【作者】 李兴忠；

【导师】 雷雨龙；

【作者基本信息】 吉林大学 ， 车辆工程， 2014， 博士

【摘要】 越野车辆通常需要行驶在环境条件复杂多样性的道路或无路地带，这样会导致车辆阻力以及附着力的突然变化，需要车辆驾驶员在很短的时间内根据车辆行驶工况快速地处理不同紧急情况，最终实现变速器档位的变化，如果处理不及时容易引起车辆的动力中断。因此提升越野车的高通过性和舒适性，实现驾驶员工作强度的轻量化是未来越野车的发展方向。而装备液力机械式自动变速器的车辆在提升车辆的通过性有着明显的优势，特别是越野工况、频繁起步的行驶环境。近年来随着电子控制技术方面的快速发展以及不断完善，先进控制技术在作为主流自动变速器的液力机械式自动变速器（AT）上得到了广泛的应用，基于现代控制理论和自动变速理论展开对自动变速器系统的关键控制技术研究，以提升车辆换档品质为需求，通过CAN总线通讯实现对自动变速器和发动机的综合控制技术。本论文以越野车用液力机械式自动变速器为研究平台，结合一汽集团所资助项目，围绕越野车对动力传动系统的高效率及舒适性的需求，开展AT控制系统关键技术的研究，主要研究内容如下：为了提升自动变速器与发动机联合控制策略的精确度，针对越野车用柴油机建立了基于三状态的发动机实时仿真模型，为了解决所选发动机和液力变矩器的工作匹配特性问题，对二者匹配后的共同工作输入、输出特性进行了深入的研究，同时建立了发动机和液力变矩器动态响应特性数学模型；为了准确地设计换档过程的综合控制策略，建立了基于改进型的离合器伍兹摩擦模型，仿真分析了给出摩擦系数与滑摩转速间的MAP关系，为设计合理的AT综合控制策略提供数据支持。为了提升电磁阀的控制精度，对影响电磁阀特性的各种因素进行了深入的研究分析，在提高液力机械式自动变速器电液控制系统的工作效率方面，提出基于不同工况的电磁阀载波控制技术，不仅实现了电磁阀的快速响应，而且解决了电磁阀工作时出现过热的问题，实现了电磁阀电流的最优控制，从而延长电磁阀使用寿命。为了解决AT动力升档过程惯性相阶段输出轴转矩波动引起的不良换档冲击问题，建立了基于转矩比的输出轴转矩估计器，为了提高估计值的精度，重新设计了考虑不同结点惯量的输出轴转矩模型，在此基础上，针对升档过程的惯性相阶段，提出了基于转矩的发动机一体化控制策略，以冲击度为评价指标的车辆换档品质得到了显著的改善。针对AT离合器的控制过程，为了提升离合器执行机构的控制精度，解决由于不合理的离合器充放油工作压力引起的离合器结合重叠或动力中断问题，提出了基于阶段域的离合器动态自适应控制策略，通过合理划分离合器的不同工作阶段域，设计参数识别模型，利用模型识别和变速器机构得到的相关控制参数作为反馈信息，设计了相应的开、闭环自适应控制策略，在所建立的整车模型上，通过对不同油门开度下对离合器升压阶段和行程压力的控制策略进行了仿真验证分析，其结果表明所设计的自适应控制策略取得了良好的效果，满足了转矩相阶段离合器压力的合理控制需求。基于dSPACE快速原型控制系统，构建了实施控制策略的仿真分析和试验验证平台，通过台架试验，试验研究了电磁阀的动态特性、主油压变化规律、离合器充放油特性等关键目标控制量。将控制系统进行整车集成，针对本文所设计的AT控制系统及控制策略进行了整车试验验证，并取得了良好的控制效果。更多还原

【Abstract】 Off-road vehicle (ORV) always travels in the road with complicated and variedenvironmental conditions or roadless area, which will contribute to a sudden change in thevehicle resistance and adhesive force. Therefore ORV drivers have to quickly deal withvarious emergencies according to the vehicle working condition as soon as possible,finally, the changing of the transmission gear ration is realized. If not timely processed,power interruption will happen. So the promotion of the ORV trafficability, strengthcharacteristics, and achieving reducing the drivers’ workload are the ORV futuredevelopment direction.The vehicles equipped with hydraulic automatic transmission (AT)have obvious advantages in improving trafficability, especially in the off-road conditionsand frequent start driving environment.Recently with the rapid development and constantly improvement of electroniccontrol technology, advanced control technology has been widely used in AT as themainstream automatic transmission. Based on the modern control and automatictransmission theory, the dissertation deals with the research of the automatic transmissionkey control technology to improve the shift quality.And the integrated powertrain controltechnology is achieved through CAN bus communication. The research platform of hisdissertation is the hydraulic automatic mechanical transmission used in ORV, andcombined with the projectsfunded by FAW. Focused on the requirements of high powertransmission efficiency and comfort, this dissertation carries out the following researches.In order to improve the accuracy of the integrated control of automatic transmissionand engine, the engine real-time simulation model based on three statesis built for off-roadvehicles with diesel engine.Meanwhile, in order to solve the matching feature problem ofthe chosen engine and hydraulic torque converter, and to conduct in-depth research ontheir input and output characteristics after them matching, the engine and hydraulicconverter dynamic response mathematical model are built. In order to accurately design the integrated control strategy in shift process, the clutch friction Woods model based onthe modified is built. And the simulation analysis provides the MAP relationship betweenfriction coefficient and sliding friction speed, which provide data support for designingreasonable integrated control strategy of AT.Various factors affecting the solenoid valve features are conducted in-depth researchand analysis to improve its control precision. And solenoid valve carrier controltechnology based on different working conditions are proposed to improve theelectro-hydraulic control system working efficiency of AT, which not only has realized itsrapid response, but also solved its overheat problem at work. Finally, the optimal controlof solenoid valve current is realized and its service life is prolonged.The output shaft torque estimator based on the torque ratio is built to solve the badshift shock problems caused by the fluctuation of the output shaft torque during theinertial phase of power-on-upshift process. And the output shaft torque model isredesigned with considering the inertia of different nodes to improve the accuracy of theestimated value. On the sebasics, engine integrated control strategy based on torque ispresented in view of the inertial phase of upshift process.Therefore vehicle shift qualitywhich takes shock as evaluation index is improved significantly.In accordance with the clutch control during the shifting process, shifting clutchdynamic control strategy is proposed based on regions. By establishing the hydraulicclutch actuator model, the corresponding closed-loop adaptive controller is designed. Thecontroller uses relevant control parameters of the model and the transmission mechanismas feedback information. During the regions1and2the open–control strategy isproposed because of none feedback information existing. The simulation platform is builtto carry out the control strategy. The analysis on simulation and experiment of the clutchoil-charging control is done under the different throttle opening condition. It is proved thatthe control strategy proposed is perfect, and the effect is good.Finally many tests are researched with the engine and automatic transmission throughthe bench test, especially including dynamic characteristics of solenoid valve and the change law of main pressure with the aid of rapid prototype control system dSPACE. Withthe integrated rapid prototype control system and off-road vehicle, control strategydesigned in this paper is validated by the vehicle experiment based on the characteristicsof the off-road vehicle, and the shift quality is improved obviously.更多还原