电动车I-AMT挡位切换电机-离合器协同控制

纯电动汽车匹配两挡变速箱能够改善整车动力性和经济性,由于其具有结构精简和无动力中断的优越性,因此高挡位摩擦离合器与低挡位单向离合器组合的传动构型成为电动汽车两档变速器的主流方案。然而,车辆在倒挡行驶时,需要挂入牙嵌离合器才能克服单向离合器只能传递单方向扭矩的问题。本文以一款基于牙嵌式离合器的新型无动力中断两挡自动变速器（I-AMT）为研究对象,协同控制驱动电机和倒挡执行机构电机使牙嵌式离合器平稳快速结合。针对驱动电机系统响应延时问题,使用史密斯预估器算法对控制系统进行预估补偿,并通过实验对控制策略进行验证。结果表明,该控制策略可有效避免牙嵌式离合器挂入时的冲击,保证了变速器可在短时间内在各个挡位之间平顺切换。     

两挡 AMT无动力中断换挡协调控制研究

针对一种纯电动汽车用离合器后置式二挡机械式自动变速器(AMT),提出将同步器布置于变速器第二轴的方案,通过离合器和同步器的切换控制实现无动力中断换挡.为使换挡过程中变速器输出扭矩变化平顺,综合考虑冲击度与滑摩功等换挡性能指标,针对换挡过程的不同阶段,采用相应的换挡协调控制策略:扭矩相时驱动电机扭矩保持不变,同时协调控制离合器扭矩;惯性相时分别采用PID、自适应模糊PID控制电机扭矩使离合器转速差跟踪目标轨迹.基于Matlab/Simulink建立整车纵向动力学模型并进行仿真试验.结果表明:所制定的换挡协调控制策略是有效的,相较于惯性相时采用PID控制离合器转速差,采用自适应模糊PID控制能有效改善换挡品质,换挡过程中最大冲击度和滑摩损失都有所减小,变速器输出扭矩变化平顺无动力中断,整车舒适性有较大提高.     

动力保持型三挡AMT动力学特性

该文研究了纯电动客车动力保持型三挡电控机械式自动变速器(AMT)的动力学特性,该AMT可消除换挡时的动力中断。利用Lagrange方程,建立动力保持型三挡AMT动力学模型;采用MATLAB/Simulink,对安装动力保持型三挡AMT和未安装变速器的目标车型,作了加速、减速全过程仿真和动力性对比;通过模型得到换挡过程中离合器、制动器的力矩曲线,分析了驱动电机输入转矩和主减速器输出转矩;结合动力学方程,验证了换挡过程动力保持的可行性。结果表明:安装动力保持型三挡AMT,有助于改善纯电动客车的动力性,实现换挡时的动力保持。     

纯电动客车自动机械变速器换挡过程控制

为了实现纯电动客车用自动机械变速器(AMT)快速、平顺、准确换挡,以交流异步电机驱动的纯电动客车为研究平台,分析了无离合器的AMT换挡过程控制方法,研究了电机驱动式AMT执行机构控制方法,开发了纯电动客车适用的无离合器多挡AMT系统.经试验场与北京公交线路上的实际考核表明,所设计的AMT换挡过程控制方法满足实用要求.采用该方式换挡的AMT系统已被小批量应用于纯电动客车和混合动力客车中.     

双电机混合动力汽车起步与换挡过程协调控制

针对采用自动变速箱(AMT)的混合动力汽车存在换挡动力中断问题,提出一种新型双电机混合动力驱动系统,该系统主要包括1台发动机、2个电机和1个四挡变速箱。通过控制发动机、电机、离合器与同步器的工作状态,该混合动力系统可实现纯电动驱动、发动机和电机并联驱动、串联驱动、制动能量回收以及行车发电等多种工作模式。采用集中质量法和牛顿第二定律对该驱动系统进行动力学分析,将其等效为质量-弹簧-阻尼系统,并建立动力学方程。通过查表法建立了发动机和电机模型。结合混合动力驱动系统结构特点,设计模式切换和换挡过程的控制策略,在模式切换和换挡过程中,结合发动机和电机的扭矩响应特性,对发动机和电机输出扭矩进行协调控制。采用基于发动机输出扭矩的电机扭矩补偿策略维持汽车驱动扭矩,避免出现换挡动力中断现象。基于AMESim和MATLAB/Simulink软件平台搭建整车模型及控制策略模型,并对模式切换和换挡过程进行仿真分析。研究结果表明:双电机混合动力驱动系统可实现车辆换挡过程中输出扭矩平顺变化,无动力中断现象;通过限制发动机和电机的扭矩变化率,以及离合器和同步器等执行机构的分离接合速度,可将模式切换和换挡过程的冲击度控制在合理范围内。     

