湿式双离合器自动变速器分析与仿真

【作者】 董永富；

【导师】 贾志绚；

【作者基本信息】 太原科技大学 ， 车辆工程， 2012， 硕士

【摘要】 双离合器自动变速器（DCT）是在平行轴式变速器基础上发展起来的一种新型的自动变速系统，其原理可简单地描述为：在换挡的时候，通过两个独立离合器组的同时滑磨，来实现动力的不中断。DCT是新一代的自动变速器，能够在不切断动力的情况下转换传动比，从而缩短换挡时间，有效提高换挡品质，同时又具有手动变速器传动效率高、结构简单紧凑、扭矩适应范围广、适合于各种车型，具有良好的发展空间。DCT使车辆性能得到了大幅度的提高，成为当前国际变速箱领域研究的热点。本文就双离合器自动变速器起步、换挡品质及其相关内容做了以下研究：1.分析双离合器自动变速器相对于其它自动变速器的特点及其发展前景，重点研究双中间轴式双离合器自动变速器的工作原理。2.建立了双离合器自动变速器动力学模型，详细分析了换挡时对车辆输出转矩的变化，介绍了起步、换挡品质的评价指标。3.对装有双离合器自动变速器车辆起步过程进行动力学分析，建立双离合器自动变速器的起步仿真模型。以某轿车参数为依据，对其三种不同起步过程进行仿真分析，并与电控机械式自动变速器起步过程仿真结果比较。4.以1挡升2挡为例，对装有双离合器车辆进行仿真，为了使车辆冲击度和离合器滑摩功能够满足换挡品质的要求，针对变速器直线型换挡过程中冲击度和滑摩功难以同时达到最优的问题,采用遗传算法对离合器油压值进行优化控制。本文对三种不同情况下双离合器车辆起步过程进行仿真分析，并与相同条件下电控机械式自动变速器的起步过程仿真结果进行比较，所装载DCT车辆能够改善车辆的起步品质评价指标。采用遗传算法对离合器油压变化斜率为参数进行优化，获得油压——时间的最优控制曲线，将优化后的控制曲线代入换挡仿真模型，结果显示冲击度和滑摩功均达到较为理想的状态。更多还原

【Abstract】 Dual Clutch Transmission（DCT） is developed base on the parallel shaft transmission，it is a kind of all-new automatic transmission. The principle of a DCT works as following: Inthe Shift time, through two independent clutch groups sliding friction, to achieveuninterrupted power. DCT is a new generation of automated mechanical transmission. itcould change the ratio under the power on, so it reduces the shift time and improves the shiftquality. It also inherits the advantage of conventional Manual transmission, such as highefficiency, compact configuration, wide torque extension, So it has a bright market prospect.The DCT incorporates the merits of MT, AT and CVT, so the research and development aboutit has become the hot point in the world. This paper focus on the study of starting and shiftquality of DCT and relevant content:1. Compared to the other automatic transmission, the advantages of DCT and itsdevelopment prospect was analyzed, and the working principle of the dual intermediatebearing type DCT was especially focused on.2. The DCT dynamic model was built, and the change of output torque of vehicle, whenshifted, was detailedly analyzed. Evaluation indexes of the starting and the shifting qualitywas introduced.3. Starting process of vehicles equipped with the DCT was dynamic analyzed; the DCTstarted simulation model was established. On the basis of a car parameters, three kind ofdifferent starting process was simulation analyzed. Then compared this simulation resultswith the simulation results of AMT starting process.4. One shifting-up two gears as an example, make a simulation for dual clutch ofvehicles. In order to make the vehicle impact degree and clutch of sliding work can meet therequirements of shift quality and due to the problem that impact degree and slipping work aredifficult to reach their optimal values simultaneously in process of linear shifting, the oilpressure of clutch was optimization controlled by genetic algorithms.The simulation of DCT vehicle starting process in three different conditions wasanalyzed, and under the same conditions automated mechanical transmission vehicle startingprocess simulation results were compared in the article, the results showed that the DCTvehicles can improve starting quality evaluation index. The oil pressure of clutch is optimization controlled by a genetic algorithm and the oil pressure-time optimal control curveis obtained in the paper. Substituting the optimized control curve in the simulation model, theresult showed that both of the impact degree and slipping work can reach the ideal statecomparatively.更多还原