【正文】 畢業(yè)設計說明書 畢業(yè)生姓名 ： 專業(yè) ： 學號 ： 指導教師 ： 所屬系（部） ： 二 〇 一 〇 年 六 月 i 摘 要 本文設計了一種汽車倒車雷達預警系統(tǒng)。該系統(tǒng)在常見的汽車倒車預警裝置的基礎上采用計算機控制技術和超聲波測距技術，通過顯示障礙物與汽車的距離并根據(jù)其距離遠近實時發(fā)出報警，解除了駕駛員泊車和起動車輛時前后左右探視所引起的困擾，提高了駕駛安全性。 本文在設計汽車倒車雷達預警系統(tǒng)過程中，運用理論分析、電路設計等手段，完成了倒車雷達預警系統(tǒng)硬件和軟件的設計。 本文在查 閱、分析國內(nèi)外倒車雷達系統(tǒng)相關技術的基礎上，結(jié)合最新研究成果，對基于超聲波測距的倒車雷達預警系統(tǒng)的研制進行了深入探討。該系統(tǒng)分為測距模塊、系統(tǒng)控制模塊和顯示報警模塊，并分別對其進行方案分析，構(gòu)建了倒車雷達預警系統(tǒng)的系統(tǒng)構(gòu)架和設計方案；在硬件電路中，詳細闡述了運用單片機技術實現(xiàn)的可視倒車雷達預警系統(tǒng)的測距實現(xiàn)原理，分析了以 AT89C52單片機為主控單元的系統(tǒng)硬件和軟件設計，并對該系統(tǒng)進行了誤差分析，給出了本系統(tǒng)的穩(wěn)定性指標。 試驗結(jié)果顯示，該系統(tǒng)對室內(nèi)有限距離的距離測量具有較高的精度，實現(xiàn)了倒車提示和距離報警 功能，同時保證系統(tǒng)的可靠性和可行性。 關鍵詞 ：倒車雷達；超聲波測距 ii ABSTRACT The thesis introduces a kind of Car Reversing AidSystem in system adopted the technology of puter controll and Ultrasonic DistanceMeasurement based on the currently Car Reversing system alarmed in time through displaying the distances between obstacles and soluted the puzzle problem because the drivers looked around through the mirrors when they stopped or started the system would greatly solve the difficulties and meanwhile improve the driving safety. In this thesis analysis in theory,design of electronic circuit and experimental investigation on real time simulation system are employed to carry out the realized the design of hardware and software. The thesis mainly analyzed deeply the research on the design of Car Reversing ,according to the latest researches in domestic and foreign system consisted of the DistaneeMeasurgment Module,Control Module mad Display or Alarm paper discussed the scheme of three module and selected the best system scheme in the ,it presented the theory and characters of Ultrasonic DistanceMeasurement and analyzed in detail design of the hardware and sottware based on the AT89C52 the fuzzy control algorithm is proposed,the simulation is introduced into the last,through the experiment and eITor analysis,it proved the stability of the system. To monitor its reliability,imitations of main Cases of the system have been carried out and stable instructions of strategic system have already been received,which veilfy its efficiency and feasibility. Key Words:Car ReversingAidSystem。Ultrasonic DistanceMeasuring iii 目 錄 摘 要 ................................................................................................................................ i ABSTRACT ...........................................................................................................................ii 第一章 緒論 ....................................................................................................................... 1 第一節(jié) 課題研究的背景 ................................................................................................. 1 第二節(jié) 課題研究的目的及意義 ..................................................................................... 2 第三節(jié) 目前國內(nèi)外的研究現(xiàn)狀 ..................................................................................... 2 第四節(jié) 超聲波的特性及作用原理 ................................................................................. 3 第二章 AT89C52 單片機簡介 ........................................................................................... 4 第一節(jié) 單片機基礎知識 ................................................................................................. 4 一、單片機的內(nèi)部結(jié)構(gòu) ................................................................................................ 4 二、單片機的基本工作原理 ........................................................................................ 7 第二節(jié) 單片機的分類及發(fā)展 ......................................................................................... 8 一、單片機的分類 ........................................................................................................ 8 二、 8 位單片機的新發(fā)展 ............................................................................................. 8 第三節(jié) 單片機 AT89C52 的特性 ................................................................................... 9 一、主要特性 ................................................................................................................ 9 二、管腳說明 .............................................................................................................. 10 三、振蕩器特性 .......................................................................................................... 12 四、芯片擦除 .............................................................................................................. 12 五、特殊功能寄存器 .................................................................................................. 12 六、引腳號功能特性 .................................................................................................. 13 七、中斷寄存器 .......................................................................................................... 13 八、數(shù)據(jù)存儲器 .......................................................................................................... 13 九、定時器 .................................................................................................................. 13 十、中斷 ...................................................................................................................... 14 第三章 系統(tǒng)構(gòu)建與方案設計 ......................................................................................... 15 第一節(jié) 系統(tǒng)設計要求 ................................................................................................... 15 第二節(jié) 系統(tǒng)構(gòu)建 ........................................................................................................... 15 第三節(jié) 系統(tǒng)方案設計 ................................................................................................... 16 一、測距系統(tǒng)方案設計 .............................................................................................. 16 二、超聲波測距方案設計 ...