无同步冲击的AMT车辆双模态自适应起步控制研究

发布时间：2018-03-03 14:36

本文选题：自动机械变速器　切入点：双模态控制策略　出处：《华南理工大学》2016年博士论文　论文类型：学位论文

【摘要】：自动机械变速器(Automatic Mechanical Transmission,AMT)以其在燃油经济性、扭矩容量、技术可实现性、制造成本等方面的突出表现,在商用车领域得到了成功应用。然而,其在起步能力、换挡品质等性能指标方面表现较差,尤其是起步阶段离合器接合时存在不容忽视的同步冲击而产生的瞬时顿挫现象,严重影响驾乘人员乘坐舒适性,使商用车起步平顺性广受诟病,也制约其在乘用车领域的推广应用。目前AMT车辆常用起步控制策略研究主要集中于提升离合器连续滑摩接合阶段的冲击度与滑摩功等性能指标,忽视了离合器同步瞬间引起的同步冲击,无法解决由此引起的瞬时顿挫而导致的车辆起步平顺性差的问题,制约了AMT车辆起步性能的提升。鉴于此,本文提出无同步冲击的AMT车辆双模态自适应起步控制策略及其分数阶控制方法,并对其原理及实现方法开展深入研究。主要内容如下:开展基于分离轴承位置和动态摩擦系数的离合器动态转矩传递机理及建模研究,为定量确定起步过程离合器接合规律提供理论依据。首先,分析离合器膜片弹簧及波形弹簧片的变形特性,研究离合器接合过程中的压力传输关系,建立基于分离轴承位置的离合器摩擦面压紧力模型;其次,基于摩擦学相关理论,分析离合器滑摩面正压力、滑摩转速、表面温度等因素对离合器摩擦系数的影响规律,依据实验数据,基于极限学习机(Extreme Learning Machine,ELM)算法,建立了包含45个隐含层神经元,具有高精度、高实时性特点的离合器动态摩擦系数神经网络预测模型,并针对实时预测动态摩擦系数所需的离合器表面温度难以直接测量的问题,基于热惯性效应原理以及滑摩功与温升之间的关系,建立了基于滑摩功的离合器表面温度迭代预测模型。提出了无同步冲击的AMT车辆双模态自适应起步控制策略。该策略以滑摩角速度为同步冲击控制模态决策参量,先后实施无同步冲击为约束的起步综合性能最优控制和无同步冲击为优化目标的滚动预测控制,确定起步过程离合器动态目标转矩。首先,当滑摩角速度高于模态决策参量阈值时,以冲击度、滑摩功、发动机转矩和起步时间等起步性能参数建立的二次型性能指标泛函为优化目标,基于线性二次型最优控制理论,设计二次型最优控制器,研究二次型性能指标权系数对起步性能的影响规律,提出以无同步冲击为约束的性能指标权系数确定方法,建立发动机目标转速、冲击度权系数和发动机转矩权系数关系MAP,结合驾驶员起步意图,实现了无同步冲击为约束的起步综合性能最优模态控制;其次,分析了系统参数摄动对同步冲击的影响,当起步过程进行到滑摩角速度等于或低于模态决策参量阈值时,以无同步冲击为优化目标,基于滚动时域控制原理,设计目标冲击度实时滚动预测控制器,通过滚动预测实现对系统参数摄动的自适应,消除因此而导致的同步冲击问题,实现了无同步冲击为目标的滚动预测模态控制;再次,分析了双模态控制策略的模态决策参量阈值大小对车辆起步性能的影响;最后,针对一款AMT乘用车,运用Matlab/Simulink软件,建立整车仿真模型,仿真研究了多种起步工况下基于双模态自适应起步控制策略的车辆起步性能,结果表明该策略在保证起步综合性能最优的同时,实现了无同步冲击的车辆起步。针对离合器系统中膜片弹簧载荷-变形特性的非线性、动态摩擦系数的时变性、外界扰动的不确定性等因素引起离合器分离轴承位置跟踪控制精度低,鲁棒性差,导致车辆起步性能下降的问题,基于分数阶微积分理论,提出了基于模糊分数阶滑模控制(Fuzzy Fractional Order Sliding Mode Control,FFOSMC)的离合器执行系统控制方法。通过选取光滑且具有缓慢传递能量特点的分数阶微分滑模面,设计等效加切换的控制律和滑模开关增益自整定模糊控制器,实现了分离轴承位置跟踪控制进入滑动模态时的抖振抑制,提高了分离轴承位置控制的鲁棒性、准确性和稳定性,提高了车辆起步性能。基于D2P MotoHawk快速原型开发平台,研制AMT台架实验系统,开展实验研究,验证了基于分数阶微积分理论的FFOSMC控制器对提高离合器分离轴承位置跟踪精度的有效性,验证了双模态起步控制策略对抑制同步冲击,提高车辆起步平顺性的有效性。
[Abstract]:Automatic mechanical transmission (Automatic Mechanical Transmission, AMT) on the fuel economy, torque capacity, technology feasibility, outstanding manufacturing cost, has been successfully applied in the field of commercial vehicles. However, in the initial capacity, poor performance in terms of shift quality and other performance indicators, especially instantaneous pause phenomenon when the clutch jointing phase synchronous impact can not be ignored and the serious impact on the occupants comfort, the ride comfort of commercial vehicle starting is widely criticized, but also restricted its application in the passenger area. The AMT vehicle starting control strategy mainly focus on continuous sliding friction lifting clutch engaging stage of shock and the friction work performance, ignoring the impact caused by the synchronous synchronous clutch moment, can not solve the frustration caused by the instantaneous vehicle starting by The problem of poor smoothness, restricting the initial AMT vehicle performance improvement. In view of this, the AMT vehicle without synchronous impact of double mode adaptive control strategy of starting and fractional order control method proposed in this paper, and the principle and method to carry out in-depth research. The main contents are as follows: the development of Research on the mechanism and modeling of dynamic torque transmission clutch separation bearing position and dynamic friction coefficient based on the determination of clutch engagement law provides a theoretical basis for the quantitative analysis. Firstly, the deformation characteristics of the diaphragm spring clutch and waveform spring, pressure transmission of the clutch engagement process, establish the model of clutch friction surface pressing force based on the position of the separation bearing; secondly, the related theory of tribology based on the analysis of clutch slip surface pressure and speed of sliding friction, influence factors of surface temperature on the friction coefficient of clutch, according to The experimental data based on extreme learning machine (Extreme Learning Machine ELM) algorithm, a contains 45 neurons in the hidden layer, with high precision, dynamic prediction model of clutch friction coefficient of neural network with high real-time, clutch surface temperature and for the real-time prediction of the dynamic friction