干式DCT升挡控制策略仿真研究

基于干式双离合器自动变速器(DCT)的工作状态,将其升挡过程划分为5个阶段,综合换挡性能评价指标离合器滑磨功和冲击度,对升挡过程关键节点进行了分析,并根据各个阶段的特点制定了相应的控制策略。运用MATLAB/Simulink建立了传动系统的仿真模型,基于该控制策略进行了DCT升挡过程的仿真计算,结果表明:在该控制策略下离合器的滑磨功和换挡冲击度都保持在理想水平,显著提升了DCT车辆的换挡品质。     

双离合器自动变速器综合控制策略仿真研究

为了提高双离合器自动变速器的换挡品质,研究了两个离合器的压力控制、发动机转速控制这一换挡过程的核心问题,提出了一种DCT升挡过程的综合控制策略。运用Matlab/Simulink建立了传动系统的仿真模型,对该综合控制策略下的DCT升挡过程进行了仿真计算。结果表明,该控制策略可以使发动机转速与高挡离合器快速同步,同时离合器的滑磨功和换挡冲击度都保持在理想水平,显著提升了DCT车辆的升挡品质。     

基于AMESIM的DCT动力换挡品质仿真

对DCT换挡品质的换挡时间,冲击度,滑磨功进行了分析,建立了基于AMESim软件的DCT系统、发动机、滑磨功模型,得到了发动机特性图.给出了具体数据实例,得到了双离合器换挡时间的变化对冲击度、滑磨功的关系图.     

双离合器自动变速系统动力学建模及功率流仿真分析

建立了双离合器式自动变速系统动力学模型,利用Matlab—simulink对双离合器自动变速器的换挡过程进行了仿真,仿真结果表明了循环功率产生的时刻,同时得到了各个挡位的滑磨功率、循环功率、冲击度的相互关系。     

基于换挡品质的变速器换挡控制策略研究

针对变速器电液控制系统及动力换挡问题,对变速器换挡控制(离合器调压系统)与换挡品质进行了研究,分别对车辆起步挂挡与换挡过程建立了动力学模型,对两个过程中影响换挡冲击的因素(离合器充油)进行了分析。根据分析的结果提出了一种新的旨在提高换挡品质的变速器换挡控制策略,利用Matlab/Simulink建立了基于换挡品质的换挡控制仿真模型,通过与理论曲线的对比,验证了基于换挡品质的换挡控制策略的正确性。研究结果表明,该控制策略达到了预期的设计要求,能够有效地降低换挡过程中产生的冲击,提高了车辆的平顺性。     

轿车自动变速器换挡品质研究

为了提高液力机械式自动变速器的换挡品质,首先分析了换挡品质的评价指标,接着在对换挡过程进行动力学分析的基础上,建立了换挡过程的简化模型(该模型可直接应用于换挡品质的实时控制),并且提出一种新的离合器压紧力控制规律;然后运用ITI SimulationX建立了整车动力学模型。基于建立的仿真模型,分析了整车载质量、离合器压紧力变化梯度、发动机节气门开度的变化对换挡过程中,冲击度及比摩擦功的影响,获得了一些有益于提高换挡品质的结果。     

双离合自动变速器换挡冲击度分析

以双离合自动变速器为分析对象,提出并建立了双离合变速器3种状态动力学模型;导出双离合自动变速器换挡过程中各状态下的冲击度表达式;详细分析换挡过程中有无功率循环现象及两离合器不同动作顺序对换挡冲击度的影响;提出了换挡过程中基于发动机转速调节的双离合器控制策略;依托Matlab/Simulink平台建立仿真模型。仿真结果表明,理论分析所得控制策略能有效降低双离合自动变速器换挡冲击。     

液力自动变速器换挡过程优化控制分析

液力自动变速器可起到缓冲冲击的作用,在工程车辆应用普遍。将反步法控制应用于变速器换挡过程,将换挡品质优化问题转化为单一目标轨迹跟踪问题。分析换挡过程中各阶段分离离合器与结合离合器运动状态,建立离合器输出扭矩数学模型。利用变速器转速变化,观测结合离合器转速情况,设定目标轨迹。结合输入状态稳定理论设计滑摩控制器,改变离合器控制电磁阀结合电流实现结合离合器转速对目标转速轨迹跟踪。结果表明,滑摩控制器输出结果对目标轨迹跟踪紧密,换挡过程中车辆冲击度幅值小于10m/s3,满足行业标准,有效提高工程车辆换挡品质,提供舒适性,为此类研究提供参考依据。     

基于CAN总线的换挡过程控制技术

根据机械式自动变速器自动换挡时的需要,分析了在动力一传动系统中应用CAN总线对换挡时间、冲击度和离合器滑磨功的影响,阐述了控制系统中总线报文的详细内容和通信过程,编制了通过总线接收和发送报文的通信程序,在此基础上设计开发了基于CAN总线的应用层协议-SAE J1939的控制模块,实现了电控柴油机转速、油门位置等车辆动力系参数的共享,同时该模块可以在换挡过程中实时控制柴油机的输出转矩和转速。试验结果表明:该项协调控制技术将使柴油机输出特性和变速器换挡过程相互匹配,因而不仅可使自动机械变速器的硬件得到简化,而且有效地减少了换挡时间,降低了离合器磨损,从而改善了换挡品质。     

双离合自动变速器换挡规律研究与仿真分析

针对汽车六挡双离合器自动变速器,研究了车辆的换挡规律,并开发了可通过改变参数设置来实现不同变速器挡位换挡规律的计算软件。根据换挡规律,建立了综合考虑了换挡时间、冲击度、燃油性能的DCTmatlab/Simulink仿真模型。通过定节气门开度下的升挡过程的仿真实验,验证了建立的DCT动力学模型的正确性和换挡控制策略的实用性。     

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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

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...