Patent attributes
A control device of a fuel injection system of an engine calculates command injection timing for starting an injection at target injection timing, and a command injection period for obtaining a target injection quantity. The control device monitors a charging voltage of a capacitor immediately before the command injection timing and estimates the charging voltage at the command injection timing based on the monitored value. If the estimated value is less than a specified value, the control device performs correction for advancing the command injection timing and correction for lengthening the command injection period in accordance with the decrease in the charging voltage. Thus, an injector can start the injection at the target injection timing and can inject the target injection quantity of fuel.