摘  要

城市交通信號控制是通過對交通流量的調(diào)節(jié)以達(dá)到改善人和貨物的安全運輸，提高運營效率。交通系統(tǒng)是一個具有隨機(jī)性、模糊性和不確定性的復(fù)雜系統(tǒng)，建立數(shù)學(xué)模型非常困難，有時甚至無法用現(xiàn)有的數(shù)學(xué)方法加以描述。目前大多采用的是自適應(yīng)信號控制，它需要數(shù)學(xué)建模，且不考慮交通延誤、停車次數(shù)等。所以經(jīng)典控制法很難得到滿意的效果。而模糊控制是一種無須建立數(shù)學(xué)模型的控制方法，它能模仿有經(jīng)驗的交警指揮交通時的思路，達(dá)到很好的控制效果。近些年來我國的許多學(xué)者也都以不同的思路對單個交叉口、交通干線的模糊控制進(jìn)行了研究，但因研究的局限性，實際中得到應(yīng)用的寥寥無幾，本文實現(xiàn)基于PLC的交通信號的控制系統(tǒng)。

    根據(jù)前后相流量來決定信號燈配時的模糊控制系統(tǒng)的理論研究成果，用PLC實現(xiàn)單個十字路口交通信號燈模糊控制的方法，以單個十字路口4相位交通燈為例，把PLC作為一個模糊控制器，采用梯形圖編程。通過實驗保證了系統(tǒng)運行穩(wěn)定可靠，能根據(jù)不同的交通流量進(jìn)行模糊控制決策，優(yōu)化信號燈的配時，從而可以有效的解決交通流量不均衡、不穩(wěn)定帶來的問題。

近年來隨著科技的飛速發(fā)展，一個以微電子技術(shù)、計算機(jī)技術(shù)和通信技術(shù)為先導(dǎo)的信息革命正在蓬勃發(fā)展。計算機(jī)技術(shù)作為三者之一，怎樣與實際應(yīng)用更有效的結(jié)合并發(fā)揮其作用。單片機(jī)作為計算機(jī)技術(shù)的一個分支，正在不斷的應(yīng)用到實際生活中，同時帶動傳統(tǒng)控制檢測的更新。在實時檢測和自動控制的應(yīng)用系統(tǒng)中，單片機(jī)往往是作為一個核心部件使用，針對具體應(yīng)用對象的特點,配以其它器件來加以完善。靠的是交通信號燈的自動指揮系統(tǒng)，來實現(xiàn)交通的井然有序。交通信號燈控制方式很多。本系統(tǒng)采用美國ATMEL公司生產(chǎn)的單片機(jī)AT89S51，以及其它芯片來設(shè)計交通燈控制。實現(xiàn)了通過AT89S51芯片的P1口設(shè)置紅、綠燈點亮的功能，通過AT89S51芯片的RXD、TXD輸入、輸出設(shè)置顯示時間。交通燈的點亮采用發(fā)光二極管實現(xiàn)，時間的顯示采用七段數(shù)碼管實現(xiàn)。單片機(jī)系統(tǒng)采用的直流供電。為了系統(tǒng)穩(wěn)定可靠，系統(tǒng)內(nèi)集成了“看門狗”芯片，避免了系統(tǒng)因為死機(jī)而停止工作的情況發(fā)生。系統(tǒng)實用性強(qiáng)、操作簡單、擴(kuò)展性好。

關(guān)鍵詞： 交通燈 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 錄

摘  要 I

Abstract II

1 引言 1

2 交通管理方案論證 2

2.1 設(shè)計任務(wù) 2

2.2 方案介紹 2

3 交通燈系統(tǒng)硬件設(shè)計 5

3.1 單片機(jī)概述 5

3.2 系統(tǒng)構(gòu)成 5

3.3芯片選擇與介紹 6

4 交通燈軟件設(shè)計 11

4.1 程序設(shè)計流程圖 11

4.2延時的設(shè)定 13

4.3 程序的主控制循環(huán)調(diào)用 15

4.4 對現(xiàn)有程序的擴(kuò)充 15

5實驗平臺 17

5.1實驗平臺 17

5.2實驗步驟 17

結(jié)   論 19

致   謝 20

參考文獻(xiàn) 21

附   錄 22