纯电动汽车加速过程转矩优化策略

为了提升纯电动汽车在加速过程中的动力性能,解决纯电动汽车在起步和急加速过程中可能存在的电机输出转矩不足而不能满足驾驶员加速意图的问题,提出了一种基于模糊控制的转矩控制策略。首先通过电机转速和加速踏板开度确定纯电动汽车的基准转矩,然后根据纯电动汽车在不同车速所需要的电机转矩不同,建立了以车速和车速偏差为输入变量,以补偿转矩为输出变量的模糊控制器。最终通过基准转矩值和转矩补偿值确定电机的输出转矩,将转矩命令发送给电机系统。仿真结果表明,该控制策略能够有效提高纯电动汽车在加速过程的动力性能。     

基于模糊推理的纯电动汽车起步意图辨识

对纯电动汽车起步过程进行了动力学分析,基于模糊控制理论设计了驾驶员意图双模糊辨识系统,通过辨识系统推理出符合驾驶员起步意图的起步目标转矩控制驱动电机,实现车辆起步。仿真结果表明,驾驶员意图双模糊辨识系统可以准确辨识出驾驶员的起步意图并量化输出起步目标转矩,该起步意图辨识系统与目标样车相比具有更好的起步动力性且冲击度更小,可以满足汽车起步的平顺性要求。     

电动汽车起步加速控制策略仿真

针对电动汽车在坡道起步的负车速现象和加速性能疲软问题,基于电机的调速特性制订了纯电动车辆的起步加速控制策略。提出了车辆坡道起步的识别方法,分析并制订了符合驾驶员上下坡及平地起步操作意图的电动汽车加速补偿控制策略。仿真结果表明,该策略可以满足电动汽车起步时平顺性要求,并改善了车辆的加速特性。     

纯电动汽车加速转矩控制优化策略

针对纯电动汽车的动力性能不足提出了基于模糊控制的纯电动汽车加速转矩控制优化策略。首先基于模糊控制对驾驶员加速意图进行识别,将加速意图分为急加速模式和一般加速模式。然后根据加速意图识别结果,在不同的加速模式下利用模糊控制对基准转矩进行不同程度的转矩补偿,提高电机转矩输出。仿真和实车实验结果表明,相比较于传统控制方法,加速转矩控制优化策略能有效地识别驾驶员的加速意图,并根据识别结果进行相应的转矩补偿以更快的响应加速意图,显著提高了纯电动汽车的动力性能。     

纯电动汽车加速过程中的驱动转矩优化控制策略

本文研究纯电动汽车在加速过程中的驱动力矩,针对纯电动汽车速度和加速度的不同要求,提出了一种基于加速器踏板开度和电机转速来确定基准转矩的方法。利用模糊算法建立模糊控制器。作为输入变量,将补偿力矩增量作为输出变量,并针对同一踏板作用下的不同驱动转矩控制策略设计了加速度对比试验。结果表明,考虑转速的转矩控制策略可以提高中低速时的加速性能,提高高速运行的稳定性。     

基于驾驶意图的插电式混合动力公交车控制策略*

为了充分挖掘插电式混合动力公交车(Plug-in hybrid electric bus, PHEB)的节油潜力、增强车辆对不同类型驾驶员的自适应性,在基于规则类的控制策略基础上,增加驾驶员意图识别模型。对驾驶风格及加速意图进行模糊识别,通过驾驶员在环的半实物仿真验证了识别模型,以驾驶风格和加速意图识别结果为输入,建立转矩修正系数k的模糊控制器,反模糊化输出k值,对需求转矩进行修正。用system test工具将模糊控制器生成对应的模糊查询表。仿真及试验结果表明：有驾驶员意图识别控制策略较无驾驶员意图识别控制策略更加适应PHEB的运营、用电机制且燃油经济性进一步提高了1.8%。     

负载变化对纯电动货车驱动控制策略的影响

针对常规驱动控制策略无法应对纯电动货车负载变化较大的问题,以电机输出的扭矩为控制对象,提出一种基于模糊控制的驱动控制策略:该控制策略的模糊控制器以加速踏板开度和加速踏板开度变化率为输入,以电机输出扭矩的补偿系数为输出;通过电机的扭矩负荷系数和转速制定驱动的基准扭矩;利用实车数据和仿真数据进行对比,验证了AVL CRUI...     

电动汽车轮毂电机场路耦合协同仿真研究

为满足当前电动汽车性能要求,根据汽车理论计算电机需要的额定转速为940.6r/m,额定转矩为396.3Nm。基于外转子直流无刷电机原理设计了一种电动汽车轮毂电机,建立了电机的几何模型,利用Maxwell软件对其在考虑负载情况下进行仿真。进一步提出了电机的控制策略,对电机进行场路耦合仿真。结果表明电机转速及转矩能满足汽车要求,控制策略能对电机的电流及转速实现控制。     

电动客车双电机章动耦合驱动系统控制策略

为了降低纯电动汽车的能量消耗,提高电动汽车的续驶里程,以一种新型双电机章动耦合动力系统为研究对象,提出了以最小电功率为目标的控制策略.基于整个控制策略框架,将控制策略分为上、中、下3层.上层控制策略为需求转矩计算,根据驾驶员意图、道路信息、电池信息等,准确获取汽车的需求转矩;中层控制策略为驱动模式划分和功率分配,模式划分依据以车速作为逻辑门限值,以最小电功率为目标制定双电机转速转矩分配策略,实现双电机动力系统功率分配;下层控制策略为模式切换过程控制,为减小模式切换的动力落差,在单电机模式切换至双电机模式过程中,采用降功率方法处理.最后,在Matlab/Simulink中建立双电机动力耦合系统仿真模型,验证了该控制策略的可靠性.     

纯电动汽车复合电源再生制动控制策略的研究

为了进一步提高纯电动汽车电机再生制动回收率,增加电动汽车续航里程,对复合电源纯电动汽车再生制动控制策略展开研究.建立串并联可变结构复合电源储能系统,利用SVPWM调制方法控制电机三相整流器的转矩输出,以路面特征值数学模型识别路面状态,建立不同附着系数下以f线组、r线组、理想I曲线和ECE法规线为制动力分配基础的再生制动力控制策略.利用MATLAB/SIMULINK仿真软件建立复合电源和再生制动控制系统仿真模型,嵌入ADVISOR纯电动汽车整车模型,进行不同制动强度下的再生制动过程仿真,并选取CYC_ECE和CYC_UDDS两种道路循环工况,对嵌入的控制策略模型进行整车仿真,与ADVISOR原有模型的仿真结果进行对比分析.仿真结果表明,所设计的改进型再生制动控制策略能量回收效果更佳,能有效提高续驶里程.     

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.