ type EPL is studied. Four quadrants of mathematical equations of the 8-shaped cross-section track of EPL, consisting of multiple arcs, are established. Mechanism program for complex cross-section welding of EPL based on angle detection is proposed according to characteristics of small size, small valleys, and large forming errors, etc. A welding velocity vector control model is established by linkage control of a welding vehicle, a small driven actuator, and a height tracking mechanism. A constant speed control model based on an angle and symmetrical analysis model of rectangular coordinate system for EPL is built. Constraint conditions of constant speed control between each section are analyzed with 4 sections in first quadrant as an example, and cooperation work mechanism of the welding vehicle and the small tracking actuator is established based on pressure detection. The constant speed control model using angle self-test can be used to avoid the need for a precise mathematical model for tracking control and to adapt manufacture and installation deviation of EPL workpiece. The model is able to solve constant speed and trajectory tracking problems of EPL cross-section welding. EPL seams welded by the studied robot are good in appearance, and non-destructive testing（NDT） shows the seams are good in quality with no welding defects. Bulge tests show that the maximum pressure of welded EPL is 35 MPa, which can fulfill expansion performance requirements.

关键词： expandable profile liner welding robot minitype driven actuator velocity vector model

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Welding Deviation Detection Algorithm Based on Extremum of Molten Pool Image Contour

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Chinese Journal of Mechanical Engineering 2016年第1期29卷 74-83页

作者： ZOU Yong JIANG Lipei LI Yunhua XUE Long huang junfen huang Jiqiang College of Automation Science and Electrical Engineering Beihang University Optical Electromechanical Equipment Technology Key Laboratory of Beijing Beijing Institute of Petrochemical Technology

The welding deviation detection is the basis of robotic tracking welding, but the on-line real-time measurement of welding deviation is still not well solved by the existing methods. There is plenty of information in the gas metal arc welding（GMAW） molten pool images that is very important for the control of welding seam tracking. The physical meaning for the curvature extremum of molten pool contour is revealed by researching the molten pool images, that is, the deviation information points of welding wire center and the molten tip center are the maxima and the local maxima of the contour curvature, and the horizontal welding deviation is the position difference of these two extremum points. A new method of weld deviation detection is presented, including the process of preprocessing molten pool images, extracting and segmenting the contours, obtaining the contour extremum points, and calculating the welding deviation, etc. Extracting the contours is the premise, segmenting the contour lines is the foundation, and obtaining the contour extremum points is the key. The contour images can be extracted with the method of discrete dyadic wavelet transform, which is divided into two sub contours including welding wire and molten tip separately. The curvature value of each point of the two sub contour lines is calculated based on the approximate curvature formula of multi-points for plane curve, and the two points of the curvature extremum are the characteristics needed for the welding deviation calculation. The results of the tests and analyses show that the maximum error of the obtained on-line welding deviation is 2 pixels（0.16 ram）, and the algorithm is stable enough to meet the requirements of the pipeline in real-time control at a speed of less than 500 mm/min. The method can be applied to the on-line automatic welding deviation detection.

关键词： welding deviation welding seam tracking molten pool contour curvature extremum gas metal arc welding(GMAW)

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防压疮异形气囊枕垫及人体外压感知方法研究

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机械设计 2024年第4期41卷 158-163页

作者：曹莹瑜王瑃黄军芬王伟毛雪松王阔北京石油化工学院机械工程学院北京102617

为解决规则形气囊枕垫设计算法不足及气囊外表面薄膜压力传感器的透气性和稳定性问题,提出一种防压疮异形气囊枕垫及基于气囊内压-高度模型的人体外压感知方法,通过建立异形气囊的压力-高度-外部载荷模型,测量异形气囊内压力和气囊高度... 详细信息

为解决规则形气囊枕垫设计算法不足及气囊外表面薄膜压力传感器的透气性和稳定性问题,提出一种防压疮异形气囊枕垫及基于气囊内压-高度模型的人体外压感知方法,通过建立异形气囊的压力-高度-外部载荷模型,测量异形气囊内压力和气囊高度,实现人体外压的推算和稳定感知,以及仰卧或俯卧位的压疮防治。试验结果表明:外压力误差为0.85 N,满足智能防压疮枕垫的压力控制精度。采用人体外压感知方法进行压力感知,避免采用压力薄膜传感器,为重症患者创造更舒适、更安全的护理环境。

关键词：压力检测气囊枕垫气囊模型压疮预防

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小口径不锈钢圆管自动TIG焊接工艺参数

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焊接 2024年第5期 16-20,29页

作者：刘刚张梦金何之薛龙黄军芬中广核研究院有限公司广东深圳518000 北京石油化工学院北京102617

壁厚大于3 mm的小口径不锈钢圆管I形坡口自熔焊接,易出现未焊透缺陷,严重影响焊接质量。针对外径ϕ32.5 mm、壁厚为3.25 mm的304奥氏体不锈钢圆管I形坡口,采用自动钨极氩弧焊自熔焊接方法,通过数值模拟和焊接试验研究焊接工艺参数中焊接... 详细信息

