摘 要

隨著社會經濟的發(fā)展和交通運輸業(yè)的不斷興旺，汽車的數(shù)量在不斷的增加。交通擁擠狀況也日益嚴重，撞車事件也經常發(fā)生，造成了很多不可避免的人聲傷亡和經濟損失，面對這種情況，設計一種響應快、可靠性高并且比較經濟的汽車防撞預警系統(tǒng)顯得非常的重要。超聲波測距法是一種最常見的距離測量方法。本文介紹的就是利用超聲波測距法設計一種倒車防撞報警系統(tǒng)。

本文的內容是基于超聲波測距的倒車防撞系統(tǒng)的設計，主要是利用超聲波的特點和優(yōu)勢，將超聲波測距系統(tǒng)和AT89S51單片機結合于一體，設計出一種基于AT89S51單片機得倒車防撞系統(tǒng)。本系統(tǒng)采用軟硬結合的方法，具有模塊化和多用化的特點。

論文概述了超聲波檢測的發(fā)展及基本原理，闡述了超聲波傳感器的原理及特性。對于系統(tǒng)的一些主要參數(shù)進行了討論，并且在介紹超聲波測距系統(tǒng)功能的基礎上，提出了系統(tǒng)的總體構成。通過多種發(fā)射接收電路設計方案比較，得出了最佳設計方案，并對系統(tǒng)各個設計單元的原理進行了介紹。對組成各系統(tǒng)電路的芯片進行了介紹，并闡述了它們的工作原理。論文介紹了系統(tǒng)的軟件結構，通過編程來實現(xiàn)系統(tǒng)功能。

Abstract

With the social and economic development and transportation continues to boom, the automobile quantity climbs in the first mate. Traffic congestion condition also day by day serous, the collision event occurred repeatedly, has caused the inevitable person casualties and the economic loss, in view of this kind of situation, designed one kind to respond quickly, the reliability was high also a more economical automobile guards against hits the early warning system imperative, the ultrasonic wave range finding was the most common one distance range finder method, this article introduces is guards against using the ultrasonic wave range finding design one kind of reversing collision avoidance system.

The paper is based on the ultrasonic distance reversing collision avoidance system design, mainly using ultrasound features and advantages, ultrasound ranging system and the integration with the integration AT89S51 monolithic integrated circuit, AT89S51 monolithic integrated circuit based on the design of a reverse collision avoidance warning systems. The system used software and hardware integrated approach of modular and multi-use characteristics.

The paper outlines the development and the basic principles of ultrasound tests on the principles and characteristics of ultrasound sensors. Some of the main parameters for the system were discussed, and introducing ultrasonic ranging system functions basic, the overall composition of the system. Through multiple launch reception circuit design comparison, the best designed programme drawn, and various system design modules principles introduced. On the composition of the system circuit chip introduced and elaborated the principles of their work. Papers introduced system software architecture, through programming to achieve system function.

目  錄

摘 要 I

Abstract I

目  錄 III

第一章 緒論 1

1.1 課題設計的目的和意義 1

1.2 國內應用現(xiàn)狀 1

第二章 總體方案 3

2.1 本設計的研究方法 3

2.2系統(tǒng)整體方案的設計 3

2.3 系統(tǒng)整體方案的論證 3

2.4 超聲測距原理 3

2.4.1 超聲波測距概述 3

2.4.2 超聲波傳感器介紹 4

2.4.3 超聲波測距的原理 6

第三章 系統(tǒng)硬件設計 8

3.1 AT89S51單片機 8

3.2超聲波測距的系統(tǒng)及其組成 10

3.2.1 超聲波測距單片機系統(tǒng) 11

3.2.2 超聲波發(fā)射、接受電路 11

3.3.3 顯示電路 13

3.3.4 供電電路 13

3.2.5 報警輸出電路 14

第四章 系統(tǒng)軟件設計 15

4.1 主程序設計 15

4.2 超聲波測距子程序及其流程圖 15

4.3 超聲波測距流程圖 18

第五章 系統(tǒng)調試與誤差分析 19

5.1調試步驟 19

我的錯誤與糾正 19

調試準備 19

5.2 調試現(xiàn)象 22

5.3 誤差分析 23

5.3.1 性能分析 23

5.3.2 誤差分析 24

結論 26

參考資料 27

致  謝 28

附錄一 超聲波測距原理圖 29

附錄二 PCB圖 30

附錄三 實物圖 31

附錄四 程序 32