【正文】
專科生畢業(yè)設計(論文) I 摘 要 交通燈的智能控制是目前智能交通系統(tǒng) ITS 領域中的一個分支。隨著城市 化速度的加快,機動車日益普及,人們受到越來越多的交通擁堵的困擾。而 城市道路中交通擁堵有多方面的原因:車輛多,道路少;道路設置不合理; 平面交通多,立體交通少:交叉路口交通燈時間設置不合理等等。而城市交 通中平面交通占得比重非常大。堵車地點多為交叉路口。主要是由于車流量 大,等燈時間不合理造成的。這是目前城市交通亟待解決的問題。 目前我國城市街道交叉路口的交通信號燈雖然是自動的,但是仔細觀察 就會發(fā)現(xiàn)紅綠燈的交 替轉換是定時式的,即轉換的間隔時間是固定不變的。 定時式并不符合實際要求。因為,如果東西和南北兩方向車流量相差很大, 而信號燈還是平均分配導通時間,就會出現(xiàn)這樣的問題:車多的方向導通時 間不足,而車少的方向導通時間剩余,造成一方向車擠另一方向車松的不合 理的局面,這就是機器自動控制不如人工現(xiàn)場指揮的差別。本論文主要對十 字路口交通燈可根據(jù)車流量的大小而改變紅綠燈的時長加以研究。 本系統(tǒng)采用單片機作為中心控制器。在單片機最小系統(tǒng)的基礎上擴展了 數(shù)據(jù)存儲器、程序存儲器、 I/ O 接口、 A/ D 轉換器,使硬件電路能適應所完成 的控制功能。該系統(tǒng)可控制紅、綠、黃燈按時間依次變換,并有倒讀秒功能。 均采用 LED 顯示器。在此基礎上,通過傳感器對車流量的情況進行數(shù)據(jù)采集。 通過 A/ D 轉換將采集的數(shù)據(jù)傳送還給控制中心,進行分析比較。根據(jù)比較的 結果,將具體的車流量轉換成兩相位車流量大小的比值。根據(jù)比值轉換成對 紅綠燈時間的控制。使交通信號燈可根據(jù)車流量改變。提高了交叉口的通行 效率。 關鍵詞: 智能交通;單片機;交通燈;控制器 ??粕厴I(yè)設計(論文) II Abstract The intelligent control of traffic light is a branch in ITS of intelligenttransportation system. As the accelerating of urbanization,motor vehicle is popularized day and day,there is apuzzles to people by traffic jam which is more and more serious. But there ale many reasons for jam ofurban tramcmore automobiles,fewer roads, unsuitable arrangement ofroads, more plane traffic, fewer stereo trafficunsuitable arrangement on time of tramc light in crossroad, etc. Plane tVd 伍 C takes up a great proportion of urban traffic. The place where jamoccuredfrequently iS crossroad. This is resulted frommore vehicle flow and unreasonable time ofwaitting traffic light. This is qproblem needed to be solved in urban tlafnc. Although,the control of ti39。amc light of crossroad in urban traffic is automatic,the alternative switch ofred and green trafjfic light is timed, bywhich the interval time ofswitching is changeless. It is not suitable for practice. Because, when there is a big difference of eastwest and northsouth’S vehicle flow,if tumon time is distributed by traffic light,the problen may appered such as tuiti on time ofdirection of more vehicles iS lack, while one of fewervehicles is excessive. Because of this problem,an unreasonable situation which is on one direction the traffic is jam which another dricetion is not jam is made. This is difference that automative control is inferior to manual cotr01. That according to the vehicle flow to changes swicthing time of red and green traffic light in crossroad is mainly studied in thearticle. The 5cm is used as center controller in the system. On thebase ofminimized scm system, data memory,program memory,FO interface, A/ D converter ale extended in order to have hardware circuit achieves control function. 111e successi~;ely switch ofred,green and yellow tvdmC light by time Can be cotrolled and attached function is read the seconds. All ofthese adapted LED display. On this basis, data on amount of vehicle flow is collected by sensor. By A/ D converting the collected datas a transmited to control center. analysed and pared. According to results,concrete vehicle flow will be convened into ratio of vehicle flow on both dircetion.,based on which switch time of red and green traffic lights canbe controlled. traffic efficiency can be increased. Keywords: intelligent; transportation; scm; traffic light; controller 專科生畢業(yè)設計(論文) III 目 錄 第 1 章 緒 論 ........................................................................................................... 1 選題依據(jù)和背景 ......................................................................................... 1 智能交通燈研究的意義 ............................................................................. 1 第 2 章 交通燈智能控制系統(tǒng)方案設計 ............................................................... 3 信號燈基本情況 ......................................................................................... 3 交通信號控制的基本參數(shù) ........................................................................ 3 城市道路平面交叉路口的類型 ................................................................ 4 交通信號的控制類型 ................................................................................. 4 交通流信息的檢測方法 ............................................................................. 4 2. 6 單交叉路口多相位交通信號的控制方案 .............................................. 5 第 3 章 硬件電路設計 ............................................................................................. 7 本系統(tǒng)電路 的組成和原理 ......................................................................... 7 信號轉換部分的設計 ................................................................................. 8 控制部分的設計 ....................................................................................... 11 3. 4 顯示部分的設計 .................................................................................... 17 3. 5 電源部分的設計 .................................................................................... 19 3. 6 控制器的延時設計 ................................................................................ 20 3. 7 看門狗技術和掉電保護在系統(tǒng)中的應用 ............................................ 23 第 4 章 軟件設計 ................................................................................................... 26 系統(tǒng)軟件總體設計 ................................................................................... 26 車流量采樣程序設計 ............................................................................... 26 單元程序塊的設計 ................................................................................... 28 第五章 總 結 ......................................................................................................... 35 參考文獻 ................................................................................................................. 36 致 謝 ....................................................................................................................... 37 ??粕厴I(yè)設計(論文) 1 第 1 章 緒 論 選題依據(jù)和背景 隨著城市化速度的加快,機動車日益普及,人