Torque control of engine clutch to improve the driving quality of hybrid electric vehicles

As a powertrain for hybrid electric vehicles (HEVs), the automatic transmission (AT) is not only convenient for the driver but also reduces hybridization costs because the existing production line is used to produce the AT. However, it has low fuel economy due to the torque converter. To overcome this disadvantage, this paper studies HEVs equipped an AT without a torque converter. In this case, additional torque control is needed to prevent the driving quality from deteriorating. This paper suggests three different torque control methods and develops a simulator for an HEV that can simulate the dynamic behaviors of the HEV when the engine clutch is engaged. The HEV drive train is modeled with AMESim, and a controller model is developed with MATLAB/Simulink. A co-simulation environment is established. By using the developed HEV simulator, simulations are conducted to analyze the dynamic behaviors of the HEV according to the control methods.     

具有双离合器的液力变矩器的结构设计

将液力变矩器与机械式自动变速器合理匹配可组成一种新型自动变速系统，其性能接近自动变速器，但成本降低。为该系统设计了具有双离合器(闭锁离合器，换档离合器)的液力变矩器。阐述了该液力变矩器的结构、工作原理及特点。试验结果表明，所设计液力变矩器可支持新型自动变速系统成为现实。     

基于W305液力变矩器的系列化设计

以W305液力变矩器为基型,通过试验研究和统计资料,确定了液力变矩器的系列化型谱;利用CFD数值分析软件对W305变矩器内部流场进行分析计算,基于计算结果进行W305液力变矩器的系列化设计;对于有效直径不同的液力变矩器,介绍了与基型变矩器相似设计的方法。     

Performance estimation model of a torque converter part I: Correlation between the internal flow field and energy loss coefficient

The objective of this paper is to improve the performance estimation model of the internal flow field of a torque converter. Compared with performance experiment results, the converter based on the one-dimensional model does not satisfy the performance requirements demanded in practice. Therefore, we need to develop more predictable and reliable performance estimation models. In order to obtain shape information on three-dimensional blade geometry, a process of reverse engineering conducts a torque converter assembly, impeller, turbine and stator. In addition, a CFD simulation including mesh generation and post-processing was carried out to extract equivalent parameters from the internal flow field. The internal flow field can be explained by analyze the correlation between a performance estimation model and CFD analysis. The equivalent performance model adopts the variation of energy loss coefficients for a given operating condition according to the application of a changing energy loss coefficient by the least mean squares method. The estimated equivalent model improves the agreement in performance between experiments and the theoretical model. This model can reduce the error to within about 3 percent. Furthermore, this procedure for predicted performance achieves eminence in the estimation of the capacity factor.     

液力变矩器膨胀变形试验研究

液力变矩器在工作载荷下，同时受到油压的面力和旋转所产生的离心力作用而发生变形。其变形的大小将直接影响到液力变矩器的性能和在工作中与相邻零部件间的位置关系。通过设计和开发液力变矩器膨胀试验机的动态自动测试系统和试验装置，对液力变矩器的轴向位移进行了试验研究。得到液力变矩器在加压情况下膨胀变形大于在加速情况下的变形，且在加压情况下变形与腔内油压呈线性关系。     

并联混合动力汽车扭矩管理的模糊控制与仿真

并联混合动力汽车中内燃机和电机之间存在动力的耦合和分离过程,能量管理策略比较复杂。为了进一步合理分配内燃机和电机的动力输出,增强其能量管理策略的鲁棒性,文中分析了电辅助控制策略的不足,提出了基于模糊逻辑控制的包含驾驶员扭矩识别和蓄电池功率平衡的并联混合动力汽车扭矩分配策略,并利用ADVI SOR2002的仿真环境,完成了该模糊逻辑扭矩控制模块的仿真。结果表明,模糊逻辑控制策略满足控制目标,对提高汽车的动力性和燃油经济性、改善排放、保证蓄电池的充放电功率平衡有明显的作用。     

