氧传感器参考电平自适应空燃比闭环控制方法研究

为了解决开关式氧传感器空燃比闭环控制点的漂移问题，建立了开关式氧传感器闭环控制的数学模型，并分析了氧传感器信号参考电平对空燃比闭环控制的影响，据此，提出了氧传感器参考电平自适应空燃比闭环控制方法，在发动机上试验了氧传感器参考电平对空燃比的影响规律，并进行了氧传感器参考电平的优化试验，结果表明，氧传感器参考电平自适应控制方法可以有效避免空燃比闭控制点随发动机工况变化的漂移问题，有效地降低了汽油机的排放。

A Study of A/F Ratio Close Loop Control System Ruled by Adaptive Reference Voltage of EGO Sensor

In order to deal with the target air/fuel ratio (A/F) floating problem occurred in the close loop A/F control system with a switch type exhaust gas oxygen sensor (EGO), the adaptive EGO sensor reference voltage control method is developed on the basis of control system mathematic model and the a-nalysis of the influence of EGO reference voltage on target A/F. The influence of EGO reference voltage on target A/F has been tested and the EGO reference voltages are optimized on an engine. The results show that this control method can effectively prevent the target A/F ratio from floating as the engine operating condition changed, so the exhaust emissions of a gasoline engine can be effectively reduced.