Feedback control of fuel injection based on online valve closure point detection

High speed solenoid valve is one of the key components in modern electronic controlled diesel fuel systems. Control quality of the fuel systems is greatly affected by unit to unit deviation of their electro-magnetic characteristics. Precise detection of the solenoid valve closure point is a feedback method to promote control quality by completing fuel injection control loop. Through mechanism modeling of the spill-valve solenoid used in electronic assemble fuel pump, the property of the valve closure point is analyzed, and its detection method and electric driving logic are proposed. Subsequently, a fuel injection feedback control algorithm is implemented in mass-production engine control unit. Fuel bench tests show that, the valve closure point can be precisely recognized by the detection method, and in cooperation with the feedback control algorithm, cylinder to cylinder unevenness of the fuel injection quantities can be reduced, which consequently leads to the promotion of the control quality of the fuel injection system.