基于PLC的交通灯控制系统设计外文翻译

毕业设计（外文翻译）

英文题目 PLC-based design of traffic lights 中文题目 基于PLC的交通灯设计 系 （院） 自动化系 专 业 电气工程与自动化 学生姓名

学 号 2009022388 指导教师 职 称 讲 师

二〇一三 年 六 月

PLC-based design of traffic lights

Abstract: One kind of traffic light control system using programmable logic controller (PLC), via software control traffic lights run automatically. In the system, the original line is the program instead of the relay, programmable logic controller (PLC) system hardware and software resources to be fair use. Normal operation and emergency transport for a detailed description and from the East and West emergencies can be mutually linked. Traffic signal systems and two seven-segment digital display in the countdown order; also discussed in detail the wiring of the hardware and PLC ladder. Traffic lights at the crossroads of the remote monitoring system design configuration software MCGS, real-time monitoring of traffic lights, greatly improving the reliability of data transmission. At the same time, we can configure the traffic lights to change the status of photographs.

Keywords: switching power,supply protection, circuit system design

1. Introduction

With the social development and progress, traffic flow becomes increasingly important. On the one hand, too many crossroads, more and more vehicles, which are causing serious traffic congestion. On the other hand, in the limited time it is necessary to maintain the vehicle and pedestrian fast and safe. Therefore, one kind of traffic light control system design, can be used to display time countdown, with computer controlled real-time data. In addition, the configuration technology for real-time images that reflect the traffic lights, understand the historical crossroads of work to get traffic lights visualization. The system consists of host computer and a low computer. MCGS configuration is installed in the host computer is lower by the PLC control system.

Normal traffic signal timing diagram shown in Figure 1. But there are some urgent matters, for example. There are a number of ambulances to transport patients to the hospital or to deal with a number of fire engines and fire. Fire engines and ambulances rushed to take precedence over other traffic scene. According to urban traffic control system, under normal circumstances, two control methods and urgency traffic control factors into account. This process can show 14 segment encoder. U.S. traffic lights instant record of the monitoring process.

Emergency control signals to control traffic emergency switch. If there is no emergency lights all work, but when an emergency open. In this case, the car is urgent priority pass. Once the emergency vehicle passes, emergency switch off immediately. The green light in the same direction of the vehicle quickly flashes three times, followed by the normal operation. If you were from the north-south and east-west two emergency vehicles, traffic control systems can respond quickly came early, and then another.

2. Traffic Control System Design

A. Hardware design

CP1H series PLC as controller, display the procedure should stop when the time series of abnormal system operation, the time will not be displayed. When the emergency procedures are completed time series, countdown display program should be reset. At 220 V AC system is used to control traffic lights, 24 V DC control segment encoder, Figure 2 shows the scheme Eastern time display. CP1H series programmable logic controller (PLC) is a simple controller, which consists of 24 inputs and sixteen outputs. Because the output to twenty In this system, an I / O

module must be extended. Circuit is shown in Figure 2.

B. Control Program Design

Six timers and two special normal open pulse is used in this system, the green light flashes for all north-south and east-timer and a special pulse; eight kinds of

interlocking internal relay is used to implement the urgency and transmit pulse two directions to PLC, shown in the figure. Two SDEC instructions are used to display the countdown display the corresponding light. As an important part of the countdown display program, east and west of the green light reflected in the view 4 in these programs downloaded to the programmable logic controller (PLC), all the traffic lights running accuracy, urgency, and things can be interlocked from north to south strictly, all the lights can be set back to the urgency of passing state. Therefore, these control program is correct, simple.

C. Monitoring System

Computer system has two main functions: an output signal acquisition and display real-time status of the programmable logic controller (PLC) to control traffic lights, traffic lights. Another notification robot status and history of the state real-time curve by examining the history and alarm window.

This monitoring system design and configuration software MCGS

configuration is easy. The serial communication is implemented as follows.

Data inspection methods: double ended

Serial Communications Number: COM0 ended

The minimum sampling period: 200 ms

Programmable Logic Controller (PLC) The parameters are defined as follows: The minimum sampling period of the basic properties: 200 ms

Three read / write channel: X0, X1, X2

Six read-only access (read U.S. traffic lights): Q0-Q5

All channels must be connected to a variable defined in a real-time database access visits and other parameters to their default values. After a successful relationship, PLC and computer control system is able to change the color of the analog signal lights in the pictur …… 此处隐藏：6938字，全部文档内容请下载后查看。喜欢就下载吧 ……