【正文】 ........ 1 課題設計的研究現(xiàn)狀 ........................................................................................................ 1 課題設計的任務和要求 .................................................................................................... 2 課題設計的任務 .......................................................................................................... 2 課題設計的要求 .......................................................................................................... 2 選題的意義 ........................................................................................................................ 3 研究內(nèi)容及論文構成 ........................................................................................................ 3 2 超聲波測距原理 .................................................................................................................... 5 超聲波簡介 ........................................................................................................................ 5 超聲波的聲學特性 ...................................................................................................... 5 超聲波的發(fā)生原理 ...................................................................................................... 6 超聲波傳感器的原理與特性 ............................................................................................ 7 原理 .............................................................................................................................. 7 特性 .............................................................................................................................. 9 超聲波測距儀的測距原理 ................................................................................................ 9 單片機最小系統(tǒng) ........................................................................................................ 11 超聲波發(fā)射電路 ........................................................................................................ 12 超聲波接收電路 ........................................................................................................ 13 超聲波測距儀顯示電路 ............................................................................................ 15 本章小結(jié) .......................................................................................................................... 15 3 超聲波測距系統(tǒng)軟件設計 .................................................................................................... 17 超聲波設計概述 .............................................................................................................. 17 主程序流程圖 .................................................................................................................. 18 定時 /計數(shù)器 T0/T1 定時程序流程圖 ............................................................................. 20 方式控制寄存器 TMOD.......................................................................................... 20 控制寄存器 TCON .................................................................................................. 21 定時器 T0 流程圖 ...................................................................................................... 21 定時器 T1 中斷服務程序流程圖 .............................................................................. 22 外部中斷服務程序流程圖 .............................................................................................. 23 顯示程序流程圖 .............................................................................................................. 23 計算程序流程圖 .............................................................................................................. 24 4 電路調(diào)試及誤差分析 .......................................................................................................... 26 系統(tǒng)軟件的調(diào)試 .............................................................................................................. 26 系統(tǒng)的軟硬件串聯(lián)調(diào)試 .................................................................................................. 28 系統(tǒng)的誤差分析 .............................................................................................................. 30 聲速引起的誤差 ........................................................................................................ 31 單片機時間分辨率的影響 ........................................................................................ 31 隨機誤差 .................................................................................................................... 32 提高測距精度的方法 ...................................................................................................... 32 本章小結(jié) .......................................................................................................................... 33 結(jié) 論 ........................................................................................................................................ 34 致 謝 ........................................................................................................................................ 35 參考文獻 :................................................................................................................................... 36 附錄： ........................................................................................................................................ 37 1 1 緒 論 課題設計的研究現(xiàn)狀 當我們的測距技術日漸趨于成熟，我們對測距的精度要求也日漸嚴苛，傳統(tǒng)的測距技術在某些場合已經(jīng)不能夠滿足人們的需要， 如在井道，水位，管道等的長度 測量方面，傳統(tǒng)的測距方式已然不再適用。超聲波有兩個特點，一個是能量大，一個是沿直線傳播，它的應用就是按照這 兩個特點展開的。 關鍵詞 ：超聲波測距儀 ,單片機 Thesis: ultrasonic range finder (software) Specialty: Automation Undergraduate: (Signed) __________ Instructor: (Signed) __________ ABSTRACT Ultrasonic Ranging is a noncontact optical measurement method which has been widely applied in recent years. It has the advantages of measuring convenience, not be the object produce damage. Obvious fe