电机参数对电动车传动系统扭转振动的影响分析

针对电动车传动系统存在的扭转振动问题,对传动系统的固有特性、电机的转矩特性及振动系统的动态响应进行了分析研究,提出了综合考虑控制电机动态特性和传动系统的机电耦合仿真方法。首先,建立了某集中式驱动电动车动力传动系统的扭转振动数学模型,分析了系统的固有特性,用实验数据验证了模型的准确性;然后,建立了永磁同步电机的矢量控制模型,分析了驱动电机的转矩特性;最后,基于驱动电机和动力传动系统的机电仿真模型,进行了电机参数的灵敏度分析。研究结果表明:在低频时,引入谐波转矩的各电机参数对动力传动系统扭转振动的影响呈正比关系;在中高频时,电机参数对传动系统的影响不成比例。     

齿轮传动系统的动态性能分析和优化设计

为了分析多级齿轮传动系统的动态性能,构建了齿轮传动系统仿真模型,通过仿真,分析多级齿轮传动系统的主要物理参数对于齿轮传动系统动态性能的影响规律。并基于仿真得到的分析数据据和相应的实验测试数据,提出了应用谐波平衡法的多级齿轮传动系统优化设计方法,并获得最优设计参数。     

履带车辆动力传动系统扭振的时域仿真研究

对某型履带车辆的动力传动系统扭振进行了仿真建模。针对动力传动系统中具有非线性特征的液力变矩器和盖斯林格联轴器等部件，建立了相应的非线性时域仿真模型，同时建立了发动机激励模型。将系统仿真得到的时域结果进行分析，并与实验数据进行了验证比较，仿真结果与实验数据较吻合。     

机电联合建模在直驱伺服系统设计中的应用

为了缩短直驱伺服系统设计周期,并保证所设计的系统的性能满足设计指标要求,提出了一种直驱伺服系统机电联合建模方法。以典型的直驱伺服系统为例,叙述了该建模方法的实现过程。建立了直驱伺服系统的动力学理论模型和基于Recurdyn和Matlab的机电联合仿真模型,在不同条件下对机电联合仿真模型进行了时域和频域仿真分析,并对仿真结果与系统实际测试结果进行了对比。结果表明：系统开环时域与频域仿真结果与实验结果基本吻合,幅频匹配度大于83%,相频匹配度大于73%,时域匹配度大于89%。得到的结果验证了提出方法的有效性和正确性,表明利用该方法可在设计过程中对设计方案进行性能预测,提高设计效率。     

车辆传动系统虚拟样机集成设计平台研究

针对车辆传动系统的特点,提出并建立了以参数化模型库为支撑的车辆传动系统虚拟样机集成设计平台,实现了结构参数化设计,以及多刚体运动学和动力学分析.通过开发相应的模型库管理系统,解决了各类异构模型管理机制和管理功能实现机制的关键技术,保证了建模和仿真分析各环节的数据共享以及模型一致性和集成性.按各模块之间传递的能量类型.建立了输入输出接口模型,可快速建立系统级的虚拟样机模型,并对其进行各类工况下的稳态和动态性能预测.最后,通过对某履带车辆传动系统虚拟样机建模和仿真分析,验证了该平台的有效性和可靠性.     

基于CATIA和ADAMS的齿轮传动系统动态特性仿真

利用CATIA软件对齿轮进行参数化三维实体造型,通过转换软件MSC.Simdesiger把其导入ADAMS中,建立齿轮传动系统动力学仿真模型,进行了动力学仿真分析,通过仿真结果分析,验证了齿轮三维参数化建模过程及传动系统建模过程的合理性。     

兼顾时频域特征量提取的非线性油气悬架参数识别

针对完全基于时域或完全基于频域的非线性参数识别方法的局限性，提出了一种兼顾时频域特征量提取的非线性油气悬架参数识别方法。在建立含非线性油气悬架车辆动力学仿真模型的基础上，采用快速傅里叶逆变换法获得标准路面不平度等级的输入激励，结合小波分析和滤波处理提取实验结果的时频域特征量，构建非线性油气悬架参数识别的优化模型，通过最小化仿真结果与实验结果在时频域的特征量，实现了非线性油气悬架参数在实际工况下的准确识别。识别的定量与定性分析表明了识别结果的准确可靠。通过将路面时域建模技术、小波滤波技术和优化模型构造方法与模拟退火算法的有机结合，为非线性悬架系统的参数识别提供了一种有效可靠的方法。     

驱动桥锥齿轮错位量的有限元建模和分析

针对驱动桥锥齿轮在设计分析时所需的错位量参数难以获得的问题,在考虑轴承刚度耦合非线性的基础上,建立了包括传动轴、轴承、锥齿轮、差速器等部件在内的驱动桥传动系统的完整有限元模型。在驱动桥桥壳和主减速器壳体建模过程中,考虑刚度的影响,使用有限元模型提取了刚度矩阵,提出了一种驱动桥有限元建模方法;通过搭建的驱动桥仿真分析模型,模拟了真实工况,计算了模型的系统变形,分析得到了锥齿轮设计时所需的错位量。研究结果表明:该方法能对驱动桥包含的各部件进行建模,可模拟试验中的载荷工况,且模型计算分析周期短,仿真结果精度满足工程需求,能够实现对锥齿轮错位量的计算分析;同时,该结果对驱动桥传动系统其他部件的设计和分析也具有一定的借鉴意义。     

基于AMESim的抓斗采矿船液粘调速系统仿真

阐述了液粘调速离合器的原理及其在抓斗采矿船动力传动系统上的应用,利用AMESim动力仿真软件对抓斗采矿船的动力传动系统进行建模,调节元件模型参数,优化模型。通过仿真抓斗采矿船的一个典型工作循环,得到了系统的动态性能曲线。通过分析仿真结果,验证了液粘调速离合器的作用效果及模型的有效性。     

基于μ方法的电动车传动系统扭振鲁棒控制

针对电动车传动系统的扭转振动问题,基于混合μ综合鲁棒控制理论对传动系统控制进行研究。建立考虑永磁同步电机高阶未建模不确定性和参数摄动的某集中驱动式纯电动车传动系统不确定性模型;采用μ方法设计传动系统鲁棒控制器;在Matlab/Simulink软件环境中进行仿真计算,以验证所设计控制器的有效性。结果表明,该控制策略能够使系统获得较强的鲁棒性能与鲁棒稳定性,有效降低系统失稳的可能性。     

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.     

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.