【作者】 高金武；

【导师】 刘志远； 郑权；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2012， 博士

【摘要】 换挡品质控制是自动变速箱控制技术中的一个关键问题,它不仅关系到换挡过程的乘坐舒适性,而且对离合器使用寿命有重要的影响,因此研究换挡品质控制具有十分重要的理论意义和工程意义。本文以装有湿式离合器的液力机械式自动变速箱为研究对象,对换挡品质的闭环控制进行了研究。受摩擦片磨损程度、润滑油氧化程度以及温度等多方面的影响,离合器摩擦特性在使用过程中会发生变化,所以如何克服和抑制离合器摩擦特性的变化对换挡品质控制的影响是本文主要考虑的问题。在解决上述问题的基础上,为进一步改善换挡品质,文中对基于动力传动系的整体换挡控制策略也进行了研究。首先,为分析和研究换挡品质控制,建立了车辆动力传动系仿真环境和控制模型。本文从换挡品质控制的角度出发,结合高精度发动机仿真软件enDYNA,在MATLAB/Simulink环境下建立了包括发动机、变速箱以及传动轴和负载的仿真、分析环境。根据车辆传动轴特征的不同,给出了刚性传动轴、柔性传动轴两种情况下的换挡品质控制模型,并在仿真环境下进行了验证。其次,针对刚性传动轴研究了基于涡轮转速调节的换挡控制器设计问题。通过涡轮转速控制能够有效控制离合器的闭合过程,在实现换挡的同时保证离合器使用寿命。本文通过静态输出反馈控制律,设计了两自由度PID涡轮转速控制器。该控制器一方面利用前馈通道抑制涡轮力矩变化对涡轮转速控制的影响,另一方面利用反馈通道解决了针对离合器摩擦特性和液压系统参数不确定性的鲁棒控制问题。再次,本文讨论了柔性传动轴下的具有抑制输出轴力矩波动能力的换挡控制器设计问题。由于液力变矩器在抑制输出轴力矩波动中具有重要作用,本文将液力变矩器引入被控对象,基于静态输出反馈的滑模控制理论设计了离合器压力控制策略,克服了离合器摩擦特性变化对输出轴力矩波动和系统稳定性的影响。该控制器融合了变速箱和底盘控制系统的测量信息,通过闭合离合器压力控制,同时实现了涡轮转速调节和输出轴力矩波动抑制控制。最后,在解决离合器摩擦特性对换挡的影响、抑制输出轴力矩波动的基础上,讨论了基于动力传动系整体的换挡控制策略。该控制策略将变速箱中液压系统输入、发动机节气门开度和点火角修正系数同时作为控制输入,基于反步法和控制量分配原则,设计了动力传动系整体换挡控制器。该控制器在保证涡轮转速控制精度的前提下,通过发动机力矩调节进一步平顺了输出轴力矩、提高了换挡品质。更多还原

【Abstract】 Gearshift control is a key point in automatic transmission control, which not onlyconcerns about the comfort in gear shifting but also plays an important role in the lifetimeof a clutch, so the research of shift quality control has great theoretical significance andhigh value in engineering.Based on a hydraulic mechanical automatic transmission with wet clutches, the dis-sertation is dedicated to study the closed-loop gearshift control. Under the in?uence of thewear of clutch materials, the oxidation of automatic transmission ?uid (ATF) and variationof temperature, clutch friction characteristics change during the usage, therefore, how toovercome and suppress its in?uence on the shift quality is the major concern in the study.After that, in order to further enhance the shift quality, the power-train integrated gearshiftcontrol is studied as well.Firstly, in order to study and analyze the gearshift control, power-train model andthe simulation environment are built. In this dissertation, from the perspective of gearshiftcontrol, combing with the professional engine simulation software enDYNA, the simula-tion platform is set up in the MATLAB/Simulink environment for the sake of analysis, inwhich the model of engine, automatic transmission, as well as axle shaft and vehicle loadare involved. With different axle shaft, two control-oriented gearshift models with stiff,torsional axle shaft are given and verified in the simulation environment.Secondly, gearshift controller design with stiff axle shaft is studied on the basis of theturbine speed regulation. When the clutch slip control is controlled effectively by turbinespeed regulation, the lifetime of the clutch can be guaranteed during gear shifting. Atwo-degree-of-freedom PID (2DOF PID) gearshift controller is designed by static outputfeedback control theory. On the one hand, feedforward channel is applied in this controllerto suppress the in?uence of changed turbine torque on turbine speed regulation; on theother hand, for the varies of clutch friction characteristics and parameter uncertainties ofhydraulic control system, robust control is discussed in the feedback channel design.Moreover, anti-shudder gearshift controller design with torsional axle shaft is pro-posed in the following. For torque converter plays an important role in the suppressionof output shaft torque oscillation, it is involved as the controlled plant in this study, and clutch pressure controller is designed on the basis of the sliding mode output feedbackcontrol technique, the in?uence of variable clutch friction characteristics on the outputshaft torque oscillation and the system stability is overcome. By clutch pressure con-trol, the proposed approach combines with the measurement information of the chassiscontrol system and gearbox, achieves turbine speed regulation and suppression of outputshaft torque oscillation at the same time.Lastly, based on anti-shudder gearshift controller, which overcomes the in?uence ofclutch friction characteristics on gearshift control and suppress the output shaft torquesoscillation, a discussion of the power-train integrated gearshift control is further presentedto enhance shift quality. The control strategy takes electro-hydraulic system inputs, enginethrottle opening and efficiency correction factor of spark angle as control inputs, and thepowertrain integrated gearshift controller is designed by applying backstepping techniqueand control allocation. By the proposed controller, not only turbine speed is controlledproperly, but also the shift quality is improved as well by further smoothing output shafttorque.更多还原