Method and apparatus for operating an electromagnetically actuated valve of a fuel injector

Abstract

Method for operating an electromagnetically actuated valve of a fuel injector, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position, and an electromagnetic actuator designed to actuate a movement of the valve element, the method comprising: - Applying an initial voltage value during an initial time period and switching off the initial voltage value after the initial time period, and - Applying a second voltage value, which is lower than the first voltage value, for a second time period and switching off the second voltage value after the second time period, wherein the duration of the first time interval and the duration of the second time interval are determined according to a desired amount of fuel injected; the first voltage value is applied constantly during the first time period and / or the second voltage value is applied constantly during the second time period; or the first voltage value is applied constantly during the first time period, so that a current in the electromagnetic actuator increases during the first time period, in particular increases monotonically, and / or the second voltage value is applied constantly during the second time period, so that the current in the electromagnetic actuator increases during the second time period, in particular increases monotonically.

Description

[0001] The present invention relates to a method for operating an electromagnetically actuated valve of a fuel injector (a fuel injection device) and a device (controller / control unit) for operating an electromagnetically actuated valve of the fuel injector. Furthermore, the present disclosure relates to a computer program product that operates a controller (control unit) or a processor for operating an electromagnetically actuated valve of a fuel injector (fuel injection device). background

[0002] Currently, the automotive industry is undergoing accelerating changes as a result of megatrends such as digitalization (shared mobility, autonomous driving, networking, but also shorter development cycles using advanced virtual tools), sustainability (emissions legislation, alternative drive solutions including hybridization and electrification of the powertrain) and globalization (developing markets, further urbanization).

[0003] However, it is generally assumed that a large proportion of propulsion systems for individual mobility will still rely on internal combustion engines well beyond 2030. In particular, the market segment for gasoline direct injection (GDI) engines is expected to continue growing, as this technology represents an attractive middle ground between performance and cost. Therefore, there is a general desire or need to further increase the efficiency of GDI engines and reduce harmful emissions through technical improvements. One obvious focus is the high-pressure fuel supply system, including the necessary algorithms for its operation, which are implemented in the electronic control unit (e.g., an engine control unit or ECU).

[0004] Currently important requirements for the fuel supply system, and especially for the injector component, are the precise injection of small injection quantities (for example, sometimes less than 15 mg or even less than 10 mg or 7 mg of fuel per injection pulse, down to quantities of 4 to 5 mg of fuel per injection pulse) for catalyst warm-up operation, for operation with closely spaced multiple injections for advanced combustion concepts such as lean combustion, and a reduction in noise emissions during idle operation.

[0005] Recent and future stricter emission regulations, e.g. for CO2 or PN6, together with modified driving test cycles, will further exert innovation pressure on internal combustion engine manufacturers, leading, for example, to the use of more advanced combustion concepts and thus a further increase in the performance requirements for the fuel supply system and the injection system.

[0006] In most prior art techniques used to control a fuel injection pulse of a fuel injector in a fuel supply system during a given injection cycle, a current value of the control current supplied to an electromagnetic actuator (e.g. an electromagnet or another type of electromagnetic actuator) of the electromagnetically actuated valve of the fuel injector is typically controlled on the basis of a desired current profile (target current profile, also referred to as current waveform).

[0007] Such a well-known current profile or waveform typically includes an initial phase (also called the "boost phase") during which the drive current is rapidly increased by applying a high voltage (generally referred to as the "high voltage" or "boost voltage") based on a predetermined target current peak value. That is, the high voltage (boost voltage) is applied to quickly excite the electromagnetic actuator and rapidly increase the drive current flowing through the electromagnet (the electromagnetic actuator) until the drive current reaches the desired target current peak value. The applied voltage is then switched off, allowing the drive current to decrease again to prevent over-opening of the fuel injector valve and thus avoid excessive noise and vibration.

[0008] Such a well-known current profile or waveform typically includes one or more current holding phases (or current control phases) in which the drive current is regulated, for example, using a current controller based on one or more predetermined target holding current values. That is, in each of the one or more current holding phases, the drive current is controlled (or rather regulated, for example, based on closed-loop current control) by the electromagnet (electromagnetic actuator) so that it is maintained at the respective predetermined target holding current value.For example, if the valve body of the fuel injector is open and positioned in the fully open position (for example, touching a stop that defines the fully open position), typically less force is required to hold the valve body in the fully open position.

[0009] Such current control or current regulation during one or more current holding phases is typically carried out using PWM (pulse width modulation) control, in which a low voltage level (also known as battery voltage) is repeatedly switched on and off based on a comparison of a measured actual current value and the respective predetermined target holding current value, in order to keep the drive current in the electromagnet approximately constant at the level of the respective predetermined target holding current value.

[0010] Examples from the prior art of such current control-based concepts for operating an electromagnetic valve of a fuel injector based on a current profile are known, for example, from patent documents EP 2 514 956 A1, DE 10 2007 024 397 A1, EP 3 150 831 A1 and US 2016 / 0 177 855 A1.

[0011] DE 10 2011 086 957 A1 relates to a method for controlling a solenoid valve. The method comprises a control signal with an engagement phase and a holding phase, wherein the engagement phase has a comparatively high current and a maximum permissible duration, and the holding phase has a comparatively low current and a minimum permissible duration. The minimum permissible duration of the holding phase depends on a target total duration of the control signal.

[0012] As already mentioned, the desired target current profile, which may be defined, for example, by the predetermined target peak current value of a boost phase and by one or more predetermined target holding current values, and which is used as a control basis in methods for operating an electromagnetic valve of a fuel injector as discussed above, may also be referred to as a current waveform in some of the prior art references.

[0013] In such a state of the art, the switches of a provided control circuit are typically actuated (switched on and off, e.g., based on PWM control) based on a comparison of the actually measured current with the desired current waveform, perhaps also taking into account a permissible tolerance or hysteresis limit.

[0014] If a constant holding current level is desired, this can lead to rapid switching between holding states (e.g., applying a battery voltage) and normal-fall states (applying a voltage that is zero or at least less than the battery voltage) under different drive states of the control circuit's switches. For example, in PWM control, this involves rapid and repeated switching between holding and normal-fall states. The goal of this type of operation is to achieve the predefined current waveform; that is, to implement a control concept based on the desired target current profile (the current waveform), sometimes referred to as the current control concept.

[0015] Typically, the current control concepts discussed above work well for larger injection quantities and injection pulses with a longer injection pulse width, especially above injection quantities of about 10 mg of fuel per injection quantity and for injection pulses with pulse widths of more than 0.5 ms.

[0016] However, with smaller injection quantities, typically less than 10 mg, or injection pulses with pulse widths of less than 0.5 ms, the prior art methods typically experience the problem that the deviations of the actual injection quantities and the actual injection pulse widths from injection pulse to injection pulse (pulse-to-pulse variation or pulse-to-pulse deviation) become increasingly pronounced. While deviations of the actual injection quantities from injection pulse to injection pulse for injection quantities of approximately 10 mg of fuel per injection and for injection pulses with pulse widths greater than 0.5 ms are typically stable at less than 1% or even only about 0.5%, deviations of the actual injection quantities from injection pulse to injection pulse for smaller injection quantities of less than 10 mg or injection pulses with pulse widths of less than 0.With a well-known current-controlled actuation system for fuel injectors, the response time typically increases significantly beyond 1% or even 2% in 5 ms.

[0017] In particular, a special case arises in the prior art where the desired fuel injection quantity (desired amount of injected fuel) is so small that the valve must be controlled in such a way that it does not open fully, i.e., a so-called half-stroke operation, in which the valve body does not reach the fully open position during the injection pulse and the closing movement occurs before the valve body reaches the fully open position. Such a case can occur when the total injection quantity per injection pulse is small. In this case, the generally known current control concepts discussed above can lead to undesirably high pulse-to-pulse injection quantity deviations.

[0018] Furthermore, some of the problems associated with the state of the art include the lack of flexibility due to the predetermined current waveform, i.e., the inability to adequately consider actual operating conditions, and difficulties in adapting to different applications and / or different working conditions.

[0019] Furthermore, there is a need for a method for operating an electromagnetically driven valve of a fuel injector that makes it possible to achieve a desired degree of adaptability without having to adapt the software that controls the actuation circuit to the given applications each time, and at the same time without increasing the complexity of the system.

[0020] Another problem arising in connection with the state of the art, as mentioned above, is that it is not easy to carry out a precise, repeatable injection of small quantities, especially below 10 mg of fuel per injection pulse, with small deviations between injection pulses, especially pulse-to-pulse deviations below 1%. Summary

[0021] One object of the present invention is to avoid the above-mentioned problems of the prior art and to provide an improved control concept for operating an electromagnetically controlled valve of a fuel injector.

[0022] A particular object of the present invention is to create a control concept that enables efficient and reliable control of the fuel injector through a simple control architecture, which preferably also enables high accuracy and high flexibility with regard to the injection pulse characteristics and preferably also enables efficient, reliable, accurate, uniform and / or stable fuel injection pulse control, particularly for operating ranges in which small fuel injection quantities and / or short injection pulses are required, preferably avoiding deviations in the fuel injection quantities and / or short injection pulse widths over several injection cycles.

[0023] In view of the problems in the prior art and to solve some or all of the above problems, a method for operating an electromagnetically actuated valve of a fuel injector according to one of the independent claims is proposed. Furthermore, suitable controllers for carrying out such control methods and computer programs for executing such control methods according to the independent claims are proposed. Specific embodiments may relate to a concept for influencing the force dynamics of the electromagnetically actuated valve of the fuel injector. Dependent claims relate to preferred embodiments.

[0024] According to one aspect of the present invention, a method for operating an electromagnetically actuated valve of a fuel injector can be proposed, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position, and an electromagnetic actuator designed to actuate a movement of the valve element, wherein the method comprises: applying a first voltage value, in particular by means of active voltage control, for a first time period and switching off the first voltage value after the first time period, and / or applying a second voltage value, less than or equal to the first voltage value, for a second time period and switching off the second voltage value after the second time period, wherein the duration of the first time period and the duration of the second time period are determined according to a desired amount of fuel injected.

[0025] According to exemplary aspects of the present invention, the duration of the first time interval and the duration of the second time interval are determined to influence the force dynamics of an electromagnetic force induced on the electromagnetic actuator in a transition state according to the desired amount of injected fuel, particularly when the desired amount of injected fuel is less than or equal to 7 mg of injected fuel per injection pulse and / or when an injection pulse determined based on the desired amount of injected fuel has a pulse width of less than or equal to 0.5 ms.

[0026] According to exemplary aspects of the present invention, the first voltage value is applied constantly during the first time period and / or the second voltage value is applied constantly during the second time period.

[0027] According to exemplary aspects of the present invention, the first voltage value is applied constantly during the first time period, so that a current in the electromagnetic actuator increases during the first time period, in particular increases monotonically; and / or the second voltage value is applied constantly during the second time period, so that the current in the electromagnetic actuator increases during the second time period, in particular increases monotonically.

[0028] According to exemplary aspects of the present invention, the method may further comprise: determining a phase profile based on the desired amount of injected fuel, wherein the phase profile specifies several successive control phases, in particular voltage control phases for controlling the voltage applied to the electromagnetic actuator for opening and closing the electromagnetically actuated valve.

[0029] According to exemplary aspects of the present invention, the phase profile comprises a target voltage profile and the target voltage profile comprises several actively voltage-controlled time periods, wherein each actively voltage-controlled time period corresponds to a respective phase of a constant application of a respective target voltage value to the electromagnetic actuator during the respective actively voltage-controlled time period.

[0030] According to exemplary aspects of the present invention, the target voltage profile further comprises one or more passively voltage-controlled time periods, wherein each passively voltage-controlled time period corresponds to a respective phase of the phase profile, during which it is made possible for a magnetic field of the electromagnetic actuator to collapse and for an induced voltage of the electromagnetic actuator to decrease during the respective passively voltage-controlled time period, in particular to decrease exponentially.

[0031] According to exemplary aspects of the present invention, the phase profile further comprises a target current profile and the target current profile comprises one or more current-controlled time intervals, each current-controlled time interval corresponding to a respective phase of the phase profile, during which a current is controlled by the electromagnetic actuator based on a target current value by a pulse width modulation control.

[0032] According to exemplary aspects of the present invention, the phase profile comprises at least a first phase, during which the first voltage value is applied constantly to the electromagnetic actuator for the first time period, and a second phase, during which the second voltage value is applied constantly to the electromagnetic actuator for the second time period.

[0033] According to exemplary aspects of the present invention, the phase profile comprises a boost phase corresponding to the first time period of applying the first voltage value, and a first voltage holding phase corresponding to the second time period of applying the second voltage value, wherein in particular the second time period is after the first time period and wherein in particular the first and the second voltage value have the same sign and the absolute value of the first voltage value is greater than or equal to the absolute value of the second voltage value.

[0034] According to exemplary aspects of the present invention, determining the phase profile includes determining a duration of the first time interval and / or determining a duration of the second time interval.

[0035] According to exemplary aspects of the present invention, the first and / or the second time period of the phase profile are determined such that an end time of the second time period is determined based on a desired upper position of a target movement path of the valve element between opening and closing movement of the valve element and / or based on a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between opening and closing movement of the valve element.

[0036] According to exemplary aspects of the present invention, the first and / or the second time period of the phase profile are determined such that an end time of the second time period is at a time when the valve element has a position that is lower than the desired upper position of the target movement path of the valve element during the opening movement of the valve element, and / or such that the end time of the second time period is during the opening movement of the valve element and before, in particular shortly before, a desired time at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element.

[0037] According to exemplary aspects of the present invention, the phase profile after the second time period and during a third time period comprises a first phase with rapid decay, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse.

[0038] According to exemplary aspects of the present invention, determining the phase profile includes determining a duration of the third time interval, in particular according to the desired amount of injected fuel.

[0039] According to exemplary aspects of the present invention, the first, second and / or third time interval of the phase profile are determined such that a start time of the third time interval and / or an end time of the second time interval are determined based on a desired upper position of a target movement path of the valve element between an opening and a closing movement of the valve element and / or based on a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between opening and closing movement of the valve element;and / or the first, second and / or third time interval of the phase profile is determined such that the start time of the third time interval and / or the end time of the second time interval is at a time when the valve element has a position that is lower than the desired upper position of the target movement path of the valve element during the opening movement of the valve element, and / or is determined such that the start time of the third time interval and / or the end time of the second time interval is during the opening movement of the valve element and before, in particular shortly before, a desired time at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movements of the valve element.

[0040] According to exemplary aspects of the present invention, the phase profile comprises a second voltage holding phase of a constant application of a fourth voltage value during a fourth time interval after the third time interval; wherein the fourth voltage value is equal to the second voltage value, the second and fourth voltage values ​​have the same sign and / or the first and fourth voltage values ​​have the same sign, and the absolute value of the first voltage value is higher than the absolute value of the fourth voltage value.

[0041] According to exemplary aspects of the present invention, determining the phase profile includes determining a duration of the fourth period, in particular according to the desired amount of fuel injected.

[0042] According to exemplary aspects of the present invention, the first, second, third and / or fourth time intervals of the phase profile are determined such that a start time of the fourth time interval and / or an end time of the third time interval are determined based on a desired upper position of a target movement path of the valve element between an opening and a closing movement of the valve element, based on a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element, and / or based on a desired closing slope of the target movement path of the valve element during the closing movement of the valve element;and / or the first, second, third and / or fourth time interval of the phase profile are determined such that the start time of the fourth time interval and / or the end time of the third time interval is at a time when the valve element has a lower position than the desired upper position of the target movement path of the valve element during the closing movement of the valve element, and / or are determined such that the start time of the fourth time interval and / or the end time of the third time interval is after, in particular shortly after, the desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element.

[0043] According to exemplary aspects of the present invention, the first, second, third and / or fourth time intervals of the phase profile are determined such that an end time of the fourth time interval is determined based on a desired closing slope of a target movement path of the valve element in the closing movement of the valve element and / or based on a desired or actual time specification at which the valve element reaches the closing position at the end of the target movement path of the valve element; and / or the first, second, third and / or fourth time intervals of the phase profile are determined such that the end time of the fourth time interval is essentially at a desired or actual time specification at which the valve element reaches the closing position at the end of the target movement path of the valve element.

[0044] According to exemplary aspects of the present invention, the phase profile after the fourth time interval comprises a second phase with rapid decay, during which an induced voltage decreases with the opposite sign compared to the sign of the first and second voltage values, in particular by allowing the magnetic field of the electromagnetic actuator to collapse.

[0045] According to exemplary aspects of the present invention, the phase profile comprises a phase with normal decay in which a fifth voltage value is held constantly during a fifth time interval between the first and the second time interval, wherein the fifth voltage value is smaller than the first and the second voltage value and, in particular, the fifth voltage value is less than or equal to zero.

[0046] According to exemplary aspects of the present invention, determining the phase profile, in particular according to the desired amount of injected fuel, includes determining a length of the fifth time interval, wherein the length of the fifth time interval is greater than or equal to zero.

[0047] According to exemplary aspects of the present invention, determining the phase profile comprises: determining one or more target motion paths of the valve element between each opening and closing movement of the valve element for an injection cycle, determining one or more actual motion paths of the valve element between each opening and closing movement of the valve element during the current and / or one or more previous injection cycles, and / or modifying the phase profile based on a comparison of the determined one or more target motion paths of the valve element with the one or more determined actual motion paths of the valve element.

[0048] According to exemplary aspects of the present invention, the one or more target motion paths of the valve element are determined on the basis of properties that specify a desired shape of the one or more target motion paths of the valve element, and / or on the basis of the desired injected fuel quantity, which is either the desired injection quantity per injection cycle or the desired injection quantity per motion path.

[0049] According to exemplary aspects of the present invention, the one or more actual movement paths of the valve element are determined based on processing at least one of the following signals: a current signal indicating a current in the electromagnetic actuator as a function of time, a pressure signal indicating a fuel pressure upstream of a fuel injector as a function of time, and a position signal indicating a position of the valve element as a function of time.

[0050] According to exemplary aspects of the present invention, the processing of the current signal indicating a current in the electromagnetic actuator comprises at least one of the following operations: processing the current signal to obtain a first time derivative of the current in the electromagnetic actuator as a function of time, and processing the current signal to obtain a second time derivative of the current in the electromagnetic actuator as a function of time.

