Abstract: In the study of the handling stability of the four-wheel steering vehicle, it is difficult to deal with the nonlinear model of the tire directly by using the linear control theory. In order to solve this problem, this paper proposes to establish a piecewise linear model of the tire according to the cornering characteristics of the tire, and uses MATLAB to simulate and compare the cornering characteristics of the piecewise linear rear tire model with the tire cornering characteristics of the "magic formula" tire model. It shows that the cornering characteristic curves of the piecewise linearized tire model and the magic "magic formula" tire model are consistent with each other. It is further shows that the model can easily obtain the cornering stiffness of the tire through linear processing and can be applied to the study of the steering stability of the four-wheel steering vehicle.

Key words: Four-wheel steering; Tire cornering characteristics; Tire nonlinear characteristics; Piecewise linearization

摘要： 在四轮转向汽车操纵稳定性的研究中，难以直接利用线性控制理论来处理轮胎非线性 模型。针对这一问题，论文提出了根据轮胎的侧偏特性建立轮胎分段线性化模型，利用 MATLAB 软件将分段线性后轮胎模型的侧偏特性与“魔术公式”轮胎模型的轮胎侧偏特性进 行仿真对比。结果表明，分段线性化轮胎模型与“魔术公式”轮胎模型的侧偏特性曲线变化 趋势一致，进而表明该模型可以通过线性处理简便得到轮胎侧偏刚度从而运用到四轮转向汽 车操纵稳定性研究中。

关键词: 四轮转向；轮胎侧偏特性；轮胎非线性特性；分段线性化