Abstract: Based on Lagrangian principle a 12-DOF a dynamic model of human-vehicle-road coupled system was built. On Matlab /Simulink platform，the vehicle speed，the road roughness，the hysteresis of vehicle’s front and rear wheel，the characteristics of coherence of left and right wheel were built. The random road incentive model were constructed. The effect of a vehicle which is on different road and at different speed，on the children’s head and hip were analyzed using the time and frequency domain. Results indicate that improving road level and speed can make the children have a good riding comfort，and children are very sensitive to the low frequency of 5-10Hz and the medium frequency of 15，23Hz. And appropriately reducing seat’s stiffness，improving the damping and putting the seat on the right position can improve children’s ridingcomfort.

Key words: human-vehicle-road coupling, 12-DOF, Matlab /simulink, power spectrum analysis, riding comfort

摘要： 根据拉格朗日原理，建立了基于人-车-路耦合振动的12 自由度动力学数学模型; 借助MATLAB/Simulink 平台，分析车速、路面不平度、汽车前后轮迟滞性及左右轮相干性的特点; 构建了随机路面激励时域模型; 采用时域和车对儿童头部、臀部振动影响。研究表明: 通过提高路面等级及车速可以提高儿童的乘坐舒适性; 儿童对5 ～ 10 Hz 的低频及15， 23 Hz 的中频振动最为敏感; 适当地降低座椅刚度、提高阻尼及合理地布置座椅位置可以提高儿童的乘坐舒适性。

关键词: 人-车-路耦合, 12 自由度, MATLAB/simulink, 功率谱分析, 乘坐舒适性