2012届毕业生毕业设计说明书题目:基于AVR单片机的汽车倒车防撞装置设计院系名称:电气工程学院专业班级:自动F0805学生姓名:曹建伟学号:200848280506指导教师:臧义教师职称:副教授2012年05月29日目次第1章引言..........................................................................................................................................11.1课题设计的背景及意义............................................................................................................11.2课题设计的研究现状...............................................................................................................1第2章系统分析....................................................................................................................................22.1超声波测距技术简介...............................................................................................................22.2本设计系统方案.......................................................................................................................22.3本文主要工作............................................................................................................................3第3章系统硬件电路设计....................................................................................................................43.1核心控制器...............................................................................................................................43.2电源电路...................................................................................................................................43.3超声波发射与接收电路............................................................................................................53.3.1发射驱动电路................................................................................................................53.3.2接收电路........................................................................................................................63.4信号放大及选频电路...............................................................................................................73.4.1信号放大电路.................................................................................................................73.4.2由带通虑波器构成的信号选频电路.............................................................................83.5检波电路.................................................................................................................................103.6显示器电路..............................................................................................................................113.7报警电路.................................................................................................................................123.8系统PCB设计与制作............................................................................................................133.9本章总结.................................................................................................................................14第4章系统软件设计..........................................................................................................................154.1超声波测距程序设计..............................................................................................................154.2显...