[0051] According to exemplary aspects of the present invention, the one or more actual movement paths of the valve element are determined by determining at least one of the following parameters based on the obtained first and / or second time derivative of the current in the electromagnetic actuator: an opening time specification for the start of the opening movement of the valve element, an opening slope of the opening movement of the valve element, a time of reaching the upper position between the opening and closing movement of the valve element, a closing slope of the closing movement of the valve element, and a closing time specification for the end of the closing time of the valve element.

[0052] According to exemplary aspects of the present invention, when the desired injected fuel quantity is below a predetermined threshold, and the injection of the desired injected fuel quantity below the predetermined threshold requires a half-stroke movement path of the valve element as the target movement path, which is determined based on the desired injected fuel quantity. In this path, the valve element opens at a desired opening time, reaches the upper position of the path at a position lower than a fully open position of the valve element at a desired time for the upper position, and closes at a desired closing time, the phase profile is determined to include: a first voltage holding phase for maintaining the first voltage value constantly for the first time interval for applying a boost voltage.a first voltage holding phase to maintain the second voltage value constantly for a second time interval after the first time interval to control an opening movement of the valve element; a first phase with rapid decay after the second time interval and during a third time interval, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse in order to actuate a change in the direction of movement of the valve element from the opening direction to the closing direction; a second voltage holding phase to maintain a fourth voltage value constantly for a fourth time interval after the third time interval to control a closing movement of the valve element; and a second phase with rapid decay after the fourth time interval.during which an induced voltage with the opposite sign to the first and second voltage values ​​decreases, in particular decreases exponentially, by allowing the magnetic field of the electromagnetic actuator to collapse; wherein the desired opening time specification of the half-stroke movement path is during the first time interval, wherein a start time of the third time interval, in particular a start time of the application of the third voltage value, is before, in particular shortly before, the valve element reaches the upper position of the target movement path and / or before, in particular shortly before, the desired time specification for the upper position, and wherein a start time of the second phase with rapid decay is essentially to the desired closing time specification.

[0053] According to exemplary aspects of the present invention, when the desired injected fuel quantity is above a predetermined threshold, and an injection of the desired injected fuel quantity above the predetermined threshold requires a full-stroke movement path of the valve element, according to which the valve element opens at a desired opening time, reaches the fully open position of the movement path, maintains the fully open position for a desired fully open time period, and closes at a desired closing time period, the phase profile is determined such that it comprises: a first voltage holding phase for maintaining the first voltage value constantly for the first time period for applying a boost voltage,a first voltage holding phase to maintain the second voltage value constantly for the second time interval after the first time interval to control an opening movement of the valve element towards the fully open position and to hold the valve element in the fully open position for the desired fully open time interval; a first phase with rapid decay after the second time interval and during a third time interval, during which an induced voltage with the opposite sign to that of the first and second voltage values ​​decreases, in particular decreases exponentially, by allowing the magnetic field of the electromagnetic actuator to collapse in order to actuate a closing movement of the valve element from the fully open position to the closed position;a second voltage holding phase of a constant holding of a fourth voltage value for a fourth time interval after the third time interval for controlling a closing movement of the valve element, and a second phase with rapid decay after the fourth time interval, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse; wherein the desired opening time specification of the full-stroke movement path during the first time interval is a start time of the third time interval, in particular a start time of the application of the third voltage value, before, in particular shortly before, the elapse of the desired fully open time interval, and wherein a start time of the second phase with rapid decay, in particular a start time of the application of the third voltage value,essentially meets the desired closing time requirement.

[0054] According to exemplary aspects of the present invention, in order to control multiple injections per injection cycle based on the desired amount of fuel injected or several desired amounts of fuel injected per injection cycle, which within a single injection cycle comprises several target movement paths of the valve element, according to which the valve element opens at a respective desired opening time, reaches the upper position of the respective target movement path at a position lower than a fully open position of the valve element at a respective desired time for the upper position, and closes at a respective desired closing time, the phase profile is determined such that it comprises: a ramp-up phase for holding the first voltage value constant for the first time period for applying a ramp-up voltage,a first voltage holding phase to maintain a constant second voltage value for a second time interval after the first time interval to control an opening movement of the valve element for a first movement path of the several target movement paths, a first rapid decay phase after the second time interval and during a third time interval, during which an induced voltage with the opposite sign compared to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse in order to actuate a change in the direction of movement of the valve element from the opening movement direction to the closing movement direction during the first movement path, and a final rapid decay phase, during which an induced voltage with the opposite sign compared to the sign of the first and second voltage values ​​decreases.in particular, decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse after the desired closing time of a last movement path of the multiple target movement paths, wherein the phase profile between the first rapid decay phase and the last rapid decay phase further comprises several voltage holding phases of a constant holding of the second voltage value for a respective holding time interval to control a closing movement of the valve element of a respective movement path of the multiple target movement paths and to control an opening movement of a respective next movement path of the multiple target movement paths, and wherein the phase profile further comprises, for each n-th movement path with n > 1, another rapid decay phase, during which an induced voltage decreases with the opposite sign compared to the sign of the first and second voltage values, in particular, decreases exponentially.by enabling the magnetic field of the electromagnetic actuator to collapse at a specified time before, in particular shortly before, a respective desired time for the upper position of the respective nth movement path, in order to actuate a change in the direction of movement of the valve element from the opening movement direction to the closing movement direction during the nth movement path.

[0055] According to exemplary aspects of the present invention, the electromagnetically actuated valve comprises an armature element that is movable between a rest position, which is lower than the open position of the valve element, and an open position of the valve element, wherein the electromagnetic actuator is configured to actuate a movement of the armature element, and the armature element is configured to move the valve element, wherein the phase profile is determined such that the armature element moves from the rest position to the open position until it comes into contact with the valve element at a first time, and in the closed position until a second time, which is greater than the first time, in particular according to a desired time interval between the first and the second time and / or according to the desired first and second times.in contact with the valve element and the anchor element and the valve element begin an opening movement from the closed position to the open position at or after the second time; and / or wherein the phase profile is determined such that the anchor element and the valve element move from the open position to the closed position until they reach the closed position at a third time, the anchor element remains in contact with the valve element in the closed position after the third time, in particular according to a desired time interval between the third and a fourth time that is greater than the third time, and / or according to the desired first and fourth times, and the anchor element begins to move from the closed position towards the rest position at or after the fourth time.

[0056] According to exemplary aspects of the present invention, the electromagnetic actuator is controlled by a control circuit comprising several switches, and the control circuit is designed to have multiple control states which are controlled based on different switching configurations of the multiple switches, wherein a first control state of the multiple control states is activated during the first time period and a second control state of the multiple control states is activated during the second time period.

[0057] According to a further aspect of the present invention, which can be combined with one or more of the above aspects, a method for operating an electromagnetically actuated valve of a fuel injector can be proposed, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position, and an electromagnetic actuator designed to actuate a movement of the valve element, wherein the method comprises: applying a first voltage value by an active voltage control during a first time interval and switching off the first voltage value after the first time interval, and / or applying a second voltage value, which is less than or equal to the first voltage value, by an active voltage control during a second time interval and switching off the second voltage value after the second time interval.wherein the duration of the first time interval and the duration of the second time interval are determined according to a desired amount of fuel injected.

[0058] According to a further aspect of the present invention, which can be combined with one or more of the above aspects, a method for operating an electromagnetically actuated valve of a fuel injector can be proposed, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position, and an electromagnetic actuator designed to actuate a movement of the valve element, wherein the method comprises: applying a first voltage value by an active voltage control during a first time interval and switching off the first voltage value after the first time interval, applying a second voltage value, which is less than or equal to the first voltage value, by an active voltage control during a second time interval and switching off the second voltage value after the second time interval, and / or enabling,that an induced voltage in the electromagnetic actuator decreases by passive voltage control during a third time interval, wherein the duration of the first time interval, the duration of the second time interval and / or the duration of the third time interval are determined according to a desired amount of injected fuel.

[0059] According to a further aspect of the present invention, a device, in particular a controller, for operating an electromagnetically actuated valve of a fuel injector is proposed, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position, and an electromagnetic actuator designed to actuate a movement of the valve element, wherein the device is designed to control the execution of a method according to one of the above aspects.

[0060] According to another aspect of the present invention, a computer program product is proposed comprising a computer program containing computer program instructions designed to cause a controller to perform the steps of a method of one of the above aspects.

[0061] Although certain exemplary aspects have been described above, it should be understood that such aspects are only illustrative of the wider invention and do not limit it, and that the exemplary aspects are not limited to the specific constructions and arrangements shown and described above, since various other modifications, combinations, omissions, alterations and substitutions are possible in addition to those explained in the paragraphs above.

[0062] Experts will understand that various adaptations, modifications, and / or combinations of the aspects described above are possible. Therefore, it is important to understand that additional aspects beyond those specifically described herein may be practiced. Experts will also understand that, in light of this disclosure, various aspects described herein may be combined to form other aspects of the present disclosure. Brief description of the drawings Fig. Figure 1 is a schematic example view of a fuel supply system in which a fuel injection device (a fuel injector), a pressure sensor, a control device and an ECU (engine control unit) are mounted by way of example on an engine with in-cylinder direct injection. Fig.Figure 2 is an exemplary vertical cross-sectional view of the fuel injection device (fuel injector) and an exemplary representation showing an arrangement of the control circuit and engine control unit (ECU) connected to the fuel injection device. Fig. Figure 3 is an exemplary illustration showing an enlarged cross-sectional view of a control unit structure of the fuel injection device of Fig. 2 shows. Fig. Figure 4 is an exemplary representation showing a control concept called "current control" and the corresponding relationships between a general injection pulse to control the fuel injection device, a specific time specification of a control voltage and a control current to be supplied to the fuel injection device, and a valve body displacement size and time. Fig.Figure 5 is a schematic example view of a control circuit of a fuel injector according to an exemplary embodiment. Fig. Figure 6 is another exemplary representation showing the control concept referred to as "current control", which relates to full-stroke operation, and includes corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 7 is another exemplary representation showing the control concept referred to as "current control", which relates to half-stroke operation, and includes corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 8 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a first exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 9 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a second exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 10 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a third exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 11 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a fourth exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 12 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a fifth exemplary embodiment relating to multiple half-stroke operating injection pulses in an injection cycle, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 13 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a sixth exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 14 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a seventh exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig.Figure 15 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including an eighth exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig. Figure 16 is a schematic example view of a further control circuit of a fuel injector according to a further exemplary embodiment. Fig.Figure 17 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a ninth exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig. Figure 18 is an exemplary representation showing a control concept comparison of fuel injection operating modes according to current control (solid lines) as in Fig. 7 and according to the control concept of the fuel injection operating mode of Fig.Figure 9 is based on two different sets of parameters (dashed lines and dotted lines respectively), showing the corresponding representations of the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. Fig. Figure 19A is an exemplary illustration showing a flowchart of a control procedure for a fuel injector according to exemplary embodiments. Fig. Figure 19B is an exemplary representation showing an exemplary flowchart of a procedure for control state regulation based on a target phase profile during an injection cycle in the control procedure of Fig. 19A according to a first exemplary embodiment of the fuel injection control method (or in the control methods of a of Fig. 20 and Fig.21 in further exemplary embodiments). Fig. Figure 19C is an exemplary representation showing an exemplary flowchart of a procedure for control state regulation based on a target phase profile during an injection cycle in the control procedure of Fig. 19A according to a second exemplary embodiment of the fuel injection control method (or in the control methods of one of Fig. 20 and Fig. 21 in further exemplary embodiments). Fig. Figure 20 is an exemplary representation showing a flowchart of a control procedure for a fuel injector according to a third exemplary embodiment of the fuel injector control procedure. Fig.Figure 21 is an exemplary representation showing a flowchart of a control procedure for a fuel injector according to a fourth exemplary embodiment of the fuel injector control procedure. Fig. Figure 22 is an exemplary representation showing an exemplary flowchart of a control state control procedure based on a target phase profile during an injection cycle in the control method of Fig. 19A according to a fifth exemplary embodiment of the fuel injection control method (or in the control methods of Fig. 20 or Fig. 21 in further exemplary embodiments). Fig. Figure 23 provides an example of a typical electrical representation of an electromagnetic actuation system of an electromagnetic actuator of a fuel injector. Detailed description of the drawings and preferred embodiments

[0063] Preferred aspects and embodiments of the present invention are described in more detail below with reference to the accompanying figures. Identical or similar features in different drawings and embodiments are indicated by similar reference numerals. It should be noted that the detailed description below, which relates to various preferred aspects and preferred exemplary embodiments, is not intended to limit the scope of the present invention. 1. Description of background and examples

[0064] The following refers to Fig. 1 to 4 (correspondingly) Fig.1 to 4 of EP 3 150 831 A1) provide a description relating to a fuel injection system, which is exemplified by several fuel injection devices (fuel injectors), a pressure sensor, and a control device. Typically, such fuel injection systems can be designed for operating methods such as those described, for example, in the following patent documents EP 2 514 956 A1, DE 10 2007 024 397 A1, EP 3 150 831 A1, and US 2016 / 0 177 855 A1, which are based on the so-called "current control" concept for operating the fuel injection devices (fuel injectors). 1.1 Example fuel supply system / fuel injection system

[0065] An exemplary arrangement of the fuel injection system is described with reference to Fig. 1 described. Fig.Figure 1 is a schematic example view of a fuel supply system in which a fuel injection device (a fuel injector), a pressure sensor, a control device and an ECU (engine control unit) are mounted by way of example on an engine with in-cylinder direct injection.

[0066] Several fuel injection devices 101A to 101D (fuel injectors) are installed in the respective cylinders such that each fuel injection device (each fuel injector) is designed to inject fuel or a fuel mixture into a respective combustion chamber 107. For example, the fuel is supplied by a fuel pump 106 (e.g., a high-pressure fuel pump), sent to a fuel supply line 105 (fuel distribution rail), and delivered to the fuel injection devices 101A to 101D (fuel injectors).

[0067] Although the fuel pressure can change depending on a balance between a flow rate of the fuel discharged by the fuel pump 106 and an injection quantity (injected fuel quantity) of the fuel injected into each combustion chamber 107 by the fuel injection devices provided in each respective cylinder, a discharge quantity from the fuel pump 106 can be controlled using a predetermined pressure as a target value based on information from a pressure sensor 102.

[0068] Fuel injection using fuel injection devices 101A to 101D can be controlled according to an injection pulse width sent by an engine control unit (ECU) 104. This injection pulse can be input into a control circuit 103 of the fuel injection device (fuel injector), and the control circuit 103 is designed, for example, to determine a control current waveform (a current profile) based on a command from the ECU 104 and to supply the control current intensity to the fuel injection devices 101A to 101D according to the control current waveform (the current profile) for a time based on the injection pulse.

[0069] Furthermore, the control circuit 103 can be mounted as part of the ECU 104 or as a substrate that is integrated with it in some cases. A device in which the control circuit 103 and the ECU 104 are integrated is referred to as a control device 150. In other examples, the ECU and the injection control circuit can be provided separately. In some examples, one or more control circuits can be provided per fuel injection device, for example, each fuel injector having its own dedicated control circuit, while in other examples, one or more control circuits can be provided for multiple fuel injection devices, for example, a single control circuit for some or all of the fuel injectors.

[0070] First, an example setup and basic operation of the fuel injection device and its control device are described.

[0071] Fig. Figure 2 is an exemplary vertical cross-sectional view of the fuel injection device (fuel injector) and an exemplary representation showing an arrangement of the control circuit and engine control unit (ECU) connected to the fuel injection device. Fig. Figure 3 is an exemplary illustration showing an enlarged cross-sectional view of a control unit structure of the fuel injection device of Fig. 2 shows.

[0072] In particular, Fig.Figure 2 shows an exemplary vertical cross-sectional view of a fuel injection device 101 (a fuel injector) and a representation showing an example of an arrangement of the ECU 104 and the control circuit 103 for controlling the fuel injection device 101. Furthermore, the illustrations are partly shown in Fig. 1 equivalent part in Fig. 2 and Fig. 3 are designated by the same reference symbols.

[0073] The ECU 104 receives a signal indicating the engine's operating state from various sensors and calculates the injection pulse width. This calculation is designed to control the amount of fuel injected from the fuel injection device according to the operating conditions of an internal combustion engine, along with a specified injection timing. Additionally, the ECU 104 can be equipped with an analog-to-digital converter and an input / output port for receiving signals from various sensors.

[0074] The injection pulse output from the ECU 104 is fed into the control circuit 103 of the fuel injection device 101 via a signal line 110. The control circuit 103 controls a voltage that is to be applied to an electromagnet 205 (electromagnetic actuator) of the fuel injection device 101 and supplies the control current according to the desired current waveform (current profile).

[0075] The ECU 104 communicates with the control circuit 103 via a communication line 111 and can switch the control current generated by the control circuit 103 according to the pressure of the fuel supplied to the fuel injection device or the operating condition and change the setting values ​​of the current and time.

[0076] The ECU 104 can be configured with one or more control programs. These control programs can be designed to cause the ECU 104 to calculate control signals based on signals received from other control devices and / or from sensors and / or based on pre-stored data. For example, the ECU 104 can be configured by one or more dedicated control programs to calculate and output control signals that are sent to the control circuit(s) 103 to control the fuel injection device(s) 101. 1.2 Example of a fuel injection device / fuel injector

[0077] Next, the exemplary configuration and operation of the fuel injection device 101 (the fuel injector) will be described with reference to the vertical cross-section of the fuel injection device 101 in Fig. 2 and a cross-sectional view of Fig.3, in which the environment of a movable anchor element 202 (movable element) and a movable valve body 214 (valve element) is enlarged, is described. Furthermore, the parts that correspond to those in Fig. 2 are equivalent, in Fig. 3 are designated by the same reference symbols.

[0078] The fuel injection device 101, which is in Fig. 2 and Fig.Figure 3 shows an example of a normally closed electromagnetic valve (an electromagnetic fuel injection device), and the valve body 214 is, by way of example, in a non-excited state of an electromagnet 205 (electromagnetic actuator) of the injection device 101, pre-loaded in a valve closing direction by a spring 210 (first spring), and the valve body 214 is in closed contact with a valve seat 218 to form a valve closing state in the non-excited state of the solenoid 205 (electromagnetic actuator) of the injection device 101.

[0079] In the closed valve state, a force acts on the movable armature element 202, which is exemplified by a return spring 212 (second spring) in a valve opening direction. At this point, a force generated by the spring 210 and acting on the valve body 214 is greater than the force generated by the return spring 212, and thus an end face 302 of the movable armature element 202 is in contact with the valve body 214 and the movable armature element 202 comes to rest.

