【作者】 宋勇道；

【导师】 程秀生；

【作者基本信息】 吉林大学 ， 车辆工程， 2013， 博士

【摘要】 纯电动汽车因其具有污染小、噪声低、节约能源、结构和维护简单等优点受到人们的广泛关注，其研发已成为汽车行业的热点。双离合器自动变速器(Dual ClutchTransmission，DCT)既保持了传统手动变速器结构简单、机械传动效率高等优点，又能实现无动力中断换档，提高车辆动力性和经济性，是一种新型自动变速器。因此，DCT已成为现今国际变速器领域研究开发的热点。基于以上背景，本文将两档双离合器自动变速器应用到纯电动汽车上，对基于两档双离合器自动变速器的纯电动汽车驱动与换档控制技术进行了深入研究，主要研究内容如下：(1)在对所研究的两档DCT纯电动汽车整车控制系统分析的基础上，应用模糊控制算法，以加速踏板开度、加速踏板开度变化率和驱动电机转速为算法输入参数，对纯电动汽车驱动转矩模糊控制策略及两档DCT纯电动汽车的动力性行驶模式和经济性行驶模式进行了较深入研究。应用Matlab/Simulink软件建立了包含驾驶员模型、驱动转矩模糊控制模型、两档DCT控制模型、驱动电机模型、两档DCT模型、动力电池模型、车辆动力学模型等的整车仿真模型，并对两档DCT纯电动汽车进行了ECE、ECE_EUDC循环工况仿真，通过仿真将驱动转矩模糊控制策略下的动力性行驶模式和经济性行驶模式与加速踏板信号线性解析的常规行驶模式进行了对比分析。结果表明两档DCT纯电动汽车按照驱动转矩模糊控制策略的行驶模式在动力性与经济性上优于常规行驶模式。(2)在对内燃机汽车坡道起步辅助系统分析的基础上，制定了基于两档DCT的纯电动汽车坡道起步控制策略及坡道起步控制流程；计算出坡道起步过程中不同阶段驱动电机的目标转矩，并推导出制动踏板位移与制动器制动力的关系。应用Matlab/Simulink/stateflow软件建立了纯电动汽车坡道起步控制模块模型，并进行坡道起步仿真，结果表明本文制定的坡道起步控制策略可以完成车辆坡道起步辅助功能。(3)对DCT换档过程中离合器的目标转矩确定方法进行了研究，在对双离合器自动变速器不同工况换档过程进行分析的基础上，制定了换档过程中不同阶段的换档策略，建立了各阶段换档动力学模型。根据换档品质评价指标，以冲击度和滑摩功确定了两个目标函数，建立了换档过程优化算法的约束条件，利用Pareto多目标遗传算法对换档过程中离合器目标转矩的轨迹进行优化，得到了换档过程中多组不同的离合器目标转矩变化轨迹，结合Matlab/Simulink模型对不同的离合器目标转矩变化轨迹的换档过程进行了仿真分析，结果表明，利用Pareto多目标遗传算法对换档过程中离合器目标转矩的轨迹进行优化所得到的换档过程中多组不同的离合器目标转矩变化轨迹都能够获得较好的换档品质，为实车换档过程中离合器目标转矩的确定提供多种可选择方案。(4)对基于两档DCT的纯电动汽车换档过程的干式离合器位移控制方法进行了研究。建立了干式离合器转矩传递模型，并对杠杆弹簧的负荷特性和比例流量阀特性进行了分析。鉴于传统的控制方法在非线性控制中存在的问题，将广义回归神经网络应用到离合器位移控制中，制定了基于GRNN的离合器位移智能控制方法，并建立了仿真模型，结果表明采用离合器位移GRNN智能控制方法进行离合器位移控制，位移跟随精度高，控制误差小，能够满足干式双离合器位移控制精度要求。(5)设计了基于两档DCT的纯电动汽车的控制系统，并进行了整车试验，通过试验验证了本文提出的控制策略的有效性。本文通过理论分析与试验研究相结合的方法，对基于两档双离合器自动变速器的纯电动汽车驱动与换档控制技术进行了较深入研究，仿真与试验结果表明在提高整车动力性与经济性、坡道起步性能、换档品质方面获得了较好的效果，本文对纯电动汽车驱动与换档控制技术的研究具有一定的参考价值。更多还原

