摘 要
可編程序控制器在工業(yè)自動化中的地位極為重要，廣泛的應用于各個行業(yè)。隨著科技的發(fā)展，可編程控制器的功能日益完善，加上小型化、價格低、可靠性高，在現(xiàn)代工業(yè)中的應用更加突出。城市交通燈控制采用的可編程制器具有可靠性高、維護方便，用法簡單、通用性強等特點，本文用三菱FX2N的可編程控制器控制十字路口信號燈來說明可編程控制器硬件、軟件的設計。解決好公路交通燈控制問題將是保障交通有序、安全、快捷運行的重要環(huán)節(jié)。但現(xiàn)在有的交通信號燈控制系統(tǒng)都是單一的固定時序控制，不能夠根據(jù)實際交通狀況進行調(diào)節(jié)控制。三菱系列的可編程序控制器和傳感技術來實現(xiàn)對交通燈的智能信號控制。可用如下方案來控制交通路況:制作傳感器探測車輛數(shù)量來控制交通燈的時長。具體如下:在入路口的各個方向附近的地下按要求埋設感應線圈，當汽車經(jīng)過時就會產(chǎn)生渦流損耗，環(huán)狀絕緣電線的電感開始減少，即可檢測出汽車的通過，并將這一信號轉換為標準脈沖信號作為可編程控制器的控制輸入，并用PLC計數(shù)，按一定控制規(guī)律自動調(diào)節(jié)紅綠燈的時長。

關鍵詞： PLC（可編程序控制器）; 三菱FX2N;傳感器探測;交通燈。

Abstract
The variable procedure controller is in industry automate the position is extremely important, extensive application in each profession. Along with the development of science and technology, the function of the programmable controller is increasingly perfect, plus smallscaled turn, the price is low, the credibility is high, the application that is in modern industry is more out standing. The city transportation light control adopts programmable to make the tool contain high credibility, the maintenance convenience, the method of using is simple, the in general use strong etc. characteristics, this text uses the design that the programmable controller of the Mitsubishi FX2N control intersections conveyance light explains the programmable controller hardware software. Resolve the good highway transportation light control problem will is guarantee the transportation contain preface, safety, fast movement of important link. But the transportation signal beacon control systems have now are all the single and fixed cycle times controls, can't carry on regulating the control according to the actual transportation condition enough. The programmable preface controller of the Mitsubishi series and spread the feeling technique to carry out the intelligence signal control toward the transportation light. Can use as follows the project controls the transportation situation on road: the creation spreads the feeling machine to probe into the vehicle quantity the hour of control the transportation light is long. In a specific way and as follows: The at go the into the underground of the each the direction neighborhood the of the street corner the to lay the to respond the coil the according to the trequest, the be the automobile to the pass by the will produce the to flow the to exhaust, the wreath the form insulates the electricity the feeling of the electric the wire to start reduce, can immediately examine pass of an automobile, and convert this signal control importation that is the programmable controller for the standard pulse signal, counteract the PLC to count, long by the hour that the certain control regulation regulates the traffic lights automatically.

Keywords：PLC( Programmable Logical Controller); Trapezoid; diagram; Instruction In proper order function diagram Transportation light

目 錄

摘 要 I
Abstract II
第 1 章 緒論 2
1.1 引言 2
1.2 課題研究背景 2
1.3 現(xiàn)在城市路口交通燈控制技術現(xiàn)狀 3
1.4 本課題主要研究內(nèi)容 3
第 2 章 PLC功能簡介 4
2.1 概述 4
2.2 可編程控制器的發(fā)展 5
2.3 主要用途 7
2.4 可編程控制器特點 7
2.5 可編程控制器的組成 9
2.6 PLC的工作原理 9
2.7 主要功能 11
2.8 可編程控制技術的發(fā)展趨勢 13
第 3 章 交通燈控制電路的設計 15
3.1 PLC正常時序 15
3.2 I/O地址分配 15
3.3 主程序流程圖 16
3.4 正常時序情況 17
3.5 急車強通情況 21
3.6 車流滯留情況紅綠燈時間長度控制 25
3.7 車流量的計算 28
3.8 運行程序語句表 29
3.9 運行效果 30
第 4 章 總結 31
參考文獻 32
致 謝 33