[0080] Furthermore, the valve body 214 and the movable anchor element 202 are designed to be relatively displaceable and are, for example, contained in a nozzle holder 201. Additionally, the nozzle holder 201 has, for example, an end face 303 that serves as a spring seat for the return spring 212. The force generated by the spring 210 can be adjusted, for example, during assembly by the pressure applied to a spring clamp 224, which is, for example, attached to an inner diameter of a fixed core 207.

[0081] Additionally, a magnetic circuit is formed by way of example from the solid core 207, the movable armature element 202, the nozzle holder 201 and a housing 203 in the fuel injection device 101 and an air gap is provided by way of example between the movable armature element 202 and the solid core 207.

[0082] A magnetic choke 211 is exemplified in a part of the nozzle holder 201, which corresponds, for example, to the air gap between the movable armature element 202 and the fixed core 207. The electromagnet 205 is exemplified in the state in which it is wound around a coil carrier 204 and is attached to an outer circumferential side of the nozzle holder 201. A rod guide 215 is exemplified in the vicinity of a pointed end of the valve body 214 on the side of the valve seat 218.

[0083] The movement of the valve body 214 in a valve axis direction is guided, for example, by two sliding sections of a spring base of the valve body 214 and the rod guide 215. An opening cap 216, in which, for example, the valve seat 218 and a fuel injection hole 219 are formed, is, for example, attached to the front end of the nozzle holder 201 to seal an interior space (fuel channel) provided from the outside between the movable anchor element 202 and the valve body 214.

[0084] The fuel to be supplied to the fuel injection device 101 is supplied by the fuel supply line 105 (see Fig.1) supplied, which is provided upstream of the fuel injection device 101 and flows through a first fuel passage hole 231 to flow to a pointed end of the valve body 214, and the fuel is sealed by a seat section formed at one end of the valve body 214 on the side of the valve seat 218 and the valve seat 218.

[0085] When the valve is closed, a differential pressure is generated between an upper and a lower side of the valve body 214 due to the fuel pressure, and the valve body 214 is pressed in the valve closing direction by the differential pressure obtained by multiplying the fuel pressure by a pressure-bearing area of ​​a seat inner diameter in a valve seat position, and the load of the spring 210.

[0086] When the control current is supplied to the electromagnet 205 in the valve's closed state, a magnetic field is generated in the magnetic circuit, a magnetic flux flows between the fixed core 207 and the movable armature element 202, and a magnetic attraction force acts on the movable armature element 202. The movable armature element 202 begins to move towards the fixed core 207 at a point in time when the magnetic attraction force acting on the movable armature element 202 exceeds the load caused by the differential pressure and the spring 210.

[0087] After the valve body 214 begins a valve opening operation (i.e., when the valve body 214 moves away from the valve seat 218 in the valve opening direction), the movable armature element 202 moves to the position of the fixed core 207, and after a certain displacement, the movable armature element 202 collides with the fixed core 207 (or another stop element). Following this collision between the movable armature element 202 and the fixed core 207, the movable armature element 202 can rebound from the fixed core 207 by absorbing a reaction force. However, the movable armature element 202 is attracted to the fixed core 207 by the magnetic attraction acting upon it and eventually stops its movement to rest in contact with the fixed core 207 (or another stop element).

[0088] At this time, the force on the movable armature element 202, due to the return spring 212, acts in the direction of the fixed core 207, thus shortening the time required for the rebound to converge. The time during which the gap between the movable armature element 202 and the fixed core 207 becomes large is reduced with a smaller rebound process, and stable operation can be achieved for smaller injection pulse widths.

[0089] The movable armature element 202 and the valve body 202, which have completed the valve opening process as described above, come to rest in a valve open state. In this state, a gap exists between the valve body 202 and the valve seat 218, and fuel is injected from the injection orifice 219. The fuel flows downstream through a central hole provided in the fixed core 207 and a lower fuel passage orifice 305 provided in the movable armature element 202.

[0090] When the excitation of the electromagnet 205 is switched off, the magnetic flux generated in the magnetic circuit disappears, and the magnetic attraction force also disappears. When the magnetic attraction force acting on the movable armature element 202 disappears, the movable armature element 202 and the valve body 214 are pressed into the valve closed position in contact with the valve seat 218 by the force of the spring 210 and the differential pressure.

[0091] Furthermore, when the valve body 214 is closed from the valve open state, it is brought into contact with the valve seat 218, and then the movable anchor element 202 is separated from the valve body 214 and moves in the valve closing direction and returns to an initial position in the valve closed state by means of the return spring 212 after it has been moving for a certain period of time.If the movable anchor element 202 separates from the valve body 214 at the moment when the valve body 214 finishes closing the valve, the mass of the movable element can be reduced by an amount equal to the mass of the movable anchor element 202 at the moment when the valve body 214 collides with the valve seat 218, and thus the collision energy at the time of collision with the valve seat 218 can be reduced, and the rebound of the valve body 214 generated when the valve body 214 collides with the valve seat 218 can be suppressed.

[0092] In the fuel injection device 101 according to the present example, the valve body 214 and the movable armature element 202 can achieve an effect of suppressing the rebound of the movable armature element 202 with respect to the fixed core 207 and the rebound of the valve body 214 with respect to the valve seat 218 by causing a relative displacement in a very short time period at the moment when the movable armature element 202 collides with the fixed core 207 during the opening of the valve and at the moment when the valve body 214 collides with the valve seat 218 during the closing of the valve.

[0093] As mentioned previously, it shows Fig.2 By way of example, an electromagnetically actuated fuel injection device 101 with a substantially cylindrical tubular body terminating in a tip having an outlet opening controlled by a valve element 214 (a valve body) actuated by an electromagnetic actuator 205. For example, the electromagnetic actuator 205 can be an electromagnet or a coil which may have n turns.

[0094] The valve element 214 can have a rod-shaped body that is axially guided in the injector body and can function as a piston. At one end, the valve element 214 can be physically contacted by an armature element 202, which, through the action of the electromagnetic actuator 205, causes a displacement of the valve element 214. The displacement is between a closed position and an open position of a valve seat 218.

[0095] The armature element 202 is movable between a rest position, which is lower than the rest position of the valve element 214, and an open position. When energized, the electromagnetic actuator 205 can in turn energize a magnetic core 207, and the armature element 202 can be moved by the electromagnetic force exerted on it by the magnetic core 207.

[0096] The armature element 202 can, in turn, move the valve element 214 by physical contact (i.e., by physically contacting a section of the valve element 214). The valve element 214 can thus be moved by the electromagnetic force via the armature element 202 between two limit positions: a closed position in which the tip of the valve element 214 rests on the valve seat 218, and a fully open position in which the tip of the valve element 214 reaches the maximum possible distance from the valve seat 218. This maximum possible distance can correspond to a position in which the valve element 214 and / or the armature element 202 come into contact with the core or a corresponding stop positioned along the axial direction defined by the rod-shaped body, which prevents the valve element and / or the armature element from moving beyond a predetermined fully open position.

[0097] The in Fig. The fuel injector shown (the fuel injection device) is exemplified as an inwardly opening type injector; i.e., excitation of the electromagnetic actuator 205 leads to a movement of the valve element in the opening direction, i.e., inwards. The valve element 214 is pulled out of its seated position, and thus a fuel injection operation can be carried out.

[0098] It should be noted, however, that the teachings of the present disclosure are not limited to the inward-opening type injector, but can easily be adapted to other types of injectors. For example, an outward-opening type valve can be used. It should therefore be understood that Fig.Figure 2 represents one possible type of electromagnetically actuated fuel injection device, and various other configurations may be possible and are indeed possible.

[0099] The electromagnetic actuator can also generally be operated such that the tip of the valve element does not reach the position that contacts the valve element stop (fully open position), but instead reaches a position between the closed and fully open positions (i.e., an intermediate position). This control operation is generally referred to as half-stroke operation. Half-stroke operation is particularly useful in some applications because it can further reduce the minimum injection quantity without affecting the maximum injection quantity. However, stable and precise injection cycles with low pulse-to-pulse variation are still desirable with such half-stroke operation of injection pulses. 1.3 Example of current control operation

[0100] Next, an exemplary description of the relationships between an injection pulse output by the ECU 104, a control voltage at both terminals of the electromagnet 205 of the fuel injection device 101, a control current (excitation current) and a displacement value (valve body behavior) of the valve body 214 of the fuel injection device is given with reference to Fig. 4 given.

[0101] Fig. Figure 4 is an exemplary representation showing a control concept called "current control" and the corresponding relationships between a general injection pulse for controlling the fuel injection device 101, a respective time specification of a control voltage and a control current to be supplied to the fuel injection device 101, and a valve body displacement size and time.

[0102] When an injection pulse signal is input into the control circuit 103, the control circuit 103 applies a high voltage VH 401 (sometimes referred to as the "boost voltage") from a high voltage source to the electromagnet 205, which is boosted to a voltage higher than a battery voltage in order to start the supply of the control current to the electromagnet 205.

[0103] When the current through the electromagnet 205 reaches a peak current value Ipeak, which can be preset for the ECU 104, the application of the high voltage 401 is stopped. Such a phase, in which the high voltage 401 ("boost voltage") is applied, can be referred to as the boost phase.

[0104] The above control of the drive current is referred to as part of a current control, since the time of applying the high voltage 401 (“boost voltage”) is determined by the condition of whether the drive current in the electromagnet 205 has reached the predetermined peak current value Ipeak.

[0105] Accordingly, such a boost phase in a current control scheme is typically characterized by the fact that the control current in each injection cycle increases to the same predetermined peak current value Ipeak and then the supply with the high voltage 401 (“boost voltage”) is terminated as soon as the control current reaches the predetermined peak current value Ipeak.

[0106] Then the applied voltage value is set to, for example, 0 V or lower, in order to determine the current value, such as a current402 in Fig.4. To reduce the current value. If the current value becomes lower than a predetermined current value 404 (target holding current value), the control circuit 103 applies a PWM-controlled voltage switching between ON and OFF between a battery voltage VB and 0 V (or lower) by PWM-controlled switching of respective control switches of the control circuit 103 and performs a control such that a predetermined current value 403 (the target holding current value) is maintained.

[0107] In this background example, the fuel injection device 101 is controlled according to the current profile described above (by current control), which is characterized in particular by the specified peak current value Ipeak (to be achieved during the boost phase) and the holding current value 403 (target holding current value) of the supplied control current.

[0108] The movable armature element 202 and the valve body 214 begin to move at a time t41 between the application of the high voltage 401 (VH) and the reaching of the peak current value Ipeak, and thereafter the movable armature element 202 and the valve body 214 reach their maximum opening positions. The movable armature element 202 can collide with the fixed core 207 at the time t42, at which the movable armature element 202 reaches its maximum opening position, and the movable armature element 202 can perform the rebound action against the core 207 (see between times t42 and t43 in Fig. 4).

[0109] Since the valve body 214 can be designed to be relatively displaceable with respect to the movable anchor element 202, the valve body 214 is separated from the movable anchor element 202 (see between times t42 and t43 in Fig.4) and the displacement of the valve body 214 can overshoot, exceeding the maximum opening position of the armature element 202. Furthermore, the valve body 214 can encounter an additional stop at the maximum opening position (fully open position). Subsequently, the movable armature element 202 comes to rest at the position with the predetermined maximum opening due to the magnetic attraction force generated by the holding current 403 and the force of the return spring 212 in the valve opening direction. The valve body 214 is then placed onto the movable armature element 202 and comes to rest at the position with the maximum opening (fully open position) at time t44, thus establishing a valve open state.

[0110] Under most operating conditions, rapid opening and closing of the injection valve is desirable. Therefore, the initial ramp-up phase is typically used as described above, resulting in a rapidly increasing control current (rapid current rise before reaching the peak current value Ipeak, which is predetermined based on the desired current profile).

[0111] During the holding period in which the injector should remain in the open position (in which the open position after time t44 in Fig.4 (where the current is held), a predefined holding current can be generated to achieve a constant electromagnetic holding force in order to keep the injection valve body 214 in the open position. In particular, a current holding phase can be used to keep the valve fully open for a desired period of time. Due to the force generated by the holding current 403, the valve body 214 and the movable armature element 202 remain in the opening state of maximum opening (fully open position) before closing again after the control current has been reduced to zero by the rapid decay phase. Specifically, at the end of the desired activation time, a rapid attenuation of the control current is typically achieved in a rapid decay or "reset" phase.

[0112] In light of the above, Fig.4 An example of controlling an injection cycle in a fuel injector according to a so-called full-stroke operation using the concept of current control, where the control operation is based on a desired target current profile or target current waveform (which may be defined by the peak current value Ipeak of the boost phase and one or more target holding current values, which are held by a closed-loop current control, e.g. based on PWM switching operations). 1.4 Example control circuit

[0113] Next, an exemplary description of an exemplary configuration of a control circuit 103 will be given with reference to Fig. 5 given. Fig. Figure 5 is an exemplary schematic view of a control circuit 103 of a fuel injector according to an exemplary embodiment.

[0114] Such a control circuit 103 can be used to control / operate the injection valve according to the current control described above. However, such a control circuit 103 can also be used, for example, for operating procedures of exemplary embodiments discussed below.

[0115] The control circuit 103 includes, for example, a high-voltage circuit side connected to a high-voltage source that supplies a high voltage V_Boost (e.g., an increased voltage that can be supplied, at least for a short period, during a boost phase, as discussed above), and to a low-voltage source that supplies a low voltage V_Bat (e.g., supplied as battery voltage from one or more batteries). The control circuit 103 also includes, for example, a low-voltage circuit side, and the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injection device is connected between the high- and low-voltage circuit sides.

[0116] For example, the high-voltage source that supplies the high voltage V_Boost is connected to the high-voltage side of the electromagnetic actuator (e.g., electromagnet 205) of the fuel injector via a switch SW_1 (which can be referred to as the "boost switch"), and the low-voltage side of the electromagnetic actuator (e.g., electromagnet 205) of the fuel injector is connected to ground potential via a switch SW_2 (which can be referred to as the "low-side switch"). Furthermore, the low-voltage source that supplies the low voltage V_Bat is connected to the high-voltage side of the electromagnetic actuator (e.g., electromagnet 205) of the fuel injector via a switch SW_3 (which can be referred to as the "battery switch").

[0117] For example, switches SW_1 to SW_3 can be implemented as MOSFET semiconductor switches controlled by a switch control logic 124 of the control circuit 103, which is connected to the respective gate terminals of switches SW_1 to SW_3 via signal lines (dashed lines). However, the invention is not limited to MOSFET semiconductor switches, and any type of controllable electrical switch can be used in a control circuit of other exemplary embodiments.

[0118] The low-voltage side of the electromagnetic actuator (e.g., electromagnet 205) of the fuel injector is further exemplified as being connected to the high-voltage source that supplies the high voltage V_Boost by a diode D1, the forward direction of which points towards the high-voltage source, thereby blocking the current from the high-voltage source to the low-voltage side of the electromagnetic actuator (e.g., electromagnet 205) of the fuel injector.

[0119] The high-voltage side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector is further exemplified by a diode D2, whose forward direction points towards the high-voltage circuit side, being connected to the ground potential, thereby blocking the current from the high-voltage circuit side towards the ground potential. 1.5 Example control states

[0120] In principle, such a control circuit 103 can be designed according to Fig. 5, which is discussed above, can be used to provide switching configurations of switches SW_1, SW_2 and SW_3 at least according to the following control states: 1.5.1 Upgrade Control State

[0121] In a “boost control state”, the switch control logic 124 of the control circuit 103 can supply activation signals to the gates of switches SW_1 and SW_2, so that both switches SW_1 and SW_2 are in the ON state (electrically closed state, i.e. in the conducting state), and switch SW_3 remains deactivated in its respective OFF state (electrically open, i.e. in the non-conducting state).

[0122] In the "boost control state", the high-voltage source that supplies the high voltage V_Boost is conductively connected to the high-voltage side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector through the electrically closed switch SW_1, and the low-voltage side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector is conductively connected to the ground potential through the electrically closed switch SW_2.

[0123] Accordingly, in the “boost control state”, the control current is enabled to flow through the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector from the high-voltage source that supplies the high voltage V_Boost, through the electrically closed switch SW_1 to the electromagnetic actuator, through the electromagnetic actuator, and then from the electromagnetic actuator through the electrically closed switch SW_2 to the ground potential side.

[0124] This means that in the "boost control state," a high voltage level of the high voltage V_Boost is actively applied, and the control current in the electromagnetic actuator is rapidly increased. Due to this rapidly rising current, the magnetic field in the electromagnetic actuator builds up rapidly. For this reason, the "boost control state" can be described as an active control state or as a control state for actively controlling the electromagnetic actuator. 1.5.2 Control state with normal drop

[0125] In a “control state with normal decay”, the switch control logic 124 of the control circuit 103 can supply activation signals to the gate of switch SW_2, so that switch SW_2 is in the ON state (electrically closed state, i.e. in the conducting state) and switches SW_1 and SW_3 remain in their respective OFF states (electrically open, i.e. in the non-conducting state) disabled.

[0126] Accordingly, during the normal decay control state, no voltage is actively applied, allowing the magnetic field in the electromagnetic actuator to dissipate and the control current in the electromagnetic actuator to decrease, e.g., according to an exponential decay, as it travels through the electrical loop via diode D2 to the electromagnetic actuator and then through the closed switch SW_2 to ground. For this reason, the "normal decay control state" can be referred to as the passive control state or the control state for passively controlling the electromagnetic actuator. 1.5.3 Hold Control State

[0127] In a “hold control state”, the switch control logic 124 of the control circuit 103 can supply activation signals to the gates of switches SW_3 and SW_2, so that both switches SW_3 and SW_2 are in the ON state (electrically closed state, i.e. in the conducting state) and switch SW_1 remains deactivated in its respective OFF state (electrically open, i.e. in the non-conducting state).

[0128] In the "hold control state", the low-voltage source that supplies the low voltage V_Bat is conductively connected to the high-voltage side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector through the electrically closed switch SW_3, and the low-voltage side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector is, for example, conductively connected to the ground potential through the electrically closed switch SW_2.

