清扫车电动助力变传动比转向系统设计分析

针对目前电动助力转向器在中型清扫车上的应用现状,为了解决电机尺寸过大、应用困难的问题,提出了新型的变传动比传动的设计方案。以某款车型的电动助力转向系统为例,研究了该车所用转向器传动方案及其电机输出力矩变化情况,建立了该转向系统数学模型;结合清扫车使用工况,确定了齿轮齿条变传动比设计参数,进行了相关计算、对比分析,验证了该方案的改进效果。采用新的设计方案可直接缩小助力电机的输出力矩变化范围,降低选取的电机功率值,达到了减小电机尺寸,扩大电动助力转向系统适用范围和节约能源的目的。     

动态负荷传感全液压转向器的工作原理

阐述了动态负荷传感全液压转向器的工作原理,设计了系统的油泵工作流量、转向器工作最高转速、转向器压力损失等参数,提高了负荷传感液压转向系统的效率和响应速度,使转向稳定可靠。     

全液压转向器计算机测控系统设计及工程实践

该文在介绍全液压转向器工作原理的基础上,根据检测项目的要求设计了液压试验系统的原理图,依据大批量快速检测的工艺要求,构思了全液压转向器计算机测控系统。在工程实践中完成了测试系统的硬件配置,并以组态软件和数据库软件为平台,实现了测试数据的记录、保存、调用、后续处理及报表生成,解决了全液压转向器大批量快速检测的技术难题,为全液压转向器的检测和性能分析提供了有力的技术支持。     

汽车转向器扭杆压入工作装置机械结构设计

汽车转向器扭杆压入工作装置的开发和利用,能够减少工人在操作过程中的劳动强度,从而提高汽车在转向器总成装配中的生产效率。本文从转向器扭杆压入工作装置机械结构的设计入手,详细介绍了压装装置、定位装置、升降装置的设计。该设计能够完成规定的动作要求,可以推广使用。     

起落架作动筒加载磨合综合试验台设计

为使新制的起落架作动筒各配合副表面状态和机械物理性能达到适合于长时期工作的状态,研制了这台起落架作动筒加载磨合综合试验台。该试验台采用立式加载结构,通过PLC控制比例方向阀和比例溢流阀,完成加载力、磨合速度、磨合行程的调节,模拟作动筒的运动工况参数,满足5种不同行程、不同加载力的作动筒的加载磨合及密封测试的需求。     

汽车动力转向器双工位耐磨损实验装置的设计与实现

汽车动力转向器可靠性直接影响汽车安全性能,为了检测汽车动力转向器耐磨损性能,采用交流伺服液压技术、智能集成技术与微机测控技术等,运用液压站+伺服系统+机械力控制+数据采集和工控组件+温度控制系统+扭矩控制等来达到转向系统的综合性能测试的要求,设计了一台汽车动力转向器双工位耐磨损实验装置系统。     

航空活塞发动机气缸磨合的建议

主要介绍航空活塞发动机磨合中胀圈和气缸壁的工作机理和作用,分析磨合中的重要环节和不利因素,提出发动机磨合过程的注意事项和要求,从发动机的磨合原理、磨合过程以及如何进行磨合三个方面进行介绍,强调磨合过程对发动机的品质和使用寿命的直接影响.     

轿车变速箱齿轮磨合次数对疲劳寿命影响的试验研究

为了使相同尺寸规格的变速箱满足不同型号车辆对变速箱强度的不同要求，也为了合理设置变速箱齿轮的磨合次数，以达到最佳强化效果，对某型轿车变速齿轮的磨合次数进行初步研究。在试验的基础上，给出该变速箱齿轮低载强化的最佳磨合次数，并总结出该齿轮在交变载荷下不同磨合次数的疲劳寿命增长规律。有助于提高轿车变速箱齿轮的疲劳寿命，也为进一步制定轿车变速箱齿轮的磨合规范提供技术依据。     

液体静压直线导轨专用磨合机研制方法

为了提高液体静压直线导轨的磨合效率,提出一套针对液体静压直线导轨磨合的新式专用机研究方法。运用现代计算机仿真技术,对液体静压直线导轨的专用磨合机进行建模,动力学仿真分析,从而为提出一套磨合工艺方案提供设计依据;同时,根据具体的磨合工艺要求,设计一套专用磨合机的电气控制系统,以适应专用磨合机的自动化控制要求。通过上述的系统开发方法,能够开发出一台专用磨合机,使其能够实现负载加压,动力系统带动液体静压直线导轨的自动往复有载运动,提高磨合负载负载均匀性、表面粗糙度分布均匀性以及缩短磨合时间。     

基于DSP控制的高精度汽车电子转向器研究

为了克服机械式转向器的弊端,设计了一种基于DSP控制的新型汽车电子转向器。采用光电旋转编码器实时检测汽车转向盘的旋转方向、旋转角度两项参数,用DSP对这两项参数进行实时处理,以恒频脉宽调制的方式完成步进电机的细分驱动,结合CPLD、A/D器件对系统工作状态进行实时监控,实现系统故障自诊断功能。实验结果证明了理论分析的正确性和该方法的可行性和有效性。     

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.