This disclosure provides system and method that can determine hydraulic start of injection (SOI) in engines using an in-cylinder pressure sensor. The system and method determine apparent heat release rate (AHRR) curve data for the cylinder from the pressure information provided by the in-cylinder pressure sensors, and the hydraulic SOI from the derivative of the AHRR curve data. The system and method provide diagnostic, control and/or compensation opportunities for fuel injector operation in high pressure fuel rail engine systems without use of expensive or complex fuel injector components.

A fuel injection feedback system comprises a light source disposed inside a fuel injector, an optical sensor disposed inside the fuel injector, and a computing device electronically connected to the optical sensor. The light source is a device configured to emit light capable of being reflected by cavitation. The light source could be disposed on or within the needle or nozzle of the fuel injector, or at a variety of other locations inside the fuel injector. The optical sensor is configured to detect an intensity of light caused by receiving light reflected from cavitation occurring inside the fuel injector.

A method for operating an internal combustion engine having at least one fuel injector that is activated for opening and closing via a solenoid valve of a respective fuel injector. Commencing with the activation of the fuel injector for opening, structure-borne sound waves emitted by the fuel injector over the time are detected by measurement. A structure-borne sound wave signal detected by measurement over the time is evaluated such that dependent on the amount of at least one maximum of the structure-borne sound wave signal and/or dependent on the number of the maximums of the structure-borne sound wave signal and/or in the presence of multiple maximums dependent on the time sequence and/or on the amount of the maximums, an operating state of the respective fuel injector is deduced.

An actuator is energized to cause a valve body of a fuel injection valve to perform fuel injection. The actuator includes a driving body to drive to open and close the valve body. Boundary energization is performed that ends energization of the actuator at a timing when the driving body is moved in an opening direction of the valve body and is assumed to have reached an end of its movement range to measure a relationship between the energization time until the energization ends and the fuel injection amount. A correspondence relationship between the energization time of the actuator and the fuel injection amount is determined by using the measured relationship. An energization time corresponding to a target injection amount is obtained with reference to the determined correspondence relationship. The actuator is energized to cause the fuel injection valve to perform fuel injection.

A driving control device for a fuel pump may include a valve-opening-rate calculating unit and a driving control unit. The valve-opening-rate calculating unit may be configured to calculate an injector valve opening rate. The injector valve opening rate may be an injection time of an injector per unit time. The driving control unit may be configured to set a voltage duty ratio of a driving voltage that should be applied to the fuel pump that supplies fuel in a fuel tank to a fuel pipe communicating with the injector. The driving control unit may be further configured to set the voltage duty ratio to a value that is proportional to the injector valve opening rate calculated via the valve-opening-rate calculating unit.

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 for learning an opening time of an injector for an engine of a vehicle may include applying, by a controller, an injection start command to the injector supplying fuel to the engine; determining, by the controller, a fuel pressure change amount in a fuel rail supplying the fuel to the injector after the injection start command is applied; and learning, by the controller, an opening delay time of the injector based on the determined fuel pressure change amount.

Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes adjusting direct injector parameters in response to a learned direct injector fueling error. The pulse-width supplied to the direct injectors is adjusted to balance cylinder fueling.

A method determines information about a change of a mobile gardening, forestry, construction or soil-working device, wherein the gardening, forestry, construction or soil-working device has a motor drive system. The method includes: a) repeated detection of a characteristic variable of the motor drive system in respect of time, b) comparison of at least one first value of the detected characteristic variable or a variable based on it from a first time period and at least one second value of the detected characteristic variable or the variable based on it from a second time period with one another, and c) storage of the information about the change of the gardening, forestry, construction or soil-working device depending on a result of the comparison.

A method for identifying a fuel injector characteristic may include generating a signal to supply electrical current to the fuel injector, and monitoring the electrical current supplied to the fuel injector. The method may also include identifying the characteristic of the fuel injector based on the electrical current, the characteristic including a type of fuel injector, and performing a corrective action based on the type of fuel injector which was identified based on the electrical current.