基于动力吸振器理论的车下设备悬挂H∞和H2优化

H∞and H2 optimization of under-vehicle equipment suspension based on dynamic vibration absorber theory

将车下设备看作动力吸振器,车体考虑成弹性欧拉梁,以使最优的动力吸振器能有效的抑制车体共振。提出4种动力吸振器优化方法,即主系统位移的H∞和H2优化。主系统加速度的H∞和H2优化,获得车下设备最优悬挂参数。建立车辆-设备的垂向耦合动力学模型,比较4种优化方法对乘坐舒适性的影响。研究结果表明:车下设备的最优刚度比范围为0.82~1.00,最优阻尼比范围为0.04~0.29。4种优化方法都能抑制车体振动,其中位移H2优化能最大程度的提升乘坐舒适性。由于车体受到随机激励力,H2优化能降低主系统在所有频率上的总振动能量,比常用的H∞优化更适合铁道车辆。

The under-frame equipment is regarded as a dynamic vibration absorber,and the car body was considered to be an elastic Euler beam.The optimal dynamic vibration absorber can effectively suppress the resonance of the car body.Four optimization methods of dynamic vibration absorber were proposed,namely H∞and H2 optimization of the displacement of the main system,H∞and H2 optimization of the acceleration of the main system,and the optimal suspension parameters of the under frame equipment were obtained.A vertical coupled dynamics model of the vehicle-equipment was established to compare the effects of the four optimization methods on ride comfort.The numerical analysis results show that the optimal stiffness ratio range of the under-frame equipment is 0.82~1.00,and the optimal damping ratio range is 0.04~0.29.Four optimization methods can suppress the vibration of the car body,and the displacement H2 optimization can maximum improve the ride comfort.Due to the random excitation force on the car body,H2 optimization can reduce the total vibration energy of the main system at all frequencies,which is more suitable for railway vehicles than the commonly used H∞optimization.