保持架铆钉孔位置度测量方法

针对深沟球轴承分离型半保持架铆钉孔孔径较小,三坐标测量机测头在孔中移动距离受限,无法测量孔位置度的问题,利用三维光学测量仪,采用1/2最大极角偏差修正方法,在极坐标系实现了小孔径孔位置度的测量,并通过实例验证了该方法的可行性。     

CMM测量中复杂零件的路径规划研究

在复杂零件的三坐标测量路径规划中,测量点的排序存在组合优化问题。以测头角度变换次数最少为原则,采用对待测几何特征按测头角度的可达性进行分组,并对其进行集中测量的方法,基于多色集合理论建立了问题的约束模型。根据此约束模型,利用遗传算法对路径规划中的几何特征测量排序进行优化。针对实例零件,验证了复杂零件的全局路径规划问题。     

用空气静压轴承定位测量同轴度

带有台阶孔的机械零件,其孔间同轴度误差的大小,对该零件或使用该零件的成品功能是至关重要的。 如图1所示零件,两台阶孔间同轴度要求较高,这种误差若采用机械量具进行测量,不仅费时费事,且由于受机械量具精度和定位件精度的限制,测量误差就大。如采用三坐标测量机或圆度仪测量,保证了精度,但成本太高,效率很低。现采用空气静压轴承定位的组合测量,既能保证测量精度,又能降低成本,提高效率。现介绍如下:     

一种锥孔锥角误差比较测量仪新结构

本文介绍了一种采用标准锥孔样件作比较，测量出锥孔锥角误差的新比较测量仪；利用此仪器原理设计出的角度测量仪，可以满足锥孔零件加工在线停机或离线的角度误差定量检测，保证了锥孔加工过程中的测量控制。     

泵类产品托架半孔同轴度检测方法

正目前,在机械制造行业中,对于半孔零件的同轴度检测,通常采用以下3种检测方法。(1)采用镗床检测。在镗刀杆上装上磁力百分表,通过镗刀杆带动百分表旋转,测量孔的同轴度。这种方法的不足:一是占用机床,造成机床资源浪费;二是费时费力,效率低下,适合单件生产,而不适合多件或批量生产。(2)采用三坐标测量仪检测。这种方法是用探头在基准孔上打点,并将打出的点拟合成圆柱,以该圆柱的最佳中心线作为测量基准线,然后用同样方法得到被测孔的中心线,通过判断被测孔中心线与基准中心线的偏差,计算出同轴度误差。在此测     

箱体类零件空间尺寸的测量方法

在生产加工中,许多零件的尺寸都是由空间尺寸构成,尤其是箱体类零件。箱体类零件通常涉及平行孔系、垂直孔系和相交孔系,这就使孔系与孔系、孔与孔之间构成了大量的空间尺寸。常规的测量工具无法实现空间尺寸的测量,需借助三坐标测量仪等精密测量仪器对工件空间尺寸进行检测。在未借助三坐标测量仪的情况下,通过自制专用检具,运用数学几何方法,将空间尺寸转换为平面尺寸,实现了对箱体类零件空间尺寸的测量。     

扭簧比较仪测量力的检测方法

介绍了用架盘天平和砝码等量具组合精准检测扭簧比较仪测量力的方法,该方法也可以被用来检测机械式比较仪及类似结构量具的测量力。通过确定该类测量仪表的测量力,可以减少薄壁零件的测量变形量,提高产品质量。     

三坐标测量仪在复杂零件检测中的应用

探讨盖板零件精度检测问题,采用三坐标测量仪进行自动化检测的方法。通过实验结果可以得出,三坐标测量仪是一种高效、准确、可靠的检测手段,具有高精度、高效率、多功能和适用性广等优点。首先,三坐标测量仪能够快速、准确地获取零件的各项数据,从而大大提高了检测效率。它具有较高的精度和重复性,能够满足对高精度零件的检测要求。此外,三坐标测量仪还具有灵活性强、适应性广等特点,适用于不同类型、不同形状的零件。采用三坐标测量仪进行精度评估是一种方便、准确的方法,特别适用于复杂零件的自动检测。三坐标测量仪还具备数据分析和统计功能,可以更好地了解零件的质量状况以及生产过程中存在的问题。然而,三坐标测量仪也存在一些局限性。由于其复杂的结构和高精度的要求,造价较高,不是所有企业都能够负担得起。其次对于大型零件或特殊形状的零件,三坐标测量仪的测量范围可能受到限制。操作三坐标测量仪需要一定的专业知识和技能,对操作人员的要求也较高。因此,三坐标测量仪是一种高效、准确、可靠的检测手段,值得在各个领域广泛应用。     

基于人工免疫算法的三坐标测量机路径规划

为了提高三坐标测量机(CMM)的测量效率,提出多色集合理论模型与人工免疫算法相结合的方式规划CMM自动测量路径。通过待测特征与测头特征、测头角度和待测面的关系建立多色集合围道矩阵,然后进行合取运算建立合取围道矩阵;结合多色集合理论约束模型,采用人工免疫算法,优化全局测量路径。实例表明,该算法提高了三坐标测量机自动检测效率,并已用于实际检测,具有一定实践意义。     

规则约束和蚁群算法三坐标测量路径规划研究

为了提高三坐标测量中测量路径的有效性和合理性,采用带有规则约束的蚁群算法对三坐标测量路径进行优化。基于新一代GPS相关思想,将"几何要素"作为规划对象,并结合实际测量规则及相关理论研究,提出了测头路径规划规则。利用多色集合中的围道布尔矩阵建立了被测几何要素与测头角度和检测平面之间关联关系的形式化描述模型,在该模型与相应规划规则的共同约束下,利用蚁群算法对路径进行优化。经实例验证,表明该方法可靠、有效。     

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...     

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。     

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...     

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。     

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.     

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.     

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.