主轴回转误差测量技术研究现状

主轴回转误差是超精密领域的一个重要参数,准确测量主轴回转误差,对控制主轴运动、提高加工精度而言具有重要意义.介绍了主轴回转误差测量技术的研究现状.现有的主轴回转误差测量技术可以分为探针法、光学法、刻痕法,对探针法中常用的反转法、多点法、多步法进行了原理论述与误差分析.     

液体静压主轴的回转精度规律及其极限预测

液体静压主轴是精密、超精密机床的核心功能部件,对机床的加工效率、加工精度和加工表面质量具有直接而重要的影响.回转精度是液体静压主轴的关键性能,目前学术界和工程界对回转精度的各种评价指标之间的内在联系尚缺乏统一认识,对回转精度的机理和形成规律尚缺乏深入研究.系统分析了回转精度各种评价指标和测试方法之间的内在联系,明确了不同误差成分的来源和成因;针对现有回转精度评价方法的局限性,提出了"最小峰峰值+同步误差+异步误差"的综合评价方法.系统比较了不同节流方式对液体静压轴承刚度的影响规律,提出了采用可控节流实现高回转精度的方法.建立了可控节流液体静压主轴的流固热耦合模型,实现了轴心运动轨迹形成过渡过程的精确定量仿真,揭示了供油压力、供油压力波动、动不平衡量和轴颈圆度误差对回转精度的影响规律.最后对液体静压主轴可能达到的回转精度极限进行了预测.     

数控车床主轴热变形检测及回转精度评定

针对主轴回转热误差包含的多种误差分量,采用双向正交法测量了不同转速温度场下数控车床主轴热变形所引起的回转误差。以复向量描述主轴回转精度理论为基础,利用FFT误差分离方法,从传感器测得的信号中分离并去除检棒的安装偏心及热变形导致的回转中心的偏移量,从而得到精确的主轴回转热误差信息,进而评定数控机床主轴热变形对加工精度的影响。     

金属切削机床主轴运动误差影响的数学分析

在研究金属切削机床加工误差的基础上,针对机床主轴回转运动误差中的径向跳动误差、角度摆动误差和轴向窜动误差,以车床和镗床主轴为例,建立了主轴回转运动误差数学分析模型,从数学几何角度分别对上述主轴回运动城的加工精度影响结果进行了定量分析,并推导出了由此产生的各类加工几何误差不同的数学表达式。通过这些数学表达式可以定量地计算出机床主轴由于回转运动误差产生的加工几何误差数值。     

对主轴回转精度测量和研究中的若干问题的看法

本文作者对主轴回转误差运动的测量和评定中的若干问题,包括主轴回转误差运动的基本概念和几何学,回转误差运动的频率特点及其对加工精度的影响,研究回转误差运动的目的和方法,误差运动的记录方式,圆图象记录中基圆半径和被测误差运动值之比的合理选择等问题,阐述了自己的看法,同时对如何提高主轴回转误差运动的测量精度和今后的研究方向,也作了简要的概述。     

车床主轴回转精度测量系统的研制

车床作为制造业的基础设备,零件加工精度受到诸多因素制约,其中主轴回转误差是主要的影响因素之一.该车床主轴回转精度计算机测量系统由光电编码器、电涡流传感器、微机、变送器、数据采集卡及辅助工具构成.在测量车床主轴回转精度的同时,可获得与主轴角位置对应的径向跳动、端面跳动和角度摆动误差,使用数理统计法误差分离技术编制LabV...     

影响数控车床主轴精度因素的研究

以TND360型数控车床为例,将数控车床主轴瞬时回转轴线位置变动分为三种独立形式:纯轴向窜动Δs,纯径向平移ΔC.和纯角度摆动Δγ,以此确定主轴回转精度的评定指标.并对影响主轴精度的几种主要因素(如尺寸误差、形状误差、位置误差等)进行深入的探讨,综合考虑尺寸误差、形状和位置误差的影响,合理确定数控车床主轴的误差范围,为界定数控机床的加工精度范围提供了一种新的途径.     

主轴回转误差运动及其对齿轮加工精度的影响

本文对主轴回转误差运动的分类及其数学描述进行了较详细的介绍。并采用圆矢量函数方法分析了主轴回转误差运动对齿轮加工精度的影响。     

对主轴回转精度测量和研究中的若干问题的看法

本文作者对主轴回转误差运动的测量和评定中的若干问题,包括主轴回转误差运动的基本概念和几何学,回转误差运动的颇率特点及其对加工精度的影响,研究回转误差运动的目的和方法,误差运动的记录方式,圆图象记录中基圆半径和被测误差运动值之比的合理选择等问题,阐述了自己的看法,同时对如何提高主轴回转误差运动的测量精度和今后的研究方向,也作了简要的概述。     

基于RSM-NSGA-Ⅱ的主轴精度调控参数优化

数控机床主轴系统的性能直接影响其加工精度。热误差和回转误差作为主轴系统精度的两个关键指标,研究其多工况下误差变化规律与对应的调控参数优化方法对主轴系统精度的提升具有重要的应用价值。基于响应面(RSM)分析法,以获取的主轴系统热误差和回转误差数据为响应值,建立多工况下的主轴精度RSM模型,基于多目标遗传算法,研究多工况下的主轴系统调控参数优化方法,得到不同工况下的主轴系统最优运行参数,并在自主搭建的主轴精度调控实验台上进行了有效性验证。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.