【作者】 陆中华；

【导师】 程秀生；

【作者基本信息】 吉林大学 ， 车辆工程， 2010， 博士

【摘要】 纯电动汽车是世界公认的节能减排技术之一,目前发展纯电动汽车已成为各国政府和汽车行业的共识,其研发已成为汽车行业的热点。纯电动汽车传动系统作为关键组成部分,也受到各汽车厂家和研究机构的重视。DCT是目前深受关注的自动变速器之一,和AMT一样,具有较高的传递效率,同时DCT还可以实现换档过程中无动力中断,有更好的动力性和换档舒适性,其中干式DCT比湿式DCT拥有更高的传递效率。目前国内关于纯电动汽车的研究,主要集中在对固定速比减速器的参数匹配和优化方面,纯电动轿车用的自动变速器还处于研发阶段。本文开发了具有自主知识产权的纯电动汽车两档双离合器式自动变速器,并对其控制技术进行了研究,其主要内容如下:(1)介绍了DCT的结构原理,对各种自动变速器进行了对比,阐述了DCT的优势。对纯电动汽车传动系统的结构和研究现状进行了介绍和分析,最后给出了本文的主要研究内容。(2)提高电动汽车的性能,有很多方法,比如提高电机的性能、提高电池性能、使用新材料减轻汽车重量等。但是在电机和电池不变的前提下,可以通过合理的匹配传动系统的参数来改善电动汽车的性能。从动力性和经济性两个方面对纯电动汽车性能评价指标进行了介绍,并给出了我国对纯电动汽车的性能要求。同时也从动力性和经济型两个方面提出了电动汽车传动系统档位数和速比设计的原则。针对本文所研究开发的纯电动汽车JF-EV,设计了固定速比减速器和两档DCT传动系统参数,并用ADVISOR对其进行了仿真计算,结果显示使用两档自动变速器的电动汽车可以提高续驶里程6%,0-60 km /h的加速时间缩短1.3s,并且增加了爬坡能力。为了进一步提高本文所研究电动汽车的性能,利用遗传算法和ADVISOR软件对两档DCT的速比进行了优化,给出了遗传算法的具体使用过程,该算法的适应度计算应用ADVISOR软件来实现,并比较了速比优化前后电动汽车的主要性能,结果显示,电动汽车的动力性和经济性都有所提高。(3)干式双离合器是两档DCT的重要组成部分,两档DCT的换档过程是通过干式离合器的分离与结合来实现的,研究干式离合器的特性,是保证离合器控制精度的前提,对两档DCT的控制具有重要意义。深入分析和研究了干式离合器膜片弹簧的负荷特性,并利用A-L法对负荷特性进行了计算。针对干式离合器的结合过程,分析了其扭矩传递特性,建立干式离合器扭矩模型。对主要影响扭矩特性的参数进行了分析,包括:温度和磨损的影响。(4)对所开发的两档DCT的电液执行机构关键元件比例流量阀的结构和特性进行了建模与分析。对两档DCT的电子控制单元、各功能模块、相关电路及参数选择进行了设计与分析。由于执行机构和离合器本身的非线性,并且控制过程中存在干扰因素,因此传统的控制理论很难保证对分离轴承移动速度的跟踪精度,本文引入了CMAC神经网络补偿控制算法,并设计了其相应的智能控制器。(5)两档DCT的换档控制包括两个方面:一是确定换档规律,即决定什么时候换档;二是确定换档过程中离合器扭矩的变化规律,即怎么换档。总结了自动变速器的换档品质的评价指标,对换档时双离合器不同重叠度的影响进行了分析。考虑到纯电动汽车和两档DCT的特性,制定了经济性换档规律和动力性换档规律,并对纯电动汽车在特殊工况下的换档模式进行了研究。针对电动汽车两档DCT的升降档过程,提出了换档控制策略,并对换档过程中的电机控制进行了研究。(6)为了验证两档DCT换档过程的控制效果和JF-EV纯电动汽车的性能,对整车进行了试验研究。对纯电动汽车JF-EV的控制系统组成和各分控制器的功能进行了分析,并设计了整车CAN通讯网络。在此基础上开发了基于CAN总线的数据采集显示软件EV-View,并介绍了软件的工作原理。最后对电动汽车进行了加速试验、爬坡试验、道路能耗试验和换档试验。试验结果表明,JF-EV电动汽车可以满足动力性的要求,节能效果明显,同时证明了两档DCT换档控制方法能得到较好的换档品质。更多还原

