The ECU design and study of small SI engine

To control a small spark ignition( SI) engine electronically,an electronic control system was designed to reduce the emissions,improve its power and economy. By Using Freescales' microcontroller MC9S12XEP100 and MC33812 controller chip,the electronic control unit( ECU) hardware circuit of microcontroller unit( MCU) control module,the power management module,the input adjustment module,the output driver module and the controller area network( CAN) communication module were designed. The board support package was written by C language. The fuel injection and ignition signals were tested and analyzed to complete the bench test by using an engine 168 F.The test results showed that the rated power was increased by 7. 6%,the minimum effective fuel consumption was decreased by 7. 9% and the maximum torque of engine could reach to 11. 15 N·m,which was increased by 2. 3%. According to the United States Environmental Protection Agency( EPA) regulation of the small non-road SI engine,the emission of CO was 259. 18 g /( k W·h) and the emission of HC+NOx was 8. 05 g /( k W·h),both of which were decreased. The electronic controlled engine can meet the limitation of EPA phase Ⅲ standards and the electronic controlled system was qualified.