基于氧传感器的空燃比控制模型

基于反馈控制建立了一种计算方便、实用性强的空燃比控制模型,该发动机空燃比反馈控制模型以氧传感器信号为基础,由激活条件、调节振幅、方波、平衡、选择和滤波等6个模块构成。激活条件模块依据发动机运行条件选定空燃比是方波调节还是氧平衡控制调节,调节振幅模块则依据催化剂上游的废气质量流量确定燃油调节的幅度,调节信号经过选择、滤波后输出空燃比反馈修正系数,进而对喷油时间进行修正。论文最后将模块写进发动机电控单元(ECU)中进行初步的台架实验,结果表明发动机稳态时控制效果较好。

Air-fuel Ratio Control Model Based on Oxygen Sensor

Based on the oxygen sensor signal of feedback control, an air-fuel ratio control model of convenient calculation and strong practicability is established in this paper. It is divided into six parts as follows： Enable Condition, Amplitude modulation, Square Wave, Balance, Selection and Filter. According to engine operation conditions, activation condition model selects square wave or balance for air-fuel ratio adjustment. Amplitude modulation model determines the amount of fuel adjustment by the exhaust gas mass flow upstream of the catalyst. After selection and filter, the final output is air fuel ratio feedback correction coefficient which is used to modify the injection time. Finally, the module is written into ECU for preliminary bench test. The results show that engine runs well at steady state.