Research on Rail Pressure Signal Processing Method of High Pressure Common Rail System

The rail pressure signal of electronic control high pressure common rail fuel injection system for diesel engines is used to the closed loop control for rail pressure and the determination of the energizing time for fuel injection. Traditionally rail pressure signal processing method uses 10 ms filter to get the average rail pressure for control the system. With the rail pressure signals measured from experiments, it is found that traditional method can´t provide the sufficient information duration the time of multiple injections and will lead to the inaccurate fuel mass of main injection. According to the characteristics of rail pressure signal, this paper suggests that rail pressure signal can be divided into two stages: steady period and injection period, proposes the classified method for determining the two stages, and the different processing methods aimed at the two stages is presented. The experimental study demonstrates that the methods of the two stages meet the requirement of rail pressure control and injection respectively.