混合动力汽车模式切换过程瞬态性能分析与优化控制

The essential operation of energy management system for hybrid electric vehicles is mode switching, which is also the most critical method to improve fuel economy and to reduce emission. Moreover, coordination control of multiple electromechanical power sources can directly affect the overall efficiency of HEV driveline and the dynamical performance. So, it makes great sense to do research on it. However, the transient behavior of mode switching is very complicate because a hybrid electric vehicle consists of several nonlinear and strong coupled components. The coordination control of mode switching can be concluded as a class of nonlinear and multi-objective optimization problem with constraints, which is too difficult to be solved by traditional methods. So, it has became one of the most difficult problems of current research. Considering the mode switching nature of hybrid electric vehicles, the dynamical modelof full vehicle, which takes into account of the mode switching dynamics, will be constructed. Then, the mechanism about the effects of mode switching transient behavior on the dynamical performance of the driveline and full vehicle for HEVs will be analyzed based on theory of differential equation oscillation. The coordination control algorithm will be designed by generalized multi-objective optimal control theory. Finally, effectiveness of the proposed control algorithm will be validated. This proposal is a frontier research involving multi-disciplines of system science, control theory and vehicle engineering. This research not only make great sense in paving the way to overcome the critical necklace in the industrilization process of HEVs, but also can significantly promote the development of theory and application for related subjects.

工作模式切换是混合动力电动汽车能量管理系统最为本质的操作，是提高燃油经济性和排放性能的最关键手段。模式切换过程中多机电动力源的协调控制则直接关乎混合动力电动汽车驱动系统综合效率和车辆性能，对其研究意义重大。混合动力电动汽车由多个非线性、强耦合部件构成，其模式切换过程瞬态特性极为复杂，其协调控制问题可归结为一类有约束、非线性、多目标优化问题，常规方法难以解决，已成为当前研究的难点之一。本项目拟从混合动力汽车模式切换本质入手，建立考虑模式切换动态的整车动力学模型，基于微分方程振荡理论深入剖析切换瞬态行为对混合动力电动汽车驱动系统及整车动态性能的影响机理，基于广义多目标优化控制理论设计可实车化的动态协调控制算法，并搭建平台予以验证。本项目属系统科学、控制理论和车辆工程多学科交叉研究，不仅有望为突破混合动力电动汽车产业化关键瓶颈提供新途径，同时对相关学科的理论和应用研究也将产生显著促进作用。

混合动力电动汽车（HEV: Hybrid Electric Vehicle）兼具传统燃油汽车与纯电动汽车的优点，已成为新能源汽车工业发展的主流方向。HEV模式切换过程中多机电动力源之间的动态协调与优化控制直接影响汽车的驾驶性、舒适性和安全性等。本项目按立项时的申请书计划顺利执行，全面研究了HEV动力系统建模、参数优化匹配、能量管理策略、HEV振动系统分析、转矩协调控制等关键科学与技术问题，以提高HEV的性能。.（1）研究了HEV动力系统建模与参数优化匹配.研究了动力系统的建模和参数优化匹配问题，提出了基于组合矩阵的HEV参数优化匹配方法。应用权重系数法，将多目标优化问题转化为单目标优化问题，最后完成了仿真验证。所提方法为能量管理策略研究提供优化的整车构型，在电动汽车工程优化设计中具有较高的应用价值。.（2）设计了基于路况模型的Plug-in混合动力汽车能量管理策略.以某校车行驶路线为例，研究了基于路况模型的Plug-in混合动力汽车能量管理策略。针对行驶路线，建立了其行驶循环的路况模型，在此基础上以油耗最低为指标，运用动态规划算法设计了基于长、短路况的能量管理策略。结果表明所设计的能量管理策略能够显著提高Plug-in混合动力汽车的燃油经济性，具有更强的实用性。.（3）分析了HEV的振动问题.HEV中振动现象对车辆的NVH(Noise, Vibration and Harshness)乃至驾驶性能影响较大，而HEV振动系统可简化抽象为一类具有时滞的二阶阻尼微分方程，故分析了二阶阻尼时滞微分方程的振动性，为解决HEV的振动问题提供了理论借鉴和参考。.（4）提出了基于改进模型预测控制的HEV转矩协调控制策略.为了实现无缝的模式切换，本项目将离合器转矩作为一个优化变量，提出了基于改进模型预测控制的HEV转矩协调控制策略，并研究了模型预测控制器对设计参数的敏感性。结果表明所提方法可以实现更小的车辆冲击度、更少的驱动系转矩中断和更小的离合器滑摩损耗。.（5）搭建了基于AVL Cruise的HEV动力系统仿真实验平台.基于Matlab、Advisor、Cruise等搭建了HEV的联合仿真实验平台，完成了本项目所提出的HEV建模、能量管理策略、转矩协调控制等方法的平台验证。.本项目的研究不仅对突破HEV产业化的关键瓶颈意义重大，而且对相关理论和应用研究也有显著促进作用。