[0129] Accordingly, in the “hold control state”, it is made possible for the control current to flow through the electromagnetic actuator (e.g. the electromagnet 205) of the fuel injector from the low voltage source that supplies the low voltage V_Bat, through the electrically closed switch SW_3 to the electromagnetic actuator, through the electromagnetic actuator, and then from the electromagnetic actuator through the electrically closed switch SW_2 to the ground potential side.

[0130] This means that in the "hold control state," a low voltage level of the low-voltage V_Bat is actively applied, and the control current in the electromagnetic actuator is increased. The magnetic field in the electromagnetic actuator then builds up based on this increasing control current. For this reason, the "hold control state" can be described as an active control state or as the control state for actively controlling the electromagnetic actuator. 1.5.4 Control state with rapid drop-off

[0131] In a “rapid decay control state” (which may sometimes be referred to as a “reset control state”), the switch control logic 124 of the control circuit 103 may not supply any activation signals to the gates of all switches SW_1, SW_2 and SW_3, so that all switches SW_1, SW_2 and SW_3 are disabled in their respective OFF states (electrically open, i.e. in the non-conducting state).

[0132] If a previous control state was one in which a voltage, for example the high or low voltage V_Boost or V_Bat, is actively applied to the electromagnetic actuator, causing a control current to flow through the electromagnetic actuator and generating a magnetic field within it, switching to the "rapid drop control state" abruptly interrupts the control current by electrically opening all three switches and blocking the current in the reverse directions of diodes 5D1 and D2, causing the magnetic field in the electromagnetic actuator to collapse or be allowed to collapse.

[0133] This typically results in an induced voltage in the opposite direction, limited to a minimum of the negative value of V_Boost (in other words, the absolute value of the induced voltage is limited by the absolute value of V_Boost) through the reverse-current connection via diode D2 with the high-voltage source that supplies the high voltage V_Boost.

[0134] Accordingly, during the rapid-fall control state, no voltage is actively applied, the magnetic field in the electromagnetic actuator can collapse abruptly, and the control current in the electromagnetic actuator is abruptly interrupted at the time of switching from an active control state to the rapid-fall control state. For this reason, the "rapid-fall control state" can be referred to as a passive control state or the control state of passive control of the electromagnetic actuator. 1.5.5 Summary of the control states

[0135] For example, in the control circuit of Fig.5 at least the four control states mentioned above – the “boost control state”, referred to as state I in the following figures, the “normal fall-off control state”, referred to as state II in the following figures, the “hold control state”, referred to as state III in the following figures, and the “rapid fall-off control state”, referred to as state IV in the following figures – can be selected by outputting corresponding control signals to the respective switches SW_1, SW_2 and SW_3 according to the following table: Control state Switch SW_1 Switch SW_2 Switch SW_3 I Upgrade control state A A OUT OF II Control state with normal drop-off OUT OF A OUT OF III Hold control state OUT OF A A IV Control state with rapid drop OUT OF OUT OF Out of

[0136] It should be noted that other types of control circuits may be provided, such as control circuits that allow more control states than those listed above.

[0137] In Fig.4. The described current control can also be controlled based on the above control states by selecting the boost control state to provide the boost voltage VH (high voltage 401) during the boost phase until it is detected that the current in the electromagnetic actuator reaches the peak current value Ipeak. When the current in the electromagnetic actuator reaches the peak current value Ipeak, then in Fig.4. The control circuit is switched, for example, to the rapid decay control state, as indicated by the negative control voltage of approximately -VH. Then, during the holding phase, in which the current is PWM-controlled based on the target holding current value 403, the control circuit is rapidly and repeatedly switched between the holding control state and the normal decay control state, and vice versa, according to the PWM-based switching. After the holding phase, the control circuit is then switched, for example, to the rapid decay control state, as indicated by the negative control voltage of approximately -VH, where the absolute value of the voltage induced in the electromagnetic actuator decays exponentially.

[0138] As previously mentioned, however, in contrast to the "current control" concept described above, the present invention and the exemplary embodiments propose methods according to a novel concept that do not control fuel injections and fuel injection cycles based on a fully current-control-based target current profile or waveform, but directly control the control states, including their sequence and / or duration, e.g., based on a target voltage profile and / or a target phase profile, and which can still use similar control circuits. Although aspects of the present invention can also make use of new control circuit arrangements, it is therefore important to note that the present invention does not utilize generally known control circuits such as the control circuit of Fig. 5 above or variations thereof can be used. 1.5.6 Injection cycle control of a full-stroke operation by current control

[0139] To better understand the aspects of the present invention, a generally known control of a single injection cycle by controlling a so-called full-stroke operation by means of the control concept referred to as current control is described here.

[0140] Here, the term "full stroke" refers to the movement of the valve (valve element and / or movable armature element) of the fuel injector, which is opened to the maximum opening position (fully open position) during the injection cycle, whereby the valve can be held in the maximum opening position for a holding period, e.g. depending on the desired fuel injection quantity (desired amount of injected fuel / desired injection quantity).

[0141] Fig.Figure 6 is an exemplary representation showing the control concept referred to as "current control", which relates to full-stroke operation, and includes corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0142] For Fig.6, but it should also be noted for the figures described later that the flow rate is an indicator of the valve movement (through an approximately direct correlation between the fuel flow rate and the valve movement), assuming that the fuel pressure in the fuel rail is kept approximately constant during the injection period, where the flow rate is then essentially determined by the opening area of ​​the valve at the position of the valve seat 218 and a fuel injection hole 219. Therefore, when the valve is held in the maximum opening position, the flow rate (similar to the position of the valve element) is approximately constant.Furthermore, when the valve opens, the flow rate typically increases with further opening of the valve until it reaches a maximum flow rate when the valve is fully open, and then, as the valve closes, the flow rate typically decreases with further closing of the valve and essentially becomes zero when the valve reaches the fully closed position. Therefore, the function of the flow rate in . Fig. Figures 6 and later describe approximately a movement of the valve element of the fuel injector as a function of time (through the approximately direct correlation of the fuel flow rate and the valve movement).

[0143] In Fig.6. For example, the control state of the control circuit is switched to the boost control state I between times t1 and t2, and the voltage signal applied to the electromagnetic actuator of the fuel injector becomes the higher boost voltage V_Boost, so that the current flowing through the electromagnetic actuator increases rapidly until the current value reaches a predetermined current peak value Ipeak at time t2.

[0144] Furthermore, between times t2 and t3, the control state of the control circuit is switched to the “control state” with normal decay II at time t2, specifically at the time when the current flowing through the electromagnetic actuator reaches the predetermined current peak value Ipeak, so that the current flowing through the electromagnetic actuator decreases again after time t2 until the current reaches a lower first threshold value at time t3, which is referred to as Ihold_1.

[0145] If, for example, the current passing through the electromagnetic actuator reaches the first threshold value, designated Ihold_1, at time t3, a current-controlled closed-loop PWM control is initiated to rapidly switch between the hold control state III and the normal fall-off control state II between times t3 and t4 in order to maintain the current value passing through the electromagnetic actuator at the first threshold value designated Ihold_1 (first current hold value), with the fuel injector valve opening during this time period, for example, at time "to" (opening time), as can be seen from the start of the increase in the flow rate at time "to".

[0146] In a second holding phase after the valve has fully opened (after time t4), another current-controlled closed-loop PWM control is initiated between times t4 and t5 to rapidly switch between the hold control state III and the normal-fall control state II, in order to maintain the current value flowing through the electromagnetic actuator at the second threshold value, referred to as Ihold_2 (second current holding value), whereby during this period the fuel injector valve is held in the fully open position (full stroke), as can be seen from the approximately constant flow rate between times t4 and t5.

[0147] Then, when the valve is to close again to complete the current fuel injection cycle, at time t5 the control state of the control circuit switches, for example, to the rapid-fall control state IV (reset control state) as the end time t6 of the current fuel injection cycle approaches, and the voltage of the electromagnetic actuator becomes negative (initially exhibiting the negative value of the boost voltage level) and rapidly decreases exponentially to zero. Simultaneously, the current flowing through the electromagnetic actuator rapidly decreases as the magnetic field induced in the actuator disappears (collapses). This results in a rapid closing movement of the valve from the fully open position until the fully closed position is quickly reached at time tc (closing time).

[0148] The above example illustrates the concept of current control (for so-called full-stroke operation), which differs from the present invention in that the control parameters are based on closed-loop control based on sensing the current flowing through the electromagnetic actuator, e.g., by ending the ramp-up phase when the current reaches the threshold of the predetermined peak value Ipeak, and by providing closed-loop control through PWM switching based on a comparison of the current with the first or second hold value Ihold_1 or Ihold_2, respectively.It is possible that the duration of the PWM control phases is used as another predetermined parameter; however, such current control differs from the control concept of the present invention in that it does not control the duration (time span) of steady-state control conditions that are maintained for the controlled duration (time span). In this sense, the present invention proposes a completely new control concept for controlling fuel injection cycles, which is very different from the conventional current control discussed above. 1.5.7 Injection cycle control of a half-stroke operation by current control

[0149] To better understand the aspects of the present invention, a generally known control of a single injection cycle by controlling a so-called half-stroke operation by means of the control concept referred to as current control is described here.

[0150] The term "half-stroke" refers to the movement of the fuel injector's valve (valve element and / or movable armature element) that opens and closes during the injection cycle before the valve element moves to its maximum opening position (fully open position). Accordingly, in half-stroke operation, the valve element does not reach its maximum opening position but returns from the opening movement to the closing movement before reaching the maximum opening position. Although such half-stroke operation is important for applications with very low fuel injection quantities per injection cycle, it is very difficult to control according to current-based control, and typically, the pulse-to-pulse variations in the injected fuel quantity are generally quite large with known control concepts.

[0151] Fig.Figure 7 is another exemplary representation showing the control concept referred to as "current control", which relates to half-stroke operation, and includes corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0152] In Fig. 7 will be exemplary and similar to Fig. 6. The control state of the control circuit is switched to the boost control state I between times t1 and t2, and the voltage signal applied to the electromagnetic actuator of the fuel injector becomes the higher boost voltage V_Boost, so that the current flowing through the electromagnetic actuator increases rapidly until the current value reaches a predetermined current peak value Ipeak at time t2.

[0153] Furthermore, between times t2 and t3, the control state of the control circuit is switched, for example, to the control state with normal decay II at time t2, specifically at the time when the current flowing through the electromagnetic actuator reaches the predetermined current peak value Ipeak, so that the current flowing through the electromagnetic actuator decreases again after time t2 until the current flowing through the electromagnetic actuator reaches a lower threshold value called Ihold at time t3.

[0154] If, for example, still similar to in Fig.6, the current flowing through the electromagnetic actuator reaches the threshold value referred to as Ihold at time t3, and furthermore, for example, a current-controlled closed-loop PWM control based on current control is initiated to rapidly switch between the hold control state III and the normal fall-off control state II between times t3 and t4 in order to maintain the current value flowing through the electromagnetic actuator at the threshold value referred to as Ihold (current holding value), wherein during this time period the valve of the fuel injector opens, for example, at time “to” (opening time), as can be seen from the beginning of the increase in the flow rate at time “to”.

[0155] As opposed to Fig.However, at time t4, as the end time t5 of the current fuel injection cycle approaches, the control state of the control circuit is switched, for example, to the rapid-fall control state IV (reset control state) to complete the fuel injection cycle before the valve actually reaches the fully open position (half stroke). The voltage of the electromagnetic actuator becomes negative (initially exhibiting the negative value of the boost voltage level) and rapidly decreases exponentially to zero. Simultaneously, the current flowing through the electromagnetic actuator rapidly decreases as the magnetic field induced in the electromagnetic actuator disappears (collapses).This leads to a change in the opening movement of the valve to a closing movement before the valve reaches the fully open position (especially because the control state is activated with rapid drop-off while the valve is still in an opening movement towards the fully open position), and the fully closed position is then rapidly reached at time tc (closing time).

[0156] The above example illustrates the concept of current control (for so-called half-stroke operation), which differs from the present invention in that the control parameters are based on closed-loop control based on sensing the current flowing through the electromagnetic actuator, e.g., by ending the ramp-up phase when the current reaches the threshold of the predetermined peak value Ipeak, and by providing closed-loop control through PWM switching based on a comparison of the current with the holding value Ihold.It is possible that the duration of the PWM control phase is used as another predetermined parameter; however, such current control differs from the control concept of the present invention in that it does not control the duration (time span) of steady-state control conditions that are maintained for the controlled duration (time span). In this sense, the present invention proposes a completely new control concept for controlling fuel injection cycles, which is very different from the conventional current control discussed above.

[0157] It should be noted that the control of a half-stroke operation is typically rather imprecise when controlled by current-based control as described above, and in particular, the pulse-to-pulse variations in the fuel injection quantity increase rapidly in different injection cycles for decreasing desired injection quantities. Specifically, for injection quantities below 7 mg / pulse, the pulse-to-pulse variations typically rise rapidly above 1–2% and cannot typically be kept below 2% at injection quantities of approximately 4 mg / pulse or less. 2. Exemplary embodiments of fuel injection operating modes 2.1 First exemplary fuel injection operating mode embodiment

[0158] Fig.Figure 8 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a first exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0159] As in the upper part of Fig. Figure 8 shows the control states of the phase profile for the injection cycle control according to Fig.8. An example of a sequence is a first phase (boost phase) lasting a time interval T_I between times t1 and t2, in which the control circuit is switched to the boost control state I to initiate control of the injection pulse of the current injection cycle, and is held in the boost control state I for the time interval T_I between times t1 and t2. In an example of a second phase (normal fall-off phase) lasting a time interval T_II between times t2 and t3, the control circuit is switched to the normal fall-off control state II and is held in the normal fall-off control state II for the time interval T_II between times t2 and t3.In an exemplary third phase (hold phase or active phase) of a time interval T_III between times t3 and t4, the control circuit is switched to the hold control state III and held in the hold control state III for the time interval T_III between times t3 and t4. Finally, in an exemplary fourth phase (rapid decay phase) of a time interval T_IV between times t4 and t5, the control circuit is switched to the rapid decay control state IV and held in the rapid decay control state IV for the time interval T_IV between times t4 and t5 to complete the control of the current injection cycle.

[0160] Accordingly, one of the fuel injection operating modes (control operating modes) of Fig.8. The assigned phase profile should, for example, specify the predetermined sequence of phases as the first phase, which is assigned to the boost control state I, the second phase, which is assigned to the control state with normal fall-off II, the third phase, which is assigned to the hold control state III, and the fourth phase, which is assigned to the control state with rapid fall-off IV.

[0161] Furthermore, the fuel injection operating mode (control operating mode) of Fig.8. Assigned phase profiles specify one, several, or all of the time intervals T_I, T_II, T_III, and T_IV to indicate the durations of the respective phases (phases of steady-state control) of the phase profile. The time intervals T_I, T_II, T_III, and T_IV of the respective phases can be specified directly in the phase profile and / or the time intervals T_I, T_II, T_III, and T_IV of the respective phases can be specified indirectly in the phase profile by a time interval from t = 0 (start of the injection cycle) to the respective start and / or end times t1 to t5 of the respective phases.

[0162] In addition, one or more switching condition criteria can be provided additionally or alternatively and specified for one, several, or all phases of the phase profile, for example by specifying one or more switching criteria that define switching states which are checked with respect to certain fuel injection cycle characteristics (such as a fuel injection quantity per injection cycle and / or a fuel injection quantity per injection pulse and / or characteristics of the fuel injection flow rate and / or the valve motion path of the fuel injector element during one or more fuel injection cycles), and if it is determined that the one or more fuel injection cycle characteristics are satisfied, the control circuit can switch to the control state of the next phase.

[0163] Furthermore, for exemplary embodiments, particularly when feedback control, forward feedback control, or even closed-loop control is to be performed to control a fuel injection cycle or one or more injection pulses thereof based on sensor information indicating fuel injection cycle characteristics and / or injection cycle characteristics of a previous injection cycle, based on averaged sensor information indicating fuel injection cycle characteristics and / or injection cycle characteristics of several previous injection cycles, and / or based on real-time sensor information indicating fuel injection cycle characteristics and / or injection cycle characteristics of a current injection cycle, one or more parameters of the phase profile can be adjusted based on the sensor information, and the phase profile can specify adjustable phase profile parameters.For example, in the phase profile above, one, several or all of the time spans T_I, T_II, T_III and T_IV can be displayed as adjustable parameters, so that one, several or all of the time spans T_I, T_II, T_III and T_IV can be adjusted based on sensor information.

[0164] As in Fig.As shown in Figure 8, during the boost phase between times t1 and t2, the high voltage value V_Boost is constantly applied to the electromagnetic actuator for the time interval T_I by maintaining the boost control state I (i.e., there is an active voltage control phase). During this boost phase, the current flowing through the electromagnetic actuator increases rapidly until the control state is switched to the normal decay control state II at time t2. In contrast to the current control described above, where the boost phase ends when the current value reaches the predetermined current peak value Ipeak, the boost phase in Fig. 8. For example, after the time interval T_I has elapsed, i.e., when the boost control state I has been kept constant for the entire time interval T_I.

[0165] Furthermore, during the normal-fall phase between times t2 and t3, no voltage is actively applied to the electromagnetic actuator. For time interval T_II, the control circuit is switched to and maintained in normal-fall control state II (i.e., a passive voltage control phase). During this normal-fall phase, while the control circuit is in normal-fall control state II, the current flowing through the electromagnetic actuator decreases until the control state is switched to hold control state III at time t3. In contrast to the current control described above, where the normal-fall phase ends when the current reaches the predetermined hold current value, the normal-fall phase in Fig.8. For example, after the time interval T_II has elapsed, i.e., when the control state with normal decay II has been kept constant during the entire time interval T_II, and then at time t3, for example, the system switches to the holding control state III.

[0166] Furthermore, during the hold phase (active phase) between times t3 and t4, the battery voltage value V_Bat is applied constantly to the electromagnetic actuator for the time interval T_III by maintaining the active (hold) control state III (i.e., an active voltage control phase is in place), and during this hold phase (active phase), the current flowing through the electromagnetic actuator increases until the control state switches to the fast-fall control state IV at time t4. In contrast to the current control described above, where the hold phase is controlled by PWM control, which repeatedly switches the voltage signal based on a target hold current value, the active (hold) phase in Fig.8. For example, the battery voltage value V_Bat is kept constant and is terminated after the time interval T_III has elapsed, i.e., when the active control state III has been kept constant during the entire time interval T_III.

