汽车电动助力转向系统研究与设计.docVIP

汽车电动助力转向系统研究与设计 作 者 姓 名 马东霞 专 业 自动化 指导教师姓名 杜永 专业技术职务 讲 师 摘 要 汽车电动助力转向系统（Electric Power Steering）简称EPS，是近些年来出现的新型动力转向系统。该系统由电动助力机直接提供转向助力，省去了液压动力转向系统（HPS）所必需的动力转向油泵、软管、液压油、传送带和装于发动机上的皮带轮，既节省能量，又保护了环境。与液压动力转向（HPS）相比，汽车电动助力转向系统(EPS)结构简单、成本低、灵活性好、能充分的满足汽车转向性能的要求，在转向操作的舒适性、安全性和节能、环保等方面显示出显著的优越性。同时可以通过软件加以改变，硬件资源利用高；低速行驶时转向轻便，高速行驶时转向有稳重感；助力电机只在汽车转向时才工作，节约能源。 汽车电动助力转向系统主要由扭矩传感器、车速传感器、电子控制单元、无刷直流电动机、电磁离合器和减速机构等部分组成。通过传感器探测机探测在转向操作时方向盘产生的扭矩或转角的大小和方向，并将所需信息转化成数字信号输入控制单元，再由控制单元对这些信号进行运算后得到一个与行驶工况相适应的力矩，最后发出指令驱动电动机工作，电动机的输出转矩通过传动装置的作用而助力。 本文根据电动助力转向系统的特点，采取PIC16F877单片机作为核心，采用传感器信号采集技术和无刷直流电动机专用芯片等，实现信号采集和助力电机的控制。 关键词： 电动助力转向 单片机 控制系统 ABSTRACT Electric Power Steering System (Electric Power Steering) referred to as EPS, is a new power steering system,which emerged in recent years. The system is provided directly by the electric power steering machine, eliminating the need for hydraulic power steering system (HPS) necessary for power steering pumps, hoses, hydraulic oil, belt and the pulley mounted on the engine, both to save energy and protect the environment. Comparing with hydraulic power steering (HPS), the electric power steering (EPS)system of the automobiles is simpler in structure,more flexible,and call fully meet the requirements of steering performances. At the same time can be changed by software, hardware resource utilization high; low speed when turning light, high speed, moved to a stable sense; power steering motor only when the work in the automotive, energy conservation. Electric power steering (EPS) system mainly combines the torque sensor ,velocity sensor, electric control unit,electromagnetic clutch and gear down machine etc. Detection by sensors detecting machine operation in the steering wheel torque generated by the magnitude and direction or angle, and the required information into digital signal input control unit, control unit by the operations on these signals to get a po