中文摘要：

电动助力转向（EPAS）系统各部件参数的正确匹配对汽车的驾驶性能有着重要的影响。对EPAS系统结构进行合理的简化和分析，以5个关键的系统参数为设计变量、制约系统转向操纵稳定性的数学关系为约束条件、转向路感频域能量的平均值为目标函数，建立该系统完整的优化设计模型。采用拟牛顿算法，利用MATLAB优化工具箱对设计模型进行求解。结果表明，优化前后目标函数值提高了91％，验证了该优化设计的有效性，从而为EPAS系统的匹配设计提供参考。

英文摘要：

Parameters matching of the Electric Power Aided Steering （EPAS） System has a significant impact on the driving performance of the vehicle. With a reasonable simplification and analysis of the structure of the EPAS system, a complete dynamics model is established. With five important system parameters as the design variables, the mathematical relationships of restrict of steering stability as the constraint conditions, the average value of the steering feelings frequency energy as objective function, a complete optimization design model is established. The model is solved by MATLAB optimize toolbox with Quasi-Newton methods. The results indi cate that the value of objective function rises up 91%. The optimization design is verified feasible and this provides reference on the matching design of the EPAS system.