中文摘要：

在建立电动助力转向系统（Electric power steering system,EPS）数学模型的基础上,将方向盘转矩传感器测得的转矩信号和估算的转向盘转角值相结合以判断转向的状态,然后运用模糊比例微分（Proportion derivative,PD）控制进行常规助力控制或回正控制。仿真结果表明,原地和低速条件下转向盘操纵转矩明显降低,车辆回正性能显著提高。并通过相关的软、硬件设计实现所设计的控制策略。为检验控制策略合理性和控制软件可行性以及自主设计控制单元（Electronic control unit,ECU）的可靠性,参照相关国家标准,进行无助力、自主研发的EPS实车对比试验,试验结果与仿真结果相吻合。

英文摘要：

Based on establishing the mathematical model of electric power steering system （EPS）, a method for estimating the state of steering wheel by the combination of the moment signal measured by steering wheel moment sensor and the estimated steering angle, then the fuzzy proportion derivative （PD） control strategy is applied for conventional power-assited or self-aligning control. The simulation results show the steering moment decreases apparently under in-situ and low speed condition, the returnability is improved remarkably. Moreover, the electronic control unit （ECU） is designed on the basis of control strategy. For verifying the feasibility of software and reliability of ECU, the comparison vehicle test is carried out on the vehicle equipped with the self-developed EPS and without EPS respectively according to the relative national standards. The test results indicate that the practical effectiveness of self-developed EPS system is consistent with the simulation results.