Abstract: An ECU, which applies a predetermined high voltage for valve-opening operation and subsequently applies a predetermined low voltage to maintain the valve-opening and thus energizes a fuel injector for fuel injection by the fuel injector, includes a current detection section that detects an energizing current flowing through the fuel injector, a drive IC that, after start of energization of the fuel injector, when a detection current detected by the current detection section arrives at a beforehand determined target peak value, switches the voltage applied to the fuel injector from the high voltage to the low voltage, and a microcomputer that calculates a slope of change in current in the detection current while the high voltage is applied to the fuel injector, and performs correction processing to correct shift of a peak point of an actual current flowing through the fuel injector based on the slope of change in current.

Abstract: An ECU calculates peak-current arrival time (time elapsed before a detected current arrives at a target peak current), and calculates predetermined-current arrival difference time (time elapsed before the detected current becomes lower than a predetermined current after exceeding the predetermined current). The ECU uses a beforehand stored relationship between the predetermined-current arrival difference time and defined peak-current arrival time to calculate the defined peak-current arrival time corresponding to the latest predetermined-current arrival difference time. The ECU uses such defined peak-current arrival time to compare the latest peak-current arrival time with the defined peak-current arrival time (for example, calculates a difference between the peak-current arrival time and the defined peak-current arrival time), and thus determines a shift in detected current of a current detection circuit.

Abstract: An ECU, which applies a predetermined high voltage for valve-opening operation and subsequently applies a predetermined low voltage to maintain the valve-opening and thus energizes a fuel injector for fuel injection by the fuel injector, includes a current detection section that detects an energizing current flowing through the fuel injector, a drive IC that, after start of energization of the fuel injector, when a detection current detected by the current detection section arrives at a beforehand determined target peak value, switches the voltage applied to the fuel injector from the high voltage to the low voltage, and a microcomputer that calculates a slope of change in current in the detection current while the high voltage is applied to the fuel injector, and performs correction processing to correct shift of a peak point of an actual current flowing through the fuel injector based on the slope of change in current.

Abstract: At least after off of an injection pulse of partial lift injection, a difference between a first filtered voltage being a negative terminal voltage of a fuel injection valve filtered by a first low-pass filter and a second filtered voltage being the terminal voltage filtered by a second low-pass filter is calculated, and time from a predetermined reference timing to a timing when the difference between the filtered voltages has an inflection point is calculated as voltage inflection time. Subsequently, an injection quantity corresponding to current voltage inflection time is estimated for each of injection pulse widths with a relationship between the voltage inflection time and the injection quantity, the relationship being beforehand stored for each of the injection pulse widths.

Abstract: A fuel injection control device includes a fuel injection control unit and a pump control unit. The fuel injection control unit controls a fuel injection amount of a fuel injection valve. The pump control unit calculates a pump control amount based on feedforward and feedback terms and controls a fuel pump based on the pump control amount. The fuel injection control unit includes a first injection control unit for performing fuel injection by the valve at a starting injection amount in a starting period after commencement of starting of an engine by its starting unit until a predetermined rotation increase of the engine is produced in association with fuel combustion. The pump control unit includes a starting control unit for calculating the feedforward term based on the starting injection amount in the starting period and for calculating the pump control amount using this feedforward term.

Abstract: A fuel injection control device includes a fuel injection control unit and a pump control unit. The fuel injection control unit controls a fuel injection amount of a fuel injection valve. The pump control unit calculates a pump control amount based on feedforward and feedback terms and controls a fuel pump based on the pump control amount. The fuel injection control unit includes a first injection control unit for performing fuel injection by the valve at a starting injection amount in a starting period after commencement of starting of an engine by its starting unit until a predetermined rotation increase of the engine is produced in association with fuel combustion. The pump control unit includes a starting control unit for calculating the feedforward term based on the starting injection amount in the starting period and for calculating the pump control amount using this feedforward term.

Abstract: A fuel injection control apparatus for an internal combustion engine includes a fuel injection valve and an ignition device. The fuel injection control apparatus further includes a determination unit and an injection control unit. The determination unit determines that an implementation condition is satisfied and the injection control unit controls the fuel injection valve. The injection control unit controls the fuel injection valve to (i) begin injecting fuel during a compression stroke of the engine and (ii) complete injecting fuel at an injection completion timing according to an ignition timing of the ignition device, during start period after the engine is started, when the implementation condition is satisfied.