基于DSP和CPLD的开关磁阻电动机数字控制

为实现对开关磁阻电动机的实时有效控制,在分析了开关磁阻电动机的调速系统和现有控制模式的基础上,设计了基于数字信号处理器(TMS320LF2407)和复杂可编程逻辑器件(EPM3064)的开关磁阻电动机全数字控制器。对DSP和CPLD的功能进行了分配,并进行了二者之间的时序仿真分析,采用分段变参数PID控制方法,有效实现开关磁阻电动机的转速、电流双闭环控制,取得预期的实验结果,满足高速电机对实时性的要求。     

开关磁阻电动机转矩特性的检测与建模研究

针对开关磁阻电动机具有很强的多变量耦合及非线性,其转矩特性的获取以及转矩的数学模型的建立均十分困难的问题,对如何获得开关磁阻电动机的转矩特性以及如何建立其转矩的数学模型进行了研究。提出了一种基于暂态电流和稳态电流的转矩检测实验方法,对一台4相8/6极开关磁阻电动机进行了转矩检测实验;与此同时,基于转矩检测实验数据,采用曲线拟合的方式对开关磁阻电动机的转矩特性进了数学建模,并提出一种基于区间分段的拟合方法。研究结果表明,该转矩检测实验以及转矩数学建模方法是有效的。     

基于Simulink的8/6极开关磁阻电动机的直接转矩控制仿真

直接转矩控制(DTC)可以有效地抑制开关磁阻电动机的转矩脉动,但是当前三相开关磁阻电动机(SRM)的直接转矩控制方法并不适用于任意相的开关磁阻电动机.为实现四相8/6极开关磁阻电动机的直接转矩控制,在分析开关磁阻电动机数学模型的基础上,介绍了开关磁阻电动机直接转矩控制方法的基本原理,在Matlab/Simulink环境下利用基本模块建立了8/6极开关磁阻电动机的直接转矩控制仿真模型.基于功率变换电路的状态,给出了8/6极开关磁阻电动机电压矢量的选取规则,介绍了磁链矢量的计算方法以及扇区的判断方法,并利用Matlab/Simulink中的二维查表模块建立了开关表.最后,加入了速度PID控制器,并对该模型进行了仿真研究.研究结果表明,该控制方法是正确且有效的.     

开关磁阻电动机直接瞬时转矩控制系统的设计与仿真

针对开关磁阻电动机转矩脉动问题,将直接瞬时转矩控制方法应用于开关磁阻电动机的转矩控制。基于四相8/6极开关磁阻电动机,给出了其速度控制系统的设计。在Matlab/Simulink环境下,利用基本模块建立了开关磁阻电动机的直接瞬时转矩控制仿真模型。为了实现转矩的反馈,构建了转矩、电流和位置之间的二维表T(i,θ)。最后,结合速度PID控制器,对开关磁阻电动机的直接瞬时转矩方案进行了仿真研究。研究结果表明,直接瞬时转矩控制能有效地减小转矩脉动,而且能够提升开关磁阻电动机的动、静态工作性能,对开关磁阻电动机是一种有效的控制方法。     

基于DSP和GPLD的开关磁阻电动机数字控制

为实现对开关磁阻电动机的实时有效控制。在分析了开关磁阻电动机的调速系统和现有控制模式的基础上，设计了基于数字信号处理器（TMS320LF2407）和复杂可编程逻辑器件（EPM3064）的开关磁阻电动机全数字控制器。对DSP和CPLD的功能进行了分配，并进行了二者之间的时序仿真分析，采用分段变参数PID控制方法。有效实现开关磁阻电动机的转速、电流双闭环控制，取得预期的实验结果。满足高速电机对实时性的要求。     

开关磁阻电动机的一种磁链建模方法研究

开关磁阻电动机（SRM）的磁链特性具有高度饱和性和非线性性,传统电动机的建模分析方法难以应用到开关磁阻电动机的研究之中,针对这一问题,对如何简单有效获取开关磁阻电动机磁链特性进行了研究,提出了一种基于实验测量的方法,详细介绍了实验的原理、电路和步骤,并搭建了实验平台,对一台四相8/6极开关磁阻电动机进行了测量实验,获取了电动机的磁链特性模型,同时将所得模型与解析法得到的模型进行了对比.研究结果表明,提出的方法简单便捷、成本低,能够准确地获取开关磁阻电动机的磁链模型,对开关磁阻电动机的仿真与控制研究具有重要意义.     

开关磁阻电动机实验平台的开发与研究

为研究开关磁阻电动机的运行特性与调速性能,在分析开关磁阻电动机的基本原理与控制方式的基础上,设计了基于数字信号处理器TMS320F2812的四相8/6极开关磁阻电动机实验平台,详细介绍了该平台硬件电路的原理、特性和软件程序的功能、流程;最后,基于所开发的实验平台对开关磁阻电动机进行了多项实验研究。研究结果表明,所开发的实验平台的软、硬件设计具有正确性和有效性,同时也证明了在速度PID控制下,开关磁阻电动机具备优异的调速性能。     

基于MSCO-RBFNN控制的开关磁阻电动机在工业缝纫机中的应用

为实现开关磁阻电动机(Switched Reluctance Motor,SRM)无位置传感器控制并减小转矩脉动,以推动SRM在工业缝纫机上的进一步应用,提出一种基于变尺度混沌优化的径向基神经网络(MSCO-RBFNN)方法,对开关磁阻电动机进行建模,以一台四相8/6极750W开关磁阻电动机为样机建立有限元模型(FEM),获得磁链、电流与转子位置关联样本数据,对MSCO-RBFNN模型进行训练和测试。Matlab/Simulink软件仿真和数字信号处理(DSP)实验结果表明,MSCO-RBFNN模型具有较好的收敛性能,所计算的转子位置与实际转子位置的误差较小,使电动机换向准确,减小了电动机的转矩脉动。     

基于DSP的开关磁阻电动机模糊控制系统

介绍了一种基于数字信号处理器（DSP）TMS320F240的开关磁阻电动机控制系统。论述了其各组成部分的工作原理,该控制系统充分利用了TMS320F240周边接口丰富、运算速度快、适于时机控制的特点,使系统硬件结构简单,并实现了采用模控制策略对开关磁阻电动机进行控制。     

基于Matlab/Simulink的开关磁阻电动机仿真分析

由于开关磁阻电动机结构与运行原理的特殊性,使其分析和设计较其他电动机文章更为困难。基于开关磁阻电动机的准线性动态模型,利用Matalab／simulink,对开关磁阻电动机建模。此模型通用性强,修改方便,在该模型基础上进行了开关磁阻电动机调速系统的仿真。仿真结果如实地反映了SRD的工作状况。     

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.