基于柔性多体动力学的地铁车辆半主动控制

为了对地铁车辆的运行性能实现更准确的评估和更有效的优化，借助有限元理论和子结构理论建立了车体和转向架构架等关键零部件的柔性动力学模型；基于天棚半主动控制算法和柔性多体动力学理论，建立了考虑半主动控制悬挂的地铁车辆刚柔耦合动力学模型；考虑轨道随机不平顺的影响，研究了半主动控制悬挂以及结构柔性对地铁车辆运行稳定性和乘坐舒适性的影响。研究结果表明:相对于传统的悬挂装置，天棚半主动控制极大降低了车辆的振动加速度，并使其变化趋势更加平缓，对车辆的低频振动有明显的抑制作用；采用本文的研究参数，天棚半主动控制在直线段可使车辆的垂向Sperling指标和垂向振动加速度均方根(RMS)分别降低26.8%和7.5%，使车体横向Sperling指标和横向振动加速度RMS分别降低8.8%和4.9%，而在曲线段，天棚半主动控制可使车辆垂向Sperling指标和垂向振动加速度RMS分别降低25.1%和5.7%，使横向Sperling指标和横向振动加速度RMS分别降低15.6%和8.3%，车辆的乘坐舒适性和运行稳定性大幅提升；考虑结构柔性时，车辆的垂向Sperling指标和垂向振动加速度RMS相比于未考虑结构柔性时分别增大了4.3%和6.8%，横向Sperling指标和横向振动加速度RMS分别增大了3.0%和3.4%。可见，车体和构架的结构柔性对车辆的动态特性有较大影响，在对车辆运行稳定性和乘坐舒适性进行计算和评估时不可忽略。 

Semi-active control of metro vehicle based on flexible multi-body dynamics

To realize more accurate evaluation and more effective optimization of the running performance of metro vehicles, based on the finite element theory and substructure theory, the flexible dynamics models of critical parts, such as car body and bogie frame, were established. Based on the algorithm of semi-active skyhook control and the theory of flexible multi-body dynamics, the rigid-flexible coupling dynamics model of a metro vehicle was established considering a semi-active control suspension.The effect of random track irregularity was considered, and the influences of semi-active control suspension and structural flexibility on the running stability and ride comfort of metro vehicles were investigated. Analysis results show that compared to the traditional suspension device, the semi-active skyhook control can significantly reduce the vibration acceleration of the vehicle and decrease its variation trend, suppressing the low-frequency vibration of the vehicle obviously. Based on the parameters adopted in this study, the semi-active skyhook control decreases the vertical Sperling index and root mean square (RMS) of vertical vibration acceleration on the straight segment by 26.8% and 7.5%, respectively, and 8.8% and 4.9% for lateral vibration acceleation, respectively. The semi-active skyhook control decreases the values of vertical vibration acceleration on the curve segment by 25.1% and 5.7%, respectively, and 15.6% and 8.3% for lateral vibration acceleration, respectively. Thus, the ride comfort and running stability of the vehicle improve significantly. Under considering the structural flexibility, the vertical Sperling index and RMS of vertical vibration acceleration of the vehicle increase by 4.3% and 6.8%, respectively, compared to those under no considering the structural flexibility, and 3.0% and 3.4% for lateral vibration acceleration, respectively. Thus, the structural flexibilities of the car body and frame significantly influence the dynamic characteristics of the vehicle and should be considered in calculating and evaluating the vehicle running stability and ride comfort. 5 tabs, 21 figs, 29 refs.