Methods and systems are provided for a fuel system. In one example, a method includes comparing a resistance of a solenoid coil of a direct injector to a threshold resistance. The method further includes selecting one of a transient or a steady-state pressure-based injector balancing (PBIB) model in response to the comparison.

A system and method for an electronic control unit adapter used to supplement existing electronic control units for enhanced or additional IO integration, the electronic control unit adapter designed to be updated easily by the end user in order to add functionality as it is developed thus prolonging the viability of an electronic control unit or vehicle, the electronic control unit adapter usable in conjunction with a vehicle or other vessel using an internal combustion engine or similar technology.

Methods and systems are provided for accounting for a difference between an expected amount of fuel scheduled to be delivered and an actual amount of fuel delivered to an engine cylinder during a fueling event. In one example, a method may include scheduling a direct injection to a cylinder based on an estimated expected amount of fuel injected to the cylinder during an immediately previous injection event. The expected amount of fuel injected during the immediately previous injection event may be a function of an average fuel rail pressure during the immediately previous injection event.

A computer-implemented method for ascertaining a closure point in time of an injector of an internal combustion engine using a classifier. The method includes: ascertaining a time series of input signals, each corresponding to a point in time within the time series, and each characterizing a deformation of the injector; ascertaining a plurality of first values using the classifier based on the time series, in each case a first value corresponding to a point in time of the time series, and the first value characterizing a probability that the closure point in time of the injector matches the point in time; ascertaining a plurality of second values, each being a sum of neighboring first values, of a first value and the first value, the second value corresponding to the point in time to which the first value corresponds; ascertaining the closure point in time based on the largest second value.

A method for operating an internal combustion engine having a common-rail injection system as a function of a quantity of fuel injected. The method includes determining an information item about a relative-pressure characteristic from a characteristic of an absolute rail pressure in a high-pressure reservoir of the common-rail injection system; determining the quantity of fuel injected as a function of the information item about the relative-pressure characteristic, and with the aid of a trained functional model, in particular, a nonparametric functional model or a neural network; operating the internal combustion engine as a function of the quantity of fuel injected.

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.

Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes adjusting port-fuel injecting parameters in response to a learned direct injector fueling error.

An engine system is provided, including a controller which estimates a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel, and controls devices of an engine at a given engine speed so that, while a demanded engine load is a first load, at least part of a mixture gas inside the cylinder combusts by flame-propagation when the estimated G/F is below a first G/F, and the entire mixture gas combusts by compression ignition when the estimated G/F is above the first G/F, whereas while the demanded load is a second load (>the first load), at least part of the mixture gas combusts by flame-propagation when the estimated G/F is below a second G/F (<the first G/F), and the entire mixture gas combusts by compression ignition when the estimated G/F is above the second G/F.

A method for controlling the total injection mass per working cycle during a multiple injection operation of a fuel injector of an internal combustion engine is provided. In the method, an injection mass difference is determined from individual injection pulse to individual injection pulse, and transferred to the next individual injection pulse, in stepwise fashion. The injection mass difference remaining in the penultimate individual injection pulse is transferred to the final individual injection pulse to achieve a total injection mass with improved tolerance.

Methods and systems are provided for balancing fuel delivery amongst all engine fuel injectors. In one example, a method may include selectively adjusting an injection timing of one or more fuel injectors of a plurality of fuel injectors to increase an inter-injection period between two consecutive fuel injections in response to a request to balance amounts of fuel injected by the plurality of fuel injectors