基于PLC步进电机位置闭环控制研发与应用

在PLC高速脉冲输出功能控制步进电机的基础上,分析了步进电机的控制特点,利用光栅尺作为步进电机的位置检测装置及反馈装置,通过PLC程序算法实现对步进电机位置的闭环控制。     

应用于远程测控系统的智能控制节点设计

主要介绍了工业远程测控系统中智能控制节点的设计。智能控制节点采用基于CAN总线的两相步进电机作为研究对象。以AT89C51单片机作为控制核心,进行控制节点电路设计。另外,给出了CAN控制器SJA1000对步进电机的控制方案及实现其控制要求的软硬件设计。文中还提供了SJA1000的初始化程序和CAN控制器采用中断形式进行数据收发的流程图,以及保证步进电机避免失步的一种控制算法。     

串行通讯在基于DSP控制的电机控制中的应用

本文介绍了以TMS320LF2407A为核心控制器的步进电机自动升降速控制系统与PC机的通讯及程序设计方法,文章分析了通讯协议及数据传输的格式,详细介绍了DSP和上位PC机的软件设计,给出了程序的流程图和人机控制界面,并在步进电机和步进式伺服电机上,进行了相关的实验,基本上达到了控制的要求。     

基于PLC的步进电机控制系统设计

基于设计步进电机控制系统的目的,主要设计以PLC为核心控制器的步进电机控制系统。在对常见的三相反应式步进电动机工作原理详细阐述的基础上,对步进电机的控制原理进行分析说明。以西门子S7-200系列PLC对步进电机的控制为例,通过对S7-200系列PLC的高速输出点直接对步进电机进行运动控制的方案设计,设计相应的外部接线图、程序,并对具体的控制参数进行说明。     

用MOS功率管控制步进电机

随着微处理器应用的迅速发展,用它来控制步进电机已日益广泛。步进电机的步进方式、速度、加速度、减速度、旋转方向及间隔,可通过存贮在存贮器内的控制程序或来自程序总线的控制信号来改变。由于一般步进电机绕组的工作电流都较大,所以微处理器输出的程序脉冲(如 TTL 电平)不能直接控制步进电机的绕组。因此,一般均用大功率晶体管来控制步进电机的绕组,但双极型晶体管速度慢,对于要求快速执行程序指令的步进电机来说就显得不足了。这时,如用     

用可编程序控制器驱动步进电机的方法

详细描述了一种用可编程序控制器控制驱动步进电机的控制系统,其工作原理、硬件组成和控制软件编程方法,最后叙述了一种用CQM1A可编程序控制器控制一种步进电机的系统制作与调试方法。     

基于PIC的步进电机细分控制器

为了实现永磁式步进电机的细分控制,采用PIC18F2331单片机作为主控单元接收外部的脉宽调制（PWM）步进电机控制信号,并辅之以外部功率驱动电路完成了步进电机细分控制器的硬件设计,并应用C语言编写了相应的PWM信号至步进电机控制信号的转换程序,实现了对2／4相步进电机的开环细分控制。此外,还利用单片机的串行通信模块,设计了与计算机的串行通信电路,方便了系统的调试和监控。测试结果表明,该控制器能实现对步进电机的细分控制。     

自动电热铆机的步进电机速度设计

在分析航空发动机自动电热铆机工业要求的基础上,以四相混合式步进电机为研究对象,提出单片机按直线规律升降频的方法控制步进电机。并根据电机运行控制方程和恒加速控制图,建立步进电机模型。通过改变单片机内部的定时器的初值对其速度控制,并给出部分C 51程序。实验表明该方法平稳性好,速度变化范围大,适合自动电热铆机快速定位的要求,满足整流器叶片旋转分度的准确性。     

基于单片机控制的步进电机设计

与其他类型的电机相比,步进电机具有更加明显的优势,步进电机中的定角转动控制利用电脉冲信号控制相绕组电流,因此实现了更精确的开环控制,同时还能够实现无积累误差,这使步进电机成为了目前常用的一种机电元件,而使用单片机控制的步进电机系统控制性能更加优良。现以步进电机的基本概念为切入点,在分析步进电机控制系统的基础上进行步进电机的单片机控制的设计,旨在为教学及实践提供切实可行的理论参考。     

一种基于微机和单片机的步进电机控制系统

介绍了一种基于微机和单片机的步进电机控制系统，利用上、下位机控制步进电机的多种运行方式，可实现步进电机正反转控制以及步进电机的无级调速。程序采用模块化设计，通过PC机容易实现各功能设置。     

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.