Fuel is injected by energizing a solenoid of a fuel injector for an on-time that terminates at a first end-of-current timing. An end-of-current trim is determined at least in part by estimating a duration between an induced current event in a circuit of the solenoid and a valve/armature interaction event. An induced current event occurs when an armature abruptly stops, and a valve/armature interaction event occurs when the armature couples with or de-couples from the valve member. Fuel is injected in a subsequent injection event by adjusting the end-of-current timing by the end-of-current trim.

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.

An electromagnetic actuation system includes an actuator having an electrical coil, a magnetic core, and an armature. The system further includes a controllable bi-directional drive circuit for selectively driving current through the electrical coil in either of two directions. The control module provides an actuator command to the drive circuit effective to drive current through the electrical coil in a first direction to actuate the armature and in a second direction subsequent to armature actuation to oppose residual flux within the actuator. The control module includes a feed forward control module configured to adapt the actuator command to converge residual flux within the actuator to a preferred flux level.

A method for providing consistent actuator events for each of a plurality of consecutive actuator events of an electromagnetic actuator, includes applying a first bi-directional current waveform for a first actuator event and applying a second bi-directional current waveform for a second actuator event immediately subsequent to the first actuator event. The first bi-directional current waveform includes applying current in a first direction when the actuator is commanded to an actuated position and applying current in a reversed second direction when the actuator is commanded to a rest position. The second bi-directional current waveform includes applying current in the reversed second direction when the actuator is commanded to an actuated position and applying current in the first direction when the actuator is commanded to a rest position.

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.

A method for operating an electromagnetic actuator includes an actuation event utilizing a current waveform for the actuator characterized by an initial peak pull-in current in a first direction of current flow when the actuator is commanded to an actuated position; and a reversed peak current in a second opposite direction of current flow applied after the actuator is commanded to a rest position. The reversed peak current has a magnitude that is greater than the magnitude of the initial peak pull-in current.

The method according to the invention calls upon a rotary electric machine (1) comprising a drive member (3) and a transmission member (4) of the belt or chain type, collaborating with the drive member and with the combustion engine (2) in order to start or restart the combustion engine, a tensioner (6) being provided to press against one strand (7) of the transmission member that extends between the rotary electric machine and the combustion engine. According to the invention, in a first stage, the rotary electric machine (1) supplies a predetermined reduced torque in the direction of starting for a predetermined duration in order to tension the transmission member (4) and then, in a second stage, the rotary electric machine (1) supplies a predetermined optimum torque for rapidly turning over the combustion engine (2) and causing it to start.

Described herein is a system for controlling a solenoid valve, which includes a driving circuit for driving a solenoid of the solenoid valve and a control unit for controlling the driving circuit. The control unit is configured for generating in the solenoid, during operation of the solenoid valve: first current signal for moving the open/close element from a first position to a second position, which is generated by the external supply network, to which the solenoid is connected; and second current signal, which is generated exclusively as a result of residual magnetism in the magnetic element of the solenoid valve and is activated when the open/close element is still in the aforesaid second position.

Systems and methods of controlling a solenoid coil in a solenoid valve provide a controller that allows a supervisory or leakage current to be used in a peak-and-hold driver. The controller introduces a delay time after detection of a dropout voltage that prevents the solenoid coil from being immediately re-energized in order to ensure proper dropout of the solenoid coil. The delay time imposes a wait period during which the controller takes no action with respect to the current in the solenoid coil, allowing the solenoid coil to deenergize and return the valve to its normally-open or normally-closed position. Such use of a delay time may be limited to instances where the controller has already gone through a power-up cycle such that the response time needed by the controller to energize the solenoid coil is minimized, thus reducing the valve startup time.