【作者】 张晓冰；

【导师】 李幼德；

【作者基本信息】 吉林大学 ， 车辆工程， 2012， 博士

【摘要】 当代社会，能源危机及环境污染越来越成为人们关注的话题，汽车是石油的主要消耗源同时其尾气排放也是城市空气的主要污染源。因此，当我们考虑要认真对待能源危机及环境污染问题时，显然需要从汽车的性能及使用方面寻求方案。此外，在大中城市中，交通拥堵现象日益严重，人们在蠕动的车流中消耗着时间，伴随着焦躁的心情，严重影响了人们的工作效率和生活品质。生活水平的提高把轿车代入了越来越多的家庭，同时也使得上述问题日益严重。现阶段，一个合理的解决以上问题的方案就是发展公共交通，鼓励大家乘坐承载效率更高的公交车辆出行。公交车辆因其运营需要，在行进过程中会频繁起停，公交司机作为专职司机需要长时间进行驾驶操作。且公交车辆乘客较多。故从降低驾驶疲劳，提高行车安全以及舒适性的角度出发，显然自动变速器是公交车辆动力传动系统的合理选择。自动变速器的换挡策略是指自动变速器的挡位在汽车行驶过程中，根据换挡参数的变化而执行的挡位变化的规律。换挡规律的制定是自动变速器开发过程的关键环节，它的好坏，直接影响到汽车的动力性、经济性，通过性，排放性，舒适性以及对环境的适应性。换挡规律的制定要根据具体情况来决定所采用的换挡策略，比如对换挡品质的要求和能够获得的车辆行驶参数。换挡策略可分为单参数、两参数和三参数换挡。按照汽车的加速性能或油耗表现，又可分为动力性换挡规律和经济性换挡规律。本文对在公交车辆中应用的自动变速器的换挡策略进行研究，提出换挡策略并通过建模仿真进行验证。站点停靠、等红绿灯使公交车辆的行驶过程含有较多的起步、加速、制动、减速等行驶工况，在车辆传动系统中增加蓄能元件以吸收制动减速时所消耗的动能，并在车辆起步加速时释放该能量以辅助车辆起步加速。这样既可提高车辆效率，降低燃油消耗，又可提高车辆的动力性能。因此本文提出在公交车辆的动力传动系统中增设液压蓄能元件，并通过理论分析计算获得合理参数，再通过建模仿真验证其性能。本课题结合企业项目“XQ6102SH2城市客车自动变速器开发试验研究”进行，该项目为一汽（无锡）客车厂为其城市客车XQ6102SH2搭载自主研发的四档自动变速器，包括配套的软硬件开发及整车试验研究。论文主要研究内容如下：（1）分析并建立了包括发动机，液力变矩器，自动变速器等模型在内的整车动力传动系统数学模型。（2）分析并建立了液压蓄能装置数学模型。（3）对换挡策略的研究：按照所选定的换挡参数数量，换挡策略可分为单参数、两参数和三参数换挡。按照汽车的加速性能或油耗表现，又可分为动力性换挡规律和经济性换挡规律。本文分析了自动换挡规律，在现有的几种典型换挡规律的基础上，通过对发动机特性参数的试验分析，提出将发动机负荷率作为综合性换挡规律的换挡参数。根据公交车辆运行工况特点，制定适合本试验车的最佳动力性和最佳经济性换挡规律，提出了基于经济动力性因数的综合性换挡规律。同时分析了特殊工况下公交车应采用的换挡策略。（4）建立了基于matlab/simulink的整车仿真模型并对换挡控制策略进行了仿真研究。对换挡控制策略的仿真结果表明所提出的基于经济动力性因数的综合性换挡控制策略具有更好的经济、动力性能。（5）对液力变矩器闭锁控制的研究：液力变矩器是车辆中理想的起步元件，汽车起步时液力变矩器较大的变矩比可帮助汽车平稳起步。并且，利用其液力传递的特性将发动机与变速器隔离，从而便于自动变速器自动换挡。但是，液力传递的效率要远低于机械传递，因此现代车辆上应用的液力变矩器都装有闭锁离合器用以在车辆起步完成后达到一定速度时将液力变矩器的输入泵轮和输出涡轮锁止为一体，变液力传动为机械传动从而提高其传动效率。本文针对所研究的公交车辆提出了液力变矩器闭锁控制策略。应用Matlab/Simulink建立的整车仿真模型对典型工况下液力变矩器的闭锁控制进行了仿真研究，仿真结果表明该控制策略可以很好的执行液力变矩器闭锁操作，提高整车燃油经济性能。（6）应用AMESim软件建立了并联式液压混合动力车辆模型，通过典型工况的仿真研究对液压蓄能装置的主要结构参数进行了优选。（7）设计了自动变速器电子控制系统，开发了自动变速器控制软件。基于FreescaleMC9s12XDT256单片机为自动变速器及液压蓄能器设计了电子控制单元。首先分析了电子控制单元的具体设计要求，然后依据设计要求设计开发了电子控制单元，分别介绍了电子控制单元软硬件设计要点。本文的主要创新之处在于首次提出应用发动机电子控制单元广播到CAN总线上的实际发动机百分转矩作为表征发动机负荷率的参数，并依据此参数制定了基于经济动力性因数的综合性换挡规律，从而能够更好的协调整车的经济性能与动力性能，尤其适合于像公交车这类载荷变化范围大，且变化频繁的车辆。更多还原

