摘要：随着社会经济飞速发展，电子产品的使用越来越频繁，造成火灾发生的可能性也越来越高，所以防火的工作越显重要，火灾报警器的研发是刻不容缓的。本文针对列车车厢设计了一种烟雾报警系统。通过对列车车厢起火原因的调查，并根据列车的特点，本文提出在列车乘务员室内和配电室都安装烟雾传感器，这些地方都是火灾防范的重要位置，需要实时监测列车车厢烟雾浓度，从而在危急时刻作出紧急处理。为及时检测到烟雾异常情况，要在乘务员室安装烟雾报警分机。本文设计了一种以单片机控制的烟雾报警器，该报警器以MQ-2作为烟雾传感器采集被测环境中的烟雾浓度，通过数模转换，产生单片机可识别的数字电压信号，由单片机进行数据数据分析和处理，从而起到火灾预警的作用。63498

毕业论文关键词： 烟雾报警器；MQ-2烟雾传感器；单片机

Design of smoke alarm system for train compartment

Abstract：With the rapid development of the economic society, the use of electronic products more and more frequently, the possibility of fire occurrence is higher and higher, so the fire prevention work is more important, so fire alarm research and development is urgent.  In this paper, a smoke alarm system is designed for the train compartment. Through the investigation of the train compartment fire, and according to the characteristics of the train, this paper puts forward to install the smoke sensor in the train crew room and the distribution room. these places are the important position of fire prevention, need real-time monitoring the smoke concentration of train compartment, and make emergency treatment in emergency. To detect the smoke abnormality in time, install the smoke alarm extension in the cabin crew room. A smoke alarm controlled by single chip computer is designed in this paper, which uses MQ as smoke sensor to collect the smoke concentration in the measured environment. through analog to analog conversion, the digital voltage signal can be identified by MCU, and the data data can be analyzed and processed by MCU, thus playing the role of fire alarm.

KeyWords：smoke alarm; MQ-2 smoke sensor; MCU

 目 录

1绪论 1

1.1 课题的目的和意义 1

1.2 采用烟雾报警系统的优势 1

1.3 国内外研究现状与发展趋势 2

1.3.1 国内外研究现状 2

1.3.2 发展趋势 3

1.4 论文主要工作与内容安排 4

2 烟雾检测报警器的硬件设计 5

2.1 烟雾报警系统的设计思路 5

2.2 烟雾传感器的选型 5

2.2.1 烟雾传感器介绍 6

2.2.2 烟雾传感器的选定 10

2.2.3 MQ-2型烟雾传感器的工作原理 10

2.2.4 MQ-2型传感器的特性及主要技术指标 12

2.3 烟雾报警器整体设计方案 13

2.4 单片机最小系统设计 14

2.4.1 AT89C51单片机简介 14

2.4.2 单片机的引脚功能描述 15

2.4.3 单片机最小系统 17

2.5 A/D转换电路 18

2.5.1 模数转换器的工作原理