Fuel injection quantity fluctuation analysis and compensation control for multiple injections of common rail system

To solve the inaccurate injection quantity problem in multiple injections of high pressure common rail injection system, in this paper, a simulation model of the system is developed in AMESim environment, and the injection quantity fluctuation characteristics with respect to the dwell time between consecutive injections and pilot injection quantity are investigated. The results show that injection quantity fluctuates periodically and the fluctuation range attenuates gradually with increasing dwell time. In addition, under the same main injection, the fluctuation amplitude of the fuel injection quantity increases with the increase of pilot injection quantity. Furthermore, the influence of rail pressure on fuel injection quantity fluctuation is also noted. Finally, a fuel compensation control strategy based on map for multiple injections is designed which can improve the injection control effectively.