基于Unity3D的焊接机器人虚拟现实仿真技术研究

以一个6自由度关节型焊接机器人为对象,对其进行了虚拟现实仿真技术的研究,提出了一种基于Unity 3D引擎、使用C#语言开发的虚拟现实仿真系统的设计。研究内容包括:三维建模和优化处理、模型及场景的实时加载、人机交互界面的设计、运动仿真、虚拟机器人与实际机器人的运动同步和位姿同步、简单临场感的实现、碰撞检测功能。通过对焊接机器人虚拟现实技术的研究,可以有效降低焊接过程中操作人员的作业风险,对焊接机器人工作过程中的远程监控具有较大的研究意义。     

机器人虚拟示教的实现方法

本文介绍了基于虚拟现实技术的机器人示教方法：通过人手引导输入装置产生示教轨迹、键盘输入作业指令实现对虚拟机器人的示教；介绍了虚拟示教系统的软硬件环境，重点介绍了虚拟现实系统中的人机交互装置，最后提出了针对MOTOMAN机器人虚拟示教的实施方案。     

面向机器人离线编程的真实感虚拟环境生成

真实感虚拟环境的生成是虚拟现实与仿真技术中的重要环节，研究如何生成一个基于虚拟现实的机器人离线编程三维图形仿真环境。首先通过对实际机器人工作单元的分析及对机器人的精确测量，在机器人几何建模系统RGMS中构造机器人及其工作单元环境的3D几何模型，然后以虚拟现实软件WTK为核心建立图形仿真环境的场景图并在其中进行渲染，最后借助于虚拟现实显示设备生成具有真实感的虚拟仿真环境。     

基于姿态辨识的遥操作液压工程机器人视觉提示

针对遥操作液压工程机器人视频传输时延问题,提出一种基于姿态辨识的遥操作液压工程机器人视觉提示方法。利用摄像机获取遥操作液压工程机器人图像,通过关键点识别堆叠沙漏网络(KPR-SHN)模型和姿态辨识神经网络(AR-NN)模型,获取遥操作液压工程机器人液压缸的位移,依此驱动虚拟工程机器人实现对操作者的视觉提示。实验结果表明:该方法简单有效,误差小于8%,可为基于虚拟现实的遥操作工程机器人的视觉提示系统设计提供指导。     

遥操作焊接机器人焊接信息采集系统研究

对于危险环境遥操作焊接机器人的监视而言,除了采用虚拟现实技术创建的、增强人机交互能力的3D虚拟工作环境之外,实际焊接过程信息的采集也是非常重要的。遥操作焊接机器人焊接信息采集系统使用数据采集模块采集焊接电压、电流。以Qt作为开发工具,使用C++语言完成了机器人焊接信息系统软件开发,主要功能包括焊接电压、电流的采集与绘制波形图,以及通过摄像机捕捉焊接现场画面并展示给操作人员。该系统具有跨平台特性优良、安全性能高等优点。焊接试验表明,开发的焊接信息采集系统能够满足机器人遥操作焊接应用的需要。     

基于人机交互技术的机器人熔化极气体保护焊再制造系统

针对再制造过程中失效零件三维模型重建难的问题,通过采用"三维建模—模型分层—逐层堆积"的零件再制造思想,提出基于人机交互技术的机器人熔化极气体保护焊再制造系统,并对该系统的人机交互模式进行了分类研究。同时,详细阐述人机交互式机器人熔化极气体保护焊再制造系统软硬件结构的组成及设计思路,并基于OpenGL开放式图形库开发了相应的人机交互界面,界面环境友好,功能强大,且便于用户实时操作。     

基于虚拟现实的焊接机器人工作站离线编程系统

在自动焊接应用中,离线编程焊接机器人通常具有一定的控制局限性。结合虚拟现实技术搭建了一套焊接机器人工作站,通过开发离线编程系统,简化机器人控制方式、灵活调整视角和自动规划焊接轨迹等,提升了焊接机器人离线编程效率。开发了同点异线焊缝识别算法,实现了单机器人的轨迹规划功能。基于焊枪基准姿态,分析横焊、平焊、立向上焊和立向下焊的焊接姿态,实现全位置焊接姿态规划。增加KBR-2Z500双轴变位机,实现多轴联动的复杂轨迹规划功能,研究了机器人运动与变位机运动的耦合与解耦问题,达成焊接机器人工作站协同运动规划。通过现实空间完全复现虚拟环境下的空间曲线焊接轨迹规划实验,验证了工作站离线编程系统的交互性、可行性和可靠性。     

基于OpenGL的多机器人仿真实验平台研究及实现

多机器人协同工作广泛应用于现代化工业生产现场,协同控制是实现多机器人协同工作的技术保障。针对多机器人协同控制研究中的轨迹规划、轨迹优化和碰撞检测等算法研究需要,以及多机器人工作站离线编程、虚拟示教等研究实现需要,提出基于OpenGL和MFC建立具有完全开放性、自主性的多机器人协同工作算法研究仿真实验平台,嵌入机器人正、逆运动学、轨迹规划、碰撞检测等算法,实现多机器人三维虚拟仿真、离线编程和虚拟示教,并进行单个实体机器人实验验证。实验结果表明:基于OpenGL和MFC建立的多机器人协同控制仿真平台,可以进行多机器人协同控制相关算法研究,另外离线编程与虚拟示教转换生成程序指令可以按照要求控制机器人运动。用户无需进行三维图形仿真编程、界面编程和辅助算法研究及实现,只需侧重其算法研究,即可基于该软件实验平台快速进行机器人、多机器人算法仿真验证及效率分析,减少工作量。     

一种跨平台多通道人机交互控制系统设计

针对一种核环境移动机器人控制的特殊需求,在分析了ROS系统架构后,提出了ROS机器人应用程序的基本架构,基于此架构设计了基于Linux和Windows系统跨平台多通道遥操作交互控制系统。实现了对机器人作业机械臂带力反馈的主从控制,对移动底盘的自主控制、手动控制、语音控制。详细说明了交互系统的设计实现过程。通过对客户端系统机器人交互模型的正确性和服务器端系统正确性进行了仿真验证,最后通过综合实验证明整个交互系统的正确性和友好性,结果表明操作者可通过本地渲染的虚拟场景和远端机器人反馈的多路视频信息和机器人本体的状态信息对机器人工作状态做出正确判断和新的规划,很好地完成作业任务。     

LabVIEW在机器人弧焊作业仿真中的应用

提出一种基于LabVIEW环境开发的虚拟控制台,用于控制弧焊机器人的作业仿真过程。根据系统的功能需求,设计了仿真系统的控制流程。建立了控制台功能模块,包括几何模型、运动模型及驱动数据、作业信息统计与采集,分析了功能模块间的相互关联、调用的方式。仿真模拟的结果表明,按上述设计的虚拟控制台能很好地实现对弧焊作业仿真过程的控制。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also