摘  要随着我国国民经济的飞速发展，铁路网络也日益发达。现如今列车的运行速度、密度和载重都在不断地提高，并且铁路线路还在不断的修建，这将使铁路道口的数量随之增加。这么多的铁路道口中有的在繁忙的交通要道，有的在经济条件落后、环境恶劣的地方。正因为受到这些条件的限制，道口采用无人值守的管理办法。无人值守的铁路道口的交通情况不佳，很容易发生交通事故。一旦发生交通事故，轻则会造成不必要的交通堵塞，重则导致惨重的人员伤亡和巨大的经济损失。针对上述问题，为了提高道口安全性，这要求我们要设计出一套安全可靠的自动报警系统。本文设计了基于PLC的铁路道口自动报警系统，该系统采用无源磁电式传感器来检测列车到来，根据检测的信号传送给可编程控制器（PLC），运用PLC对无人值守的铁路道口进行一系列控制。通过系统控制道口的交通信号灯、栏木机并及时进行报警提示，来保证过往车辆以及行人的安全。通过一段时间的测试，证明该系统具有很高的可靠性和实时性。74905

该论文有图23幅，表1个，参考文献20篇。

毕业论文关键词：铁路道口  磁电传感器  可编程控制器  自动报警系统

The Design of Automatic Warning System of Railway Crossing Based on PLC

Abstract With the rapid development of China's national economy, the railway network is also becoming more and more developed。 Now the train running speed, density and the load in the continuously improve, and the railway line also continued to build, which will enable the number of railway crossing increases。 So many of the railway crossing in some busy traffic, some of the economic conditions behind the harsh environment of the place。 Because of these limitations, by crossing unattended management measures。 The traffic situation of unattended railway crossing is poor, it is prone to traffic accidents。 In the event of a traffic accident, it will cause unnecessary traffic jams, heavy casualties and huge economic losses。 Aiming at the above problems, in order to improve the safety of the crossing, which requires us to design a safe and reliable system which requires us to design a set of safe and reliable automatic alarm system。 This paper designs the automatic alarm system for railway crossing based on PLC。 The system uses passive magnetoelectric sensor to detect the arrival of the train, according to the detection signal is transmitted to the programmable controller (PLC), using PLC for unattended railway crossing a series of control。 Through the system control intersection traffic signal lamp, keurboom machine and timely alarm, to ensure the passing vehicles and pedestrians。 Through a period of testing, it is proved that the system has a high reliability and real-time performance。

Key words: Railway crossing  magnetoelectric sensor  Programmable controller    automatic alarm system

目   录

摘要 I

Abstract II

目录 III

图清单 V

表清单 V

1 绪论 1

1。1 课题研究背景及意义 1

1。2国内外研究现状 3

1。3本文研究主要工作 4

2 系统的硬件设计 5

2。1传感器 5

2。2 磁电传感器工作原理 7

2。3 传感器输出信号处理电路