：基于单片机的交通灯设计 Title：Design of Traffic Light Based on MCU
Abstract: The ages is an automation ages nowadays and traffic light control's waiting a lot of equipments of professions is closely related with calculator. Therefore, a good traffic light control system will hustle for road, give technique innovation. This paper describes a 80C52 microcontroller-based traffic light control system, detailed description of the use 89C52 development process of the traffic light control system. Focus on a detailed analysis of the hardware design, software programming, analysis and debugging process of the modular system, on the part of the circuit are introduced one by one. The circuit is made up of 80C52 microcomputer, keyboard ,digital tube and LED lamp display and realize simulation in the Protues software.
Keywords:Traffic Control; Single Chip Microcomputer ;89C52
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2008级电子信息工程专业毕业设计 目 录
摘 要 ······································································································· I Abstract ····································································································· II
1绪论 ········································································································ 5 1.1交通灯的发展历史及研究意义 ································································· 5 1.2我国当前的交通现状 ·············································································· 6 1.3本课题的主要研究工作··········································································· 6 2设计方案 ·································································································· 7 2.1 系统机构总框架 ··················································································· 7 2.1.1 自动控制方式 ················································································· 7 2.1.2 人工控制方式 ················································································· 8 2.2 交通管理的方案论证 ··········································································· 10 2.3 系统电路框图 ···················································································· 10 2.4 电路的工作原理 ················································································· 11 3 硬件设计 ······························································································· 12 3.1 MCS-51单片机简介 ············································································ 12 3.1.1 单片机的内部结构 ········································································· 12 3.1.2单片机应用系统 ············································································· 13 3.1.3单片机的发展趋势 ·········································································· 14 3.2 系统电路 ·························································································· 14 3.2.1 最小系统模块 ··············································································· 15 3.2.2 LED显示模块 ··············································································· 15 3.2.3 数码管显示模块 ············································································ 16 3.2.4 按键控制模块 ··············································································· 17 3.2.5 驱动模块 ····················································································· 17 4 软件设计 ······························································································· 19 4.1 主程序流程图 ···················································································· 19 4.2子程序流程控制 ·················································································· 