摘要汽车电动助力转向系统具有传统液压动力转向系统无法比拟的优势，是汽车动力转向发展的必然趋势。电动助力转向采用电动机直接提供助力，经减速机构传递给转向器，助力大小由电子控制单元（ECU）控制。它能节约能量，提高安全性，且有利于环保，是一项紧扣现代汽车发展主题的高新技术。62919

本文在明晰了EPS的组成和工作原理后，首先针对特定车型本田飞度电动助力转向系统中的助力电机进行选型和计算；对蜗轮蜗杆减速机构以及齿轮齿条减速器进行了设计计算和校核；同时也对助力特性进行了初步分析，给出了电动助力转向系统的控制策略。   

毕业论文关键词  电动助力转向系统  蜗轮蜗杆减速机构  齿轮齿条转向器  ECU 

毕业设计说明书（论文）外文摘要

Title    Electric Power Steering System Design                     

Abstract Electric power steering is inevitable developing direction for automobile power steering system, which is much superior to hydraulic power steering system. The assist torque is provided by motor directly in EPS system, whose value is controlled by ECU, and then being transmitted to steering gears through the reduction gear. EPS can save energy, improve vehicle safety, benefit environment protection, and is a new high-tech that follows modern vehicle development topic closely.

In this paper, after defining the EPS composition and the principle of work, firstly, the typical type of blushless dc motor is selected for the Honda fit electric power steering system by several calculation and check. Secondly, the worm reducer and the rack and pinion automobile steering-gears are designed on the base of the motor and the parameter of the Honda fit. Also, assist characteristic is analyzed theoretically and the control strategy of EPS is described in detail.

Keywords  electric power steering system   worm reducer   rack and pinion automobile steering-gears   ECU

1  绪论 1

1.1  引言 1

1.2  电动助力转向系统的优点 1

1.3  国内外的研究现状 2

1.4  电动助力转向系统的发展趋势 3

2  EPS系统的结构与工作原理及性能分析 4

2.1  EPS系统的工作原理 4

2.2  EPS系统的主要构件及选型 5

3  EPS系统蜗轮蜗杆减速机构设计 9

3.1  EPS系统中电机选择 9

3.2  EPS系统中蜗轮蜗杆参数设计 11

3.3  轴的设计 16

3.4  预紧装置设计 18

4  EPS系统齿轮齿条式转向器的设计 19

4.1  齿轮齿条的工作原理简介 19

4.2  齿轮齿条式转向器设计 20

4.3  齿轮轴的设计 24

5  ECU控制单元分析 26

5.1  助力特性分析 26

5.2  控制策略的研究 27

5.3  控制系统硬件设计 30

结    论