汽车转向系统方向盘怠速振动特性是评价其舒适性的重要指标． 本研究提出了 转向系统模态固有频率的计算方法，通过灵敏度分析确定转向系统上下支架连接处 5 个 钣金件的厚度值为设计变量． 基于响应面模型和序列二次规划算法相结合，给出了转向系统模 态的优化方法． 在转向系统质量增加 0． 14kg 的条件下，系统一阶固有频率增加了 2． 66Hz． 本研究提出的转向系统模态分析与优化方法对转向系统的设计具有一定的指导意义．

The idle vibration of steering wheel in the vehicle steering system is an important index to evaluate its comfort． A calculation method of steering system's natural frequency was put forward． Through sensitivity analysis， the thicknesses of five sheet metal parts at the upper and lower connections of steering system was determined as the design variables． Based on the combination of response surface model and sequential quadratic programming algo- rithm，the modal optimization method of steering system was presented． The first-order natural frequency of the system increased by 2. 66 Hz when the mass of the steering system increased by 0. 14 kg． The steering system mo- dal analysis and the proposed optimization method can provide certain guidance for steering system design．