Development And Test Research On Electronic Control System For High Pressure Common Rail Diesel Engine

With the increasingly strict emission regulation and the development of diesel engine electronic control technology, the high pressure common rail (CR) injection system has become a trend of diesel engines technology because of its remarkable advantages, such as the neatly control of fuel injection and rail perssure,etc. Research on hardware and software design of ECU for CR engines is essential for the advancement and self-exploitation ability of inland diesel.Based on the control principle and the construction of electronic control system, a total design scheme of hardware, software and the control strategy for CR diesel engines has been made out. The peripheral components of system are introduced, including various sensors and driver devices, etc. By analying the working requirements of CR diese engine, this paper has designed the hardware circuit of system, which contains the input circuit module, output circuit module and the CAN communication module.For software design, Freescale's MC9S12XEP100 micro controller unit is used as the electronic control chip. After Processing the digital signal and converting the analog signal from sensor, the diesel rev has been calculated and the cylinder phase has been judged by programme. According to analyze the driving principle of injector solenoid valve and supply pump PCV with the phase of diesel, the flexible injection time and injection pulse width could be adjusted flexibly. In addition, a variety of fuel injection control strategies have been given for special working conditions, such as starting, idling state, etc.At last, this paper validats the hardware module and debugs the sofeware module. The experiment of ECU results show that the basal functions of ECU are achieved. It can handle signals from sensors, complete speed calculation and cylinder phase discrimination. The output drive circuit can drive solenoid valve quickly and effectively and meets the qualification of high pressure common rail diesel in various working conditions.