Rail Pressure Control System Design Based on Linear Active Disturbance Rejection

The high pressure pump and injector of the direct injection engine in the cylinder are connected with the common rail pipe. The oil fluctuation of high pressure pump and the high frequency working cycle of engine lead to the large fluctuation of rail pressure, which makes the engine fuel injection pressure unstable. The control mathematical model of high pressure common rail system is established based on fluid mechanics. A linear active disturbance rejection controller is designed to estimate the uncertain state and disturbance information by means of extended state observation for the unmeasurable state and disturbance. The controller is verified by idle speed and acceleration condition. The simulation results show that the linear active disturbance rejection is effective and easier to implement in engineering.