建立电动助力转向系统的力学模型,并对系统电动机在比例控制和比例加微分控制下汽车电动助力转向系统特性进行分析,对系统的频率特性和时间响应进行数值仿真,分析比例系数和微分系数对系统特性的影响,研究参数变化下系统特性的变化规律,为优化控制规律提供依据。关键词:汽车;电动助力转向;系统特性;理论分析Abstract :A mechanics model of elect ric power steering ( EPS) system is set up in this paper1 The characteristics of EPS are analyzed in theory1Under the case that EPS motor is in the cont rol of a pure proportion cont roller and pro2 portion2plus2derivative cont roller. The f requency response and time response of the system are numerically simula2 ted1 The authors also consider the effect s of the proportional and derivative coefficient s to EPS , study the variational rule of the system property on the effect of variation of the coefficient s , and provide basis for optimizing the cont rol law1Key words :Vehicle ; EPS ; System characteristic ; Theoretical analysis