中文摘要：

准确的模态参数是评价车辆平顺性的基础,也是验证仿真模型的关键;传统的跌落法存在二次冲击、数据处理复杂等局限。提出一种基于整车四通道激振实验的模态参数识别方法,首先建立整车七自由度模型,通过仿真分析验证方法在原理上可行;然后在实验台上对实验车进行垂向、俯仰和侧倾三种形式的等幅固定步长扫频激励,通过响应信号的幅频特性曲线直接获得模态参数。该方法的结果与跌落法结果吻合,相对误差在5%以内,证明了识别方法的简便性和可行性。

英文摘要：

Accurate modal parameters are not only essential to obtain vehicle inertial parameters, but also play a key role to validate the simulation model. However, the presence traditional drop method is limited in application due to second impact and complex data processing. In this study, a modal parameters identification method is proposed based on the four poster shaker rig for sprung mass. Firstly, the seven degrees of freedom vehicle model is established and simulation analysis is conducted to validate its feasibility in principle. Secondly, frequency sweep excitations with constant amplitude and fixed step size are applied to the test vehicle by the test-bed in three forms： bounce, pitch and roll, respectively. Then, modal parameters are obtained directly through the frequency-response characteristic curve with signal amplitude. The results agree with those obtained by the drop method with the relative error is less than 5%, which demonstrate the simplicity and effectiveness of the proposed identification method.