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关键词： GPS导航仪   中国经济   方向盘   离合器   税收   汽车时代   保障   才能  

摘要： 对于我们这个已经进入汽车时代、成为四个轮子上的国家，我们说，税收是中国经济的油门·刹车·离合器·方向盘，GPS导航仪，是说税收必须根据中国经济的路况．不断地作出调整。只有如此，才能保障中国经济的列车安全快速正点，才能保障中国经济的积极稳健，生机勃勃，民富而国强。

关键词： 机械产品   设计缺陷   辨识   约束关系网   最优修正  

摘要： 提出了机械产品装配设计参数与其约束判定函数的关联方法,研究了装配约束关系网中节点的数据结构,给出了装配约束关系网的构建方法,描述了装配约束关系网的禁忌表访问方式,在此基础上提出了基于装配约束关系网的装配设计缺陷的辨识模型与方法。从装配约束关系网中的设计缺陷节点出发,以约束路径的权值之和为目标函数,采用蚁群算法对装配设计缺陷的修正路径进行了优化。以膜片离合器的装配设计为实例进行了装配设计缺陷的辨识与修正,结果表明,提出的装配设计缺陷辨识模型与修正方法不仅能够快速辨识出装配设计缺陷,而且能够有效地提高装配设计缺陷的修正质量和效率。

关键词： Hybrid electric vehicle (HEV)   Powertrain   Active damping   Vibration control   Dynamics   OSCILLATIONS  

摘要： The purpose of this paper is to investigate the active damping of automotive powertrains for the suppression of gear shift related transient vibrations. Conventionally, powertrain vibration is usually suppressed passively through the application of torsional dampers in dual clutch transmissions (DCT) and torque converters in planetary automatic transmissions (AT). This paper presents an approach for active suppression of transient responses utilising only the current sensors available in the powertrain. An active control strategy for manipulating engine or electric machine output torque post gear change via a proportional-integral-derivative (PID) controller is developed and implemented. Whilst conventional internal combustion engine (ICE) powertrains require manipulation of the engine throttle, for HEV powertrains the electric machine (EM) output torque is controlled to rapidly suppress powertrain transients. Simulations for both conventional internal combustion engine and parallel hybrid vehicles are performed to evaluate the proposed strategy. Results show that while both the conventional and hybrid powertrains are both capable of successfully suppressing undesirable transients, the EM is more successful in achieving vibration suppression. (c) 2014 Elsevier Ltd. All rights reserved.

关键词： Dual-clutch transmission (DCT)   Gearshift   Backstepping   Input-to-state stability (ISS)   Uncertainty   Nonlinear control   AUTOMATIC-TRANSMISSION   DYNAMICS   DESIGN   MODEL  

摘要： In this paper, a model-based nonlinear gearshift controller is designed by the backstepping method to improve the shift quality of vehicles with a dual-clutch transmission (DCT). Considering easy-implementation, the controller is rearranged into a concise structure which contains a feedforward control and a feedback control. Then, robustness of the closed-loop error system is discussed in the framework of the input to state stability (ISS) theory, where model uncertainties are considered as the additive disturbance inputs. Furthermore, due to the application of the backstepping method, the closed-loop error system is ordered as a linear system. Using the linear system theory, a guideline for selecting the controller parameters is deduced which could reduce the workload of parameters tuning. Finally, simulation results and Hardware in the Loop (HiL) simulation are presented to validate the effectiveness of the designed controller. (C) 2014 ISA. Published by Elsevier Ltd. All rights reserved.

关键词： multistage centrifugal extractor   magnetic clutch   half coupling   mismatch angle of half couplings   frequency converter  

摘要： A frequency converter (inverter) with a standard torque-limit function is used for reliable starting of a multistage extractor with an induction motor. The proposed design of the multistage extractor was tested on a production bench; no failures caused by fault of the magnetic clutch were detected.