SPFB3—323外分流液力机械变矩器的设计与研制

本文对外分流液力机械变矩器的多种方案作了分析,确定FB_2-323变矩器为原型变矩器。同时,计及行星传动中能量损失,进行了SPFB_2-323变矩器的特性计算,并且成功地研制出这种新型变矩器的样品。     

基于ANSYS的液力变矩器叶轮模态分析

针对叶轮系统结构设计优化问题,利用有限元分析软件ANSYS Workbench对某型汽车液力变矩器叶轮建立有限元模型进行模态分析,得到工作轮的各阶固有频率及相应振型．同时考虑结构应力刚化和旋转软化对运动状态下“叶轮固有频率的影响,分析了可能产生的共振频率,为变矩器的结构改进、结构优化和动力修改提供理论依据。     

双状态无级变速车辆起步控制

通过发动机和液力变矩器台架试验，采用拟合的方法得到发动机及变矩器模型，建立了用变矩器作起步装置的双状态无级变速传动系统动力学模型，提出了串联式双状态无级变速车辆起步控制策略和液力变矩器锁止离合器闭锁解锁控制规律，并进行了计算机仿真。     

基于Simulink/Cruise的6AT液力变矩器闭锁性能联合仿真

根据液力变矩器的工作原理及闭锁条件,制定液力变矩器控制策略。利用Simulink建立液力变矩器控制模型,并利用Cruise和Simulink进行联合仿真,验证控制策略的可行性。仿真结果表明,液力变矩器控制模型正确,闭锁离合器能够准确按照闭锁条件闭锁,并且可以显著改善车辆的燃油经济性和排放性能。本文的研究可以为液力变矩器的闭锁研究提供一定的理论依据。     

Engine clutch torque estimation for parallel-type hybrid electric vehicles

This paper mainly focuses on the accurate estimation of the torque transferred through the engine clutch installed between the engine and the drive motor in parallel-type hybrid electric vehicles. The estimation of the engine clutch torque primarily relies on the forward-direction observer which uses the nominal engine net torque information. To overcome the limitation of using the nominal engine torque information that it may not be accurate during the transient states or due to the influence of external disturbance such as the road condition and wind, the forward-direction observer is supplemented by the use of reverse-direction observer which uses the driveline model and wheel speed measurements. In addition, the drive motor torque information is used to calibrate the nominal engine torque during the idle charging state, so that the driveline characteristic unique to parallel-type hybrid electric vehicle can be utilized to increase the estimation accuracy. Finally, the estimation performance of the designed observer is tested via simulation and experiments based on a real vehicle.     

Improved optimal controller for start-up of amt trucks in consideration of driver’s intention

A linear-quadratic optimal controller is proposed for vehicle start-up, which is designed as a linear feedback form of the states and the measured (estimated) disturbances. The requirements of less friction loss and less driveline shock are represented by the weighting matrices of the cost function. The driver’s intension is also considered and the controller gains are adjusted on-line accordingly. The designed control strategy is tested on a complete powertrain simulation model. Through large amount of simulations, it is verified that the system is robust to the variations of driving conditions, such as variation of vehicle mass and road grade. It is also shown that the control performance is influenced greatly by the estimation error of engine torque and clutch torque, and the acceptable level of mean estimation error is about ±10%.     

Observer-based clutch disengagement control during gear shift process of automated manual transmission

A clutch disengagement strategy is proposed for the shift control of automated manual transmissions. The control strategy is based on a drive shaft torque observer. With the estimated drive shaft torque, the clutch can be disengaged as fast as possible without large driveline oscillations, which contributes to the reduction of total shift time and shift shock. The proposed control strategy is tested on a complete powertrain simulation model. It is verified that the system is robust to the variations of driving conditions, such as vehicle mass and road grade. It is also demonstrated that the revised system with switched gain can provide satisfactory performance even under large estimation error of the engine torque.     