【Abstract】 Because of low pollution and noise, energy conservation, simple structure andmaintenance, pure electric vehicles is widespread concerned and has become a hot spot inthe development of automotive industry. Dual clutch automatic transmission (Dual ClutchTransmission, DCT) maintaining the traditional manual transmission simple structure andhigh mechanical efficiency advantages, achieving uninterrupted power shift and improvingvehicle dynamics and economy performace, is a new automatic transmission. Therefore,DCT has become a hot spot in the field of research and development of gearbox.Based on the above background, this paper applies two speed dual clutch transmissionto pure electric vehicle, and research on drive and shift control technology for electricvehicle with two speed dual clutch transmission. the main contents are as follows:(1) Based on the analysis of control system for pure electric vehicle with two speedDCT, drive torque fuzzy control strategy for pure electric vehicle is developed using fuzzycontrol algorithm according to accelerator pedal opening degree, the accelerator openingchange rate and the drive motor speed and two driving modes including power mode andeconomy mode is proposed. The driver model, accelerator pedal fuzzy analytical model,two speed DCT control model, drive motor model, two speed DCT model, battery model,vehicle dynamics model and simulation model of vehicle are established using the Matlab/Simulink software, and simulation tests for pure electric vehicle with two speed DCT underthe ECE, ECE_EUDC cyclie are carried out.The simulation comparative analysis in powermode, economy mode and the normal linear analytic mode are carried out. The results showthat the power and economy performance of pure electric vehicle with two speed DCTbased on drive torque fuzzy control strategy are better than the normal linear analytic mode.(2) Based on the analysis of hill-start assist system of internal combustion enginevehicle, the hill-start control strategy and control flow of pure electric vehicle with twospeed DCT are presented, drive motor target torque of different hill-start process stage iscalculated, the brake pedal and braking force displacement relationship is derived, hill-startof pure electric vehicle is obtained by adjusting motor torque according to braking force.Pure electric car hill-start control model is established using Matlab/Simulink/stateflow,and hill-start simulation results show that the proposed control strategy can assist vehicle complete hill-start with no slip, small jerk, and good starting results.(3) Methods for determining the clutch target torque during shift process of DCT areresearched based on the analysis of different stages of the shift, and dynamic model of eachshift phase is established. According shift quality evaluation indicators, two objectivefunctions is determined using jerk and friction work, the shift process optimizationconstraints are established, clutch target torque is optimized during shift using paretomulti-objective genetic algorithm, different sets of clutch target torque trajectory areobtained, and the simulation of shfit is carried out. The simulation resluts show that usingpareto multi-objective genetic algorithm for the target torque trajectory optimization ofclutch during shift can obtain different sets of clutch target torque trajectory, recieve a bettershift quality, and supply more selectable programs for clutch target torque control duringshift.(4) Dry clutch torque model is established based on the analysis of dry dual clutchstructure, lever spring load characteristics and proportional flow valve characteristics areanalyzed. Because the traditional control methods has problems in nonlinear control, thegeneralized regression neural network is applied to the clutch shift control. GRNNintelligent control method for the displacement of clutch is proposed, and simulation modelis established. The simulation results show that the displacement is controlled with highprecision and small error by using clutch displacement GRNN control algorithm which canmeet the control accuracy requirements of dry dual clutch shift.(5) Electronic control system of electric vehicle with two speed dual clutchtransmission is designed, hardware and software for pure electric vehicle electronic controlsystem are developed, and vehicle test is carried out to verify the proposed control strategy.Through theoretical analysis and experimental study, drive and shift control technologyfor electric vehicle with two speed dual clutch transmission are researched. The test resultsshow that dynamics and economy, hill-start performance, shift quality of vehicle areimproved, and this paper has a certain reference value for pure electric vehicle drive andshift technology research.更多还原