【正文】 MOV A R6 。畢業(yè)設(shè)計（論文）基于超聲波的汽車防撞系統(tǒng)設(shè)計 本科學(xué)生畢業(yè) 基于超聲波的汽車防撞系統(tǒng)設(shè)計 系部名稱 汽車 專業(yè)班級 B067 班 學(xué)生姓名 指導(dǎo)教師 職 稱 黑 龍 江 工 程 學(xué) 院 二年月 The Graduation Design for Bachelors Degree The Design of The Automotive Anticollision Systen Based on The Ultrasonic DepartmentAutomotive ngineering SpecialtyVehicle ngineering ClassB067 The Students Name Qi Guodong SupervisorLv Degang TitlesLecturer Heilongjiang Institute of Technology 202106Harbin 摘 要 近年來我 國高速公路追尾碰撞事故頻繁發(fā)生而車載追尾碰撞預(yù)警系統(tǒng)在解決高速公路行車安全中具有良好的前景因此引起了研究人員的廣泛關(guān)注 根據(jù)超聲波測量距離系統(tǒng)給出了汽車測距防撞報警系統(tǒng)的設(shè)計該系統(tǒng)能在汽車行駛以及倒車過程中自動檢測出汽車與最近障礙物之間的距離 或行車中的車距 并通過 L E D 顯示出來 當(dāng)?shù)竭_極限距離時． 系統(tǒng)能發(fā)出聲光報警． 進而提醒司機雌防撞車 在公路街道停車場車庫等擁擠狹窄的地方倒車時駕駛員既要前瞻又要后顧稍微不小心就會發(fā)生追尾事故據(jù)相關(guān)調(diào)查統(tǒng)計 15％的汽車碰撞事故是因倒車時汽車的后視能力 不良造成的因此增加汽車的后視能力研制汽車后部探測障礙物的倒車?yán)走_便成為近些年來的研究熱點安全避免障礙物的前提是快速準(zhǔn)確地測量障礙物與汽車之間的距離為此設(shè)計了以單片機為核心利用超聲波實現(xiàn)無接觸測距的倒車?yán)走_系統(tǒng) 超聲波一般指頻率在 20 kHz以上的機械波具有穿透性強衰減小反射能力強等特點工作時超聲波發(fā)射器不斷發(fā)射出一系列連續(xù)脈沖給測量邏輯電路提供一個短脈沖最后由信號處理裝置對接收的信號依據(jù)時間差進行處理自動計算出車與障礙物之間的距離超聲波測距原理簡單成本低制作方便但其傳輸速度受天氣影響較大不能精確測距另外超聲 波能量與距離的平方成正比衰減因此距離越遠靈敏度越低從而使超聲波測距方式只適用于較短距離目前國內(nèi)外一般的超聲波測距儀其理想的測量距離為 4～ 5 m 因此大都用于汽車倒車?yán)走_等近距離測距中本文根據(jù)聲波在空氣中傳播反射原理以超聲波換能器為接口部件介紹了基于 TC89C52 單片機的超聲波測距器該設(shè)計由超聲波發(fā)射模塊信號接收模塊單片機處理模塊數(shù)碼顯示以及聲光告警顯示模塊等部分組成文中詳細介紹了測距器的硬件組成檢測原理方法以及軟件結(jié)構(gòu)超聲波發(fā)射模塊中采用555定時器構(gòu)成的時基電路接收電路使用 SONY公司的 CX20216A紅外 檢測專用芯片該芯片常用于 38kHz 的檢波電路文中通過對芯片內(nèi)部電路的仔細分析設(shè)計出能夠成功對 40kHz 超聲波檢波的硬件電路并且增益可調(diào)與傳統(tǒng)超聲波檢波電路相比電路變得精簡調(diào)試變得相對容易測距器使用數(shù)碼管顯示目標(biāo)物的距離 關(guān)鍵詞 汽車防撞報警系統(tǒng) 單片機 TC89C52 超聲波測距 ABSTRACT The accident of automobile rearend collision has taken place frequently in recent yearsand rearend collision warning system has good use in improving expressway traffic safetyso the warning system has been paid more attention in the world The vehicle collision avoidance alarm apparatus system was introdued according to the ultrasonic measurement distances system The system can automaticanlly xeamine the distance between the back and the nearest obstacle or the distance among cars whicwould be demonstarted through LED that when it arrives the limit distance the systemb can send out the warning and reminds the driver for preventing the vehicle colliding The experimental results showed that the system illustrates a good prospect of application and xetension Highways streets parking garage and other crowded places narrow reverse the driver should not only forward but also looking back a little rearend careless accidents can occur According to related statistics 15 of motor vehicle collisions when the vehicle is reversing as the capacity of the latter caused by badSo after the increase of motor vehicles as the ability to detect obstacles on the development of the rear of the car reversing radar has bee the research hotspot in recent years Security to avoid obstacles on the premise that the rapid and accurate