液力变矩器叶片设计的准三维理论与方法

本文推导了适合于液力变矩器叶片设计的S_1流面改进流线曲率法计算方程,提出了流场判别准则和环量分配原则。在此基础上,提出了用多个S_1流面积叠进行变矩器叶片设计的准三维方法,以及在传统的叶片设计方法中加入流场计算环节的叶片设计新途径。并把利用本文提出的设计方法和利用传统的设计方法所设计出来的YB300变矩器进行了特性试验对比,结果表明:新提出的设计方法与传统方法所设计出的变矩器相比,最高效率提高了1.80%,而其它性能基本相同。     

液力变矩器计算机辅助设计与制造

本文简述了液力变矩器设计与制造的研究和发展，以及计算机在液力变矩器设计与制造行业的应用，指出了存在的问题；建立了液力变矩器计算机辅助设计与制造的一体化系统；实现了液力变矩器性能预估、叶形判断与叶栅系统入，出口参数计算的有机统一。     

液力变矩器机器人FCAW技术

根据液力变矩器上盖连接块焊接接着形式、动平衡使用特点、焊缝金属高性能指标、焊接质量零缺陷控制要求，采用机器人＋变位器柔性焊接系统，解决了焊缝几何尺寸一致性、空间位置对称性、填充金属均匀性的技术关键。并阐述了机器人系统的焊接电源、变位顺和送丝机构的合理配置，通过工艺试验确定了液力变矩器上盖连接块ＦＣＡＷ工艺参数以及防止焊接缺陷的工艺措施。     

Idle speed controller based on active disturbance rejection control in diesel engines

This study proposes a design for an idle speed controller to compensate for varying engine load and friction torque in passenger car diesel engines. An active disturbance rejection control (ADRC) framework, comprised of a disturbance compensator and a feedback controller, is applied to an idle speed controller to compensate for disturbances such as engine load and friction torque. In addition, a feedforward compensator is designed into the ADRC framework to improve disturbance rejection performance. The proposed controller is validated by engine and vehicle experiments and the experiment results are compared with a commercial controller.     

Torque coordinating robust control of shifting process for dry dual clutch transmission equipped in a hybrid car

For a hybrid car equipped with dual clutch transmission (DCT), the coordination control problems of clutches and power sources are investigated while taking full advantage of the integrated starter generator motor's fast response speed and high accuracy (speed and torque). First, a dynamic model of the shifting process is established, the vehicle acceleration is quantified according to the intentions of the driver, and the torque transmitted by clutches is calculated based on the designed disengaging principle during the torque phase. Next, a robust H_∞ controller is designed to ensure speed synchronisation despite the existence of model uncertainties, measurement noise, and engine torque lag. The engine torque lag and measurement noise are used as external disturbances to initially modify the output torque of the power source. Additionally, during the torque switch phase, the torque of the power sources is smoothly transitioned to the driver's demanded torque. Finally, the torque of the power sources is further distributed based on the optimisation of system efficiency, and the throttle opening of the engine is constrained to avoid sharp torque variations. The simulation results verify that the proposed control strategies effectively address the problem of coordinating control of clutches and power sources, establishing a foundation for the application of DCT in hybrid cars.     

汽车自动变速器锁止离合器控制策略

分析了锁止离合器的典型结构和锁止点的选取，以及采用车速和发动机节气门开度为主要参数，辅之以其他参数，共同确定液力变矩器锁止的控制策略。     

Damping Performance of Power Transmission System with Hydraulic Torque Converter

In this work three first-order nonlinear, nonstationary differential equations describing a hydraulic torque converter in a power transmission system are used.

A linear model is obtained on the basis of these equations. This model is verified both theoretically and by an experimental test. On the basis of the calculations the torsional damping was determined. This permitted the damping performance of a power transmission system with a hydraulic torque converter to be defined and established.