[0167] Finally, during the rapid decay phase between times t4 and t5, or more precisely after time t4 in the current injection cycle, no voltage is applied to the electromagnetic actuator by switching to the rapid decay control state IV for the time interval T_IV (i.e., a passive voltage control phase is in place), and during this rapid decay phase, in which the control circuit is in the rapid decay control state IV, the current flowing through the electromagnetic actuator decreases rapidly.

[0168] Examples include: Fig.8 For example, the durations T_I, T_II and T_III of the raising phase, the phase with normal fall-off or the active phase (holding phase) and / or switching times t1, t2 and t3 are determined (e.g., predetermined) such that the valve opens at a time t_o (the opening time), which is, for example, shortly before time t4, and the duration T_III and its corresponding time t4 are determined (e.g., predetermined) such that the valve then closes at a time tc (closing time).

[0169] Accordingly, the injection pulse begins at time t_o, and the flow rate starts to increase from the opening time t_o. However, the switch from active control state III to fast-fall control state IV at time t4 still occurs during the opening movement of the injector valve before it fully opens. The induced negative voltage value during the fast-fall phase slows the opening movement of the valve, and the valve element begins its closing movement, closing completely at time tc (closing time). Similarly, the flow rate stops increasing and decreases again shortly after the switch from active control state III to fast-fall control state IV at time t4.

[0170] As mentioned previously, the durations T_I, T_II and T_III of the boost phase, the normal fall phase or the active phase (holding phase) or the switching times t1, t2, t3 and t4 can be determined (e.g. predetermined) based on the desired target conditions, which include, for example, a desired fuel injection quantity (which is essentially given by the area under the flow rate function between times t_o and tc).

[0171] For example, the phase profile, which specifies the durations T_I, T_II, and T_III of the ramp-up phase, the normal decay phase, and the active hold phase, respectively, and / or the switching times t1, t2, t3, and t4 (to the rapid decay control state) can be predefined to achieve a desired fuel injection quantity. Such a phase profile can, for example, be pre-stored in the electronic control unit's (ECU) memory for a specific desired fuel injection quantity per injection cycle. Furthermore, feedback and / or feedforward control based on a variable desired fuel injection quantity can be implemented. For example, a fuel injection quantity can be controlled based on adjusting one or more parameters of the phase profile, such as the durations T_I, T_II, and T_III and / or the switching times t1, t2, t3, and t4.

[0172] For example, the switching time t4 can be adjusted, and then, if a higher injection quantity is required, the switching time t4 can be selected to be set to a later time in the injection cycle, or, if a lower injection quantity is required, the switching time t4 can be selected to be set to an earlier time in the injection cycle.

[0173] Experiments have shown that such control based on phase profiles, in which activation time specifications and / or activation durations for control states are determined or predetermined, especially for low injection quantities of approximately 7 mg / pulse or lower (even down to approximately 0.5 mg / pulse or higher, e.g., for injection pulses of approximately 0.3 ms), can significantly reduce pulse-to-pulse variations compared to the current control described above, and pulse-to-pulse variations of less than 1% or even approximately 0.5% for higher and lower injection quantities can be maintained by such phase profile control, especially also for 7 mg / pulse or less (even down to approximately 0.5 mg / pulse or higher, e.g., for injection pulses of approximately 0.3 ms). 2.2 Second exemplary fuel injection operating mode design

[0174] Fig.Figure 9 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a second exemplary embodiment relating to a half-stroke operation, and containing the corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0175] The control of Fig. 9 differs, for example, from the control in Fig. 8 in that the phase profile is adapted by adding a further (second) active phase with a held active control state III after the first phase with rapid decay and by providing a second phase with rapid decay after the other (second) active phase.

[0176] As in the upper part of Fig. Figure 9 shows the control states of the phase profile for the injection cycle control according to Fig.9. An exemplary sequence of a first phase (boost phase) of a time interval T_I between times t1 and t2, in which the control circuit is switched to the boost control state I to start the control of the injection pulse of the current injection cycle, and is held in the boost control state I between times t1 and t2 for the time interval T_I, is provided. In an exemplary second phase (normal fall-off phase) of a time interval T_II between times t2 and t3, the control circuit is switched to the normal fall-off control state II and is held in the normal fall-off control state II between times t2 and t3 for the time interval T_II.In an exemplary third phase (first holding phase or first active phase) of a time interval T_III,1 between times t3 and t4, the control circuit is switched to holding control state III and held in holding control state III for the time interval T_III,1 between times t3 and t4. In an exemplary fourth phase (first rapid drop phase) of a time interval T_IV,1 between times t4 and t5, the control circuit is further exemplary switched to rapid drop control state IV and held in rapid drop control state IV for the time interval T_IV,1 between times t4 and t5 to cause the opening movement of the valve to be delayed and the valve to be influenced to initiate a closing movement again before the valve element reaches the fully open position (half-stroke operation).

[0177] Unlike in Fig.8 The control circuit is then used in an exemplary fifth phase (second holding phase or second active phase) of a time span T_III,2 between times t5 and t6 in Fig.9 is switched to hold control state III and is held in hold control state III for the time interval T_III,2 between times t5 and t6. This has the effect of allowing the electromagnetic field in the electromagnetic actuator to rebuild and delaying the closing speed of the valve element in order to reduce noise and vibration at the time the valve element reaches the fully closed position (thus making contact with the valve seat) due to the reduced closing speed.Finally, by way of example, in an exemplary sixth phase (second phase with rapid decay) of a time interval T_IV,2 between times t6 and t7, the control circuit is switched to the control state with rapid decay IV and held in the control state with rapid decay IV for the time interval T_IV,2 between times t6 and t7 in order to complete the control of the current injection cycle and in particular to keep the valve closed after it has reached the fully closed position (for example, the switching time t6 is essentially equal to the closing time tc).

[0178] Accordingly, one of the fuel injection operating modes (control operating modes) of Fig.9. The assigned phase profile should specify, for example, the predetermined sequence of phases as the first phase, which is assigned to the boost control state I, the second phase, which is assigned to the control state with normal fall-off II, the third phase, which is assigned to the hold control state III, and the fourth phase, which is assigned to the control state with fast fall-off IV, a further fifth phase, which is again assigned to the hold control state III, and a sixth phase, which is again assigned to the control state with fast fall-off IV.

[0179] Furthermore, the fuel injection operating mode (control operating mode) of Fig.9. The assigned phase profile specifies, for example, one, several, or all of the time intervals T_I, T_II, T_III,1, and T_IV,1, as well as the additional time intervals T_III,2 and T_IV,2, to indicate the duration of the respective phases (phases of steady-state control) of the phase profile. The time intervals T_I, T_II, T_III,1, and T_IV,1, as well as the additional time intervals T_III,2 and T_IV,2 of the respective phases, can be specified directly in the phase profile and / or the time intervals T_I, T_II,1, and T_IV,1, as well as the additional time intervals T_III,2 and T_IV,2 of the respective phases, can be specified indirectly in the phase profile by a time interval from t = 0 (start of the injection cycle) to the respective start and / or end times t1 to t7 of the respective phases.

[0180] Until shortly after time t4 and before time t5, the phase profile of Fig.9 and the associated control of fuel injection during the injection cycle, similar to, for example, that of Fig. 8. At time t5, however, the control circuit is switched back to active control state III and held there for the time interval TIII,2, so that the magnetic field in the electromagnetic actuator of the fuel injector begins to rebuild and the deceleration force acting on the valve element and / or the armature element is exerted, which leads to a slowing of the valve closing speed in order to advantageously reduce noise and vibration when the valve strikes the valve seat at time tc (the closing time). To keep the valve closed at this time, the control circuit is then switched off at time t6 (which is, for example, essentially equal to the closing time tc in Fig. 9 is) switched to the control state with rapid drop IV.

[0181] Similar to the tax operation of Fig. 8 above, can also refer to Fig. 9 the durations T_I, T_II, T_III,1, T_IV,1 and TIII,2 of the ramp-up phase, first phase with rapid fall-off and second active phase (holding phase) and / or switching times t1, t2, t3, t4, t5 and t6 are determined (e.g. predetermined) based on desired target conditions, which include, for example, a desired fuel injection quantity (which is essentially given by the area under the flow rate function between times t_o and tc).

[0182] For example, the phase profile, which defines the durations T_I, T_II, T_III,1, T_IV,1, and T_III,2 of the ramp-up phase, the normal-fall phase, the first active phase (hold phase), the first rapid-fall phase, and the second active phase (hold phase), and / or switching times t1, t2, t3, t4, t5, and t6 (to the final rapid-fall control state), can be predefined to achieve a desired fuel injection quantity. Such a phase profile can, in turn, be pre-stored in a memory of the electronic control unit (e.g., ECU) for a specific desired fuel injection quantity per injection cycle. Furthermore, feedback and / or feedforward control based on a variable desired fuel injection quantity can be implemented. For example, a fuel injection quantity can be determined based on adjusting one or more parameters of the phase profile, such as...the respective durations thereof and / or the switching times t1, t2, t3, t4, t5 and t6, are controlled.

[0183] For example, the switching times t4, t5 and / or t6 can be adjusted, and then, if perhaps a higher injection quantity is required, the switching times t4, t5 and / or t6 can be selected to be set to later time specifications in the injection cycle, or, if perhaps a lower injection quantity is required, the switching times t4, t5 and / or t6 can be selected to be set to earlier time specifications in the injection cycle.

[0184] Experiments have shown that such a phase-profile-based control system, in which activation time specifications and / or activation durations for control states are determined or predefined, significantly reduces pulse-to-pulse variations compared to the current-based control described above, particularly for low injection quantities of approximately 7 mg / pulse or less. Furthermore, pulse-to-pulse variations of less than 1%, or even approximately 0.5% for higher and lower injection quantities, can be maintained by such a phase-profile control system, especially for 7 mg / pulse or less. It was also determined that the additional active phase of time interval T_III,2 was suitable for significantly reducing noise and vibration occurring at or shortly after the closing time tc. 2.3 Third exemplary fuel injection control method implementation

[0185] Fig.Figure 10 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a third exemplary embodiment relating to a half-stroke operation, and containing the corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0186] The control of Fig. 10 differs, for example, from the control in Fig.9 such that the phase profile is adjusted by controlling the time interval for slowing down the closing speed of the valve element between times t5 and t6, for example based on a PWM control of repeated switching between the control state with normal drop II and the active (holding) control state III between times t5 and t6 in a time interval T_PWM, until the control circuit is finally switched to the control state with fast drop IV at time t6.

[0187] Although the present invention aims to simplify fuel injection control by simultaneously increasing the accuracy of the injection quantities and preferably reducing noise and vibration during the injection cycle by providing control based on phase profiles with multiple phases (time spans) of maintained steady-state control conditions, the invention nevertheless makes it possible to provide one or more phases of PWM control in addition to multiple phases (time spans) of maintained steady-state control conditions, if this is preferred based on desired valve motion paths or the like. 2.4 Fourth exemplary fuel injection control method implementation

[0188] Fig.Figure 11 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a fourth exemplary embodiment relating to a half-stroke operation, and containing the corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0189] The control of Fig. 11 differs, for example, from the control in Fig. 9 in that the phase profile is adjusted by changing the total time required to slow down the closing speed of the valve element between times t5 and, for example, t7, based on an initial steady-state active phase in which the active control state III is similar to that in Fig. 9 (during a shorter time period T_III,2) is maintained until time t6, is controlled, and an additional PWM phase of PWM control is provided for repeated switching between the control state with normal fall-off II and the active (hold) control state III, for example, between times t6 and t7 in a time period T_PWM, until the control circuit is finally switched to the control state with fast fall-off IV at time t7.

[0190] As previously mentioned in connection with Fig.As mentioned in paragraph 10, the invention makes it possible, although the present invention aims to simplify fuel injection control by simultaneously increasing the accuracy of the injection quantities and preferably reducing noise and vibration during the injection cycle by providing control based on phase profiles with multiple phases (time spans) of maintained steady-state control conditions, nevertheless to provide one or more phases of PWM control in addition to multiple phases (time spans) of maintained steady-state control conditions, if this is preferred based on desired valve motion paths or the like. 2.5 Fifth exemplary fuel injection control method implementation

[0191] Fig.Figure 12 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a fifth exemplary embodiment relating to multiple half-stroke operating injection pulses in an injection cycle, and containing the corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0192] Although the exemplary tax operating modes of Fig. 8, Fig. 9, Fig. 10 and Fig.11. By way of example, relating to the injection control of the injection of a very low fuel injection quantity by a half-stroke operation of the fuel injection valve in a single injection pulse per injection cycle, the inventors found that exemplary embodiments of the present invention, based on exemplary phase profiles, further enable it to very advantageously control several injection pulses per injection cycle at very low injection quantities per injection pulse, e.g. below 7 mg of fuel per individual pulse, whereby the pulse-to-pulse variations between pulses of the same injection cycle as well as between pulses of different injection cycles could be reduced to below 1%.

[0193] Illustrated by example Fig. 12 the control of an injection cycle, for example with three injection pulses per injection cycle with a phase profile according to the control states of the upper part of Fig. 12.

[0194] As in the upper part of Fig. Figure 12 shows the control states of the phase profile for the injection cycle control according to Fig.12. An exemplary sequence of a first phase (boost phase) is provided for a time interval T_I between times t1 and t2, in which the control circuit is switched to the boost control state I to initiate control of the injection pulse of the current injection cycle, and is held in the boost control state I for the time interval T_I between times t1 and t2. In an exemplary second phase (normal fall-off phase) for a time interval T_II between times t2 and t3, the control circuit is switched to the normal fall-off control state II and is held in the normal fall-off control state II for the time interval T_II between times t2 and t3.In an exemplary third phase (first holding phase or first active phase) of a time interval T_III,1 between times t3 and t4, the control circuit is switched to the holding control state III and held in the holding control state III for the time interval T_III,1 between times t3 and t4. In an exemplary fourth phase (first rapid decay phase) of a time interval T_IV,1 between times t4 and t5, the control circuit is further exemplary switched to the rapid decay control state IV and held in the rapid decay control state IV for the time interval T_IV,1 between times t4 and t5 to force the injection valve to slow down its opening movement and return to the closing movement in order to complete the control of the first injection pulse of the current injection cycle. Up to time t4, the control is similar to the control of . Fig.8 to 11 above.

[0195] Similar to in Fig. 9 and Fig. 11. At time t5, the control circuit is switched back to the holding control state III (active control state III) to slow down the closing speed of the valve and avoid noise and vibration when the valve element closes after the first injection pulse. Then, in Fig. 12 Instead of completing the injection cycle by switching to the control state with rapid drop IV when the valve closes after the first injection pulse, the holding control state III (active control state III) is also maintained after the valve has closed following the first injection pulse, so that the magnetic field in the electromagnetic actuator can continue to build up until an electromagnetic force is sufficient to open the valve again for a further, second injection pulse during the same injection cycle.

[0196] Accordingly, in an exemplary fifth phase (second holding phase or second active phase) of a time interval T_III,2 between times t5 and t6, the control circuit is switched back to the holding control state III and held in the holding control state III for the time interval T_III,2 between times t5 and t6. In an exemplary sixth phase (second phase with rapid decay) of a time interval T_IV,2 between times t6 and t7, the control circuit is further exemplary switched to the control state with rapid decay IV and held in the control state with rapid decay IV for the time interval T_IV,2 between times t6 and t7 to force the injection valve to slow down its opening movement and return to the closing movement in order to complete the control of the second injection pulse of the current injection cycle.

[0197] Here, at time t7, the control circuit is switched back to the holding control state III (active control state III) to slow down the valve closing speed and avoid noise and vibrations when the valve element closes after the second injection pulse. Then, in Fig. 12 Instead of completing the injection cycle by switching to the control state with rapid drop IV when the valve closes after the second injection pulse, the holding control state III (active control state III) is also maintained, for example, after the valve has closed after the second injection pulse, so that the magnetic field in the electromagnetic actuator can continue to build up until an electromagnetic force is sufficient to open the valve again for a further, third injection pulse during the same injection cycle.

[0198] In an exemplary seventh phase (third holding phase or third active phase) of a time interval T_III,3 between times t7 and t8, the control circuit is, for example, again switched to the holding control state III and held in the holding control state III for the time interval T_III,3 between times t7 and t8. Furthermore, in an exemplary eighth phase (third phase with rapid decay) of a time interval T_IV,3 between times t8 and t9, the control circuit is again switched to the control state with rapid decay IV and held in the rapid control state with rapid decay IV for the time interval T_IV,3 between times t8 and t9 to force the injection valve to slow down its opening movement and return to the closing movement in order to complete the control of the third injection pulse of the current injection cycle.

[0199] Although the control state with rapid decay IV could then be maintained (e.g., similar to the phase of the time span T_IV in Fig. 8), an optional further active phase is provided as an example to slow down the final closing movement of the valve in the injection cycle (e.g. similar to the phase of time interval T_III,2 in Fig. 9). That is, in an exemplary ninth phase (fourth holding phase or fourth active phase) of a time span T_III,4 between times t9 and t10 in Fig.12 the control circuit is switched to the holding control state III and is held in the holding control state III between times t9 and t10 for the time interval T_III,4 in order to reduce noise and vibration at the time when the valve element reaches the fully closed position due to the slowed closing speed.Finally, for example, in an exemplary tenth phase (fourth phase with rapid decay) of a time interval T_IV,4 between times t10 and t11, the control circuit is switched to the control state with rapid decay IV and held in the control state with rapid decay IV for the time interval T_IV,4 between times t10 and t11 in order to finally complete the third injection pulse and the control of the current injection cycle and, in particular, to keep the valve closed after it has reached the fully closed position after the third injection cycle (for example, the switching time t10 is essentially equal to the closing time tc).

[0200] Accordingly, one of the fuel injection operating modes (control operating modes) of Fig.12. The assigned phase profile exemplifies the predetermined sequence of phases as follows: first phase, which is assigned to the boost control state I; second phase, which is assigned to the control state with normal decay II; third phase, which is assigned to the hold control state III; fourth phase, which is assigned to the control state with rapid decay IV; fifth phase, which is again assigned to the hold control state III; sixth phase, which is again assigned to the control state with rapid decay IV; seventh phase, which is again assigned to the hold control state III; eighth phase, which is again assigned to the control state with rapid decay IV; ninth phase, which is again assigned to the hold control state III; and tenth phase, which is again assigned to the control state with rapid decay IV. Although Fig.12 and its associated phase profile are intended, for example, to control three injection pulses for the same injection cycle. It is possible, however, to adapt such a phase profile for only two injection pulses per injection cycle (e.g., by activating the control state with rapid decay IV at the time when the valve closes after the second injection cycle during the duration T_III,3). Similarly, the phase profile can also be designed to control four or more injection pulses per injection cycle.

