A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

An injection control device includes: an area correction unit that calculates an energization time correction amount when executing a current drive of the fuel injection valve to inject a fuel from the fuel injection valve; an estimation unit that independently calculates an estimated energization time correction amount; a comparison unit that compares the energization time correction amount c with the estimated energization time correction amount; and a first abnormality determination unit that determines that the energization time correction amount is abnormal.

An injection control device of capable of correcting an energization time even in an S/N non-guaranteeable situation includes: an energization controller calculating an energization time correction amount based on an area correction performed by an energization time correction amount calculator regarding electric current flowing in a fuel injection valve when the fuel injection valve is electrically driven for injecting fuel; and an energization instruction time calculator correcting an energization instruction time for fuel injection in a next cycle and thereafter by using the energization instruction time correction amounts in or before a current cycle.

Provided is a control device for a fuel injection device capable of detecting a variation in valve opening start timing of the fuel injection device and stabilizing a fuel injection quantity. Therefore, the control device for the fuel injection device of the present invention is a control device for a plurality of fuel injection devices each including: a valve body that opens a fuel passage by separating from a valve seat; a movable element that causes an opening/closing operation of the valve body; and a stator that attracts the movable element by a drive current flowing through a coil. This control device includes a control unit that controls the energization time of the drive current by a pulse width of a drive command pulse. The control unit estimates a valve opening start timing having a correlation with a detected valve closing completion timing. Further, the pulse width of the drive command pulse is corrected based on the valve opening start timing.

A method of determining the electrical resistance of an actual harness connecting the Engine Control Unit (ECU) to a solenoid valve. The method includes providing a dummy harness connected at one end to the ECU and at the other end to a terminal connection in the vicinity of the solenoid valve. The method also includes determining the estimated RMS current through the actual harness and passing a current through the dummy harness such that the heat exchange to the environment is substantially the same as the actual harness. Power consumption of the dummy harness is measured and resistance of the actual harness is determined from estimated RMS and power consumption of the dummy harness.

An injection control device of capable of correcting an energization time even in an S/N non-guaranteeable situation includes: an energization controller calculating an energization time correction amount based on an area correction performed by an energization time correction amount calculator regarding electric current flowing in a fuel injection valve when the fuel injection valve is electrically driven for injecting fuel; and an energization instruction time calculator correcting an energization instruction time for fuel injection in a next cycle and thereafter by using the energization instruction time correction amounts in or before a current cycle.

An injection control device includes: an area correction unit that calculates an energization time correction amount when executing a current drive of the fuel injection valve to inject a fuel from the fuel injection valve; an estimation unit that independently calculates an estimated energization time correction amount; a comparison unit that compares the energization time correction amount c with the estimated energization time correction amount; and a first abnormality determination unit that determines that the energization time correction amount is abnormal.

Systems and methods for improving accuracy of an amount of fuel injected to an engine are disclosed. In one example, a maximum fuel injector holding current value is adjusted from a higher value to a lower value within a predetermined amount of time of an end of fuel injection. By adjusting the maximum fuel injector holding current value, it may be possible to reduce variation in an amount of fuel that is injected via the fuel injector.

Systems and methods for improving accuracy of an amount of fuel injected to an engine are disclosed. In one example, a maximum fuel injector holding current value is adjusted from a higher value to a lower value within a predetermined amount of time of an end of fuel injection. By adjusting the maximum fuel injector holding current value, it may be possible to reduce variation in an amount of fuel that is injected via the fuel injector.