基于NX MCD的工业机器人视觉分拣数字孪生系统设计

针对制造业中多类型、多颜色工件人工重复分拣出错率高的问题，设计一个基于工业视觉的工业机器人自动分拣物理控制系统和数字孪生系统。提出融合工业视觉、工业机器人、PLC等设备的以太网通信控制方案；基于视觉检测原理，应用视觉检测工具，结合PLC程序能够正确识别工件信息；基于NX MCD软件构建了工业机器人、输送带、工件等数字孪生系统；最后，对工业机器人和PLC进行联合编程，实现视觉分拣虚实系统同步作业。实验结果证明：该系统工件识别正确率高，工件分拣效率高，数字孪生系统能够实现虚实同步，为系统的动态监控、维护管理与虚拟调试提供了便利。     

基于数字孪生的物流拣选虚拟调试系统设计

为降低调试周期和成本，提前预知系统级风险，基于数字孪生的虚实一致特性，提出一种基于数字孪生的固定轨物流拣选虚拟调试系统设计方法。根据固定轨物流拣选系统的特性和调试需求，建立虚拟物理模型、虚拟执行系统和虚拟控制系统，同时对控制器-虚拟模型接口进行设计，实现虚实之间的通信。通过物流拣选系统实例，验证了基于此数字孪生模型进行虚拟调试的有效性与实用性，基于数字孪生的固定轨物流拣选虚拟调试系统能够降低物流拣选系统的调试周期和成本，进而提高调试效率。     

数字孪生驱动的车间管理系统开发

在传统车间管理的基础上扩充了物理实体车间在虚拟空间的真实的三维可视化效果,提出了新的数字孪生驱动的车间管理体系架构。用MesWork Data Factory数字孪生虚拟仿真平台,进行孪生车间信息建模,通过OPC UA的数据采集网络架构感知设备的生产数据,前端接收设备运动的实时信号,根据工艺规划,驱动孪生模型运动,从而实现了同步运行的、虚实交互的、数字孪生驱动的车间管理系统。将其应用于某生产车间,实现数字孪生的某车间运行的新模式,验证了系统的有效性以及实用性。     

基于数字孪生车间的虚实融合研究综述

数字孪生车间近年来逐渐成为大众关注的热点,它可借助虚实融合技术实现物理车间与虚拟车间的互联互通,使得虚拟车间的信息更加贴合现实,有助于实际生产。基于数字孪生概念、数字孪生车间的特性和研究应用,对数字孪生车间的虚实融合研究进行综述。介绍了虚实研究对象,即物理车间和虚拟车间;论述了虚实融合系统中车间服务系统的工作过程;分析了虚实融合技术的三大关键部分及相关技术的支撑。最后对数字孪生车间的虚实融合问题进行了展望。     

基于双目视觉的机器人虚拟拖动示教技术的研究

针对工业机器人拖动示教技术可拓展性差及市场应用推广难等问题，基于双目视觉研究机器人虚拟拖动示教技术，降低机器人拖动示教成本。根据机器人末端姿态获取要求，设计基于双目视觉的末端姿态获取实验平台，并研究末端姿态获取方法。通过坐标变换技术研究机器人虚拟样机和末端执行器虚拟样机融合方法，实现ADAMS环境中机器人虚拟拖动示教模型的构建。以末端姿态数据设计虚拟模型驱动函数，研究机器人关节角度序列获取方法，实现机器人虚拟拖动示教轨迹再现。以毛笔为机器人末端执行器的实例验证了基于双目视觉的机器人虚拟拖动示教技术的可行性。虚拟拖动示教技术避免了复杂的机器人逆运动学求解问题，为机器人轨迹规划提供了便捷的方法。     

基于数字孪生的MPS智能控制系统设计与应用北大核心

为了提高对MPS系统的自动化管理、使得MPS系统更加符合实际生产要求,提出了一种基于数字孪生的MPS智能控制系统和方法。基于MPS数字孪生五维模型架构,对其物理MPS、虚拟MPS、连接、孪生数据和服务系统五维结构进行分析。设计了MPS数字孪生智能控制系统框架,对系统开发中的虚拟模型建立、数据采集、实时驱动等关键技术进行了阐述。结合案例设计开发了MPS数字孪生智能控制系统,完成了对MPS系统可视化监控、安全管理与决策、智能控制、MES追溯等功能的实现,反映了MPS系统的全生命周期过程。     

基于数字孪生的生产状态可视化平台开发北大核心

为实现生产状态各要素、各工艺、各信息数据的可视化展示,提出了基于数字孪生虚拟模型及数据驱动图表的生产状态可视化平台(DT/DC-VP)。并基于数字孪生虚实融合技术和图表可视化技术设计了DT/DC-VP的体系架构,在此基础上对DT/DC-VP的多源异构数据采集、孪生场景的模型以及运动学构建、数字孪生前端可视化构建等的关键实现方法以及功能展开研究。最后借助实际项目将该可视化平台应用于某示范焊接生产线,实现了生产状态实时、稳定、高效、精准的可视化效果,从而验证了DT/DC-VP的可靠性与稳定性。     

虚实融合的工业机器人实验平台研究

以ABB工业机器人为例,提出六角结构的工业机器人实验平台,通过功能设计和工艺仿真搭建实验平台,构建Unity3D虚拟仿真实验平台,包括工业机器人的工艺虚拟仿真和拆装虚拟仿真。利用工业通信标准OPC UA协议实现虚拟与真实工业机器人间的数据通信,实现了虚拟与真实机器人同步运动。分析了虚拟与真实机器人运动的位置误差,实验结果表明该平台可为智能制造提供虚拟解决方案,同时也是数字孪生概念下的具体技术应用,具有较强的推广性和应用性。     

旋转压合成形数字孪生系统构建及应用

针对口罩生产这种新型旋转压合成形技术生产过程中的数字孪生技术进行了研究。研究阐述了数字孪生在旋转压合生产中的框架和系统组成，利用西门子的NXMCD软件构建了数字孪生模型，并建立了其中的运动关系，在运动关系上利用传感器和模型之间的映射来实现模型的驱动，实现了虚实同步。此外，通过接口将深度学习的神经网络和数字孪生系统结合，实现以虚预实，对传感器的数据源进行不断地迭代，实现了产线的实时优化。这种融合了数字孪生与旋转压合技术的方法，为制造业的智能制造提供了宝贵的数据和参考，推动了生产过程的高效化和智能化。     

基于视觉的工业机器人离线编程系统的设计

针对传统离线编程系统通用性差、可靠性低和二次开发难度大等问题,开发一套基于机器视觉的工业机器人离线编程系统。基于模块化思想,将该系统划分为机器视觉模块、虚拟环境模块、运动学模块、轨迹规划模块、离线程序模块和外部通信模块。借助机器视觉模块解构视觉系统与机器人末端位姿的坐标映射关系,得到规划机器人运动所需的位姿数据;基于虚拟现实建模语言构建机器人虚拟仿真环境,基于运动学模块与轨迹规划模块将位姿数据转化为机器人的作业〖JP2〗指令;基于离线程序模块与外部通信模块实现控制器指令与虚拟仿真环境的无缝衔接。最后,以一种六轴工业机器人为测试对象验证了该离线编程系统的基本功能。实验结果表明:该系统定位误差最大为0.4 mm,精度高,可满足工业应用需求。     

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.