新型5-UPS/PRPU 5自由度完全并联机床

介绍了一种新型5自由度完全并联机床.该机床具有5个驱动分支和1个约束分支,可以实现3维移动和2维转动.该机床结构设计采用了多种新型构件,运动控制系统采用开放式、模块化设计,实现了机床的运动伺服控制、位姿实时检测等功能.加工试验表明,该机床具有良好的运动稳定性和较高的位置精度,可实现5坐标加工.     

双工位数控焊接机床设计

在对汽车后桥轴端法兰的焊接加工工艺分析的基础上,结合现在焊接机床的功能特点,设计出双工位数控焊接机床,重点描述了对机床工作原理、机床结构、控制系统的研究设计与实现.该机床可同时完成双工位的焊接加工,且加工零件类型多样,满足用户要求.     

特种轧机的研究

螺旋叶片应用越来越广泛,目前能够生产厚螺旋叶片的企业在国内还很少,用于其生产的专用机床的研制已经成为新的课题。本文通过对锥辊轧机的分析比较,提出生产厚螺旋叶片轧机的合理方案。该机床是用于生产螺旋叶片的专用特殊轧机,以裁制好的钢板为原料来生产螺旋叶片。     

超导材料制备用真空等离子焊箱的研制

根据NbTi超导材料电极焊接的工艺要求，研制出了NbTi电极焊接专用真空等离子焊箱。本文介绍了真空等离子焊箱的系统组成和功能。同时对自动焊接过程的实现作了详细的阐述，其涉及到了PID，PLC和伺服控制技术，该机的研制成功，极大改善了我国NbTi低温超导材料制备手段。     

中国数控机床展览会（CCMT2010）“春燕奖”获奖机床（四）

YK73400L数控成形磨齿机齐重数控装备股份有限公司 该机床采用齐重自主研发的齿轮测量及加工软件。真正实现了高智能的数控齿轮加工机床;可实现人机对话,参数输入后,机床可自动计算、调整、测量及自动加工,并评定出所加工齿轮的精度等级。     

多功能自动焊接机床控制设计分析

多功能自动焊接机床控制设计融入到机械焊接工作中对保证焊接工作质量的提升,满足当前多功能的焊接需求具有重要的作用。对此本文对自动焊数机床控制系统、多功能自动焊接机床控制设计具体内容、多功能自动焊接机床控制设计关键技术、注重设计系统改善升级进行了相关的分析,得到了多功能自动焊接机床控制设计体系是一个复杂的设计体系,需要综合考虑多方面内容,才能保证设计的全面性、实用性等结论,期望对提高多功能自动焊接机床控制设计水平有所帮助。     

CMK1116型数控纵切自动车床

CMK1116型数控纵切自动车床(参看本期封四照片)是原机械部下达的重点开发新产品,于去年12月通过了国家鉴定。该机采用微型计算机控制,保留了凸轮式纵切自动车床的加工特点,又改变了纵切机床长期沿用凸轮杠杆的传动方式,使用调整方便,适于多品种,中、小批量加工的要求。 该机床主传动采用直流电机无级调速,用发那科(Fanuc)编码器(Encoder)作为局部闭环的反馈元件实现螺纹加工。主轴箱和各刀架进给驱动用步进电机和滚珠丝杆副实现。加工精度达到部颁的单轴纵切自动车床精度标准(JB 1464-84)。数控系统共控制九个坐标,可以实现四坐标同时动…     

离心式三元叶轮焊接坡口五轴加工刀位算法

根据三元叶轮焊接坡口大多采用手工修磨方法加工的现状和某企业对焊接坡口加工的图纸要求,首先将叶片中性面盖盘曲线拟合为NURBS曲线,并对其进行离散处理.再根据切削平面内圆柱铣刀与坡口的几何关系,开发出圆柱铣刀五轴侧铣加工三元叶轮焊接坡口的刀位算法.经仿真与试切加工,完全满足图纸要求.本算法不仅适用于两件焊式三元叶轮,同时适用于手把焊式二元叶轮和开槽焊式二元叶轮焊接坡口的五轴侧铣数控编程.实现了叶轮类零部件焊接坡口的数控加工,可有效的提高叶轮的加工精度和加工效率,提升焊接后叶轮的强度,并极大的减轻了操作工人的负担.     

线切割机床数控系统的开发与应用

数控系统是保证数控机床加工精度的关键所在.根据线切割机床的加工特点和要求,采用模块化设计思想,设计开发了一种基于Windows操作系统的快走丝线切割机床数控系统.系统以工业计算机和多轴运动控制器为硬件控制核心、实现了上位机(工控机)和下位机(运动控制器)的可靠通信及机床工作台运动控制,并以VB6.0为软件开发环境设计了友好的人机交互操作界面.该系统具有全绘图式编程、短路自动回退、自动切割等多种功能,通过适当的参数设置,可对工件进行自动多次切割.经过实验验证表明,开发的数控系统能够较好地满足机床对加工精度和加工质量的要求,具有广泛的市场前景和较高的应用价值.     

基于MACH3的五轴数控机床设计

设计了一款经济型五轴数控机床,进行了五轴数控机床的结构与电路硬件系统设计,以计算机操作系统为平台,应用开放式CNC软件MACH3进行控制,降低了机床的成本。经实际加工使用证明,该机床经济实用,可以满足培训和一般精度加工使用要求。     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.