面向微电子器件封装作业的三自由度串并联混合式高速高精度机器人

针对微电子器件封装作业对高速高精度自动设备的需求,提出了一种由平行四边形支链的平面并联机构和直线运动模块组成的新型三自由度串并联混合式机器人。机器人采用两个集成了高分辨率角位移反馈元件的旋转直接驱动电机和直线音圈电机作为驱动元件。结合了并联机构和直接驱动的优点来实现高速高精度的三自由度平动运动。实验结果表明平面并联机构具有较高的重复定位精度、加速度和较短的建立时间。     

基于ADAMS的冗余驱动并联机器人动力学仿真研究

为使机器人具有良好的结构性能和工作性能,其结构系统必须具有良好的动力学特性.针对动力学特性问题,以ADAMS仿真软件为平台建立了简化的二自由度冗余驱动并联机器人模型,求出了运动学逆解,采用冗余驱动力控制电机的方法,完成了动力学仿真.结果表明该方法能减小驱动力变化范围和降低驱动力峰值,优化电机驱动力,提高并联机器人的驱动性能.研究所得的方法和结论具有较强的通用性,对相关冗余驱动并联机器人的动力学研究具有普遍的应用意义,同时为并联机器人的调试与控制提供了理论依据.     

6_PUS并联机器人动力学性能参数优化设计

为优化一种风洞6_PUS并联支撑机器人的动力学性能参数,采用螺旋理论推导了该机构的力雅可比矩阵和Hessian矩阵,并基于一、二阶影响系数法,在全域工作空间内,对影响6_PUS风洞并联支撑机器人动力学性能指标的主要结构参数进行了优化分析.对该机器人动平台、球铰位置、拉杆长度、平行梁宽度等参数对动力学性能的影响进行了仿真.从仿真结果来看,6_PUS并联机器人的动力学性能较差,要使机器人获得最佳的综合性能,则需要对这些参数进行综合优化.通过对这些参数和性能关系之间的全面考虑,最后选定了并联机器人的主要设计参数,使机构性能达到了设计要求.     

微操作机器人的显微视觉自标定方法

在分析微操作机器人结构特点的基础上确定了待标定参数,提出了一种基于显微视觉的自标定方法。通过动态跟踪随机器人运动的目标来计算其图像坐标,采用最小二乘法拟合目标运动轨迹在显微镜坐标平面中的投影直线,并结合高精度机器人的位移量,经过几何投影和变换,标定出待标定坐标到显微镜坐标的转换矩阵。该标定方法无需特殊辅助测量仪器。实验表明,角度标定重复性好,位置标定误差小于 2 个像素。     

三自由度并联分拣机器人的动力学建模与仿真

目的 针对自动化生产线上分拣机器人的动力可控性问题,提出一种2UU-UPU三自由度并联分拣机器人,以提高分拣的精度可控性。方法 分析该机器人的机构自由度,以及各参数之间的关系,基于闭环矢量法建立并联机构的运动学逆解模型;利用拉格朗日动力学方程推导该机器人的动力学表达式,并进行数值计算,采用Matlab Simulink和Adams进行动力学联合仿真,对理论值和仿真值进行误差分析。结果 揭示了该机器人动平台的运动规律,得到了驱动力矩曲线,理论值与仿真值的误差较小,3个驱动力矩的最大误差分别为0.379%、0.283%、0.146%。结论 通过验证可知,该机构具有较好的动力学特性,这为后续电机的选型和精准控制奠定了基础。     

一种新型平面并联机器人机构及其解耦控制

结合同时考虑机构设计和控制策略的思想，提出一种新型的可应用于微电子封装与组装行业中的两自由度平面并联机器人机构，其具有高刚度、高速度、高精度的特点。对机构进行了运动学、动力学分析和基于加速度反馈的解耦控制研究。解耦控制的仿真分析表明了该控制策略的有效性。     

递纸机构简化模型及动态研究

印刷机递纸机构的性能对整机的套准精度有着重要的影响．为了改善高速递纸机构的动态特性,建立了递纸机构的三维模型以及机构简化模型,分析了交流电机驱动系统的转矩波动,在此基础上建立了递纸机构的机电耦合方程,得出交流电机驱动系统的转矩波动等因素对机构的动态性能产生的影响,以及系统动态性能与其驱动系统参数和结构参数之间的关系,从而有利于改善、提高印刷机递纸机构的动态性能．     

独立旋转车轮直线电机地铁车辆动力学分析

为了减小直线电机和感应板的间隙以提高直线电机工作效率,便于直线电机安装和减小直线电机对转向架结构设计要求,提出一种采用独立旋转车轮的直线电机地铁车辆转向架．利用多体动力学软件SIMPACK,对采用独立旋转车轮的直线电机车辆系统进行动力学计算．动力学仿真分析结果表明,采用独立旋转车轮的直线电机车辆具有良好的运行平稳性和曲线通过性能,满足城市轨道交通车辆的要求．     

新型平面直线驱动系统及其在机器人末端操作器中的应用

研制了一种机器人微驱动末端操作器用新型二自由度平面直线驱动系统 ,该二自由度电动机由于在X及Y方向采用共用永磁体的结构 ,与传统电机系统比较具有较高的性能体积比 ,应用于实际操作器系统中取得良好的效果     

新型平面直经驱动系统及其在机器人末端操作器中的应用

研制了一种机器人微驱动末端操作器用新型二自由度平面直线驱动系统，该二自由度电动机由在Ｘ及Ｙ方向采用共用永磁体的结构，与传统电机系统比较具有较高的性能体积比，应用于实际操作器系统中取得良好的效果。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from