measurement of obstructions and the distance between motor vehicles To this end the design of a singlechip microputer as the core the use of ultrasonic ranging to achieve noncontact reversing radar system Generally refers to ultrasonic frequencies above 20 kHz mechanical waves with perating and attenuation of small reflecting the ability and so on Work the ultrasonic transmitter continuously emits a series of consecutive pulses to the measurement of logic circuits to provide a short pulse Finally signal processing devices based on the received signal for processing the time difference automatic calculation of turnout and the distance between obstacles Ultrasonic Ranging simple low cost easy production but the transmission speed by a larger weather can not be precise range In addition the ultrasonic energy and the attenuation is directly proportional to the square of the distance the farther the distance the lower sensitivity and thus Ultrasonic Ranging way so that only apply to a shorter distance At present ultrasonic range finder at home and abroad in general the ideal distance of the measurement 4 5 m thus reversing radar are used in cars such as close range in this paper according to the spread of sound waves in air reflection to ultrasonic transducer interface ponents based on MCU STC89C52 ultrasonic rangefinder Designed by the ultrasonic transmitter module receiver module singlechip processing module a digital display and alarm sound and light display module such as parts the text in detail the range of hardware devices detection theory methods and software architecture The use of ultrasonic transmitter module consisting of 555 timebase timer circuit receiving circuit using the SONY pany dedicated CX20216A infrared detecting chip the chip used in the detector circuit 38kHz the text of the chip through the careful analysis of the internal circuit design can successfully 40kHz ultrasonic detection of hardware circuitry and adjustable gain and pared to conventional ultrasonic detection circuit the circuit has bee streamlined and easier to debug The use of digital rangefinder display the distance between objects Key wordsAutomotive anticollision alarm systeminglechip STC89C52 Silent Wave Measure Distance 目 錄 摘 要 I Abstract II 第 1 章 緒論 1 11 課題研究的現(xiàn)狀和發(fā)展歷史及意義 1 12 汽車防撞系統(tǒng)的發(fā)展現(xiàn)狀 2 13 本課題的主要研究內(nèi)容 3 第 2 章 系統(tǒng)的總體設(shè)計與分析 4 21 超聲波測距原理 4 22 超聲波發(fā)生器 4 23 壓電式超聲波發(fā)生器原理 4 24 測量與控制方法 5 25 控制系統(tǒng)方框圖 5 26 超聲波發(fā)射部分的設(shè)計 6 27 超聲波接收器的設(shè)計 6 28 理論計算 8 29 影響精度的因素分析 8 210 提高精度的方案及系統(tǒng)設(shè)計 9 211 本章小結(jié) 11 第 3 章 系統(tǒng)的硬件結(jié)構(gòu)設(shè)計 12 31 系列單片機的功能特點及測距原理 12 52 系列單片機的功能特點 12 52 單片機實現(xiàn)測距原理 13 32 超聲波發(fā)射電路 13 33 超聲波檢測接收電路 14 34 超聲波測距系統(tǒng)的硬件電路設(shè)計 15 35 本章小結(jié) 17 第 4 章 系統(tǒng)的軟件設(shè)計 18 41 軟件設(shè)計 18 42 超聲波測距儀的算法設(shè)計 19 43 主程序流程圖 20 44 超聲波發(fā)生子程序和超聲波接收中斷程序 22 45 系統(tǒng)的軟硬件的調(diào)試 23 46 本章小結(jié) 23 結(jié) 論 24 參考文獻 26 致 謝 28 附 錄 29 第 1 章 緒 論 11 隨著科技發(fā)展的