关键词： LIFE-HISTORY EVOLUTION   TREE SWALLOWS   CLIMATE-CHANGE   SEASONAL DECLINE   REPRODUCTIVE SUCCESS   SONG SPARROWS   PARENTAL CARE   BICOLOR   BIRDS   GENUS  

摘要： In a study of almost 16 000 nest records from seven swallow species across the entire Western Hemisphere, clutch sizes decline with relative laying date in each population, but the slope of this decline grows steeper with increasing distance from the equator. Late-laying birds at all latitudes lay clutches of similar sizes, suggesting that latitudinal differences may be driven primarily by earlier-laying birds. Focused comparisons of site-years in North America with qualitatively different food availability indicate that food supply significantly affects mean clutch size but not the clutch size-lay date regression. Other studies on the seasonality of swallow food also indicate that steeper clutch size-lay date declines in the North are not caused by steeper earlier food peaks there. The distribution of lay dates grows increasingly right-skewed with increasing latitude. This variation in lay-date distributions could be due to the predominance of higher quality, early-laying (and large-clutched) individuals among populations at higher latitudes, resulting from latitudinal variation in mortality rates and the intensity of sexual selection. Our results underscore the importance of studying clutch size and lay date in tandem and suggest new research into the causes of their joint geographic variation.

关键词： 重型车辆   电控液压转向系统(E—ECHPS)   电磁离合器   节能   助力特性  

摘要： 为降低重型车辆液压转向系统(HPS)的能耗,改善高速工况转向驾驶员路感、提出一种节能型电磁离合器电控液压转向系统(E-ECHPS),该系统采用电磁离合器控制转向泵转矩和转速。运用有限元分析法,建立电磁离合器主、副电机仿真模型,研究主、副电机的动力特性;研究电磁离合器功率输入输出的关系,分析该E-ECHPS的节能性;对E-ECHPS转向工况下的助力性能和直行工况下的能耗进行了仿真分析。结果表明:在转向工况,电磁离合器的输出转矩随车速增大而减小;在直行工况,在车速为10、40、80 km/h的时段内,该E-ECHPS的总能耗相比HPS减少71%。该E-ECHPS可实现随车速可变的助力特性,并具有明显优于HPS的节能性。

关键词： 高转速离合器   带排工况润滑特性   沟槽形式  

摘要： 车用湿式离合器带排工况的润滑特性,对减少带排转矩和离合器的工作可靠性有重要的影响。考虑离合器润滑油离心力作用的基础上,对稳态雷诺方程进行了改进,建立了润滑特性研究模型,该模型可以研究不同离合器沟槽形式的润滑膜承载力特性和润滑膜的温升特性,以及使对偶片之间充满润滑油在不同转速差下所需的润滑油流量。对偶片间隙较沟槽深度对承载力的影响更大,润滑膜的温升随对偶片间隙的减少而增加,使润滑油充满对偶片间隙所需的流量将随对偶片间隙及沟槽深度的增大而增大。对工程实际的设计具有指导意义。

关键词： 干式双离合器自动变速器(DCT)   自适应起步   等效坡度   驾驶员意图  

摘要： 干式双离合器自动变速器(DCT)的起步过程对其驾驶体验和使用寿命有很大影响;而车辆起步路况和驾驶员操作极其多样化,因此需要随之调整起步控制策略,来实现起步性能优化。该文基于车辆动力学从车速、等效坡度、路面附着和驾驶员意图4方面对起步工况进行识别,其中驾驶员意图识别结合了模糊推理模型。在起步工况识别基础上进行起步自适应控制,根据车速和路面附着选择最优的起步挡位,根据等效坡度和驾驶员意图控制双离合器的结合方式和结合速度。应用该识别方法和自适应起步控制策略进行仿真和实车测试,结果表明:车辆能有效识别不同的起步工况并采用适合该工况的起步方式,该控制策略有效提升了DCT的起步性能。

关键词： 双离合器变速器   滑模控制器   起步方式   仿真验证  

摘要： 对双离合器式自动变速器(DCT)的结构特点进行分析,利用Matlab/Simmechincs建立起步过程中DCT车辆的物理模型。分析车辆起步时发动机输出转矩和发动机转速的变化规律,实现发动机恒转速起步。根据发动机的输出转矩、离合器传递转矩、离合器滑差率以及车辆的阻力矩建立了滑模控制器,控制输出离合器控制油压。制定双离合器同时接合的起步和l挡单离合器结合起步控制策略,在轻载、中载和重载三种工况下对车辆起步进行仿真,从而验证滑模控制器的正确性,并以离合器结合时间、起步平顺性以及离合器滑模功为评价指标。最后,在轻载工况下,将滑模控制器控制双离合器起步与PID控制双离合器轻载进行仿真对比。仿真结果表明,滑模控制器能够实现DCT车辆平稳起步,并且双离合器起步可以缩短起步时间,可以减少单个离合器滑摩功,有利于提高离合器的寿命。