基于OMAP3530的高性能数控系统设计

提出一种基于OMAP3530双核微处理器的嵌入式数控系统。介绍了系统软硬件平台。系统以ARMCortex—A8为控制核心,强实时性的粗插补计算由TMS320C64x＋DSP核处理,高速并行运算的FPGA作为精插补器,CPLD管理系统I／O信号和键盘接口。嵌入式Linux操作系统实现系统资源管理,DSP运行DSP／B10S实时操作系统。重点讨论了系统软硬件构架,系统任务分配方案以及ARM与DSP之间的双核通信机制。     

基于80486模块的嵌入式数控系统设计

提出了基于80486模块和可编程逻辑器件的嵌入式数控系统的设计方案,系统结构上采用两级控制,完成了实时性要求较高的插补功能。采用CPLD／FPGA器件进行逻辑运算处理,提高了系统的集成度和稳定性。     

基于ARM9的嵌入式数控系统的设计

对传统的数控系统进行了比较与研究,发现传统的数控系统硬件大多数基于工业控制器之上,分析了基于一般工业控制器的传统数控系统的缺陷,提出了一种基于ARM9微处理器为核心的嵌入式数控系统.该嵌入式数控系统以ARM9微处理器作为硬件平台,采用Windows CE5.0作为操作系统,利用Embedded Visual C++在Windows CE5.0系统平台上开发用户所需程序.系统较好地弥补了传统数控系统的局限性,大大降低了成本,系统能可靠地实时地进行多任务处理,同时由于采用了硬件插补代替了传统的软件插补,提高了加工表面质量.     

基于Linux的嵌入式数控机床控制系统设计

为了克服传统嵌入式数控系统的局限性，提高系统插补运算和人机交互能力，提出了基于ARM＋FPGA＋DSP＋Linux架构的嵌入式数控系统设计方案，并设计了该系统的软硬件体系结构。为同时满足数控系统的多线程和实时性要求，采用了Linux＋DSP结构，并结合实时性指标，对系统任务进行了详细的实时性分析与划分。为建立系统通讯，采用了模块化设计理念，并对模块间通讯机制的实现方法进行了详细论述。结果表明，基于Linux的嵌入式数控系统的实时性好，性能高，可移植性好。     

基于TMS320C32的数字控制器的设计

数字信号处理器（DSP）TMS320C32具有高效的数值运算能力,并能提供良好的开发环境,通过采用TMS320C32浮点DSP和可编程逻辑器件（FPGA）的组合运用来构成SH-2000TH数控系统的高速高精运动控制器,该系统运用离散FID算法对运动过程加以控制以及通过B样条插值法对运动曲线进行平滑处理,控制效果接近于连续系统。     

嵌入式数控系统的体系结构与系统设计

将嵌入式技术与数控系统相结合,研究嵌入式数控系统的体系结构,提出了嵌入式数控系统的六大基本硬件结构模块,和分层次结构的软件体系,具有软硬件可裁剪、结构精简优化、插补控制实时性强、工作可靠的系统.基于OAN现场总线结构,对ARM10嵌入式微控制器芯片进行接口扩展,设计出上下位机多微处理器结构的嵌入式数控系统,适合于控制交流伺服电动机实现多轴联动,用于加工复杂型面.采用FPGA硬件插补技术,设计源码开放的伺服控制软件,实现2ms级的实时信号响应控制,形成开放性的具有自主知识产权的基于ARM微控制器和CAN现场总线结构的多轴联动嵌入式数控系统.     

可编程逻辑器件FPGA/CPLD在Webit Device Server中的应用

可编程逻辑器件FPGA／CPLD技术作为一种灵活的设计手段已经广泛应用在微电子领域。这里对嵌入式Internet系统Wbeit Device Server如何结合FPGA／CPLD技术，提高自身的集成度、设计灵活性及可重用性等问题进行了探讨。     

基于FPGA的硬件可重构数控系统的研制

可重构要求是21世纪制造系统的核心能力,为了实现数控系统的重构,提出了一种硬件实现方法将数控系统模块化,各模块采用硬件描述语言设计为数控IP(NC Intellectual Protocol),通过数控IP的集成完成数控系统的设计,改变下载到现场可编程逻辑器件中的配置数据来完成数控系统功能的重构.通过一经济型可重构数控系统原型的开发验证这种方法的可行性.     

基于ARM的嵌入式数控系统方案研究与应用

讨论了基于ARM的嵌入式数控系统软硬件平台开发.重点研究了软件平台的体系结构和实现.体系结构紧紧围绕满足新一代数控系统对体系结构的诸多要求进行设计,如：强实时性,高速计算能力,网络功能,开放性,友好的人机交互界面等.     

基于MC68K和FPGA的嵌入式可重构数控系统的研究

提出了一种基于嵌入式微处理器MC68K和FPGA的可重构数控系统的硬件设计方法,解决了硬件逻辑电路变化的问题,提升了数控系统的通用性和柔性。     

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.