分布式驱动电动汽车电动轮-悬架系统高频振动特性研究

Distributed Electric Drive Vehicle becomes the develop direction of future vehicles with its advantages of typical component and performance, and the critical part named "Electric Wheel-Suspension System" has been the focus of development and research. The crucial scientific issues such as variation of motor torque fluctuation under complicated driving conditions, dynamic characteristics of high frequency vibration theory and test research of electric wheel-suspension system are the premise of research about Distributed Electric Drive Vehicle and also lay a solid foundation of vehicle simulation analysis, system design and dynamic control. There is no systematic and in-depth investigation operated by relevant research units at present, so to launch this research program has significant theoretical sense and creativity. Electric wheel-suspension system in the Distributed Electric Drive Vehicle is so intricate due to the multi-physics field coupling. The dynamic model of drive motor torque fluctuation is established to analyze the coupling dynamics of the motor and driving wheel. The dynamical model of the electric wheel is set up. And dynamic characteristics of high frequency vibration of electric wheel-suspension system under complicated operating conditions is to be analyzed in order to illustrate transfer characteristics of suspension and variation of tire-road adhesion performance under transient operation conditions. Finally, the optimized solution is proposed for reducing torque fluctuation, to design new structure of wheel-suspension system, to improve its vibration behaviour. So to start with this research program has significant academic and engineering application values.

分布式驱动电动汽车以其特有的结构及性能优势成为未来汽车发展的方向，而其关键部件"电动轮-悬架系统"成为开发研究的核心。复杂行驶条件下的电机转矩波动变化规律，电动轮-悬架系统高频动态振动特性理论与试验分析等关键科学问题的研究是开展分布式驱动电动汽车研究的前提，也是对车辆进行仿真分析、系统设计及动力学控制的基础。目前还没有相关单位做过系统和深入的研究，所以开展本项目的研究具有重要的理论意义和创新性。 电动轮-悬架系统是一个多物理场耦合的复杂系统，建立驱动电机转矩波动动态模型，开展电机与轮胎耦合动力学分析，建立电动轮动力学模型，分析电动轮-悬架系统高频动态振动特性，揭示瞬态工况下电动汽车悬架的传递特性和轮胎-路面附着特性变化规律，并提出减少转矩波动影响的优化方案，确定新型电动轮-悬架系统结构，改善系统振动特性，为分布式驱动汽车的理论设计研究提供有效工具，所以本项目具有重要学术和工程应用价值。

本项目针对分布式驱动电动车电动轮-悬架系统在电磁激励下所面临的高频动力学问题进行研究，主要分析了电机转矩波动激励下系统高频阶次振动特性并提出了主动阻尼和自适应卡尔曼滤波的减振策略。. 研究工作主要分为以下四方面内容：（1）轮毂驱动电机转矩波动规律及影响因素分析，具体包括a)建立了考虑死区和转角误差的电机控制系统建模并揭示了电流谐波特征分析;b)耦合考虑电流谐波和电机非理想结构特征分析了转矩波动规律；c)通过台架试验验证了电流谐波和转矩波动特征；（2）电动轮系统高频建模及动力学特性分析，具体包括a) 考虑衬套、悬架和轮胎高频动力学特性建立了电动轮系统纵-扭耦合动力学模型；b)通过关键部件特性试验辨识了模型中主要参数；c) 确定了电动轮系统主要模态特征进而解释了系统高频振动机理；（3）不同工况下电动轮耦合动力学行为及高频振动特性分析，具体包括a) 分析了稳态工况下电动轮系统振动，揭示了转矩波动下纵向振动的阶次特征和高频特性；b) 分析了瞬态工况下电动轮系统振动，揭示了瞬变转矩下车身抖动及簧下质量冲击问题；c) 考虑电动轮系统的机电耦合效应，分析了电磁参数和结构参数对系统振动的耦合影响机理；（4）转矩波动削弱及高频振动抑制的方案设计，具体包括a) 设计了自适应卡尔曼滤波降低了转矩波动，从激励源角度降低了高转速下振动；b) 设计状态反馈的主动阻尼控制器，通过抑制共振改善了中低转速下的振动特性。. 本项目以新型的轮毂电机驱动构型为研究对象，从电磁激励、高频动力学和主动减振控制等方面透彻地揭示了电动轮系统存在机电耦合动力学问题，并给出了一套行之有效的动力学主动优化方案。项目针对高频机电问题提出了一套完整的分析流程和研究方法，具有理论意义和学术价值；项目给出了分布式驱动电动汽车的关键动力学问题的解决思路，具有实际工程意义。