摘要：目前我国经济发展进入飞速发展的阶段,汽车的数量也正在以惊人的速度增加,汽车的安全性越来越为人们所重视,其中汽车中所产的CO就是其中大一个安全隐患，汽车在正常的运转状态下（发动机转速在1500——3000转每秒）时，发动机所产生的一氧化碳量很低，但如果汽车发动机的转速在小于的1500转每秒时，发动机中的燃料就会燃烧不充分，废气中的一氧化碳含量就会大大的增高。还有一种情况就是在发动机转速超过3000转每秒时同样会产生大量CO。尤其是一些即将报废的旧车，因其三元催化器老化，也会出现CO的产生和泄露。因此，设计一个车载CO报警装置是十分重要的。

我的这篇论文主要是对汽车内部的CO浓度进行测量与报警。采用探测器、单片机控制电路设计思路，我在设计中用传感器 MQ7对CO进行检测，因为它价格便宜，购买方便而且稳定；对于空气中的一氧化碳浓度进行检测，我采用AT89C51 单片机作为中央处理器，当CO的浓度不在安全范围内，控制电路将启动蜂鸣器进行报警。

关键词：CO;车载;单片机;报警

Design of Vehicle CO Alarm Device Based on Single Chip Microcomputer

Abstract: The continuous development of science and technology is bound to promote the continuous innovation of manufacturing technology, the automotive industry has reached a peak period of development. With the continuous improvement of people's living standards, the car has become a common consumer goods from the luxury of the family. In recent years, people's ideas are constantly updated, more and more attention to the safety of the car. From the birth of the first car, automobile manufacturers have been in continuous research on how to make the car more secure. Automotive electronic detection alarm equipment involved, by the automotive public recognition.

Automobile engine in high-speed operation of the state, the carbon monoxide content in the exhaust gas is very low, but when the engine idling, because of incomplete combustion, carbon monoxide content in exhaust gas will be increased; if it is under the condition of parking the air-conditioning, at the same time window is not open, the car air can only be through the air conditioning equipment produce convection, when the engine emission of carbon monoxide will through the air conditioning equipment transported to the car and gather more, as with the car discharge of carbon dioxide, a long time, reduce the oxygen inside the car, the personnel inside the vehicle will not know not feel poisoning, serious, you will die.

This paper mainly focuses on the measurement and alarm of the CO concentration in the car. The design of the detector and the MCU control circuit is adopted. The scheme has the advantages of fast response, small error and so on. Of carbon monoxide concentrations were detected by using a very stable CO sensor MQ7, using AT89C51 single-chip microcomputer as the central processing unit and the concentration signal acquisition, data processing, display, alarm and open the exhaust etc. work. When the carbon monoxide concentration exceeds the allowable value, the control circuit for alarm.

Key words: CO; Vehiclesingle chip microcomputer; Alarm

目  录

摘要 1

1. 绪论 3

1.1 课题研究背景及意义 3

1.2 国内外研究现状 3

2. 车载CO报警装置硬件设计 4

2.1 系统硬件设计 4

2.2 主控单元设计 5

2.3 调节执行单元的设计 5

2.4 报警单元的设计 6

2.5 检测单元设计 6

3. 车载CO报警装置设计 7

3.1 车载CO报警装置检测软件设计 7

3.2 车载CO报警装置电路设计 8

4. 总结与展望 10

4.1 总结 10

4.2 展望 10

参考文献 11

附录 12

附录1 硬件电路仿真电路图 12

附录2 主模块部分程序 13

致谢 14

基于单片机的车载CO报警装置的设计