汉字细化数控雕刻技术研究

提出一种新的汉字数控雕刻加工方法,利用数学形态学的细化方法,取出汉字骨架并进行短枝后处理及矢量化处理,可对汉字任何字体进行单线化数控雕刻。本方法对于微小汉字的数控雕刻加工具有很好的效果,可满足模具汉字雕刻等特殊要求的数控加工。     

汉字字型加工在MasterCAM中的实现方法

为了在MasterCAM中实现汉字字型的加工 ,采用图形格式转换的方式 ,解决了各类汉字字型在数控类机床中加工的问题。     

喷油器体数控加工仿真研究

以6190柴油机喷油器体为研究对象分析了喷油器体零件的结构特点,确定了零件的加工工艺;研究了喷油器体零件的数控车削加工,确定了数控加工刀具及加工参数,编制了数控加工程序,并借助于宇航数控仿真软件,进行了模拟加工仿真。实践证明所设计的工艺和加工程序是合理有效的,对喷油器体的加工质量和喷油性能的提高具有重要的意义,可为中小企业借鉴使用。     

基于NX软件的回转曲面单线汉字四轴加工

介绍了在NX软件中产生汉字的两种方法,分析了回转曲面上单线汉字的刀轨问题,并通过定制后处理程序输出四轴加工数控程序。基于NX软件实现回转曲面单线汉字四轴加工,可以在回转零件表面上进行刻字、刻线或刻标记等四轴加工操作,进而提高加工自动化水平与效率。     

汉字灯箱铝板数控剪齿机的冲裁机构设计

汉字灯箱是一种新流行的广告灯箱,目前在我国主要靠手工制作加工,导致价格昂贵无法普及,故设计汉字灯箱铝板数控剪齿机是很有必要的.以汉字灯箱铝板数控剪齿机的冲裁机构的设计为例,对冲模和压料装置的设计方法做了详细介绍,并且给出了冲模间隙和冲裁力的计算方法.针对冲裁力较大的情况,设计了斜刃冲模,有效的降低了冲裁力.通常用户对汉字灯箱的尺寸大小要求不一,将铝板定位装置设计成柔性的,这样冲裁机构就可以加工不同带宽的铝板,以满足用户不同的加工要求.     

龙门刨床的数控改造与罗茨泵叶轮的加工

介绍数控改造龙门刨床加工罗茨泵叶轮.刨床数控改造控制系统的硬件采用开放式的PC总线结构,软件采用模块化、结构化设计,操作界面采用图形汉字菜单,其功能集图形编程、列表曲线编程、模拟运行、自动对刀、刀具磨损补偿、实时加工控制和动态跟踪显示等功能于一身.     

提高数控加工精度方法的探讨

探讨了提高数控加工精度的途径,研究了CAD/CAM一体化、高精度的插补方法及加工状态控制等环节对数控加工精度的影响。     

数控重型立式铣车加工中心刀架及卡体加工夹具设计

设计了数控重型立式铣车加工中心数控刀架,精度高、稳定性好.数控刀架滑枕内部设置主轴,滑枕下端设置卡紧体,卡紧体与刀库中刀具附件上的卡体配套使用,完成自动换刀.卡爪槽加工是卡体加工中的关键工序,但由于卡体结构限制,使其加工时装夹变得十分困难.设计了卡体加工夹具,以方便工件装夹,并能够快速地将夹具及工件定位、固定在机床工作...     

上下异形体零件线切割数控加工的探讨

从上下异形体零件线切割加工的原理、数控加工程序的编制以及加工过程中注意的事项进行了探讨，为正确实现上下异形体零件的线切割数控加工提供依据。     

基于光线跟踪法的多轴铣削加工仿真研究

在数控加工中．对数控代码进行集成的几何仿真和物理仿真，可以快速检验加工代码的正确性并对加工参数进行优化。运用光线跟踪法研究了多轴数控铣削加工的几何仿真和物理仿真问题，运用解析法对工件和刀具扫描体进行求交离散．依据数控代码提取刀位信息并计算刀具扫描体。工件与扫描体的布尔减运算，一方面可获得每一步切削结果并进行实时的立体显示，另一方面可依据材料切削速率模型实时计算切削力。     

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。     

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.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.