基于激光跟踪的V形坡口焊接机器人

介绍了激光跟踪焊接机器人的结构组成和工作原理。在分析了V形坡口焊缝空间位置和形状特征的基础上,采取结构光法标定焊缝图像。经过焊缝条纹图像处理,提取焊缝特征点,根据三角测量原理建立了特征点的三维坐标。通过建立图像空间到机器人末端焊枪的笛卡尔空间雅可比矩阵,计算出焊枪在基坐标下的位姿;利用机器人逆运动学方程,求得机器人各关节的位置值,最后由关节控制器控制各个关节的运动,实现了机器人V形坡口焊接的视觉控制。     

弧焊机器人焊缝位置的电流检测法

本文介绍了弧焊机器人在进行“Ｖ”型坡口对接焊或角接焊时,为了跟踪焊缝轨迹而进行的焊缝位置检测方法－电流检测法,通过对焊接电流信号的数字处理,提取了反映焊枪与焊缝相对位置的特征信号,定时向机器人控制器提供修正信号,从而使固定在机器人手臂上的焊枪准确地跟踪焊缝。     

弧焊机器人空间焊缝焊接参数与姿态规划研究

针对弧焊机器人空间焊缝焊接工艺参数和焊枪姿态规划问题,提出了焊缝特征坐标系的概念,定义了“立坡焊”和“横坡焊”的概念,采用焊缝特征坐标系来描述各种焊接接头复杂空间焊缝的焊接位置,引用齐次变换技术求解空间焊缝的转角和倾角,将复杂空间焊缝的规划问题分解为“立坡焊”和“横坡焊”2种焊接位置的组合,并运用于马鞍型焊缝机器人焊接。实验结果表明,该方法正确可行。     

J形坡口焊接机器人运动控制系统设计

核电压力容器的焊接制造中,半球形封头与圆管相贯形成空间曲线J形坡口焊缝,通用焊接机器人难以满足焊接要求.针对研发的悬挂式J形坡口专用焊接机器人,设计开发了机器人运动控制系统.介绍了机器人机械结构特点及运动控制算法.机器人控制系统核心采用工业控制计算机(IPC)与DMC数字运动控制器,交流伺服电机为执行端,利用三级控制结构实现作业管理,组织各轴协同运动完成焊接作业.进行了空间曲线J形坡口焊缝焊接实验.实验结果表明,设计开发的运动控制系统能够很好地控制机器人各轴协同运动,满足空间曲线J形坡口焊缝的焊接需求,可以提高核电压力容器焊接制造的自动化水平.     

基于旋转电弧传感方式的焊接机器人路径生成方法

介绍了一种空间全位置焊接条件下的焊枪姿态自动规划方法.系统以旋转电弧传感器和工业机器人为平台而采集焊接电流数据,通过对电流处理,提取焊枪的姿态和焊缝的位置信息,据此计算机器人的运动轨迹;使焊枪自动跟踪平滑的三维焊缝,并随焊缝调整焊枪姿态;同时根据不同情况调整焊接参数,在焊缝终点自动结束焊接过程.最后,基于工业机器人的实验数据仿真,验证了所设计方案的可行性和有效性.结果表明:焊枪姿态自动规划方法可以自动跟踪三维焊缝和自动调整参数,且不需要另外附加传感器,使其成本降低和系统的复杂程度简化;焊枪姿态自动规划方法使得生产更加自动化,且前进速度均匀,焊接角度有保证,对提高焊接质量很有益.     

弧焊机器人激光焊缝跟踪系统的应用研究

焊缝自动跟踪是实现焊接自动化的关键,在传统弧焊机器人系统的基础上设计了一种基于激光传感器的焊缝跟踪子系统,构建了激光传感器的数学模型及机器人手眼标定方法,并针对搭接焊缝的图像特点,提取出焊缝特征点位置坐标.同时设计开发了焊缝跟踪控制算法和机器人焊缝跟踪程序,最后通过对储气罐环形搭接焊缝进行焊接实验,结果证明了该焊缝跟踪系统的有效性和可靠性.     

采用激光线光源的焊接坡口间隙视觉检测

针对生产过程中焊件的加工装配误差、焊件热变形等因素导致的焊接坡口间隙变化从而影响焊缝质量的问题,设计基于激光线性光源的焊接坡口间隙视觉检测系统.运用LabVIEW的Vision Builder AI 3.0图像处理模块对焊接坡口间隙变化进行实时测量,实现坡口间隙变化视觉信号的图像采集和检测.实验表明,焊接坡口的检测精度和实时性可以满足焊枪姿态、焊枪摆动角度和焊接过程中焊接规范的实时修正与控制要求.     

焊枪自转角对焊接机器人能量消耗的影响

结合弧焊焊接的内在特性,给出了机器人焊枪自转角的定义.基于三相功率分析仪,搭建了机器人功率消耗的测量平台.针对1G、2G和3G位置的直焊缝焊接,使用该平台测量了CMT弧焊焊接机器人在不同焊枪自转角作业过程中消耗的瞬时功率.计算并对比了机器人的平均功率,发现在这3种位置,改变焊接起点和终点的焊枪自转角,机器人在整个运动过程和焊缝段消耗的平均功率都有显著变化.机器人在焊缝段和整个运动过程中的功率消耗变化规律相似,存在着能量最优的起点和终点焊枪自转角.结果表明改变焊枪自转角,可以节省焊接机器人能量消耗.在1G、2G和3G位置,分别以各焊接位置所有焊枪自转角组合的平均值计算,最大可以减少11.1%、5.9%和8.3%的功率消耗.定义了功率消耗最小值附近区间表示取得功率最小值的难易程度,发现该区间概率很小,这进一步说明了焊枪自转角对机器人的功率消耗有显著影响,为了减少弧焊焊接中机器人的功率消耗,需要注意焊枪自转角的选择.最后,简述了焊枪自转角与机器人功率消耗,以及工件摆放位置与机器人功率消耗关联模型的建立思想,并给出了相关初步结果.该方面的研究对焊接机器人能量优化和实际焊接生产有着重要的指导意义.     

基于Kohonen网络弧焊机器人摆动跟踪时摆幅与频率的智能识别

针对10mm厚钢板V型坡口接头的弧焊机器人摆动跟踪焊接,实时测量电弧电压和焊接电流的瞬时值,对其进行两次统计处理,构建不同摆幅和摆动频率时的焊接电参数特征矢量,采用Kohonen网络识别技术,建立了焊接电参数特征矢量与摆动焊接摆幅和频率的内在联系,为定量研究摆幅和频率对V型坡口焊缝成形的影响提供依据。     

基于机器视觉的施工现场钢结构焊缝坡口识别

基于线结构光视觉传感技术建立了一种适用于施工现场钢结构焊缝坡口识别方法.以南京某超高层建筑钢结构为工程背景，首先设计开发了适用于施工现场的图像采集装置，通过识别算法从采集图像中截取结构光线条感兴趣区域图像；其次，提出了基于分组教学优化算法-大津法(GTO-Otsu)的图像局部阈值分割方法，实现了结构光线条与背景的有效分割；然后，构建了线性结构元素用于修复结构光线条断裂区域；最后，通过比较相邻像素点的灰度和与一阶差分值的方法提取了结构光线条中心线及特征点坐标，并建立了像素转化方法，完成特征点像素坐标的转换，实现坡口几何尺寸测量.3组施工现场钢结构焊缝坡口图像处理和识别结果表明了该方法的准确性与适用性.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.