【Abstract】 Nowadays, the energy crisis and environmental pollution has increasingly become the subject of attention, the car is a source of oil consumption, at the same time it’s emissions are urban air pollution sources.Therefore, when we consider the energy crisis and environmental pollution problems to be taken seriously, it is clear that we need to seek the solution from the performance and the use of motor vehicles. In addition, in the large and medium-sized cities,traffic congestion is worsening day by day, people waste their life in creeping traffic, along with the mood of anxiety, it’s a serious impact on people’s work efficiency and quality of life.More and more families possess cars because of there improving income, and this makes the problems mentioned above more serious. At this stage, a reasonable program to solve the above problem is to develop pubilc transport, and encourage everyone to take the trip by more efficient public transport vehicles.Public transport vehicles because of its operational needs, and in the process of moving the frequent starts and stops, bus drivers take a long time as a chauffeur driving operation. And public transportation vehicle more passengers.Therefore, starting to reduce driver fatigue and improve driving safety and comfort point of view, obviously the automatic transmission is a reasonable choice of public transport vehicle powertrain. The automatic transmission shift strategy is the law of the automatic transmission gear the vehicle was performed according to the change of shift parameters of the gear change. The formulation of the shift schedule is a key link in the development process of the automatic transmission, it is good or bad, directly affect the car’s dynamic economy, emissions, comfort, and adaptability to the environment. The shift schedule should be formulated according to the specific situation to determine the shift strategy, driving parameters such as shift quality requirements and the availability of vehicles. Shift strategy can be divided into a single parameter, the shift of two parameters and three parameters. Power Shift and economic shift schedule in accordance with the acceleration of the car or the fuel consumption performance can be divided into. Automatic transmission shift strategy in public transport vehicles to shift strategy and validated through the modeling and simulation.Site parking, traffic lights to make public transport the vehicle process contains more start, acceleration, braking, deceleration and other driving conditions, increase energy storage in the vehicle driveline components to absorb the kinetic energy consumed in the brake deceleration, and release the energy to assist the vehicle started to accelerate when the vehicle started to accelerate.This will not only improve vehicle efficiency, reduce fuel consumption, but also improve the dynamic performance of the vehicle. In this paper, additional bus vehicle powertrain components of the hydraulic accumulator, and through theoretical analysis and calculation for reasonable parameters, and then through the modeling and simulation to verify its performance.The subject combined with enterprise project "XQ6102SH2 urban bus automatic transmission development test", the project for the FAW (Wuxi) Bus plant for city buses XQ6102SH2 equipped with self-developed four-speed automatic transmission, including supporting software and hardware development and vehicle Experimental study. Paper as follows:(1) analysis and the establishment of a mathematical model of the vehicle powertrain including the engine, torque converter, automatic transmission model.(2) analysis and the establishment of the mathematical model of the hydraulic energy storage device.(3) shift strategy:shift in accordance with the selected number of parameters, the shift strategy can be divided into a single parameter, the shift of two parameters and three parameters. Power Shift and economic shift schedule in accordance with the acceleration of the car or the fuel consumption performance can be divided into. This paper analyzes the automatic shift schedule, on the basis of several typical shift schedule, test analysis through the characteristic parameters of the engine, the engine load rate as the shifting parameters of the shift schedule. According to the characteristics of public transport vehicles operating conditions, the development of optimum power for the test car and the best economic shift schedule, shift schedule based on the economic dynamic factor. Special conditions buses should be used to shift strategy.(4) the establishment of a simulation study based on the vehicle simulation model in Matlab/Simulink, and shift control strategy. Shift control strategy, simulation results show that the proposed comprehensive shift control strategy based on economic power factor has a better economy, dynamic performance.(5) Control of torque converter lockout:torque converter is the ideal starting components in the vehicle, the torque converter when the car started torque ratio that car a smooth start. And hydraulic transmission characteristics of the engine and transmission, isolation, and to facilitate the automatic transmission automatic transmission. However, the hydraulic efficiency of the transmission is far lower than the mechanical transmission, torque converter applications in modern vehicles are equipped with a locking clutch for the completion of the vehicle starting to reach a certain speed, the torque converter input pump wheel and the output turbine lock as a whole, variable hydraulic mechanical transmission, the transmission in order to improve its transmission efficiency.Torque converter lockout control strategy was proposed for the study of public transport vehicles., Matlab/Simulink vehicle simulation model of the typical conditions of a torque converter lockout control simulation, the simulation results show that the implementation of the control strategy can be a good torque converter locking operations, improve vehicle fuel economy performance.(6) Application AMESim software to establish a parallel hydraulic hybrid vehicle model, the main structural parameters of the hydraulic accumulator devices are optimized through the simulation study of the typical operating conditions.(7) The design of the automatic transmission electronic control system, the development of the automatic transmission control software. Based on the Freescale MC9s12XDT256 single-chip design of the electronic control unit for automatic transmission and hydraulic accumulators. First analysis of the specific design requirements of the electronic control unit, and then according to the design requirements of the design and development of the electronic control unit, electronic control unit hardware and software design features. The main innovation is the first proposed application of the engine electronic control unit broadcast to the CAN bus engine percentile torque as a parameter of the characterization of engine load rate, and economic momentum factor was developed based on this parameter change file rule, in order to be able to better coordination of economic performance and dynamic performance of the vehicle, especially suitable for such as bus load range, and frequent change of vehicles.更多还原