The Study Of Control Strategy For High Pressure Common Rail Diesel Engine

High pressure common rail fuel injection system can realize a flexible control on rail pressure, fuel injection quantity, injection timing and injection rate on total working conditions. To improve system's performance, mainly on ECU control strategy and control algorithm , besides the mechanical aspects and ECU hardware circuit performance.With the analysis of system's structure and control principle, control strategy research has been done, including pressure control strategy and injection control strategy. After that a study on the technologie of hardware and software for ECU development has been done.The precise pressure control is the premiss for many other parameters's optimal control, at starting condition, it requests establishment of rail pressure speedly; after starting, it should adapt to the changes of working conditions, and maintain stability. In order to control pressure better, PID, fuzzy and fuzzy self-adapted PID control algorithm have been contrasted, the simulation analysis and development board experiment have proved that fuzzy self-adapted PID control algorithm is more effective.The injection control includes fuel injection quantity control, injection timing control and injection rate control. For the sake of good quality of the cylinder gas mixture, in addition to adjust injection pressure flexibly with the changes of working conditions, the more important is the precise control of the injection quantity and injection timing. Injection control is by the means of looking up MAP through open-loop control, and the MAP including basical MAP and modified MAP.Finally, in order to verify control strategy, control algorithm simulation analysis has been done with MATLAB\Simulink, and the tecnology of method-based software development for ECU has been studied at the same time. Using RCM3400 module for the ECU development, with the drive modules, the driving control experiment has been done on fuel injection control and pressure control. The results show that the ECU has a good performance. Application PID fuzzy self-adapted control algorithm on pressure control, the actual control results show that, the static precise and dynamic performance of the system is improved by it..