coefficient is difficult to directly measure the relationship between problems. The effect of thermal inertia and friction work principle and Wen Sheng based on the surface temperature prediction model is established for clutch friction work based on iteration is proposed. The AMT vehicle without synchronous impact of double mode adaptive start control strategy. The strategy with slip angular velocity synchronization control modal parameters impact decision-making, implementation has no impact for synchronization the optimal control performance constraints and start without synchronous impact rolling forecast optimization control target, determine the clutch dynamic target torque first, When the slip angle speed is higher than the modal parameters of decision threshold, the degree of impact and the friction work of the two type performance index function is established starting performance of the engine torque and starting time as the optimization objective, linear quadratic optimal control in two based on the theory, design two optimum control device, the influence of the two type the performance index weight coefficient on the starting performance, put forward the method for determining the impact of non synchronous performance index weight coefficient constraint, a target engine speed, the impact of the weight coefficient and the relationship between the engine torque coefficient MAP, combined with the driver's starting intent to realize non synchronous control of the impact modal comprehensive performance start optimal constraint; secondly, analysis the system parameter perturbation effect on synchronous shock, when starting to slip angular velocity is equal to or lower than the modal parameters of decision threshold, with no synchronization impact for the optimization goal, base In the receding horizon control principle, design target impact real-time scrolling through the realization of adaptive predictive controller, system parameter perturbation prediction of rolling, resulting in elimination of synchronous impact problems, has no impact to the target prediction mode of synchronous rolling control; thirdly, analyzed the influence of the size parameters of double threshold decision modal modal control strategy the initial performance of the vehicle; finally, according to a AMT passenger car, the use of Matlab/Simulink software, establishes the vehicle simulation model, the simulation of dual mode adaptive vehicle control strategy based on step starting performance under various starting conditions, the results show that the strategy can guarantee the initial optimal comprehensive performance at the same time, the vehicle starts without synchronous impact for nonlinear system - clutch diaphragm spring load deformation characteristics, time-varying dynamic friction coefficient, the disturbance of uncertainty Clutch bearing position tracking control accuracy caused by low qualitative factors such as poor robustness, resulting in a decline in vehicle starting performance, based on the fractional calculus theory, is proposed based on Fuzzy fractional order sliding mode control (Fuzzy Fractional Order Sliding Mode Control, FFOSMC) execution control system of clutch. By fractional differential and smooth sliding mode selection with the slow energy transfer characteristics, design and equivalent switching control law and sliding switch gain self-tuning fuzzy controller to realize the position tracking control of buffeting into separate bearing sliding mode suppression, improves the robustness of the separation bearing position control, accuracy and stability, improve the vehicle performance. D2P MotoHawk quick start the prototype development platform based on the development of AMT platform experiment system, experimental study was carried out to verify the theory of fractional calculus based on FF The effectiveness of OSMC controller for improving the position tracking accuracy of clutch release bearing is verified. It is verified that the dual mode start control strategy is effective for restraining synchronous impact and improving vehicle starting smoothness.

【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：U463.2

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