20 4.2.1 自动控制模式程序 ········································································· 20 4.2.2人工控制模式程序 ·········································································· 20 4.2.3键盘扫描程序 ················································································ 21 4.2.4 数码管中断显示程序 ······································································ 22 4.2.5 定时器T1子程序 ·········································································· 23 5 调试分析 ······························································································· 24 5.1 proteus软件简介 ················································································· 25 5.2 proteus仿真图 ···················································································· 25 5.2.1 自动控制仿真 ··············································································· 26 5.2.2 人工控制仿真 ··············································································· 28 结 语 ····································································································· 29
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：基于单片机的交通灯设计 参考文献 ·································································································· 30 致 谢 ····································································································· 32 附录1 ······································································································ 33
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1绪论
1.1交通灯的发展历史及研究意义
早在1850年，城市交叉口处不断增长的交通就引发了人们对安全和拥堵的关注。世界上第一台交通自动信号灯的诞生，拉开了城市交通控制的序幕，1868年，英国工程师纳伊特在伦敦威斯特敏斯特街口安装了一台红绿两色的煤气照明灯，用来控制交叉路口马车的通行，但一次煤气爆炸事故致使这种交通信号灯几乎销声匿迹了近半个世纪。1914年及稍晚一些时候，美国的克利夫兰、纽约和芝加哥才重新出现了交通信号灯，它们采用电力驱动，与现在意义上的信号灯已经相差无几。1926年英国人第一次安装和使用自动化的控制器来控制交通信号灯，这是城市交通自动控制的起点。
1917年，在美国盐湖市开始使用联动式信号系统，把六个交叉路口作为一个系统，以人工方式加以集中控制。1922年，美国休斯顿市建立了一个同步系统，它以一个交通亭为中心控制十二个交叉路口。1928年，上述系统经过改进，形成“灵活步进式”定时系统;由于它简单、可靠、价格便宜，很快在美国推广普及。这种系统以后不断改进、完善，成为当今的协调控制系统。20世纪30年代初，美国最早开始用车辆感应式信号控制器，之后是英国，当时使用的车辆检测器是气动橡皮管检测器。
计算机技术的出现为交通控制技术的发展注入了新的活力，1952年，美国科罗拉多州丹佛市首次利用模拟计算机和交通检测器实现了对交通信号机网的配时方案自动选择式信号灯控制，而加拿大多伦多市于1964年完成了计算机控制信号灯的实用化，建立了一套由IBM650型计算机控制的交通信号协调控制系统，成为世界上第一个具有电子数字计算机城市交通控制系统的城市。这是道路交通控制技术发展的里程碑。
国外对城市区域交通控制的研究，开始于20世纪60年代初。1967年，英国运输与道路实验室(TRRL)成功开发出TRANsYT(TraffioNetworkStudyTools)交通控制系统，后来又在TRANsYT的基础上开发了seOOT(split Cyele and offset OPtimization Technique)系统。澳大利亚在70年代末也开发了基于配时方案实时选择方法来实现路网协调控制的SCAT(Sydney Coordinated Adaptive Traffic Method)系统。这些系统己经在西方国家的城市网络交通中取得了成功的应用。
进入20世纪80年代后期，随着城市化进程的加快和汽车的普及，城市交通
：基于单片机的交通灯设计 拥挤、阻塞现象日趋恶化，由此引发的事故、噪声和环境污染己成为日益严重的社会问题，交通问题成为困扰世界各国的普遍性难题。于是，智能交通系统应运而生，并得到迅猛发展。除在技术和功能上得到增强和完善的SCOOT和SCATS以外，STREAM、ITACA、MOTION、RT-TRACS、SURFZ000、PRODYN和UTOPIA等新一代城市交通控制系统相继推出并投入应用[1]。
1.2我国当前的交通现状
我国是一个文明古国，许多城市已有上千年的历史，城市布局和道路结构是在漫长的历史进程中逐步形成的，近几年虽然作了些改建和扩建，但毕竟还难以冲破原来的基本格局。
目前我国城市道路普遍存在以下三个弊端：①路网密度低；②交通干道少；③路口平面交叉。
道路状况与车辆状况的综合作用形成了我国城市交通的特殊性，主要有以下表现：
城市路网稀，干道少，间距大，市区人口稠密，出行需求集中，迫使车辆集中于少数干道上行驶。尤其是一些中小城市 ，干道特征更为明显，往往只有一两条干道贯穿全市，而其他支路上交通量极小。从流量变化情况来看，除外围过境干道外，都是有一定规律的，高峰小时基本上都集中在几个时段内。
我国城市机动车车种繁杂，从50年代的老式车到80年代的新型车，从大货车到小轿车都在一个平面上行驶，不少城市拖拉机还是一种主要运输工具，前面一辆旧车挡道，尾随的新型车只能跟着爬行，过交叉口时经常出现启动慢的车挡住启动快的车，严重影响了人们的生活节奏和出行效率[2]。
1.3本课题的主要研究工作
本课题主要通过利用89C51单片机设计一个交通控制系统通过对十字路口的实际调查，由交通状况的车流量的大小，确定车辆放行时间为60秒，即当一条干道的车辆处于放行状态时，另一条干道禁止放行，持续60秒；并在最后10秒时，放行车道的路灯闪烁，警示行人注意红灯的到来。
为了应对可能发生的突发状况，使其中一条干道随时可以强制放行，因此，整个系统的设计分为两种模式：自动控制模式和人工控制模式。在自动控制模式中，两个干道依次各放行60秒，轮流进行。人工控制模式中，通过按键操作，使某个干道处于强行通行状态，另一车道禁止通行。由此大大改善了交通运营状
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