基于智能启停系统的公交车性能研究

针对公交车载重质量增加所产生的性能问题,采用智能启停系统来改善公交车整车性能。通过分析智能启停系统操作过程和电控单元,分别对装载智能启停系统的公交车和传统公交车在AVL-Cruise中进行建模,计算公交车载重质量变化对油耗的影响。通过仿真,分别计算了装载智能启停系统前后公交车起步时的发动机转速、正常行驶过程中的车辆速度及动力因数。分析结果标明,公交车在安装智能启停系统后,其性能方面有一定的提升。     

基于Start-Stop技术的微混轿车仿真及试验研究

对比分析了采用BSG系统混合动力轿车和加装智能启停(Smart Start-Stop)系统轿车的结构及其主要零部件,并介绍了Start-Stop系统工作原理。通过仿真,分别计算了传统车与加装Start-Stop系统轿车在ECE、EUDC和NEDC循环工况下的燃油经济性,并对仿真结果进行试验验证。试验结果表明,加装Start-Stop系统轿车的燃油经济性与排放性有显著改善。     

基于节能减排的发动机智能启停系统关键技术

针对日益严峻的环境污染及能源问题,汽车的节能减排技术得到越来越多的关注,其中发动机智能启停技术由于具有节能减排效果显著、成本较低等优势更是成为研究的热点.介绍了发动机智能启停技术的应用背景、关键技术的工作原理及控制策略,并结合某带有智能启停系统的车辆进行性能试验,试验结果表明发动机智能启停系统具有降低油耗和减少汽车排放物的作用.     

汽车发动机智能启停技术控制策略分析研究

发动机智能启停系统控制策略是影响其节油效果及在城市路况适应性的关键因素,目前的智能启停系统控制策略都存在一定不足,主要分析研究发动机智能启停系统的的控制策略,在确保人车安全,并力求不改变驾驶员操作习惯的前提下,对启停系统控制策略进行了分析和优化。通过道路实验,提出了优化控制策略的措施,具有一定实际应用参考价值。     

内燃动力总成双层隔振系统瞬态计算方法研究

内燃机被广泛应用于生活生产各个方面,但其工作过程中产生的振动与噪声一直困扰着人们。为了减少内燃动力机组整机振动对周围环境产生的不利影响,可将机组通过单层或双层隔振系统安装在基础上。结合相关研究可知,进行内燃动力机组整机振动分析时,除了要计算机组工作转速范围内的整机振动外,掌握机组启停过程的共振响应情况也是必要的。本文以隔振系统中较为复杂的内燃动力总成双层隔振系统为研究对象,首先通过试验掌握了采用双层隔振系统的内燃动力机组启停过程典型共振响应特性,同时试验结果也为验证计算方法正确性的提供了依据。然后,建立了双层隔振系统动力学模型,采用中心差分法为数值计算方法,结合内燃动力总成特点对机组启停过程加载了激振力,仿真计算所得结果与实测结果的共振响应频率基本一致,最大幅值接近。本文提出的隔振系统瞬态计算方法,能够对机组启停过程的共振响应进行准确计算,为在设计阶段掌握内燃动力机组启停过程的共振响应特性提供了可能。该方法虽然是以内燃动力总成双层隔振系统为对象进行研究,对于采用单层隔振系统的内燃动力机组也可适用。     

汽车启停系统及启停电池的应用研究

启停电池是汽车启停系统的主要零件。介绍了汽车启停系统及其发展历程,分析了汽车启停系统的三种类型,并论述了启停电池的先决条件与性能要求。从电池匹配、功能特点、布置环境等方面对启停电池的选型进行了研究。     

考虑不同加速工况的滑动轴承的启停性能分析*

滑动轴承的摩擦磨损主要发生在启停阶段。为了研究启停工况下的滑动轴承的摩擦学性能,建立一种面向径向滑动轴承的混合润滑数值分析模型。采用质量守恒边界条件的雷诺方程求解流体压力,采用Greenwood和Tripp接触模型预测固体表面接触,而通过Johnson载荷分配概念将润滑模型和接触模型联系起来,从而实现对滑动轴承在启停工况下从混合润滑过渡到动压润滑的摩擦学行为分析。利用该模型,研究轴承系统在启停阶段从边界润滑、混合润滑到动压润滑演化过程中的摩擦学性能;以径向滑动轴承系统为例,结合不同的轴承转速变化函数,分析轴承加速对轴承启停性能的影响;同时研究工作工况、润滑油温度、轴承的结构参数对轴承启停性能的影响。结果表明：轴承启动加速度在合理范围内越大越好,能使轴承更快进入动压润滑;较高的转速、较低的润滑油温度和较大的径向轴承间隙能使轴承拥有更好的启停性能。     

混合动力电动汽车综合能量流模型仿真

随着电动汽车技术的发展和综合性能要求的提高,辅助能量系统(Auxiliary power units,APUs,例如,空调系统、动力转向系统、制动系统、发动机冷却系统等)在混合动力汽车中发挥着愈来愈重要的作用.研究辅助能量系统在车辆行驶过程中的能量流变化,可进一步完善整车的综合能量流管理.分析APUs的工作特点,提出基于能耗map图的仿真思路,通过对ADVISOR软件的二次开发,设计APUs的仿真模型,分别建立传统公交车、串联混合动力和并联混合动力城市公交车的综合能量流模型,完善了传统汽车及HEV的仿真模型.在此基础上对APUs对整车经济性的影响进行仿真研究,仿真研究结果表明,电动汽车附件系统在整车能耗上占有相当的比重,在美国城市循环、ECE循环工况和武汉城市公交车循环工况下,公交车辅助能量附件系统能耗比例最大为10%、最小为6.1%.     

“车-货”耦合的高速货运动车组动力学性能分析

针对货运动车组的特点,在传统多刚体仿真模型的基础上,综合考虑集装器的结构、布置和安装方式,在SIMPACK动力学仿真软件中建立更接近实际的考虑货运动车组车厢和集装器货物的装载加固关系的“车-货”耦合动力学仿真模型.仿真计算了耦合模型在不同速度下的运动稳定性、运行平稳性及曲线通过性能.结果 表明,各项动力学指标均符合要求...     

发动机怠速起停系统性能联合仿真分析

针对汽车车速较低时低效率、高排放和怠速工况油耗较高等问题,对采用启停技术来达到城市汽车节油减排的作用进行研究。首先阐述了发动机怠速停机启动控制原理、电控单元和控制策略,建立发动机启动时动力学模型。其次在Simulink软件中建立了执行发动机怠速停机启动的控制策略模型,通过和Cruise软件联合仿真,在NEDC和Japanmode两种循环工况下对采用启停技术前、后的汽车的油耗和排放做了对比分析。仿真结果表明,整车HC、CO和NOx排放在采用启停技术后显著下降,油耗水平在采用启停技术后改善明显。证明所设计的联合仿真平台和控制策略的可行性和正确性,对汽车怠速起停系统的研究具有重要的指导意义。     

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.