Design On Electronic Control System Of Lean Burn Gasoline Engine

As the energy source crisis continuously increases, fuel economy of automobiles has become the key problem which influences the development of automobile industry. Lean burn technology offers considerable potentiality in improving gasoline engine fuel economy.To satisfy the special requirements of lean burn technology and the emission control of gasoline engine, an electronic control system suitable for lean burn gasoline engine has been developed. This system can achieve twice injection and control the proportion of the fuel injected at the first time to the second time and the injection angles. It can also adjust mixture to be rich periodically for a short time which enables the NOx storage-reduction catalyst to work, so the emission can be reduced. While the mixture's density changes, the constant output power is obtained by synchronized control of the ignition time and throttle opening.The ECU of the system has C167 series single-chip as its microprocessor, and controls the engine in the centralized way. The ECU can function as those of the advanced automobiles and also has certain ability to extend its capability. Using fuzzy parameter self-tuning PID controller, the fluctuation of the speed during the transitional time can be adjusted within the estimated and acceptable range.The system is mainly used in lean burn experiment on YH465 gasoline engine. Experiments show that Quasi-Homogeneous Lean Mixture Combustion and after treatment by NOx storage-reduction catalyst converter is feasible for lean burn technology and its emission, and this lean burn gasoline electronic control system can basically satisfy the requirements of accuracy and speed of control. In addition, it has reliable performances, strong resistance to disturbance, perfect function and convenient use.