[0201] In analogy to Fig. 8 to 11 above can be used for Fig. 12 the fuel injection operating mode (control operating mode) of Fig.12. For example, specify one, several or all of the time periods associated with the phase profile, e.g. T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2 T_III,3, T_IV,4 T_III,4 and / or T_IV,4, to indicate the duration of the respective phases of the phase profile. The time spans T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2 T_III,3, T_IV,4 T_III,4 and / or T_IV,4 of the respective phases can be specified directly in the phase profile and / or the time spans T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2 T_III,3, T_IV,4 T_III,4 and / or T_IV,4 of the respective phases can be specified indirectly in the phase profile by a time span from t = 0 (start of the injection cycle) to the respective start and / or end times t1 to t11 of the respective phases.

[0202] In addition, one or more switching condition criteria can be provided additionally or alternatively and specified for one, several, or all phases of the phase profile, e.g., by one or more switching criteria specifying switching conditions that are checked with respect to certain fuel injection cycle characteristics (such as a fuel injection quantity per injection cycle and / or a fuel injection quantity per injection pulse and / or characteristics of the fuel injection flow rate and / or the valve motion path of the injector element during one or more fuel injection cycles), and if it is determined that the one or more fuel injection cycle characteristics are satisfied, the control circuit can be switched to the control state of the next phase.

[0203] Furthermore, for exemplary embodiments, particularly when feedback control, forward feedback control, or even closed-loop control is to be performed to control a fuel injection cycle or one or more injection pulses thereof based on sensor information indicating fuel injection cycle characteristics and / or injection cycle characteristics of a previous injection cycle, based on averaged sensor information indicating fuel injection cycle characteristics and / or injection cycle characteristics of several previous injection cycles, and / or based on real-time sensor information indicating fuel injection cycle characteristics and / or injection cycle characteristics of a current injection cycle, one or more parameters of the phase profile can be adjusted based on the sensor information, and the phase profile can specify adjustable phase profile parameters.For example, in the phase profile above, one, several or all of the time spans T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2 T_III,3, T_IV,4, T_III,4 and / or T_IV,4 may be specified as adjustable parameters, so that one, several or all of the time spans T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2 T_III,3, T_IV,4, T_III,4 and / or T_IV,4 can be adjusted based on sensor information.

[0204] The durations T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2 T_III,3, T_IV,4 T_III,4 and / or T_IV,4 of the respective phases and their switching time specifications can also be determined (e.g., predetermined) based on desired target conditions, which include, for example, a desired fuel injection quantity per injection cycle (which is essentially given by the area under the flow rate function relating to all injection pulses of the same injection cycle), the desired number of injection pulses per injection cycle and / or a desired fuel injection quantity per injection pulse (which is essentially given by the area under the flow rate function of the respective injection pulse).

[0205] For example, the phase profile, which defines the durations T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2, T_III,3, T_IV,4, T_III,4 and / or T_IV,4 of the respective phases and / or switching time specifications thereof, can be predefined such that a desired fuel injection quantity per injection cycle and / or injection pulse is obtained and / or that a desired number of injection pulses per injection cycle can be obtained. Such a phase profile can, for example, be prestored in a memory of the electronic control unit (e.g., the ECU) for a specific desired fuel injection quantity per injection cycle. Furthermore, feedback and / or feedforward control based on a variable desired fuel injection quantity can be implemented. For example, a fuel injection quantity can be determined based on adjusting one or more parameters of the phase profile, such as...The time durations T_1, T_II, T_III,1, T_IV,1, T_III,2, T_IV,2 T_III,3, T_IV,4, T_III, 4 and / or T_IV,4 of the respective phases and / or their switching time specifications are controlled.

[0206] Experiments have shown that such control based on phase profiles, in which activation time specifications and / or activation durations for control states are determined or predetermined, especially for low injection quantities of approximately 7 mg / pulse or less, significantly reduces pulse-to-pulse variations even for the control of multiple injection pulses per injection cycle, and maintains pulse-to-pulse variations between injection pulses of the same injection cycle and injection pulses of different injection cycles below 1% or even at about 0.5% for higher and lower injection quantities, especially for 7 mg / pulse or less. 2.6 Sixth exemplary fuel injection operating mode design

[0207] Fig. Figure 13 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a sixth exemplary embodiment relating to a half-stroke operation, and containing corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0208] The inventors have discovered that the control system, which is based on a phase profile defining time spans of steady-state control conditions, can be further optimized to precisely control the movement of the valve element and the displacement of the armature element separately for a specified opening time, in particular to control the armature element movement more accurately before it comes into contact with the valve element prior to the specified opening time, to further smooth a valve movement path and / or to reduce noise and vibrations also around the time of the valve opening, in particular to reduce noise and vibrations when the armature element comes into contact with the valve element at or before the specified valve opening time t_o.

[0209] In particular, it shows Fig.13. For example, a control system based on a phase profile, in which the opening of the valve is based on a phase sequence of a ramp-up phase during a time period T_1, a normal fall-off phase during a time period T_2, and a (first) active phase (holding phase) during a time period T_III,1 (similar to in Fig. 8 and Fig. 9 above), where, for example, a further (optional) second active phase (holding phase) as in Fig. 9 is provided for during a time period T_III,2.

[0210] By extending the ramp-up phase by a longer time period T_I and extending the normal fall-off phase by a longer time period T_2 before switching to the (first) active phase (holding phase) at time t3 in comparison to Fig. 8 and Fig.9. The electromagnetic force dynamics can be influenced before the valve opening in such a way that the displacement of the armature element before contact with the valve element can be controlled more slowly, so that the armature element smoothly touches the valve element and remains in contact with the valve element for a short period of time before the electromagnetic force of the electromagnetic actuator builds up to a sufficient level during the active phase of the time period T_III,1, so that the armature element opens the valve element slowly and smoothly without noise and vibrations at the specified opening time t_o.

[0211] The displacement of the anchor element is exemplified by the dashed line in the lower displacement drawing. Fig. 13 is shown, whereas the valve element movement is shown by the solid line in the lower displacement drawing of Fig. 13 is shown.

[0212] Accordingly, a very smooth valve movement path can be controlled and the noise and vibrations during the injection cycle, especially around the valve opening time, can be further reduced. 2.7 Seventh exemplary fuel injection control method implementation

[0213] Fig. Figure 14 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including a seventh exemplary embodiment relating to a half-stroke operation, and containing the corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0214] For example, the phase profile in Fig. 14 similar to in Fig. 13 optional switching times t1, t2, t3, t4 and t5, to optionally also control a smooth opening of the injection valve by precisely controlling the displacement of the armature element before the opening time specification t_o.

[0215] The inventors have discovered that the control system, which is based on a phase profile defining time spans of steady-state control conditions, can be further optimized to precisely control the movement of the valve element and the displacement of the armature element separately at a closing time, in particular to control the armature element movement more accurately after the closing time specification, to further smooth a valve movement path and / or to reduce noise and vibrations also around the time of valve closing, especially to reduce noise and vibrations when the valve element comes into contact with the valve seat.

[0216] In particular, the second holding phase between times t5 and t8 is exemplified by an additional (second) phase with normal fall-off (in addition to the first regular phase with normal fall-off of the time span T_II,1) between times t6 and t7, which is divided into two holding phases, activated at time t6 shortly before the valve element contacts the valve seat at the closing time specification tc, which is essentially the same as the switching time specification t7.

[0217] For example, similar to the phase profile of Fig. 9 and Fig. 13. A further (second) holding phase is activated when the control circuit, after the first phase with a rapid decrease in the time interval T_IV,1, is switched to the active (holding) control state III at time t5 in order to delay the closing movement of the valve element. However, instead of then proceeding as in Fig. 9 and Fig.13. To switch directly to the control state with rapid decay when the valve element closes, the control state is, for example, switched back to the control state with normal decay II for a short period T_II,2 in a second phase with normal decay of the time interval T_II,1 for a short period T_II,2 shortly before the contact of the valve element with the valve seat, so that the current in the electromagnetic actuator decreases, and at time t7, essentially when the valve element closes at the closing time specification tc, the control circuit is switched back to the active (hold) control state III for a period T_III,3 before finally the injection cycle is ended with the switch to the control state with rapid decay IV at time t8.

[0218] The displacement of the anchor element is exemplified by the dashed line in the lower displacement drawing. Fig.14 is shown, while the valve element movement is shown by the solid line in the lower displacement drawing of Fig. 14 is shown. And, as exemplified in Fig. As shown in Figure 14, the phases of the time intervals T_II,2 and T_III,3 lead to a gentle closing of the valve element, with the armature element remaining in contact with the valve element in the fully closed position before the armature element is then quickly moved to its rest position after being switched to the control state with rapid drop IV at time t8.

[0219] Accordingly, a very smooth valve movement path can be controlled and the noise and vibrations during the injection cycle, especially around the valve closing time, can be further reduced. 2.8 Eighth exemplary fuel injection control method implementation

[0220] Fig.Figure 15 is an exemplary representation showing a control concept of a fuel injection operating mode, relating to exemplary embodiments including an eighth exemplary embodiment relating to a half-stroke operation, and containing the corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0221] Although Fig. While figures 8 to 14 above refer by way of example to the control of a half-stroke operation, it should be specifically noted that exemplary embodiments may also refer to the control of a full-stroke operation based on a phase profile of exemplary embodiments of the present invention, such as, for example, a phase profile according to Fig. 15.

[0222] As in the upper part of Fig. Figure 15 shows the control states of the phase profile for the injection cycle control according to Fig.15. An example of a sequence is a first phase (boost phase) lasting a time interval T_I between times t1 and t2, in which the control circuit is switched to the boost control state I to start the control of the injection pulse of the current injection cycle, and is held in the boost control state I for the time interval T_I between times t1 and t2. In an example of a second phase (first phase with normal fall-off) lasting a time interval T_II,1 between times t2 and t3, the control circuit is switched to the control state with normal fall-off II and is held in the control state with normal fall-off II for the time interval T_II,2 between times t2 and t3.In an exemplary third phase (first holding phase or first active phase) of a time interval T_III,1 between times t3 and t4, the control circuit is switched to holding control state III and held in holding control state III for the time interval T_III,1 between times t3 and t4. In an exemplary fourth phase (second phase with normal release) of a time interval T_II,2 between times t4 and t5, the control circuit is again exemplary switched to control state with normal release II and held in control state with normal release II for the time interval T_II,2 between times t4 and t5 to cause the opening movement of the valve to be delayed shortly before the valve element reaches the fully open position (full-stroke operation).Then, when the valve element essentially reaches the fully open position, in an exemplary fifth phase (second holding phase or second active phase) of a time interval T_III,2 between times t5 and t6, the control circuit is switched to the holding control state III and is held in the holding control state III for the time interval T_III,2 between times t5 and t6. In an exemplary sixth phase (first rapid drop phase) of a time interval T_IV,1 between times t6 and t7, the control circuit is further exemplary switched to the rapid drop control state IV and held in the rapid drop control state IV for the time interval T_IV,1 between times t6 and t7 to cause the valve to begin a closing movement again.Then, in an exemplary seventh phase (third holding phase or third active phase) of a time span T_III,3 between the times t7 and t8 in . Fig.15. The control circuit was switched back to the holding control state III and held in the holding control state III for the time interval T_III,3 between times t7 and t8. This has the effect that the electromagnetic field in the electromagnetic actuator rebuilds and the closing speed of the valve element is delayed at the time when the valve element reaches the fully closed position (and thus touches the valve seat) in order to reduce noise and vibrations due to the slower closing speed.Finally, by way of example, in an exemplary eighth phase (second phase with rapid decay) of a time interval T_IV,2 between times t8 and t9, the control circuit is switched back into the control state with rapid decay IV and is held in the control state with rapid decay IV between times t8 and t9 for the time interval T_IV,2 in order to complete the control of the current injection cycle and in particular to keep the valve closed after it has reached the fully closed position.

[0223] Accordingly, one of the fuel injection operating modes (control operating modes) of Fig.15. The assigned phase profile should exemplify the predetermined sequence of phases as follows: first phase, which is assigned to the boost control state I; second phase, which is assigned to the control state with normal fall-off II; third phase, which is assigned to the hold control state III; fourth phase, which is again assigned to the control state with normal fall-off II; fifth phase, which is again assigned to the hold control state III; sixth phase, which is assigned to the control state with rapid fall-off IV; seventh phase, which is again assigned to the hold driver state III; and eighth phase, which is again assigned to the control state with rapid fall-off IV.

[0224] Furthermore, this can be the fuel injection operating mode (control operating mode) of Fig.15. Assigned phase profiles, specify one, several or all of the time spans T_I, T_II,1, T_III,1, T_II,2, T_III, T_IV,1, T_III,3 and T_IV,2 to indicate the duration of the respective phases (phases of steady-state control) of the phase profile. The time spans T_I, T_II,1, T_III,1, T_II,2, T_III,2, T_IV,1, T_III,3 and T_IV,2 of the respective phases can be specified directly in the phase profile and / or the time spans T_I, T_II,1, T_III,1, T_II,2, T_III,2, T_IV,1, T_III,3 and T_IV,2 of the respective phases can be specified indirectly in the phase profile by a time span from t = 0 (start of the injection cycle) to the respective start and / or end times t1 to t8 or t1 to t9 of the respective phases.

[0225] Similar to the tax operation mentioned above, the same applies to... Fig.15 the durations T_I, T_II,1, T_III,1, T_II,2, T_III,2, T_IV,1, T_III,3 and T_IV,2 of the respective phases and / or switching times t1, t2, t3, t4, t5, t6, t7, t8 and / or t9 are determined (for example, predetermined) on the basis of desired target conditions, which include, for example, a desired fuel injection quantity (which is essentially given by the area under the flow rate function between times t_o and tc).

[0226] For example, the phase profile, which specifies the durations T_I, T_II,1, T_III,1, T_II,2, T_III,2, T_IV,1, T_III,3, and T_IV,2 of the respective phases and / or the switching times t1, t2, t3, t4, t5, t6, t7, t8, and / or t9, can be predefined to achieve a desired fuel injection quantity. Such a phase profile can, in turn, be pre-stored in a memory of the electronic control unit (e.g., ECU) for a specific desired fuel injection quantity per injection cycle. Furthermore, feedback and / or feedforward control based on a variable desired fuel injection quantity can be implemented. For example, a fuel injection quantity can be controlled based on adjusting one or more parameters of the phase profile, such as its respective durations and / or the switching times.

[0227] For example, the switching times t6, t7 and / or t8 can be adjusted, and then, if perhaps a higher injection quantity is required, the switching times t6, t7 and / or t8 can be selected to be set to later times in the injection cycle, or then, perhaps if a lower injection quantity is required, the switching times t6, t7 and / or t8 can be selected to be set to earlier times in the injection cycle.

[0228] Even for full-stroke operation as described above, experiments have shown that high accuracy in pulse-to-pulse variations of the fuel injection quantities can be achieved, down to less than 1%, even approximately 0.5%. However, a key advantage for higher injection quantities obtained through the phase profile control described above, compared to conventional current-based control concepts, is the ability to control very smooth valve movements and significantly reduce noise and vibration. It is even possible to achieve desired valve motion trajectories, with valve opening and / or closing speeds being controlled very precisely according to the desired valve motion characteristics. 2.9 Example of a modified control circuit

[0229] In the exemplary control circuit of Fig.In section 5 above, two different voltage levels for active voltage control phases were provided by respective voltage sources, i.e., a boost voltage V_Boost at a high level and a battery voltage V_Bat at a lower level.

[0230] However, the present invention is not limited to the use of such control circuits which provide two different voltage levels for active voltage control phases, but in other exemplary embodiments, control circuits with only a single voltage source or a single voltage level or control circuits with three or more different voltage levels for active voltage control phases are also possible.

[0231] Fig.Figure 16 is a schematic example view of a further control circuit of a fuel injector according to a further exemplary embodiment, which provides, by way of example, a single voltage source or a single voltage level V_Drive for active voltage control phases.

[0232] Such an alternative exemplary control circuit 103 can be used to control / operate the fuel injector according to the current control, however, such a control circuit 103 can also be used by way of example for operating procedures of exemplary embodiments, as is discussed below.

[0233] The control circuit 103 of Fig.Figure 16 includes, by way of example, a single voltage source that supplies a voltage level V_Drive (which is supplied, for example, as battery voltage from one or more batteries). For example, the voltage level V_Drive can be greater than or equal to the typical battery voltage level V_Bat discussed above, and it can, by way of example, be less than or equal to the typical boost voltage level V_Boost discussed above.

[0234] The control circuit 103 further includes, by way of example, a control voltage circuit side and a ground potential circuit side, and the electromagnetic actuator (for example, the electromagnet 205) of the fuel injector is connected, by way of example, between the control voltage circuit side and the ground potential circuit side.

[0235] For example, the control voltage source that supplies the control voltage V_Drive is connected to the control voltage side of the electromagnetic actuator (e.g., electromagnet 205) of the fuel injector via a switch SW_1 (which may be referred to as the "battery switch" or "control switch") and the ground potential side of the electromagnetic actuator (e.g., electromagnet 205) of the fuel injector is connected to ground potential via a switch SW_2 (which may be referred to as the "low side switch" or "ground switch").

[0236] For example, switches SW_1 and SW_2 can be implemented as MOSFET semiconductor switches controlled by a switch control logic 124 of the control circuit 103, which is connected to the respective gate terminals of switches SW_1 and SW_2 via signal lines (dashed lines). However, the invention is not limited to MOSFET semiconductor switches, and any type of controllable electrical switch can be used in a control circuit of other exemplary embodiments.

[0237] The ground potential side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector is furthermore connected, for example, to the control voltage source that supplies the control voltage V_Drive via a diode D1, which has its forward direction in the direction of the control voltage source, thereby blocking the current from the control voltage source in the direction of the ground potential side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector.

[0238] The control voltage side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector is furthermore connected to the ground potential via a diode D2, which has its forward direction in the direction of the control voltage circuit side, thereby blocking the current from the control voltage circuit side towards ground potential. 2.9.1 Active control state / Hold control state

[0239] In an “active control state” or “hold control state”, the switch control logic 124 of the control circuit 103 can supply activation signals to the gates of switches SW_1 and SW_2, so that both switch SW_1 and switch SW_2 are in the ON state (electrically closed state, i.e. in the conducting state).

