城市交通灯控制系统.doc

摘  要

城市交通信号控制是通过对交通流量的调节以达到改善人和货物的安全运输，提高运营效率。交通系统是一个具有随机性、模糊性和不确定性的复杂系统，建立数学模型非常困难，有时甚至无法用现有的数学方法加以描述。目前大多采用的是自适应信号控制，它需要数学建模，且不考虑交通延误、停车次数等。所以经典控制法很难得到满意的效果。而模糊控制是一种无须建立数学模型的控制方法，它能模仿有经验的交警指挥交通时的思路，达到很好的控制效果。近些年来我国的许多学者也都以不同的思路对单个交叉口、交通干线的模糊控制进行了研究，但因研究的局限性，实际中得到应用的寥寥无几，本文实现基于PLC的交通信号的控制系统。

    根据前后相流量来决定信号灯配时的模糊控制系统的理论研究成果，用PLC实现单个十字路口交通信号灯模糊控制的方法，以单个十字路口4相位交通灯为例，把PLC作为一个模糊控制器，采用梯形图编程。通过实验保证了系统运行稳定可靠，能根据不同的交通流量进行模糊控制决策，优化信号灯的配时，从而可以有效的解决交通流量不均衡、不稳定带来的问题。

近年来随着科技的飞速发展，一个以微电子技术、计算机技术和通信技术为先导的信息革命正在蓬勃发展。计算机技术作为三者之一，怎样与实际应用更有效的结合并发挥其作用。单片机作为计算机技术的一个分支，正在不断的应用到实际生活中，同时带动传统控制检测的更新。在实时检测和自动控制的应用系统中，单片机往往是作为一个核心部件使用，针对具体应用对象的特点,配以其它器件来加以完善。靠的是交通信号灯的自动指挥系统，来实现交通的井然有序。交通信号灯控制方式很多。本系统采用美国ATMEL公司生产的单片机AT89S51，以及其它芯片来设计交通灯控制。实现了通过AT89S51芯片的P1口设置红、绿灯点亮的功能，通过AT89S51芯片的RXD、TXD输入、输出设置显示时间。交通灯的点亮采用发光二极管实现，时间的显示采用七段数码管实现。单片机系统采用的直流供电。为了系统稳定可靠，系统内集成了“看门狗”芯片，避免了系统因为死机而停止工作的情况发生。系统实用性强、操作简单、扩展性好。

关键词： 交通灯 PLC 智能控制

Abstract

City traffic signal control is through the adjustment of the traffic flow in order to improve the safety of transport of people and goods, improve operational efficiency. Transport system is a random, fuzzy and uncertainty of complex systems, it is difficult to build mathematical model, sometimes impossible to use existing mathematical methods described. At present most adaptive signal control is used, it needs mathematical model, without considering traffic delays, number of stops. So the classical control method is very difficult to get a satisfied effect. Fuzzy control is a kind of does not need to establish the mathematical model to control methods, it can imitate experienced police directing traffic, ideas, achieve good control results. In recent years, many Chinese scholars have different ideas of fuzzy control to the traffic single intersection, were studied, but because of the limitations of the research, application of scanty practice, the implementation of traffic signal control system based on PLC.

Decision fuzzy signal control system theory research results according to the method and flow, using PLC to achieve a single traffic lights at the crossroads of fuzzy control, the single crossroads 4 phase of traffic lights, for example, the PLC as a fuzzy controller, using ladder programming. Through the experiment to ensure the reliable operation of the system, can be fuzzy control decision according to the different traffic flow, optimize signal distribution, which can effectively solve traffic imbalance, instability problems.

In recent years, with the rapid development of science and technology, a microelectronics technology, computer technology and communication technology as the forerunner of the information revolution is booming. As one of the three computer technology, combined with practical application more effective and play its role. Single chip microcomputer as a branch of computer technology, has been applied to real life, and promote the traditional control detection update. In real-time detection and automatic control system, SCM is often used as a core component, according to the characteristics of the specific application object, match with other devices to be perfect. Relying on the automatic command system of traffic signal lamp, traffic in order to achieve. A lot of traffic signal control. This system uses the American ATMEL company AT89S51 microcontroller, and other chip to design the control of traffic lights. Through the implementation of the AT89S51 chip set P1 mouth red, green light function, through the AT89S51 chip RXD, TXD input, output is set to display the time. Traffic lights lit by the light emitting diode, the time display using seven digital tube. DC power supply used in SCM system. In order to the system is stable and reliable, the system integrates "watchdog" chip, to avoid the system crashed and stop work because of the situation. The system practical, simple operation, good scalability.

Key words：The traffic lights PLC intelligent control

 

目 录

摘  要 I

Abstract II

1 引言 1

2 交通管理方案论证 2

2.1 设计任务 2

2.2 方案介绍 2

3 交通灯系统硬件设计 5

3.1 单片机概述 5

3.2 系统构成 5

3.3芯片选择与介绍 6

4 交通灯软件设计 11

4.1 程序设计流程图 11

4.2延时的设定 13

4.3 程序的主控制循环调用 15

4.4 对现有程序的扩充 15

5实验平台 17

5.1实验平台 17

5.2实验步骤 17

结   论 19

致   谢 20

参考文献 21

附   录 22