基于单片机控制的汽车倒车雷达实时超声波测距系统设计.doc

摘  要

    随着社会经济的发展交通运输业日益兴旺，汽车的数量大幅攀升。交通拥挤状况也日益严重，撞车事件屡屡发生，造成了不可避免的人生伤亡和经济损失，针对这种情况，设计一种响应快，可靠性高且较为经济的汽车防撞预警系统势在必行，超声波测距法是最常见的一种距离测距方法，本文介绍的就是利用超声波测距法设计的一种倒车防撞报警系统。控制系统核心部分就是超声波测距仪的研制。因此，设计好的超声波测距仪就显得非常重要了。

　　　本设计采用以AT89C51单片机为核心的低成本、高精度、微型化数字显示超声波测距仪的硬件电路和软件设计方法。整个电路采用模块化设计，由主程序、预置子程序、发射子程序、接收子程序、显示子程序等模块组成。各探头的信号经单片机综合分析处理，实现超声波测距仪的各种功能。在此基础上设计了系统的总体方案，最后通过硬件和软件实现了各个功能模块。相关部分附有硬件电路图、程序流程图。

　　　设计通过多种发射接收电路设计方案比较，得出了最佳设计方案，并对系统各个单元的原理进行了介绍。对组成系统电路的芯片进行了介绍，并阐述了它们的工作原理。论文介绍了系统系统的软件结构，通过编程来实现系统功能。最后，通过对系统的误差分析，给出了较完善的方案。

　　

　　关键词：AT89C51; 超声波；测距                           Abstract


　　With the development of science and technology, the improvement of people's standard of living, speeding up the development and construction of the city. urban drainage system have greatly developed their situation is constantly improving. However, due to historical reasons many unpredictable factors in the synthesis of her time, the city drainage system. In particular drainage system often lags behind urban construction. Therefore, there are often good building excavation has been building facilities to upgrade the drainage system phenomenon. It brought to the city sewage, and it is clear to the city sewage and drainage culvert in the sewage treatment system. comfort is very important to people's lives. Mobile robots designed to clear the drainage culvert and the automatic control system Free sewage culvert clear guarantee robot, the robot is designed to clear the culvert sewage to the core. Control System is the core component of the development of ultrasonic range finder. Therefore, it is very important to design a good ultrasonic range finder.  

　　At the core of the design using AT89C51low-cost, high accuracy, Micro figures show that the ultrasonic range finder hardware and software design methods. Modular design of the whole circuit from the main program, pre subroutine fired subroutine receive subroutine. display subroutine modules form. SCM comprehensive analysis of the probe signal processing, and the ultrasonic range finder function. On the basis of the overall system design, hardware and software by the end of each module.

　　The research has led to the discovery that the software and hardware designing is justified, the anti-disturbance competence is powerful and the real-time capability is satisfactory and by extension and upgrade, this system can resolve the problem of the car availably, building construction the position of the workplace and some industries spot supervision.

　　　

Key words:AT89C31; Silent Wave；Measure Distance

　　　　　　　　　　　　　　　　　　　　

　　　

　　　目  录


摘    要···························································I

Abstract··························································II

绪    论···························································1

    I.1   课题设计的目的及其意义·································1

    I.2   超声波测距系统的设计思路·································1

　　　I.3   课题设计的任务和要求·········································3

1  课题的方案设计与论证···········································4

    1.1   系统整体方案的设计·····································4

    1.2   系统整体方案的论证·····································4

2  系统的硬件结构设计·············································4

    2.1   单片机的功能特点及测距原理·····························5

    2.2   超声波发射电路的设..