集成多挡变速器的电传动系统多变量耦合扭振特性分析与控制研究

Electric vehicles equipped with a multi-speed transmission can effectively improve the driving range. However, the nonlinear torsional vibration characteristics of the electric drive system integrating a 2-speed automated manual transmission and a permanent magnet synchronous motor can lead to poor smoothness and comfort of the gearshift process of the multi-speed transmission based electric drive system. Based on this, the analysis of the multi factors coupling nonlinear torsional vibration characteristics will be investigated and the corresponding control strategy will be developed in this project. Firstly, the torsional vibration analysis oriented dynamic model of the electric drive system is developed, and the nonlinear stiffness and damping of the half shaft are considered. Secondly, the influences of several time varying parameters on the nonlinear torsional vibration behavior of the electric drive system are analyzed, and the state transition matrixes for the different gearshift stages are built for the transmission and driving motor. Then, the dynamic simulation of the torsional vibration model is carried out after the order reduction process. Further, the active and passive torsional vibration control strategies are discussed under the excitation of multi coupling influence factors. The passive control strategy is to optimal the output characteristics of the driving motor torque and the stability of the switching of different gearshift stages so that the sources of the torsional vibration are reduced. The active control strategy is to adjust the torque of the driving motor slightly so that the generated torsional vibration can be suppressed. The results can reveal the nonlinear torsional vibration mechanism of the multi-speed transmission based electric drive system, and it is beneficial to develop control strategies that lower the torsional vibration phenomenon. The research can lay a theoretical foundation for the development and optimization of multi-speed transmission based electric drive system.

电动汽车装用多挡变速器可有效提高其续航里程，但电机+多挡变速器构成的电传动系统中存在的非线性扭振现象，使得换挡平顺性和舒适性显著变差。针对该问题，开展多因素耦合作用下电传动系统非线性扭振特性分析与控制研究。包括：建立面向电传动系统扭振特性分析并考虑半轴非线性刚度和阻尼的数学模型，分析多项时变因素对电传动系统非线性扭振特性的影响，研究换挡过程变速器、电机各阶段工作域切换的状态转移条件，进行扭振模型的降阶求解与动力学仿真研究；研究换挡平顺性控制策略，建立多重耦合激励作用下换挡平顺性最佳控制方法，提出主被动控制策略，即以改善电机输出特性和换挡过程工作域切换稳定性为目标的被动控制策略和产生扭振后对电机输出转矩进行微调的主动控制策略。本项目的研究有利于揭示集成多挡变速器的电传动系统换挡条件下非线性扭振特性影响机理与调控方法，为电传动系统的优化控制与应用奠定科学理论基础。

纯电动汽车电传动系统采用多挡变速器可有效提高其续航里程和驾驶性能，但现有驱动电机+多挡变速器所组成的电传动系统的换挡性能存在提升的空间，特别是非线性因素所导致的扭振现象使得传动系统平顺性和舒适性变差。本项目针对该问题，提出一种基于双电磁直线执行器的新型换挡系统，建立了考虑多因素耦合的电传动系统数学模型，特别是考虑了半轴非线性刚度和阻尼，研究了新型换挡系统的换挡特性，分析了非线性因素对换挡过程特别是换挡性能的影响，提出最优换挡力方法并设计了轨迹跟踪控制方法，研究了换挡过程各个阶段的特性及工作切换的状态转移条件，根据该电传动系统存在的非线性因素建立扭振模型，分析了非线性因素的影响机理并设计了合适的控制方法降低各非线性因素对换挡性能的影响，试验结果验证了控制方法的有效性。最后通过分析扭振模型，研究了电传动系统的扭振特性，并通过驱动电机控制方法设计有效抑制了传动轴的扭振现象。本项目的研究有利于推进多挡电传动系统的技术进步，揭示电传动系统非线性扭振的机理与控制方法，为电传动系统性能优化与应用奠定科学理论基础。