利用离子信号进行发动机空燃比控制方法的研究  

Air-Fuel Ratio Control Using Ionization Signal in Internal Combustion Engine

作　　者：吴筱敏[1] 李康[1] 魏若男[1] 蒋德明[1] 杨中乐[1] 

机构地区：[1]西安交通大学能源与动力工程学院汽车系,西安710049

出　　处：《内燃机工程》2007年第3期55-57,62,共4页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金项目(50276049)

摘　　要：直接利用燃烧中所产生的离子信号进行了空燃比控制方法的研究。试验表明,燃烧中的离子信号在火焰前锋与后区存在两个峰值,其峰值以及分别到达该峰值的时间均与空燃比有关,但其关系并非单值,在相对空燃比等于1附近信号峰值达极大值,而到达峰值时间达极小值。通过增加少量供油量,并对其油量变化前后信号时间大小的计算,提出了一种能有效判断混合气是处于浓或稀混合区的软件识别法。当空燃比在控制范围外采用分段法根据公式直接计算出所需的燃料,而当空燃比已经在控制范围内,则采用定值法,并选取较小的供油量,以同时满足控制效率和精度的要求。The objective of this paper was to investigate the control of air-fuel ratio （AFR） using an ionic signal produced by combustion. Experimental measurements indicate that there are two peak ionic signals which occur in front flame and post flame respectively. Both peak values and the time from ignition to peak value strongly depend on AFR during combustion. When AFR closes to stoichiometric value, the maximum values of ionic signal will occur and the time from ignition to peak value will be minimized. An algorithm for identifying the lean or rich mixture combustion was proposed, by adding a small amount of fuel and caculating the time before and after adding fuel. The required fuel can be calculated directly by the formula if AFR is out off the control range while a less fuel can be chosen if AFR is within the control range, in order to meet the requirements of control efficiency and accuracy.

关 键 词：内燃机 离子信号 空燃比 控制 供油量 

分 类 号：TK406[动力工程及工程热物理—动力机械及工程]