轮毂电机驱动电动汽车耦合动力学特性参数灵敏度分析

以两后轮轮毂电机驱动电动汽车为研究对象,考虑车辆动力学纵向、横向和垂向的主要耦合因素,建立了整车16自由度非线性耦合动力学模型;并基于Adams/Car对模型的正确性进行了验证。在此基础上,以侧向加速度、横摆角速度、侧倾角、俯仰角、垂向加速度及轮毂电机定转子间的相对位移为评价指标,对前后悬架刚度、车身与电机质量比、定转子质量比、轴承与轮胎刚度比对动力学评价指标的影响进行分析。在分析各项系统参数对动力学评价指标影响的基础上,采用扰动法对各项系统参数进行灵敏度分析。结果表明,对侧向加速度和横摆角速度影响最大的均为定转子质量比,灵敏度分别为4×10-3和1.21×10-2;前悬架刚度对侧倾角和垂向加速度的影响最大,灵敏度分别为2.69×10-2和2.06×10-2;后悬架刚度对俯仰角的影响最大,灵敏度为2.9×10-3;定转子质量比对两轮毂电机定转子间的相对位移最为敏感,灵敏度分别为9.550 2×10-7和1.007 3×10-6。为后续轮毂电机驱动电动汽车结构参数优化设计及动力学控制的进一步研究奠定了理论基础。

Parameter Sensitivity Analysis of Coupling Dynamics of In-Wheel Motor Driving Electric Vehicle

Considering the vehicle dynamics of the longitudinal, lateral and vertical coupling relation, a 16 degree-of-freedom nonlinear dynamics model is established for in-wheel motor driving electric vehicle, which accuracy is verified by using Adams/Car software. Based on the correct model, the dynamic evolution indicators for lateral acceleration, yaw rate, roll angle, pitching angle and body vertical acceleration are selected. Those evolution indicators are applied to analyze the effects of some important system parameters, such as the stiffness of suspension, the mass ratio of the body to the in-wheel motor, the mass ratio of the stator to the rotor, the stiffness ratio of the bearing to the tire and the relative displacement between the stator and the rotor. Based on the analysis of the system parameters influence on the dynamic indicators, the sensitivity analysis of system parameters are conducted by adopting the perturbation method. The results show that the stator-to-rotor mass ratio is the greatest influence factor of the lateral acceleration and yaw rate, with the corresponding sensitivities being up to 4E-3 and 1.21E-2, respectively; that the front suspension stiffness is the greatest influence factor of the roll angle and body vertical acceleration, with the corresponding sensitivities being up to 2.69E-2 and 2.06E-2, respectively; that the rear suspension stiffness is the greatest influence factor of the pitching angle, with the corresponding sensitivities being up to 2.9E-3; and that the stator-to-rotor mass ratio is the most sensitive factor of the relative displacement between the stator and the rotor, with the corresponding sensitivities being up to 9.5502E-7 and 1.0073E-6, respectively. It will build foundation for the further study of subsequent system parameters optimization and dynamic control.