基于运动控制技术的数控系统

以PMAC运动控制器为例，论述了基于运动控制技术的PC 运动控制器的数控系统的构成方法及特点，给出了数控外圆磨床数控系统硬件和软件的结构框图。提出了运动控制技术在应用发展中的有关问题。     

并联机床加工中心数控系统的研究

分析了并联机床加工中心数控系统的设计。此数控系统以Kollmorgen运动控制卡为运动控制核心，包括多个软件控制模块，实现复杂曲面零件的定位和加工。此外，该系统设计了刀库和工艺管理功能，保证了机床加工过程的自动化。     

基于PC＋运动控制卡的开放式数控系统的研究

通过对开放式数控系统的发展及定义的分析,提出了一种基于PC机和运动控制卡的开放式数控系统的设计方案,并分析了以PC机和运动控制卡为基础搭建开放式数控系统硬件平台和软件平台的理论依据及实现方法.     

开放式数控系统运动控制可配置的研究

采用模块化设计方法进行了开放式数控系统的设计,在PC+可编程I/O卡体系结构及上层软件架构基础上,对数控系统运动控制配置需求进行分析。基于RCS(real-time control system)库,实现了系统命令和状态信息在不同进程间的通信,所设计数控系统可根据不同用户的需求进行运动控制参数的设置,测试结果显示,较好地实现了数控系统运动控制可配置。     

基于GT400-SG运动控制卡的数控实验平台系统的研究

对基于运动控制卡的开放式数控系统平台结构进行研究,在此基础上针对GT400-SG运动控制卡开发了一个数控系统,并对该系统进行了指导性实验,分析了系统的硬件结构。对运动控制器的工作原理做了简单的介绍,运用运动控制器对运动控制进行了实验。     

数控系统应用层接口的兼容性研究及实现

运动控制卡是基于计算机并行总线的运动控制器,是构造新一代数控系统的核心装置.由于目前尚无统一标准实施,市面上流行的各种运动控制卡都配套各个厂商自己的指令系统,且这些指专系统之间,没有兼容性.因此,开发者一旦选定或者改选某种运动控制卡,就必须对针对所选定的运动控制卡及其配套指令系统重新设计和调试自己的应用软件.这给运动控制卡的应用和数控系统的开发带来困惑.且不利于降低系统的开发周期和成本.本文针对此问题,研究了一种数控系统应用层接口.通过该接口,用户可直接调用所选用的运动控制板卡厂家提供的通讯函数库采实现对所开发的数控系统的各种操控,从而缩短了数控系统的研发周期,降低了系统的研发成本.     

基于DSP技术的数控系统设计研究

研究了一种基于DSP技术机床数控系统，PC机完成数控系统的非实时任务，DSP运动控制卡完成电机能置和速度的实时控制，实现四轴高精度的运动控制。     

基于生产线实验台的运动控制方案研究

数控机床的多样性和数控系统中PLC使用的特殊性使得数控机床的生产线运动控制方案具有一定的难度。文中在生产线实验台的基础上,对不同数控系统和外围设备的运动控制方案进行了研究。     

基于嵌入式硬件的总线式数控机床动态性能测试工具研究

随着数控系统往总线化方向发展,数控系统与伺服驱动器间因总线协议而绑定。在机床动态性能不理想时,无法区分是数控系统运动控制上的原因,还是伺服驱动电机系统响应性的原因。为排除数控系统运动控制算法等的影响,将耦合问题解耦,研发了一款基于嵌入式硬件的支持Ether CAT总线和MetroLink-Ⅲ总线的机床动态性能测试工具。该测试工具可替代数控系统控制伺服驱动器的运动,可自由配置总线过程数据,可自由调整运动控制参数,并存储机床位置反馈元件反馈位置信息,对典型运动进行直观的图形化显示,便于测试结果的呈现和运动控制参数的调优。     

基于开放结构控制器的可重构数控系统

讨论了可重构制造系统、可重构机床和可重构数控系统的内涵及关系，提出以开放体系结构控制器为基础构建可重构数控系统，并结合运动控制器的开放性，分析了数控系统重构的可行性。利用组件技术，阐述了可重构数控系统的实现机理和开发流程。最后，通过可重构数控系统的开发实例，表明该方法在实际应用中具有很好的实用性和易用性。     

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.     

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....     

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。     

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.