[0240] In the “active control state”, the control voltage source, which supplies the control voltage V_Drive, is conductively connected to the control voltage side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector via the electrically closed switch SW_1, and the ground potential side of the electromagnetic actuator (e.g., the electromagnet 205) of the fuel injector is, for example, conductively connected to the ground potential via the electrically closed switch SW_2.

[0241] Accordingly, in the “active control state”, the control current can flow through the electromagnetic actuator (e.g. the electromagnet 205) of the fuel injector from the control voltage source, which supplies the control voltage V_Drive, via the electrically closed switch SW_1 to the electromagnetic actuator, through the electromagnetic actuator, and then from the electromagnetic actuator through the electrically closed switch SW_2 to the ground potential side.

[0242] This means that in the "active control state," a control voltage level of V_Drive is actively applied, and the control current in the electromagnetic actuator is rapidly increased, causing the magnetic field in the electromagnetic actuator to build up quickly due to the rapidly increasing control current. For this reason, the "active control state" can be referred to as the active control state or the control state of actively controlling the electromagnetic actuator. 2.9.2 Control state with normal drop-off

[0243] In a “control state with normal decay”, the switch control logic 124 of the control circuit 103 can supply activation signals to the gate of switch SW_2, so that switch SW_2 is in the ON state (electrically closed, i.e. in the conducting state), and switch SW_1 remains deactivated in its respective OFF state (electrically open, i.e. in the non-conducting state).

[0244] Accordingly, during the normal decay control state, no voltage is actively applied, allowing the magnetic field in the electromagnetic actuator to decay and the control current in the electromagnetic actuator—which flows through the electrical loop via diode D2 to the electromagnetic actuator and then through the conducting switch SW_2 to ground—to decrease, for example, according to an exponential decay. For this reason, the "normal decay control state" can be described as a passive control state or a control state for the passive control of the electromagnetic actuator. 2.9.3 Control state with rapid drop-off

[0245] In a “rapid decay control state” (which can sometimes also be called a “reset control state”), the switch control logic 124 of the control circuit 103 may not be able to supply activation signals to the gates of all switches SW_1 and SW_2, so that all switches SW_1 and SW_2 are disabled in their respective OFF states (electrically open, i.e. in the non-conducting state).

[0246] If a previous control state was one in which a voltage, for example the control voltage V_Drive, is actively applied to the electromagnetic actuator, causing a control current to flow through the electromagnetic actuator and a magnetic field to be built up in the electromagnetic actuator, then switching to the "rapid decay control state" accordingly cuts off the control current abruptly by electrically opening all three switches and blocking the current in the reverse directions of diodes D1 and D2, so that the magnetic field in the electromagnetic actuator collapses or is allowed to collapse.

[0247] This typically results in an induced voltage in the opposite direction, limited to a minimum of the negative value of V_Drive (in other words, the absolute value of the induced voltage is limited by the absolute value of V_Drive) through the reverse-current connection via diode D2 to the drive voltage source that supplies the drive voltage V_Drive.

[0248] Accordingly, during the rapid-fall control state, no voltage is actively applied, and the magnetic field in the electromagnetic actuator can collapse abruptly. The control current in the electromagnetic actuator is then abruptly interrupted at the moment of switching from an active control state to the rapid-fall control state. For this reason, the "rapid-fall control state" can be described as a passive control state or the control state for passive control of the electromagnetic actuator. 2.9.4 Summary of the control states

[0249] For example, in the control circuit of Fig.16. At least the three control states above – “active control state”, which is referred to as state I* in the following figures, “normal decay control state”, which is referred to as state II in the following figures, and “rapid decay control state”, which is referred to as state IV in the following figures – can be selected by outputting suitable control signals to the respective switches SW_1 and SW_2 according to the following table: Control state Switch SW_1 Switch SW_2 I* Active control state A A II Control state with normal drop-off OUT OF A IV Control state with rapid drop OUT OF OUT OF 2.10 Ninth exemplary fuel injection control method implementation

[0250] Fig.Figure 17 is an exemplary illustration showing a control concept for a fuel injection operating mode, relating to exemplary embodiments including a ninth exemplary embodiment relating to half-stroke operation, and containing the corresponding representations of the control states of the control circuit switches as a function of time, the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time. The control of Fig. 17 is the control of Fig. 9 similarly, whereby the ramp-up phase and holding phases are controlled based on the same control state, i.e., for example, the active control state I*.

[0251] As in the upper part of Fig. Figure 17 shows the control states of the phase profile for the injection cycle control according to Fig.17. An example of a sequence of a first phase (active phase) of a time interval T_I*,1 between times t1 and t2, in which the control circuit is switched to the active control state I* to start the control of the injection pulse of the current injection cycle (similar to the boost phases above), and is held in the active control state I* between times t1 and t2 for the time interval T_I*,1. In an example of a second phase (normal fall-off phase) of a time interval T_II between times t2 and t3, the control circuit is switched to the normal fall-off control state 511 and held in the normal fall-off control state II between times t2 and t3 for the time interval T_II.In an exemplary third phase (second active phase) of a time interval T_I*,2 between times t3 and t4, the control circuit is switched back to the active control state I* and held in the active control state I* for the time interval T_I*,2 between times t3 and t4. In an exemplary fourth phase (first rapid decay phase) of a time interval T_IV,1 between times t4 and t5, the control circuit is further exemplary switched to the rapid decay control state IV and held in the rapid decay control state IV for the time interval T_IV,1 between times t4 and t5 to cause the opening movement of the valve to slow down and the valve to initiate a closing movement again before the valve element reaches the fully open position (half-stroke operation).Then, in an exemplary fifth phase (third active phase), a time span T_I*,3 between the times t5 and t6 in . Fig.17. The control circuit is switched back to the active control state I* and held in the active control state I* for the time interval T_I*,3 between times t5 and t6. This causes the electromagnetic field in the electromagnetic actuator to rebuild and slows down the closing speed of the valve element at the time when the valve element reaches the fully closed position (and thus touches the valve seat) in order to reduce noise and vibration due to the delayed closing speed.Finally, by way of example, in an exemplary sixth phase (second phase with rapid decay) of a time interval T_IV,2 between times t6 and t7, the control circuit is switched to the control state with rapid decay IV and held in the control state with rapid decay IV for the time interval T_IV,2 between times t6 and t7 in order to complete the control of the current injection cycle and in particular to keep the valve closed after it has reached the fully closed position (by way of example, the switching time t6 is essentially equal to the closing time tc).

[0252] Similar to the control operation described above, the durations T_I*,1, T_II, T_I*,2, T_IV,1 and T_I*,3 of the first active phase, the normal decay phase, the second active phase, the first rapid decay phase and the third active phase and / or the switching times t1, t2, t3, t4, t5 and t6 can be determined (e.g., predetermined) based on desired target conditions, which include, for example, a desired fuel injection quantity (which is basically given by the area under the flow rate function between times t_o and tc).

[0253] For example, the phase profile, which specifies the durations T_I*,1, T_II, T_I*,2, T_IV,1, and T_I*,3 of the respective phases and / or the switching times t1, t2, t3, t4, t5, and t6 (into the final control state with rapid decay), can be predefined to achieve a desired fuel injection quantity. Such a phase profile can, in turn, be pre-stored in a memory of the electronic control unit (e.g., ECU) for a specific desired fuel injection quantity per injection cycle. Furthermore, feedback and / or feedforward control based on a variable desired fuel injection quantity can be implemented. For example, a fuel injection quantity can be controlled based on adjusting one or more parameters of the phase profile, such as its respective durations and / or the switching times t1, t2, t3, t4, t5, and t6.

[0254] For example, the switching times t4, t5 and / or t6 can be adjusted, and then, if perhaps a higher injection quantity is required, the switching times t4, t5 and / or t6 can be selected to be set to later time specifications in the injection cycle, or, if perhaps a lower injection quantity is required, the switching times t4, t5 and / or t6 can be selected to be set to earlier time specifications in the injection cycle.

[0255] Experiments have shown that such a phase-profile-based control system, in which activation time specifications and / or activation durations for control states are determined or predefined, significantly reduces pulse-to-pulse variations compared to the current-based control described above, particularly for low injection quantities of approximately 7 mg / pulse or less. Furthermore, pulse-to-pulse variations of less than 1%, or even approximately 0.5% for higher and lower injection quantities, can be maintained by such a phase-profile control system, especially for 7 mg / pulse or less. It was also determined that the additional third active phase of the time interval T_I*,3 was suitable for significantly reducing noise and vibrations that occur at or shortly after the closing time tc. 2.11 Comparison of tax concepts

[0256] Fig.Figure 18 is an exemplary representation showing a control concept comparison of fuel injection operating modes according to current control (solid lines) as in Fig. 7 and according to the control concept of the fuel injection operating mode of Fig. Figure 9 is based on two different parameter sets (dashed lines and dotted lines, respectively), showing the corresponding representations of the control voltage as a function of time, the control current as a function of time, and the fuel injection flow rate as a function of time.

[0257] As in Fig. 18, which is obtained from actual fuel injection control experiments for both parameter sets (dashed lines and dotted lines with different durations of the respective control states) according to respective phase profiles, which correspond to the phase profile of Fig.As can be seen in diagram 9, vibrations, especially after the closing time, can be significantly reduced. Furthermore, as is particularly evident for the phase profile corresponding to the dashed line, a very smooth valve movement path can be controlled compared to conventional current control. 3. Exemplary embodiments of fuel injection control methods 3.1 First exemplary embodiment of a fuel injection control method

[0258] Fig. Figure 19A is an exemplary illustration showing a flowchart of a control procedure for a fuel injector according to exemplary embodiments.

[0259] The procedure of Fig.19A includes, for example, a step S191 for selecting a desired fuel injection operating mode (for example, based on target operating conditions). Such fuel injection operating modes can include one or more of the exemplary fuel injection operating modes described above, and the currently desired fuel injection operating mode can be selected based on target operating conditions, for example, whether full-stroke or half-stroke operation should be performed, whether a single injection pulse or multiple injection pulses should be performed, and / or whether the injector control should be optimized for low pulse-to-pulse variations, low noise and vibration, and / or high injection quantity accuracy.

[0260] Furthermore, in step S192, the procedure includes determining one or more desired fuel injection cycle characteristics (e.g., based on target operating conditions). The desired fuel injection cycle characteristics may, for example, include at least one desired fuel injection quantity per injection cycle (and / or per injection pulse).

[0261] This can be specified, for example, by a desired total fuel injection quantity per injection cycle and / or also as a desired number of injection pulses per injection cycle and desired fuel injection quantity per each of the injection pulses of the injection cycle.

[0262] Furthermore, the desired fuel injection cycle characteristics can include a desired valve motion path or characteristics of the desired valve motion path per injection cycle or per injection pulse. It should be noted that the desired fuel injection cycle characteristics can also include only the desired valve motion path or the characteristics of the desired valve motion path per injection cycle or per injection pulse, in which case the desired valve motion path or the characteristics of the desired valve motion path per injection cycle or per injection pulse are preferably predetermined based on further target parameters, including at least the desired fuel injection quantity(ies) per injection cycle, so that the desired fuel injection cycle characteristics are preferably still determined based on the desired fuel injection quantity.

[0263] In step S193, the procedure further includes determining (selecting) a current target phase profile from among several preset injection phase profiles based on the fuel injector operating mode selected in step S191 and / or based on the desired fuel injection cycle characteristics determined in step S192.

[0264] As described in the preceding examples and exemplary embodiments, a phase profile specifies several control phases, and control states or a control switch control thereof are assigned to each respective phase of the phase profile.

[0265] Specifically, the phase profile can specify the multiple phases of the fuel injection control for a given injection cycle and determine their sequence. In this sense, a phase profile can be viewed, for example, as specifying a sequence of several control phases to be executed per injection cycle.

[0266] Furthermore, for a given phase profile, the phase profile can additionally specify a duration (time span) of one, more, or each of the specified control phases for each control phase of the assigned phase sequence.

[0267] For example, the phase profiles for one or more fuel injection operating modes for one or more target fuel injection cycle characteristics and / or for one or more target fuel injection quantities can be pre-stored in a memory or data storage of the electronic control unit (e.g., ECU 104) to be provided. This also advantageously allows phase profiles to be added or removed by means of software or firmware updates.

[0268] In step S194, the procedure for the current injection cycle includes controlling the fuel injector operation during the respective injection cycle by controlling the control states of the fuel injector control circuit based on the target phase profile determined / selected in step S193.

[0269] After controlling the fuel injector for the current injection cycle, the procedure may optionally include step S195 to determine whether the target operating conditions might have changed. If the target operating conditions have not changed (step S195 returns NO), the procedure proceeds to control the next injection cycle and repeats, for example, step S194 for the next injection cycle.

[0270] However, if the target operating conditions may have changed (step S195 results in YES), the procedure continues with step S191 to select a new desired fuel injection mode based on the changed target operating conditions. Alternatively, if the changed target operating conditions only affect the desired fuel injection characteristics, the procedure may retain the previously selected fuel injection mode and determine only the changed desired fuel injection cycle characteristics in step S192.

[0271] Then, in step S193, another target phase profile can be selected based on the changed target operating conditions, the changed desired fuel injector operating mode and / or the changed desired fuel injection cycle characteristics, in order to then control the fuel injector in step S194 based on the newly selected target phase profile, and so on.

[0272] Fig. Figure 19B is an exemplary representation showing an exemplary flowchart of a procedure for control state regulation based on a target phase profile during an injection cycle in the control procedure of Fig. 19A according to a first exemplary embodiment of the fuel injection control method (or in the control methods of a of Fig. 20 and Fig. 21 in further exemplary embodiments).

[0273] In particular, according to exemplary embodiments, the method of Fig. 19B must be executed to complete step S194 in Fig. 19A to perform (or to complete step S204 in Fig. 20 or step S204 in Fig. 21).

[0274] First, the procedure includes, for example for n = 1, step S1941 to determine a current control state based on the preset nth control state (e.g. first the 1st control state, which can typically be the boost control state) of the current target phase profile (as selected, for example, in step S193).

[0275] In this exemplary embodiment, it is assumed by way of example that the selected preset phase profile not only specifies the sequence of control phases (or sequence of control states) of the phase profile, but can also specify, e.g. for each control phase of the phase profile, the associated duration or time span of the respective control phase.

[0276] In light of this, the procedure in step S1942 determines the duration (nth time interval) associated with the nth drive state of the phase profile determined in step S1941, based on the additional duration information specified in the phase profile. For example, for n = 1, if the first drive state is perhaps the boost drive state, the phase profile may specify as the first time interval the duration of the phase associated with the boost drive state, and step S1942 determines the duration of the phase associated with the boost drive state based on the information in the current target phase profile.

[0277] After determining the current target control state (nth control state) in step S1941 and determining the associated duration (nth time interval) in step S1942, the control circuit is controlled so that in step S1943 it is controlled according to the determined current target control state (e.g., in the case of the boost control state, the control circuit is controlled to electrically close the boost switch and the low-side switch, while the battery switch remains electrically open).

[0278] Furthermore, in step S1943, the current target control state is maintained for a duration corresponding to the duration (nth time interval) associated with the nth control state of the phase profile (i.e., the control circuit is held in the current target control state, e.g., in the boost control state, the control circuit is held in the boost control state for the duration of the boost time interval).

[0279] Once the target duration associated with the current target control state has expired, the procedure either continues with the next target control state or terminates the injection cycle (in order to proceed to the next injection cycle, see, for example, step S195 above).

[0280] For example, the procedure in step S1944 determines whether the phase or control state of the current target phase profile was the last phase (the last control state) of the current target phase profile, i.e., the last phase (the last control state) of the current injection cycle. If step S1944 is YES, the control of the current injection cycle ends (to proceed, for example, to the next injection cycle; see, for example, step S195 in...). Fig. 19A.)

[0281] If, on the other hand, step S1944 returns NO, the procedure continues with the next phase (the next control state) of the current injection cycle. That is, the procedure continues with the (n+1)th control state of the current target phase profile (step S1941 with n → n + 1).

[0282] For example, the procedure for n = 2 includes step S1941 to determine a current control state based on the preset second control state (which is typically a normal fall-off or hold control state) of the current target phase profile (as selected previously in step S193).

[0283] In light of this, the procedure in step S1942 determines the duration (2nd time span) assigned to the second drive state of the phase profile determined in step S1941, based on the additional duration information specified in the phase profile. For example, for n = 2, if the 2nd drive state is the normal-fall drive state or the hold drive state, the phase profile can specify as the 2nd time span the duration of the phase assigned to the normal-fall drive state or the hold drive state, and step S1942 determines the duration of the phase assigned to the normal-fall drive state or the hold drive state based on the information in the current target phase profile.

[0284] After determining the current target control state (second control state) in step S1941 and the associated duration (second time span) in step S1942, the control circuit is controlled so that it switches in step S1943 according to the determined current target control state. Furthermore, in step S1943, the current target control state is maintained for a duration corresponding to the duration (second time span) associated with the second control state of the phase profile (i.e., the control circuit is held in the current target control state; for example, in the boost control state, the control circuit is held in the boost control state for the duration of the boost time span).

[0285] For example, the procedure for n = L (L specifies the last control state / last phase) includes, for example, step S1941 to determine a current control state based on the preset L-th control state (which is typically a fast-fall control state) of the current target phase profile (as selected previously in step S193).

[0286] In light of this, the procedure in step S1942 determines the duration (L-th time interval) associated with the L-th drive state of the phase profile determined in step S1941, based on the additional duration information specified in the phase profile. For example, if the L-th drive state is the fast-fall drive state, the phase profile for n = L can specify the duration of the phase associated with the fast-fall drive state as the L-th time interval, and step S1942 determines the duration of the phase associated with the fast-fall drive state based on the information in the current target phase profile.

[0287] After determining the current target control state (L-th control state) in step S1941 and determining the associated duration (L-th time span) in step S1942, the control circuit is controlled to be switched in step S1943 according to the determined current target control state, i.e. by opening the boost switch, the battery switch and the low-side switch.

