中文摘要：

为研究汽车在制动过程中的低频振动，提出了一个五自由度非线性模型，并对五自由度模型进行了稳定性分析．通过分析和计算，不仅说明了在一定的参数组合情况下即使是恒定的摩擦系数系统也会不稳定，而且给出了各种参数组合情况下参数平面上系统的稳定与不稳定区域，以此说明了在一定范围内增大底板的等效刚度可以提高系统稳定性．

英文摘要：

To study the low frequency vibration of automobile in the course of applying brake, a 5- degree of freedom non-linear model is presented to analyze the stability. By the analysis and calculation, it illuminate that even when the friction coefficient is constant, the vibration and instability can occur with the combination of some specific parameters. And the stable-unstable area on the parameter plain on the condition of the combination of some specific parameters is presented to illuminate that the increasing of baseplate stiffness can increase the system stability.