自动变速器模糊换挡及其控制理论研究

以结构简单、传动效率高的电控机械自动变速器(AMT)为研究对象,引入模糊控制技术,将经验知识和数学过程结合起来,根据专家经验建立模糊控制规则,依据自动变速器的实际工况确定输入和输出参数,并对输入量进行模糊化和模糊推理,对输出量进行解模得到模糊控制表,以实现对自动变速器的换挡决策控制.最后进行模糊控制仿真,仿真结果表明,基于模糊控制的机械自动变速器(AMT)对于不同的驾驶条件和运行工况均具有较理想的换挡品质和较强的适应能力.     

拖拉机电控机械式自动变速器模糊换挡策略

利用模糊控制技术,通过引入反映作业状态和环境状态的参数,对拖拉机电控机械式自动变速器(AMT)参数控制换挡规律进行了模糊化修正,设计了模糊控制器。利用设计的模糊控制换挡策略,以东方红-1302R型履带拖拉机为模型,进行了仿真研究。仿真结果表明,能有效避免换挡循环,降低换挡次数,进而改善拖拉机的动力性和经济性。     

两挡AMT纯电动汽车换挡控制研究

对于搭载无离合器电控机械式自动变速器(AMT)的电动车而言,提升换挡品质,减小车辆换挡时冲击度一直是研究的热点问题。针对两挡AMT纯电动汽车,基于MATLAB/Simulink对整车建立模型:包括驾驶员模型、换挡电机模型、车身模型、AMT传动系统模型及驱动电机模型。围绕着减少换挡冲击度这一目标制定出一套换挡策略,并给定整车上坡路面换挡和下坡路面换挡两种工况进行仿真。仿真结果显示,所设计的换挡策略能有效将换挡时的冲击度控制在国家标准范围内,验证了控制策略的正确性。     

电磁执行器直接驱动的AMT换挡机构

为提高机械式自动变速器（AMT）换挡品质并缩短换挡过程动力中断时间,提出了一种电磁直线执行器直接驱动的AMT换挡机构。换挡机构运动总质量为1.37 kg,较传统全电式AMT换挡机构总质量（约1.78 kg）降低23%。对换挡过程进行了分段研究,并在换挡过程数学模型和AMT试验台架基础上,验证了设计方案的可行性。换挡机构换挡过程中无选挡操作,可实现挡位切换时退、进挡同时进行的功能,转速差为500 r/min、转动惯量为0.03 kg·m2,换挡时3挡至4挡的换挡时间约为120 ms,提升了AMT的换挡品质,且仍有进一步提高的余地。研究表明,电磁直线执行器直接驱动的AMT换挡机构可实现自动换挡功能。     

电控机械式自动变速器换挡柔性控制试验

分析了电控机械式自动变速器（AMT）产生换挡卡滞的原因，提出了消除换挡卡滞的柔性控制方法，即在换挡过程中发生卡滞时，电控单元ECU控制换挡执行机构在空挡槽中小范围微动，消除卡滞后再执行相应的换挡操作。在装有AMT的某重型载货汽车上进行了有、无柔性控制的换挡对比试验，试验结果表明，该柔性控制方法可以有效避免换挡卡滞，提高了AMT车辆的换挡成功率。     

AMT对燃油经济性的贡献

通过将自动变速器换挡规律图解方法应用到AMT的经济性换挡规律中,从燃油经济性角度论证该方法的可行性.利用仿真手段,通过对比AMT和MT的燃油经济性,阐释了AMT提高燃油经济性的机理.AMT在燃油经济性方面的出色表现,为推广普及AMT具有一定的帮助.     

双离合器式自动变速器换挡控制研究与仿真

为提高双离合器式自动变速器的换挡质量,研究换挡过程中双离合器的协调控制方法。分析了双离合器自动变速器的结构和动力传递路线,并建立传动系统的数学模型。综合考虑整车动力性、经济性和换挡平顺性等因素,采用模糊控制理论设计了综合智能型的换挡策略。以MATLAB/Simulink/Stateflow为软件平台,开发动力传动系统的仿真模型并对换挡过程进行仿真试验。结果表明,该策略可以较好地减少换挡时间和缓和冲击度,优化了换挡品质。     

电控机械式自动变速器换挡过程控制

提出了一种基于离合器传递扭矩的AMT（电控机械式自动变速器）换挡过程控制方法。以乘坐满意的冲击度最大值为约束条件，对离合器的分离和接合速度进行控制，利用推迟点火提前角与停缸工作相结合的方法，使发动机的工作与离合器的分离或接合相协调，从而达到提高换挡品质，延长离合器使用寿命的目的。     

基于田间工况的拖拉机AMT起步过程控制

AMT在拖拉机上的应用能够弥补手动机械式变速器换挡时机不易把握、操作复杂困难等缺点,为了实现拖拉机AMT良好的起步性能,对拖拉机AMT起步性能影响因素进行分析,根据拖拉机的田间作业工况,制定出AMT起步过程控制策略,并建立拖拉机AMT系统及控制策略仿真模型,对拖拉机AMT起步过程进行仿真分析。结果表明,所制定的控制策略能够满足拖拉机AMT起步过程要求。     

无动力中断电控机械式自动变速器换挡特性研究

通过对无动力中断电控机械式自动变速器(Seamless AMT,简称SAMT)的设计、建模与仿真,得到SAMT的换挡时间为90 ms,验证了换挡无动力中断、换挡时间短等优点,并且和AMT的百公里加速曲线进行了对比,验证了SAMT的优越性。换挡时离合器有不需要分离,只需要改变压紧力的换挡特性,在发动机的输出转速的配合下,提高了换挡的品质。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。