【Abstract】 The pure electric car is one of the engergy saving technology which is recognized by the whole world. At present time, government of each country and automotive industry have agreed on developing pure electric car, and its development has become hot spot of automotive industry. Powertrain system is the key part of pure electric car, and it’s valued by more and more automotive companis and institues. DCT is the most concerned about in the automatic transmission. It has the advantage of AMT, and it can shift under the power on, so it has better power performance and comfortable adaptability. At present, the researches about pure electric car in our cou ntry are match and optimization on fix ratio reduction gear. No one has studied automation transmission which used in pure electric car, and there has never been a automatic transmission. This essay proposed a two gears DCT automation transmission system applied to pure electric car. And also proposed the CMAC nerve network control to slove the dry clutch control problem.The article’main contents are as follows.(1)Introduced the structure and the development state of the pure electric car powertrain, and made analysis about it. Introduced some transmissions of pure electric car. Also introduced DCT’s structure and principle. Base on the comparing various automation transmissioms, expressed the advantages of DCT. Summarized pure electric car requirements for automatiom transmission. Finally, show the main contents of this article.(2)There are several methods to improve the performance of electric car. For example, improving the performance of the motor, improving the performance of the battery and reducing the mass of car. But our research is match parameters of the prowertrain system to improve the performance. The performance evaluating indicator of pure electric vehicle was presented from two aspects: dynamic property and economic property, and the pure electric vechicle performance needs of our country were given. At the same time, the principle of the gear number and ratio design of transmission system of EV was introduced from two aspects mentioned before. In connection with the pure electric vechicle JF-EV this article involved, reduction gear with fixed ratio and transmission system parameter was designed, and its simulation was done by ADVISOR. The results showed that the performances of electric vechicle with two gears DCT were better in all aspects than electric vehicle with fixed ratio reduction gear. The concept of genetic algorithm was introduced, and the contents and use methods of genetic algorithm tool box. Taking two-gears DCT as example, the use process of genetic algorithm was illustrated, and the ratio of two-gear DCT was optimized combining with ADVISOR. Lastly, certain performances of EV with and without optimation were compared. The result indicated that the travel distance was improved after the ratio of EV had been optimized under the premise of the dynamic property.(3)The dry clutch is the important part of two gears DCT. Controlling the dry clutch’move can make the transmission shift. The research of dry clutch characteristics is the key of control clutch better. Analysised and studied of the dry clutch diaphragm spring load characteristics, and calculated. load characteristics by A-L method. Established the dry clutch torque model about the combination process of dry clutch. Analysised various parameters which effect torque characteristics, including: reverse shock absorber, temperature and wear. And put forward the model of the clutch torque correction method.(4)The principle of actuator of two gears DCT was presented, and the structure and characteristic of proportional flow valve was introduced. The electric control unit of two gears DCT was designed, introducing the function and designed electric circuit. Because of the control system is nonlinear and there are some interferees, the traditional control system is difficult to ensure the control precision. This essay proposed the CMAC nerve network control method to slove the dry clutch control problem. And designed the intelligent controller.(5)The shift control of two gears DCT includes two parts. One is shift rule, another is moving rule of clutch. The evaluating indicator for shifting quality of two-gears DCT was summarized and analysed the effect of different overlap. In this paper, the pure electric car used two parameters type shift rule. According to the characteristics of pure electric car, developed the best economic optimum shift rule and the best power optimum shift rule. Finally, researched the up-shift and down-shift process of two gears DCT, and the control method for dry clutch was proposed. While the motor coordination control in shifting process was studied.(6)Analyzed the electric vehicle control system components and functions of the sub-controller of JF-EV. Based on the CAN of JF-EV, developed the data acquisition display software EV-View, and described the software works. Finally, did accelerated test, hill climbing test and shift test. The results showed that, JF-EV electric car meet the dynamic requirements and had a better shift quality.更多还原