The Study Of Electronic Control Unit For The Four Cylinder Gasoline Engine

2010,China replaced America became the world largest car market, in the field of automobile industry, china is a large country but not power country. Domestic independent vehicle brand market share less than 40%, a few of key components are got by means of importing, such as the engine electronic control unit. 90% of them are monopolized by BOSCH and Delphi. In order to break the foreign monopoly of the core technology of ECU, recently years, the engineers began to research and develop the engine electronic control unit independently.In view of the present domestic research situation of the electronic control unit, the author developed a set of the velocity- density method, sequential ignition, multipoint intake fuel injection engine control system; completed engine timing of synchronization; designed the corresponding fuel injection and ignition timing control strategy at different engine working conditions; based on freescale MC9S12XEP100 microcontroller, completed ECU hardware circuit design and PCB production; according to the modular design thinking, wrote the control program of ECU with C language in CodeWarrior IDE5.3 development software platform, finally completed the software debugging.To achieve precise control on ignition advance angle and fuel injection at different gasoline engine operating conditions, the author calibrated the initial data of related control parameters of control system and made the charging efficiency MAP and ignition advance angle MAP. In order to verify the feasibility and accuracy of the self-developed ECU, the author operated the be nch experiments on JL473 Q gasoline engine.The experimental results shows that EC U can start engine quickly, the attenuation characteristic of fuel injection quantity consistent with the theoretical value in the process of start; idle speed fluctuation rate is less than 5%,the engine is relatively stable in and out of idle condition; at steady load condition, the Lambda value remains within the range of 0.97~1.03;when the engine speed accelerate or decelerate, the fuel injection quantity will increase or decrease.