真实路面的函数可以描述为路面不规则函数q=q(x,y)，其x和y坐标轴分别表示纵向和侧向轴。路面不平度被描述成具有高斯分布、稳态阶段、遍历性和零均值的随机过程。因此我们可以利用自己定义的单个轨迹和相干函数的二平行轨迹的功率谱密度来描述路面不平度。自定义的单轨迹功率谱密度可用如下方程描述：-In ride comfort research, it is important to simulate the vibration of automobile on uneven road. To build a more accurately model, the nonlinear factors should be taken into consideration. In this paper, an uneven road with certain auto-PSD is generated in MATLAB software.In ADAMS software, a 126-DOF nonlinear ride comfort model is constructed and simulated on this irregular road. The results of simulation are converted into frequency domain, and compared with those of road tests. This method of ride comfort research is proved to be reliable and feasible.