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.     

现代弧焊控制在爬行式全位置弧焊机器人中的应用研究

简述了焊接工艺过程自动化的国内外发展现状,介绍了大型工件工地焊接机器人的研制和开发,重点介绍了爬行机构和机器人控制系统的研究现状以及传感器的设计与选择要求。焊接实验和试生产结果证明,样机运行平稳、可靠,具有很好的跟踪精度。     

弧焊机器人焊接单元研制

从汽车焊接零件的产品特点及焊接要求出发,结合研制的弧机器人焊接单元的使用情况,分析了系统构成及系统特征,着重研究了机器人焊接夹具有设计、电气控制系统的配置、焊接工艺的选定等。     

焊接机器人制作风机底座的效果分析

通过对中厚板焊接机器人与人工焊接的对比分析,论证了在风机底座的焊接制造中,中厚板焊接机器人的应用可以大大提高生产效率,充分确保焊接质量,并且节省焊接材料和节约成本。     

复杂焊接机器人系统的协同控制

利用Petri网理论对多台机器人焊接系统进行了建模,根据系统的特点设计了基于局域网络通信的软件控制系统,实现系统的全局调度;利用建立的系统模型设计了多机器人铝合金交流脉冲GTAW的悬空角焊工艺实验.实验结果表明:系统各个机器人动作协调正确,未发生动作干涉等异常情况;焊接电弧燃烧稳定,工艺设计合理,加工过程流畅.焊接实验验证了系统建模控制的正确性,拓展了Petri网理论在焊接领域的应用.     

基于多轴运动控制卡的伺服控制系统研究

以工控机为核心 ,应用研华三轴运动控制卡PCL 832 ,建立了机器人用数控焊接变位机的高精度控制系统 .研究分析了焊接变位机的位置控制精度、速度和运动轨迹的控制过程 ,给出了负载变化和速度变化的位置控制结果 ,其结果满足与弧焊机器人配合使用的精度要求 .     

基于BP的机器人摆动焊接视觉跟踪模糊控制

在建立机器人摆动焊视觉跟踪系统的基础上，构造了用于焊接纪盼望匠模糊控制系统，并提出利用三层ＢＰ神经网络来模拟模糊控制量之间的映射关系，从而实现了基于Ｂ宾机器人摆动焊接神经网络模糊控制。     

基于刚柔混合建模的移动焊接机器人系统仿真

以某移动焊接机器人为例,在刚柔混合建模理论与方法的基础上,利用Pro/E对移动焊接机器人进行整体造型;不仅将模型导入到仿真软件ADAMS环境,而且利用ADAMS/AutoFlex模块对机器人部分构件建立柔性体,同时通过ADAMS/View构建了机器人的刚柔多体动态仿真模型。仿真分析说明：该模型能够准确的反映焊接机器人的...     

爬行焊接机器人在球罐自动焊接中的应用

为了实现大型钢结构件的自动化焊接,尤其解决球罐三维曲面的自动化全位置焊接难题,需要设计一种可在球形表面上稳定行走的机构及适用于多种复杂工况的焊接跟踪控制系统。爬壁机器人将履带与轮式结合,解决了爬壁机构运行的灵活性与负载能力之间的矛盾,通过视觉跟踪系统自动识别焊缝位置,智能判断焊缝路径轨迹,实现机器人沿焊缝的自主运动和焊缝跟踪。无轨道、无导向的爬行机本体适应球罐的大曲率变化,可以实现在球罐表面的自由行走,满足球罐焊接高效化和智能化的自动焊接需求。     

膨胀波纹管焊接机器人的研制及其机构运动分析

对一种满足"8"字型膨胀波纹管自动焊接的机器人进行研究。分析膨胀波纹管结构特点,提出基于焊接小车、微型跟踪执行机构、微型焊枪、高低跟踪机构的机器人系统机构方案,对机器人系统机构方案进行运动分析,建立基于D-H法则的焊接机器人运动学模型,通过模型分析及Matlab仿真验证机构模型的正确性。结果表明,建立的基于压力检测的焊接小车与微型跟踪执行机构协同作业机制,解决了"8"字形波纹管断面的机器人焊缝轨迹跟踪问题。仿真结果验证了所建机构模型的正确性。     

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.     

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.     

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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