四轮独立电动轮直驱汽车底盘系统机电耦合摆振控制

Setup the mechanical-electronic coupling nonlinear self-excited shimmy models for an electric vehicle(EV) which is equipped with the 4 wheels independent wheel-side motors drives and the multi-wishbones suspension chassis. Put more attentions on the self-excited oscillation effects which come from the control strategies for the basic running functions of the vehicle. Those basic functions are necessary for running of a 4-wheel independent motors drived vehicle and all are electric-controlly realized. The functions include the Electric Differential for vehicle corcering, Traction Control System for skidding prevention, Direct Yaw-moment Control for lateral stabilization, etc. Study the mathematics analysis and the visionable simulation methods. The Differential Geometric methods which are suitable to analyze the global and local characteristics details of the nonlinear systems will be used, they include the Spectral Element Method for system stability analysis, the center manifold local stability analysis about the non-hyperbolical equilibrium. Developing the singularity and high order bifurcation analysis under the parameters variation, master the bifurcation and limit circles. Study the needed adaptivity about the system shimmy control and the EV's driving functions control, especially about its stabilization, the dimension decreasing and control decoupling for this high dimension nonlinear system according to the strategies of Anti-Disturbance Control. Modeding the clearances distributied in the mechanism and the variations of the tyre-road relations as the composite multi-source disturbances with the uncertain. The high dimension characteristic of the system is because of those distributied disturbances. The local feedback linearization and local stabilization will be studied as well. Because those composite multi-source uncertain disturbances, the system will have the un-determinated characteristics about its parameters and the disturbance power, so it is necessary to consider the global stabilization and the adpative robust control law. Under the conditions of get the efficient analysis methods, master the main facters and find the reasonable control logic and allocation, we will be able to get the chassis mechanism design law, the control and manage strategies for the basic running functions control of the vehicle, and decrease the probability of the shimmy arise.

建立独立电动4轮驱动多连杆悬架底盘系统的机电耦合摆振问题非线性颤振动力学模型，关注4轮独立驱动行驶要求的电子差速等电控策略对系统自激颤振的效应；研究对应数学分析及可视化分析方法，使用可把握非线性系统整体特征和局部细节的微分几何方法，包括稳定性分析谱单元法，非双曲平衡点中心流形局部稳定性分析方法，发展参数摄动下奇异性和高阶分叉分析，把握其极限环特征；研究摆振控制和电动车驱动功能控制算法逻辑上应具有的协调；特别研究系统的可镇定性，建模轮胎路面特性和机构间隙等为多源复合不确定性干扰，按ADC方式处理干扰特征导致的高维非线性系统的降维和解耦，局部反馈线性化及局部镇定；针对干扰和参数不确定性，考虑全局镇定和自适应鲁棒控制准则；在获得有效分析方法、把握主要因素和合理控制分配逻辑基础上，研究出能降低系统摆振发生几率和有效应对摆振的底盘机构设计准则和独立电动轮4轮驱动的功能控制逻辑管理策略。

基于轮毂电机四轮独立驱动电动汽车（4WID），研究发展了新的非线性摆振动力学模型：综合了悬架绕纵轴的摆动和主销后倾角的影响，采用张弦模型的假设来推导约束公式；考察了轮毂电机的引入导致的簧下质量增大对系统摆振的影响；稳定性分析结果与数值仿真结果完全吻合，证明了模型的可靠性；此外，该模型可以分析任意参数对系统动力学性能的影响。.轮胎模型的使用是汽车前轮摆振分析的一个重要的因素。分别采用魔术公式和时滞轮胎模型来估算侧向力，并根据刷子模型和张弦模型推导约束公式，对此四种非线性模型进行了非线性和拟线性化的动力学分析和比较。总的来说，两种轮胎模型得到的稳定性图结构类似、范围接近，但它们却又很不同：从原理上说，魔术公式将轮胎接地印记假设为一条直线（只在尾部引入了由滑移而产生的非线性），而时滞轮胎模型不限制轮胎接地印记的形状；从结果来看，时滞轮胎模型可以描述尤其高速情况下更丰富的动力学行为。.为了研究独立悬架车辆的摆振问题，建立了双叉臂结构独立前悬地面车辆摆振系统8自由度动力学模型，并考虑了车身的侧倾运动、俯仰运动、横摆运动和垂向运动与汽车前轮绕其主销的摆振之间的耦合作用。研究了摆振模型的分岔特性，分析了极限环产生的条件。采用MATLAB软件进行仿真，讨论了车速，车身质量，车身重心前后位置和汽车前悬架弹簧倾角等参数对转向轮摆振和车身运动的影响。分析和仿真结果证明了车身运动与转向轮摆振之间有相互的耦合作用，也证明了结论的正确性。.为车辆摆振问题测试的难题，进行了试验用四轮独立驱动电动汽车（4WID）样车研发，确定了整车的总体布置和整车控制系统，全新自开发的控制算法及动力电池管理系统。利用有限元方法对车架进行校核和优化设计。对悬架系统进行设计并利用多体动力学虚拟样机进行优化分析。建立整车虚拟样机模型，根据汽车操纵稳定性试验方法对整车进行操纵稳定性分析及摆振分析评价。根据试验车的设计准则，完成了试验车的装配并成功完成自有控制算法的控制系统及动力总成的研发及总调，进行了各种工况的路试。