斜摆头五坐标数控加工机床的后置处理算法研究

基于DMU80P五轴联动加工中心的结构特点,针对第五旋转轴的旋转中心线和三直线轴不重合的特殊回转轴机构,分析该结构类型机床的联动加工方式及角度坐标变换规律,依据机床采用的HEIDENHAIN系统设计了该机床的后置处理算法.加工实验表明,该后置处理方法能满足工程使用要求.     

特殊双转台结构五轴联动加工中心后置处理算法研究

针对非传统笛卡尔坐标系统的特殊双转台结构五轴联动加工中心,通过研究机床结构及其后置处理算法,推导出转台运动角度计算和直线坐标变换公式,开发了其后置处理器并集成到UG软件中,利用DMU 70eV五轴联动加工中心进行了复杂工件加工实验,验证了该算法正确性,实现了复杂零件产品的CAD/CAM一体化无图纸设计与制造.     

非正交五轴联动数控机床后置处理技术研究与应用

通过对非正交五轴加工中心德玛吉DMU50E机床结构及参数的分析,构建该机床运动学模型,推导出工作台运动角度计算和直线坐标变换公式。将该算法通过Tcl语言编程并应用于UG后置处理器中,配制出该机床的非正交五轴联动数控加工后置处理程序。应用机床仿真软件VERICUT对该后置处理生成的NC程序进行验证,该后置处理程序稳定可靠,现已成功应用于工程中。     

附加转台数控机床的五坐标后置处理算法研究

基于SAJO8000五轴联动加工中心的结构特点,针对其主转台及附加转台的联动方式及坐标变换规律,设计了该机床的后置处理算法,编制相应后置处理软件并投入工程应用。     

DMU50 eVolution非正交五轴机床的后置处理研究

由于DMU50 eVolution五轴加工机床具有高精度、高性价比,因此被广泛使用。然而机床工作台的B轴与机床的Y轴不重合,属于非正交结构,使得加工程序的后置处理相对困难。通过对双转台五轴机床开展结构分析,对任意刀具轨迹数据点,先求解出机床双转台的B轴和C轴后置处理转角大小,然后利用求解出的转角大小,通过坐标变换,求解出该刀具轨迹数据点对应的机床位置。利用后置处理算法开发了DMU50 eVolution五轴机床程序后置处理软件,该软件可将UG软件编制的加工程序转换为通用G代码程序。     

基于Vericut的摇篮式五轴机床加工仿真研究

结合DMU65 mono BLOCK五轴联动加工中心的应用,介绍AC摇篮式五轴联动加工中心的部件三维建模、机床构建、数控系统配置等操作方法,并进行数控多轴联动程序的仿真验证。此外,针对AC摇篮式五轴机床中A、C轴组件坐标偏心引起的运动错误、主轴坐标位置配置及数控系统旋转轴设置等问题,提出有效的解决方案,为相关结构的五轴机床仿真系统配置提供借鉴。     

基于Powermill的五轴加工中心后处理模块

基于DMU40monoBLOCK高速五轴联动加工中心的机床运动原理,针对iTNC530控制系统程序格式的特点,给出了运用Powermill的后处理工具PostProcessor定制后处理模块的方法,开发了该型五轴加工中心的后处理模块,并在3轴～5轴加工中得到了应用。     

摆头转台加工中心五轴联动加工的后置处理与仿真验证

在对东芝BTU-14五轴加工中心结构特性、东芝TOSS999控制系统特性以及五轴联动加工编程特点进行分析的基础上,提出其五轴联动加工的后置处理算法。在该算法基础上,利用VisualC++6.0开发出单独的后置处理程序,将加工刀轨的刀位文件处理生成东芝格式的G代码文件。为了验证后置处理程序的正确性,利用数控仿真软件Vericut 7.0建立机床的仿真模型,对后置处理程序生成的G代码文件进行仿真。最后实际加工了一个测试样件,证明了后置处理程序的正确性。     

威力铭W518S加工中心五轴联动UG后置处理设计

针对瑞士威力铭公司W518S加工中心进行了五轴联动加工的UG后置处理设计研究。其具体内容包括:FANUC数控系统五轴联动专用模块程序的特点及相关指令介绍;五轴联动后置处理设置内容介绍;特殊指令的TCL程序语言说明;叶轮等试验零件五轴联动加工等。通过对成熟使用的UG五轴联动后置处理开发的介绍,为其他设备的UG五轴联动后置处理开发提供了借鉴。     

基于VB BV100五轴联动加工中心后置处理的研究

针对于Pro/E、UG等通用后置处理器生成的NC代码一般与用户使用的数控机床和系统的要求不符。为了提高自动编程效率,充分发挥加工设备优势,以某机电院研发的BV100双转台五轴联动加工中心为例,对于AC回转工作台式五轴联动数控机床结构,系统地推导了其后置处理的相关算法,包括旋转角度的计算、坐标转换以及新刀位点坐标的计算等;通过VB语言,开发了该机床的专用后置处理器,并通过某叶轮的切削加工实验验证了该后置处理器的正确性和实用性。     

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...     

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.     

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.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.