壁厚大于3 mm的小口径不锈钢圆管I形坡口自熔焊接,易出现未焊透缺陷,严重影响焊接质量。针对外径ϕ32.5 mm、壁厚为3.25 mm的304奥氏体不锈钢圆管I形坡口,采用自动钨极氩弧焊自熔焊接方法,通过数值模拟和焊接试验研究焊接工艺参数中焊接电流和起弧预热时间对焊缝成形的影响。由数值模拟得出焊接电流、起弧预热时间与焊缝成形参数的对应关系,初步确定圆管自熔焊接试验的焊接电流和起弧预热时间范围。然后,通过自动钨极氩弧焊自熔焊接试验,得出了焊缝成形良好时的具体焊接电流、起弧预热时间。试验结果表明,焊接速度为100 mm/min、焊接电流为105 A,115 A时,圆管环缝中间焊段能够实现熔透,且焊缝不会产生塌陷缺陷。焊接电流为115 A、起弧预热时间为4 s和5 s时,起弧段焊缝背面熔宽较为稳定,能够确保焊缝可靠熔透。

关键词：自动钨极氩弧焊自熔焊接焊缝成形焊接过程数值模拟

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减重步行康复训练装置研究现状与发展趋势

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北京石油化工学院学报 2024年第1期32卷 15-19,45页

作者：黄军芬宁浩强曹莹瑜薛龙胡帅陈腾飞北京石油化工学院机械工程学院北京102617

针对脑卒中、神经损伤等患者的运动障碍,减重步行康复训练是一种重要的康复方式,相应训练装置的研究对于减轻治疗师劳动强度、提高疗效起到了重要作用。康复训练装置按照结构类型划分为悬吊式减重训练装置、气囊式减重训练装置、骨盆式... 详细信息

针对脑卒中、神经损伤等患者的运动障碍,减重步行康复训练是一种重要的康复方式,相应训练装置的研究对于减轻治疗师劳动强度、提高疗效起到了重要作用。康复训练装置按照结构类型划分为悬吊式减重训练装置、气囊式减重训练装置、骨盆式减重训练装置等。阐述了减重步行康复训练装置的发展历程,分析不同类型减重步行康复训练装置的特点与不足之处并提出相应发展方向。为减重步行康复训练装置能够满足不同患者的训练需求提供参考。

关键词：减重训练步行康复装置机械结构综述

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基于神经网络模式识别的人体大便便意识别模型研究

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北京石油化工学院学报 2024年第1期32卷 60-64页

作者：曹莹瑜高尊黄军芬云欣怡赵震玺北京石油化工学院机械工程学院北京102600

针对医院患病老人长期卧床、缺乏自理能力,尤其是大便护理难以解决的问题,提出了基于神经网络的大便便前监测模型。根据人体便前90 s生理参数会发生明显变化的特点,通过采集人体有便意和无便意状态下的生理参数制定数据集,构建大便便意... 详细信息

针对医院患病老人长期卧床、缺乏自理能力,尤其是大便护理难以解决的问题,提出了基于神经网络的大便便前监测模型。根据人体便前90 s生理参数会发生明显变化的特点,通过采集人体有便意和无便意状态下的生理参数制定数据集,构建大便便意识别模型并使用数据集对其进行训练,最终通过训练后的模型实现对卧床失能老人的大便便意识别和便前监测。临床实验结果表明:该预测模型进行便意识别和便前监测的准确率在80%~87%之间,具有较高精度和实用价值。

关键词：神经网络模式识别大便便意识别人体生理参数

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High-Precision Measurement Method of Time-Interval Based on Pseudo-Random Sampling

High-Precision Measurement Method of Time-Interval Based on ...

引用

The 2011 International Conference on Automation and Robotics(ICAR 2011)

作者： Minshuang huang junfen huang Yinqi Feng Opto-Mechatronic Equipment Technology Beijing Area Major Laboratory Beijing Institute of Petrochemical Technology

Based on pseudo-random sampling a high-precision measurement method of time-interval for pulsed laser ranging is presented for the first time. In the method, time-intervals of laser pulses are controlled by a chirp signal generated using a Voltage-Controlled Crystal Oscillator. The time-intervals are unequal pseudo-random sequences. Pulse laser signals reflected from the object become sampling signals after they pass through a time discriminating circuit. Characteristics of measured signals are represented by the mapping of sampling time points on a referenced sinusoid signal. Then high-precision measurement of time-intervals can be implemented using a phase estimation algorithm. This method is simple in theory and easy to realize. In experiments using 15 MHz reference clock, it is achieved that the measurement precision of time is 16 ps.

关键词： Pseudo-random sampling Time-interval measurement Phase estimation

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布里渊光子晶体光纤环形移频器

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红外与激光工程 2012年第8期41卷 2125-2129页

作者：黄民双黄军芬北京石油化工学院光机电装备技术北京市重点实验室北京102617

通过实验研究了一种光子晶体光纤环形移频器,该移频器基于布里渊频移原理,利用光子晶体光纤布里渊增益高、阈值低的特点,同时利用光纤环形腔选频放大技术获得窄线宽高增益激光输出。实验结果表明:在波长为1 548 nm单纵模光纤激光泵浦下,... 详细信息

通过实验研究了一种光子晶体光纤环形移频器,该移频器基于布里渊频移原理,利用光子晶体光纤布里渊增益高、阈值低的特点,同时利用光纤环形腔选频放大技术获得窄线宽高增益激光输出。实验结果表明:在波长为1 548 nm单纵模光纤激光泵浦下,10 m长光子晶体光纤的受激布里渊散射阈值功率约为457mW,环形腔输出的受激布里渊散射Stokes光相对于入射光移频量为9.778GHz、线宽500 kHz,并且移频量可以通过温度进行微调。该移频器可以用于分布式光纤布里渊传感器和微波发生器。

关键词：光子晶体光纤光纤环形振荡器受激布里渊散射温度特性光纤移频器

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