Methods and systems are provided for injecting fuel through three different rows of injector nozzles, where each row of the injector nozzle is arranged along a different vertical plane of the injector body. In one example, an injector needle housed movably inside the injector body may supply high-pressure fuel to each of the rows of injector nozzles sequentially to deliver up to five fuel injections in one actuation cycle of the fuel injector. In another example, a fuel injector may include three injector needles, where movement of each injector needle inside a respective chamber of the fuel injector body may supply high-pressure fuel to the chamber from where the fuel may be injected through the coupled fuel injector nozzles.

A method for switching over a solenoid valve having a movable valve body between a first position and a second position, wherein the method comprises at least the following method steps: a) adjusting a switching current to a pre-energization current intensity, in which the valve body remains in the present position, for a first time interval, and b) adjusting the switching current to a first switchover current intensity, which introduces a switchover movement of the valve body, for a second time interval.

Methods and systems are provided for adjusting injection timing of closely spaced multiple injections via a same injector. In one example, during an inter-injection spacing between a first injection and a second injection in a set of multiple injections being lower than a threshold period, an opening time of the second injection in the set of multiple injections may be adjusted based on another opening time of another second injection in a previous set of multiple injections.

An injection control device includes: an arithmetic unit that obtains a valve-closing time for stopping injection of fuel from a fuel injection valve based on a degree of variation in a time change of a voltage generated when the fuel injection valve is driven based on a required injection amount; an injection amount change unit that increases or decreases the required injection amount; and a learning unit that repeats injection control of the fuel to learn the valve-closing time obtained by the arithmetic unit.

A method for controlling at least one switchable valve, a brake impulse that slows down the valve movement being produced during the controlling of the at least one valve. At least one parameter of the brake impulse determines the position and/or the duration of the brake impulse. A parameter is modified, and the reaction of a measurement quantity or of a characteristic feature derived from the measurement quantity is evaluated.

An electromagnetically-activated actuator includes an electrical coil, an armature moveable between rest and actuated positions, and a bi-directional driver. A method for controlling an actuator event includes applying a supply voltage at a first polarity across the coil for a first duration to drive a forward current through the coil effective to move the armature away from the rest position. The forward current has a forward current peak at the end of the first duration. After the first duration, the supply voltage is applied at a second polarity across the coil for a second duration to drive a reverse current through the coil. The second duration terminates when the reverse current attains a predetermined reverse current peak, wherein the predetermined reverse current peak is coincident with the armature returning to the rest position.

A method for correcting an injector characteristic defining a relationship between an injector injection time and a valve closing time for a cylinder of an internal combustion engine by sensing an injector closing time includes steps of: sensing the injector closing time; determining a compensation amount for compensating for a commanded injection time using a number of sensing failures or a result of a learning of a relationship between a required commanded injection time and the injector closing time in a relevant cylinder, in addition to the number of sensing failures when there is a failure to sense the injector closing time; and controlling a commanded injection time according to an amount of required fuel injection in the relevant cylinder, based on the determined compensation amount.

An electric current detection apparatus, the electric current detection apparatus is configured to detect an electric current flowing in a solenoid configured to be electrified by a PWM control, the apparatus includes a switch, an electric current value detection portion configured to detect a first electric current value at a first timing corresponding to a timing when the switch transitions from a closed state to an open state, the electric current value detection portion being configured to detect a third electric current value at a third timing, and a second electric current value calculation portion configured to calculate a second electric current value on the basis of the first electric current value and the third electric current value, the second electric current value being an electric current value of the electric current at the second timing.

A method for sensing a closing time of an injector using an artificial neural network may include: sensing, by a controller, a voltage generated by an injector; performing, by the controller, a preprocess to derive an input matrix using variation characteristics of the voltage; and performing, by the controller, a closing time prediction to derive a closing time of the injector by an artificial neural network model including an input layer including the input matrix, a hidden layer, and an output layer.

A method is disclosed of controlling operation of a fuel injector in response to measuring a quantity of fuel injected by the fuel injector from a fuel accumulator to an engine cylinder during operation of a fuel pump that delivers fuel to the accumulator, comprising: determining an average pressure of the fuel accumulator during a first time period before a fuel injection event; predicting a mass of fuel delivered to the fuel accumulator during a pumping event (Q.sub.pump); determining an average pressure of the fuel accumulator during a second time period after the fuel injection event; estimating a leakage of fuel; computing the injected fuel quantity by adding the average pressure during the first time period to Q.sub.pump, and subtracting the average pressure during the second time period and the leakage; and using the computed injected fuel quantity to control operation of the fuel injector.