电动汽车动力保持型机械式自动两挡变速器仿真与试验

该文以实现动力不中断的高效动力传动系统为基本目标,对一种适用于电动汽车的动力保持型机械式自动两挡变速器进行了仿真与试验研究。该变速器主要由单排行星齿轮系统、膜片弹簧式离合器以及鼓式制动器构成,旨在解决换挡过程中的动力中断问题。该文建立了一个采用新型变速器的纯电动汽车前置前驱传动系统动力学模型。在MATLAB/Simulink环境下,搭建了一个纯电动车整车仿真模型。该模型用来进行分析、选定变速器的基本参数,研制出一台变速器功能样机。该仿真模型适合于实时仿真与试验,在试验过程中可以灵活地改变调整各种参数。根据新型变速器试验的需求,该文建立了一个变速器硬件在环仿真平台,搭建了一个变速器样机的试验台,进行实时仿真和台架试验。仿真和试验结果表明:该变速器解决了在换挡过程中存在的动力中断问题,使驱动电机工作在高效区间,提高了纯电动汽车的动力性和经济性。     

纯电动汽车动力系统匹配与性能仿真

兼顾纯电动汽车动力性与经济性指标,完成驱动电机、动力电池组和变速器的优化选型.然后,围绕电池组容量与质量之间对整车性能影响的矛盾关系,利用电涡流测功机测试不同电池质量等速行驶200 km的能量消耗,对动力电池进行优化选型.最后,采用区间优化设计方法对传动系参数进行优化设计.针对两挡电控机械式自动变速器(AMT)换挡过程中存在换挡冲击的影响,提出一种基于电机转矩控制的换挡策略及搭载电动汽车联合仿真模型,并对换挡控制策略和整车性能指标进行仿真分析.结果表明:动力系统优化匹配方法能很好地满足动力性和经济性行驶要求,续驶里程测试过程中变速器换挡冲击度小,换挡品质较高,验证了匹配方案、仿真模型与控制策略的有效性和准确性.     

纯电动车辆坡道自动换挡综合策略与试验研究

为了使配置AMT变速器的纯电动汽车能够更好地发挥电机驱动系统的动力优势,提出了根据换挡后离合器接合时的发动机转速识别坡道行驶工况。根据当时的车速选择合适挡位的坡道换挡策略,并在装有AMT的纯电动汽车上进行了坡道换挡试验。试验结果表明,车辆在坡道行驶过程中,虽然初次选择的挡位不一定能适应该坡道,但通过连续式换挡或跳跃式换挡,最终能选择适合于该坡道的挡位。利用车辆现有的传感器,坡道换挡控制策略实现了坡道换挡控制,不仅满足车辆实际行驶工况的需要,而且使控制系统硬件得以简化。     

两挡AMT纯电动汽车换挡协调控制及试验研究

为提高两档AMT纯电动汽车的换挡平顺性及减少换挡时间,建立了详细的纯电动汽车动力传动系统的数学模型,制定驱动电机参与换挡过程的综合协调控制方法,从允许的最大换挡冲击度出发得出转矩相阶段电机扭矩控制律,惯性相阶段采用PID和有限状态切换的控制策略进行电机调速.最后搭建纯电动汽车传动系统试验台架,对升挡和降挡过程中换挡协调控制策略进行仿真分析与试验验证.仿真结果显示:0～100 km/h全加速的升挡时间为0.5 s,纵向冲击度在8.0 m/s~3以内,NEDC市区工况升降挡时间均在0.6 s以内,最大冲击度未超过7.8 m/s~3;试验结果显示:驱动电机在固定转速下的升降挡时间分别为0.6 s和0.8 s,输出轴转速变化平滑.传统AMT车辆的换挡时间为0.8～1.0 s,上述结果表明该换挡综合协调控制策略能够实现快速、平稳换挡.     

超越离合器辅助换挡变速器的换挡控制研究

提出一种仅用一个摩擦离合器实现无动力中断换挡的新型自动变速器——超越离合器辅助换挡自动变速器.该变速器采用摩擦离合器与超越离合器交替传递动力的方式实现连续换挡.为研究该自动变速器的换挡平顺性问题,搭建了两个挡位的6自由度变速器动力学模型,提出了换挡过程中离合器和动力源的协调控制策略,开展了仿真和台架试验研究.结果表明:所提升挡和降挡控制策略能有效降低换挡冲击,使得换挡时的冲击度保持在10m·s~(-3)以内.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.