Abstract: In order to better evaluate the handling stability of the vehicle, a linear three degree of freedom vehicle model including roll motion is established on the basis of the linear two degree of freedom vehicle model, and its motion differential equations are organized. Based on MATLAB software, sensitivity analysis is conducted by simultaneously changing the size of certain specific parameters in the three degree of freedom model and the two degree of freedom model. The results indicate that reducing the driving speed of the vehicle and increasing the lateral stiffness or rotational inertia of the vehicle tires can effectively improve the handling stability of the vehicle, and the linear three degree of freedom vehicle model can better reflect the operational characteristics of the vehicle compared to the two degree of freedom vehicle model.

Key words: MATLAB; Three degree of freedom model for vehicle; Handling stability; Angular step input response; Sensitivity analysis

摘要： 为更好地判断汽车的操纵稳定性，在线性二自由度汽车模型的基础上，建立了包含侧 倾运动的线性三自由度汽车模型，并整理出其运动微分方程。基于 MATLAB 软件，通过同时 改变三自由度模型与二自由度模型中某些特定参数的大小进行灵敏度分析。结果表明，降低 汽车行驶速度，以及增大汽车轮胎侧偏刚度或转动惯量，可以有效提高汽车操纵稳定性，且 线性三自由度汽车模型相比于二自由度汽车模型能够更好地反映汽车的操作特性。

关键词: MATLAB；汽车三自由度模型；操纵稳定性；角阶跃输入响应；灵敏度分析