直流电机驱动控制器的技术改进

介绍了SSD直流调速系统 590序列电机速度控制器的特点 ,分析其控制原理 ,提出了对 540序列电机速度控制器的改进方法     

直流无刷高速电机驱动电路设计及改进

采用无传感器无刷直流低速电机专用调速控制芯片ML4425,设计制作了航模用直流无刷高速电机的控制器。针对目前航模用直流无刷电机速度高的特点,对用于直流无刷低速电机的传统ML4425控制系统中的相关环节进行了改进,尤其是电机的启动、驱动和保护部分。简化了航模用直流无刷高速电机的控制系统,减少了成本。     

欧陆590＋直流驱动器在电缆挤出生产线上的应用

在电缆生产设备中，直流驱动得到了广泛应用。欧陆590＋调速范围宽，具有良好的无级调速性能，电机从低速到高速有良好的线性关系，能够保证产品质量。我主要介绍590＋在挤出生产线上的应用方法，在不同生产速度下，保证电缆护套挤出线径稳定。     

小功率直流伺服电机调速系统的设计

该课题是设计一个"小功率直流伺服电机调速系统",使其可以通过12XS128单片机来控制直流电机的调速和正反转。主要思路是借助于12XS128单片机,h型驱动电路,通过键盘电路控制单片机以此来控制电机的正反转,实现了电流和转速双闭环的恒速调节,具有自动起动、自动停止、速度自动控制、方向自动控制等功能。并具有结构简单,控制精度高,成本低,易推广等特点,而且各项性能指标优于模拟直流调速系统,从而能够实际应用到生产生活中,满足现代化生产的需要。     

直流调速装置在大型冲压设备上的应用

介绍了西门子6RA70系列直流调速装置在大型冲压设备上的应用情况。分别从安装调试和正常生产使用两个角度,结合现场经验,阐述了直流调速装置控制冲压设备主电机运行的解决方案。     

用PLC和D/A转换电路实现镗床转速给定

可控硅直流调速系统的给定信号一般为模拟信号，此方法是将T615K镗床调速器给出的30档转速通／断信号通过PLC控制，用D／A电路转换成相应的模拟量，作为调速系统的速度给定信号，控制电机的转速，使之与镗床各档转速要求一致。     

复卷机张力同步控制系统的设计

复卷机的性能决定着纸张生产最后的质量.在对复卷机控制系统的改造中,我们用交流传动代替直流传动,用变频器对交流电机进行调速控制.为保证卷取电机和放卷电机的同步运行,放卷电机工作在开环速度控制方式,卷取电机工作在闭环张力控制方式,控制算法采用积分分离式PID算法,两种控制方式相互协调配合,使复卷机的线速度保持恒定.     

直流电动机变负载抗扰动控制系统的建模与仿真

基于MATLAB/Simulink仿真软件,对直流电动机的双闭环控制调速系统进行建模与仿真.该系统通过电流控制器和速度控制器两大模块,对电机的电枢电流和电机的转速进行控制,使电机在负载变化时具有较好的抗负载扰动性.     

利用PCI-1780实现直流电动机PWM调速

在利用电机作为动力源的场合,直流电动机的调速是一个必须考虑的问题。脉宽调制（PWM）调压法是常用的方法之一,本文利用PCI-1780定时计数卡产生PWM信号,通过LabVIEW编程实现对占空比的改变,再经过驱动器控制直流电动机改变速度。该方法调节简便,充分利用软面板实现直流电动机的调速。     

多电机同轴拖动公共电源方式数字直流调速系统

本文以翻车机卸车系统中拨车机调速系统的实用经验，介绍了多电机同轴拖动公共电源方式数字直流调速系统的设计应用方法，为多电机拖动直流调速系统的设计提供了一种可靠而经济的设计方案。     

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.     

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....     

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.