【作者】 马其华；

【导师】 边耀璋；

【作者基本信息】 长安大学 ， 交通运输规划与管理， 2006， 硕士

【摘要】 本文简述了电控汽油喷射式发动机的发展与现状，针对电喷发动机的工作原理及常见故障，介绍了此类发动机故障诊断的方法、步骤以及注意事项。 空燃比控制系统作为电控汽油喷射式发动机保证良好经济性、排放性和动力性的重要组成部分，其控制原理与过程对发动机的正常运行起着非常重要的作用。氧传感器对尾气排放中氧的实时监控是空燃比控制系统合理配制混合气的关键。氧传感器随发动机运转的变化特点以及其控制范围是本文的研究重点。通过模拟发动机故障试图找到由氧传感器诊断发动机故障的方法。 通过对数字存储示波器采集到的传感器正常和异常信号的波形分析，证实了波形分析法作为一种快捷、准确的诊断方法具有实用意义。小波分析法作为示波法的补充，具有信号除噪和特征辨析的功能，可作为判断发动机故障的依据。更多还原

【Abstract】 This dissertation formulates the development and actuality of the electronic controlled gasoline engine, introduces the approach and method of diagnosis this kind of engine, and some advert proceeding.The Air-fuel ratio control system is the important composing part to pledge its fuel economy, low emission and good driveability. The principle and control process are very important to run engine normally. Oxygen sensor stakeout to oxygen in let gas simultaneity is the key link for A/F ratio control system confect mixed gas logically. The emphases of this dissertation are to research the change characteristic of oxygen sensor with engine running and the control bound. Through simulation experimentation, this dissertation tries to find the method of diagnosis engine by oxygen sensor.Through the analyse of natural and exceptional wave shape of oxygen sensor collected by digital memory oscillograph, the wave shape analyse method is proved exactly and fast in practice. The wavelet analysis method qua complementarity to wave shape analyse method, has function of wiping off yawp and discern character. So it can become gist to diagnosis engine malfunction.更多还原