Abstract: A method for operating an injection valve by ascertaining an opening time and/or closing time of the injection valve on the basis of a sensor signal. The method includes: providing an analysis point time series by sampling a sensor signal of a sensor of the injection valve; using a nonlinear, data-based first submodel in order to obtain a first model output on the basis of the analysis point time series; using a linear, data-based second submodel in order to obtain a second model output on the basis of the analysis point time series; ascertaining the opening time and/or closing time as a function of the first and second model outputs.

Abstract: A method for operating an injection valve by determining an opening or closing time of the injection valve based on a sensor signal. The method includes: providing an evaluation point time series by sampling a sensor signal of a sensor of the injection valve; using a non-linear data-based first sub-model to obtain a first output vector based on the evaluation point time series, wherein each element of the first output vector is associated with a specific time; using a linear, data-based second sub-model to obtain a second output vector based on the evaluation point time series, wherein each element of the second output vector is associated with a specific time; limiting the time determined by the first output vector depending on the second output vector in order to obtain the opening or closing time.

Abstract: A method for training a data-based evaluation model to determine an opening or closing time of an injection valve based on a sensor signal. The method includes: measuring an operation of the injection valve in order to determine at least one sensor signal and an associated opening or closing time; sampling the sensor signal at a sampling rate in order to obtain a sensor signal time series with sensor signal values; determining a plurality of training data sets by assigning a plurality of evaluation point time series generated from a sensor signal time series to the opening or closing time associated with the sensor signal, wherein the evaluation point time series has a lower temporal resolution than the sensor signal time series; training the data-based evaluation model depending on the determined training data sets.

Abstract: A computer-implemented method for training a data-based time determining model for determining an opening or closing time of an injection valve based on a sensor signal. The method includes: providing an unlabeled analysis point time series by sampling the sensor signal of a sensor of the injection valve; training the data-based time determining model to assign a time specification which represents a specific opening or closing duration to an analysis point time series, the training process being carried out using a first shifting function to time-shift the analysis point time series and a second shifting function in order to time-shift the time specification. A consistency loss function is used for the training process.

Abstract: A method for operating an injection valve by ascertaining an opening time and/or closing time of the injection valve on the basis of a sensor signal. The method includes: providing an analysis point time series by sampling a sensor signal of a sensor of the injection valve; using a nonlinear, data-based first submodel in order to obtain a first model output on the basis of the analysis point time series; using a linear, data-based second submodel in order to obtain a second model output on the basis of the analysis point time series; ascertaining the opening time and/or closing time as a function of the first and second model outputs.

Abstract: 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.

Abstract: 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.

Abstract: A method is for operating a fuel injector, in particular of an internal combustion engine of a motor vehicle, the fuel injector including a piezoelectric actuator for driving a valve needle, which is connected, preferably hydraulically, to the actuator, and the control voltage of the piezoelectric actuator being analyzed to infer an operating state of the fuel injector. According to this method, the second time derivative of the control voltage and/or a variable depending on the second time derivative of the control voltage is/are analyzed.

Abstract: In a method for determining a needle closing of a valve needle that is driven by a piezoactuator, a signal of a voltage present at the piezoactuator is measured and the needle closing is detected from a curve of the signal.

Abstract: A method is for operating an injector, in particular a fuel injector of an internal combustion engine in a motor vehicle, the injector having a piezoelectric actuator for driving a valve needle coupled, preferably hydraulically, to the actuator. Starting from a starting voltage corresponding to a first operating state of the injector, the actuator is recharged, i.e., charged or discharged, by a predefinable voltage swing to a target voltage corresponding to a second operating state of the injector.

Abstract: A method is for operating a fuel injector, in particular of an internal combustion engine of a motor vehicle, the fuel injector including a piezoelectric actuator for driving a valve needle, which is connected, preferably hydraulically, to the actuator, and the control voltage of the piezoelectric actuator being analyzed to infer an operating state of the fuel injector. According to this method, the second time derivative of the control voltage and/or a variable depending on the second time derivative of the control voltage is/are analyzed.

Abstract: In fuel injection system having at least one fuel injector and a control unit for triggering the injector, each injector has a piezoelectric actuator, a nozzle element having at least one nozzle opening and at least one movable nozzle needle for selectively closing and opening the at least one nozzle opening, a hydraulic coupling element, which is connected between the piezoelectric actuator and the nozzle needle, and at least one stroke stop, against which the nozzle needle rests in its completely open and/or completely closed position. To be better able to ascertain when the stroke stop is reached in such injectors, the needle stroke stop is ascertained during an energization pause of the piezoelectric actuator by analyzing a voltage signal applied to the piezoelectric actuator. Oscillations of the voltage signal during the energization pause are preferably analyzed.