[0288] Furthermore, in step S1943, the current target control state is maintained for a duration equal to the duration (L-th time span) associated with the L-th control state of the phase profile (i.e., the control circuit is held in the current target control state; for example, in the case of a fast-fall control state, the control circuit is held in the fast-fall control state for the duration of the fast-fall time span or longer, since the next switching may not occur before the ramp-up phase of the next injection cycle). 3.2 Second exemplary fuel injection control method implementation

[0289] Fig. Figure 19C is an exemplary representation showing an exemplary flowchart of a procedure for control state regulation based on a target phase profile during an injection cycle in the control procedure of Fig.19A according to a second exemplary embodiment of the fuel injection control method (or in the control methods of one of Fig. 20 and Fig. 21 in further exemplary embodiments).

[0290] In particular, according to embodiments, the method of Fig. 19C must be executed to perform step S194 described above in Fig. 19A (or step S204 in Fig. 20 or step S204 in Fig. 21) to carry out the procedure. The procedure may be similar to Fig. 19B steps S1941, S1942, S1943 and S1944 are included. Fig.However, in 19B it is assumed that a phase profile only includes phases of steady-state control conditions of phase time spans in which the respective associated target control condition is maintained throughout the entire phase, and in particular that the phase profile does not include any phase of PWM switching. In the present embodiment, however, it is assumed that the phase profile includes one or more phases of PWM switching operation and one or more phases of an associated steady-state control condition during the respective phase.

[0291] In light of this, the procedure includes Fig.19C exemplified by step S1940 of determining the nth phase specified in the current phase profile, first for n = 1, in order to then determine whether the nth determined phase of the current target phase profile is a PWM phase (i.e., a phase of PWM switching, a phase of PWM switching operations), and whether the current nth phase is not a PWM phase (or more precisely, whether the current nth phase is a drive state phase of a steady-state drive state). The procedure then proceeds, exemplified by the following, similarly to the procedure described in Fig. 19B continues with steps S1941, S1942, S1943 and S1944.

[0292] However, if the current nth phase is determined to be a PWM phase, the procedure proceeds with the optional step S1941' of determining two drive states based on drive states preset for the nth phase based on the current target phase profile. Step S1941' is optional because the two drive states for PWM switching may be predefined, for example, designated drive states for PWM switching, such as the battery drive state (hold drive state) and the normal decay drive state.

[0293] In step S1942', the procedure includes determining an associated duration (nth time interval) of the nth phase of the PWM switching based on the current target phase profile, and in step S1943', the procedure includes determining an associated duty cycle for the nth phase of the PWM switching based on the current target phase profile.

[0294] In step S1944', the procedure continues by controlling a PWM switch between the specified two control states (or the predetermined two control states), determining the duty cycle for the nth phase of the PWM switch. Then, when the specified nth duration expires, the PWM switch is stopped, and the procedure continues with the next phase, i.e., the (n+1)th phase (n -> n + 1). That is, the procedure repeats step S1940 for the (n+1)th phase.

[0295] Here, optional testing of the last phase, similar to step S1944, is not provided, since the PWM phase is typically not the last phase, and the last phase is typically a steady-state control phase (e.g., a control state with normal decay or rapid decay). However, in other exemplary embodiments, it is possible to provide phase profiles with a PWM phase as the last phase, and further testing of the last phase may also be provided after step S1944'. 3.3 Third exemplary fuel injection control method implementation

[0296] Fig. Figure 20 is an exemplary representation showing a flow chart of a control procedure for a fuel injector according to a third exemplary fuel injector control procedure implementation.

[0297] For example, Fig.19A does not implement feedback control (such as closed-loop control) or feedforward control, but instead performs, for example, the control of injection pulses based on a preselected, predetermined and / or prestored phase profile, which, for example, is not adapted or adjusted during the control of the subsequent injection pulses unless the target operating conditions change in order to select another preselected, predetermined and / or prestored phase profile.

[0298] However, the present invention also includes options for feedback control or feedforward feedback control, as exemplified by reference to Fig. 20 and also the other exemplary embodiments of Fig. 21 and Fig. 22 below is described.

[0299] The procedure of Fig.Section 20 includes, for example, step S201 of selecting a desired fuel injection operating mode (e.g., based on target operating conditions). Step S201 can be compared to the above in conjunction with Fig. Step S191 discussed in 19A should be similar.

[0300] Furthermore, the procedure includes in one step S202 (e.g., similar to the one above in conjunction with Fig. (Step S192, discussed in section 19A) involves determining one or more desired fuel injection cycle characteristics (e.g., based on the target operating conditions). The desired fuel injection cycle characteristics may, for example, include at least one desired fuel injection quantity per injection cycle (and / or per injection pulse).

[0301] In step S203 (e.g., similar to the one above in conjunction with Fig.In addition to step S193 discussed in 19A, the procedure further includes determining (selecting) a current target phase profile based on the fuel injector operating mode selected in step S201 and / or optionally based on the desired fuel injection cycle characteristics determined in step S202 from among several preset phase profiles.

[0302] As described in previous examples and exemplary embodiments, a phase profile specifies multiple control phases and control states, or a control switch control thereof, which are assigned to each respective phase of the phase profile. The phase profile may only include phases of steady-state control conditions (excluding PWM switching phases), as exemplified in conjunction with Fig. 19B is described, or can include one or more PWM phases, as exemplified in connection with Fig. 19C is described.

[0303] In step S204 (e.g., similar to the one above in conjunction with Fig. 19A discussed step S194, e.g. by procedure according to Fig. 19B or Fig. 19C) The procedure for the current injection cycle includes controlling the fuel injection operation during the respective injection cycle by controlling the control states of the control circuit of the fuel injector based on the current target phase profile determined / selected in step S203.

[0304] After controlling the fuel injector for the current injection cycle, the procedure may optionally include step S205 to determine whether the target operating conditions have changed. If the target operating conditions have not changed (step S205 returns NO), the procedure proceeds, for example, to step S206, described below. However, if the operating conditions have changed (step S205 returns YES), the procedure proceeds to step S201 to select a new desired fuel injector operating mode based on the changed target operating conditions. Furthermore, if the changed target operating conditions affect only the desired fuel injection cycle characteristics, the procedure may retain the previously selected fuel injector operating mode and determine only the changed fuel injection cycle characteristics in step S202.

[0305] On the other hand, as mentioned above, if the target operating conditions have not changed (step S205 results in NO), the procedure continues, for example, with step S206 of determining sensor information that indicates the current fuel injection cycle characteristics.

[0306] Such sensor information can use sensor information from known sensors, such as sensor information from a pressure sensor that detects pressure in the fuel distributor, and / or from a current sensor that detects current in the electromagnetic actuator of the fuel injector.

[0307] For example, using a sensor signal from the pressure sensor and / or a first and / or a second time derivative thereof, the opening and closing times of fuel injector valves can be determined by observing and analyzing the sensor signal from the pressure sensor and / or the first and / or the second time derivatives thereof.

[0308] It was also found that a sensor signal from a current sensor, which detects the current in the electromagnetic actuator of the fuel injector, can be analyzed to reconstruct or determine properties of the valve movement in the valve of the fuel injector, which makes it possible to reconstruct or at least analyze the properties of the valve movement path of the valve element of the fuel injector.In particular, it has been found that observing, processing and analyzing the first and / or second time derivative of the current in the electromagnetic actuator of the fuel injector, after processing, indicates several properties of the valve movement in the fuel injector valve, including, for example, the opening time, closing time, closing velocity of the movement of the valve element before the closing time (based on the properties of a second time derivative of the current signal before the detection of the closing time), a time of impact on a stop or other obstacle (for example, the core) in the fully open position, a time of change of movement from the opening direction to the closing direction in a half-stroke operation, a time of impact of the armature element on the valve element at an opening time, and more.

[0309] In addition, the method can also be used for other sensor information, such as vibration sensors that detect vibrations in the fuel injection structure, such as vibrations of the valve element, the armature element and / or the valve seat, and / or noise sensors that detect noises in the fuel injection structure, such as vibrations of the valve element, the armature element and / or the valve seat.Furthermore, it is additionally or alternatively possible to provide sensors that allow the flow rate to / through the fuel injector to be measured as a function of time, in order to reconstruct or determine the properties of the valve movement in the fuel injector valve. This enables the reconstruction or at least analysis of the properties of the valve movement path of the fuel injector valve element (based on the correlation between the flow rate and the valve movement). Additionally or alternatively, it is also possible to provide sensors that directly measure or detect valve movement, in order to reconstruct or determine the properties of the valve movement in the fuel injector valve and to reconstruct or at least analyze the properties of the valve movement path of the fuel injector valve element based on the direct movement measurements.

[0310] Since some first and / or second time derivatives of sensor signals exhibit fluctuations at high sampling frequencies, filters can be used to smooth the specific first and / or second time derivatives of the sensor signals, and the procedure may include analyzing the filtered first and / or second time derivatives of the sensor signals from the aforementioned sensors or sensor information.

[0311] Furthermore, step S206 may include analyzing (e.g., by data processing) the sensor information to determine or reconstruct the current fuel injection cycle characteristics based on the analyzed / processed sensor information.

[0312] In step S207, a comparison is made between the determined (or reconstructed) current fuel injection cycle characteristics based on the output of step S206 and the desired fuel injection cycle characteristics. It is then determined whether the current fuel injection cycle characteristics match the desired fuel injection cycle characteristics determined in step S202. If the current fuel injection cycle characteristics match the desired fuel injection cycle characteristics (at least at a predetermined sufficient level), i.e., if step S207 outputs YES, the procedure proceeds to the next injection cycle to perform step S204 for that cycle.

[0313] However, if the current fuel injection cycle characteristics do not match the desired fuel injection cycle characteristics, i.e., if step S207 outputs NO, the procedure proceeds to step S208 of adjusting at least one parameter of the current target phase profile based on a comparison of the current fuel injection cycle characteristics and the desired fuel injection cycle characteristics, in particular based on the determined differences between the current fuel injection cycle characteristics and the desired fuel injection cycle characteristics.

[0314] For example, one or more adjustable parameters of the target phase profile can advantageously be the durations of specific phases and / or the durations of specific control states therein. For example, one or more durations of specific phases and / or durations of certain control states of the target phase profile can be changed independently of one another. Furthermore, durations of certain phases and / or durations of certain control states of the target phase profile can be changed together by the same factors, for example, by changing the durations of all or some durations of certain phases and / or durations of certain control states of the target phase profile by the same proportionality factor, or the like.In rare cases, alternatively or additionally, adjusting the target phase profile may also involve removing and / or adding one or more phases or control states and may include changing a sequence of phases and / or control states of the target phase profile.

[0315] Following the adjustment of at least one parameter of the current target phase profile based on the comparison of the current fuel injection cycle characteristics and the desired fuel injection cycle characteristics in step S208, the procedure continues with the next injection cycle in order to again perform step S204 based on the adjusted target phase profile for the next injection cycle, and so on. 3.4 Fourth exemplary fuel injection control method implementation

[0316] Fig.Figure 21 is an exemplary representation showing a flowchart of a control procedure for a fuel injector according to a fourth exemplary embodiment of the fuel injector control procedure.

[0317] Basically, steps S201 to S206 can be used by Fig. 21 similar to the corresponding steps S201 to S206 described above Fig. 20 will be carried out. However, it uses Fig. 21 instead of adjusting the target phase profile according to feedback control of Fig. 20, where feedback of sensor information obtained during a specific injection cycle is used, for example, to adjust the target phase profile for the next injection cycle (cycle-to-cycle feedback control). For example, Fig.21 a forward feedback control in which average sensor information from a number M (M ≥ 2 or more) of injection cycles can be used to adjust the target phase profile for the next M injection cycles.

[0318] For example, the procedure includes a step S211 (e.g. after step S206) in which it is checked whether M injection cycles have been carried out since the last forward coupling adjustment, and then, if step S211 outputs NO, the procedure repeats step S204 for the next injection cycle without adjusting the target phase profile.

[0319] However, if step S211 returns YES (i.e., if M injection cycles have been performed since a last forward coupling adjustment), the procedure proceeds to step S212 of determining average fuel injection cycle characteristics based on the fuel injection cycle characteristics determined for the last M fuel injection cycles during the last M times of executing step S206, after M injection cycles have been performed since a last forward coupling adjustment based on the same target phase profile.

[0320] In step S213 (which is similar to step S207 but designed for average fuel injection cycle characteristics), a comparison is made between the average fuel injection cycle characteristics based on the output of step S212 and the desired fuel injection cycle characteristics. It is then determined whether the average fuel injection cycle characteristics match the desired fuel injection cycle characteristics determined in step S202. If the average fuel injection cycle characteristics match the desired fuel injection cycle characteristics (at least at a predetermined sufficient level), i.e., if step S213 outputs YES, the procedure proceeds to the next injection cycle to perform step S204 for that cycle.

[0321] However, if the average fuel injection cycle characteristics do not match the desired fuel injection cycle characteristics, i.e., if step S213 outputs NO, the procedure proceeds with step S214 (similar to step 208 above) of adjusting at least one parameter of the current target phase profile based on a comparison of the average fuel injection cycle characteristics and the desired fuel injection cycle characteristics, in particular based on the determined differences between the average fuel injection cycle characteristics and the desired fuel injection cycle characteristics.

[0322] After adjusting at least one parameter of the current target phase profile based on the comparison of the average fuel injection cycle characteristics and the desired fuel injection cycle characteristics in step S214, the procedure continues with the next M injection cycles to again perform step S204 based on the adjusted target phase profile for the next M injection cycles, and so on. 3.5 Fifth exemplary fuel injection control method implementation

[0323] Fig. Figure 22 is an exemplary representation showing an exemplary flowchart of a control state control procedure based on a target phase profile during an injection cycle in the control method of Fig. 19A according to a fifth exemplary embodiment of the fuel injection control method (or in the control methods of Fig. 20 or Fig.21 in further exemplary embodiments). In particular, according to exemplary embodiments, the method of Fig. 22 must be executed to perform the step S194 described above in Fig. 19A to be carried out.

[0324] Fig. 22 is based, for example, on a closed-loop feedback control in which sensor information is processed / analyzed in real time and a target phase profile or at least one or more parameters thereof are adjusted or adapted based on the sensor information in real time during the current controlled injection cycle.

[0325] Step S221 is basically similar to the one above in conjunction with Fig.19B described step S1941 and determines, first for n = 1, a current control state based on the preset nth control state of the current target phase profile (as selected previously in step S193).

[0326] In step S222, the procedure includes determining an associated control switching condition criterion for the specified nth control state (or the nth phase, optionally including the possibility of a PWM phase) based on the current target phase profile. Such a control switching condition criterion can be specified in the target phase profile for the nth control state (e.g., in addition to or as an alternative to a duration or nth time interval of the nth control state, or in addition to a maximum duration or a maximum nth time interval of the nth control state).Such a control switching condition criterion can include one or more switching criteria that specify that the nth control state or the nth phase should be switched to the next control state or phase, such as one or more thresholds in one or more sensor signals and / or first or second (optionally filtered) time derivatives of the sensor signal(s), e.g., among the sensor signals or sensor signal information described above.

[0327] In step S223, the control circuit switches (such as the amplifier switch, battery switch and / or low-side switch mentioned above) of the control circuit of the respective fuel injector switch to the specific current control state (nth control state) and the respective nth control state is maintained.

[0328] In step S224, the sensor information indicating the current fuel injection cycle characteristics is preferably determined (e.g., observed) in real time, which optionally includes observing (optionally filtered) first and / or second time derivatives of one or more sensor signals of the determined (observed) sensor information, including, for example, the sensor signals discussed above.

[0329] In step S225, it is checked (preferably in real time) whether the observed (and / or processed) sensor information matches one or more switching condition criteria specified in the current target profile for the nth control state (for example, proceeding to step S224 if one or more switching condition criteria specified in the current target profile for the nth control state have not yet been met and step S225 outputs NO), and if step S225 outputs YES when the observed (and / or processed) sensor information matches one or more switching condition criteria specified in the current target profile for the nth control state, the procedure can optionally check in step S226 whether the nth control state was the last control state (such as a last control state with a rapid decay).to move on to controlling the next injection cycle.

[0330] Otherwise, the procedure proceeds to the next control state (n -> n + 1) if the observed (and / or processed) sensor information matches one or more switching condition criteria specified in the current target profile for the nth control state (which is not the last control state of the current target phase profile), and continues with steps S221, S222 and S223 of switching to the (n+1)th control state, and so on. 6. Variations

[0331] In the above description, the time intervals of a phase profile were determined or predetermined in connection with and / or based on the desired amount of injected fuel. However, those skilled in the art would readily recognize that the teachings of the present invention are not limited to this, and the time intervals can also be conveniently determined in connection with a desired movement path of the valve element (valve movement path or needle movement path), e.g., between the opening and closing movements of the valve element. Furthermore, the time intervals can be determined based on parameters that specify the movement path of the valve element.

[0332] These parameters can be, for example, the current flowing in the electromagnetic actuator or a function thereof, such as the first derivative with respect to time, the second derivative with respect to time, or a derivative of order n with respect to time.

[0333] However, the present invention is not limited to this, and other parameters can be used. An example of a further suitable parameter is a pressure signal that can indicate a fuel pressure upstream of the fuel injector as a function of time. For certain applications, it may be useful to investigate the time derivative (or the n-order time derivative) of the pressure.

[0334] It should be noted that the motion of the valve element is closely related to the amount of fuel injected. In particular, the actual amount of fuel injected can be considered to be approximately proportional to the integral of the valve motion with respect to time.

[0335] Furthermore, the phase profile can, for example, control the opening, closing and intermediate positions along the axial direction of the electromagnetically actuated valve, i.e., the phase profile can refer to a desired movement path of the valve element.

[0336] The control of the actual movement path of the electromagnetically actuated valve can be indirect, and for example the actual movement path can be controlled directly based on a desired amount of injected fuel, or alternatively the control of the actual movement path can be direct, and for example the movement path is controlled based on a desired movement path that can be determined or predetermined based on the desired amount of injected fuel. 7. Underlying theoretical background and considerations

[0337] Fig.Figure 23 provides an example of a typical electrical representation of an electromagnetic actuation system of an electromagnetic actuator of a fuel injector.

[0338] When scattering fluxes (with indices l, s in Fig. ) neglected, the following set of equations describes the interaction of relevant electrical, magnetic and mechanical quantities (where the magnetic quantities are strongly nonlinear, as typical operation exhibits important saturation effects, these dependencies are not explicitly mentioned here for the sake of clarity): {U=R⋅I+n⋅Φ˙n⋅I=Θ=Rm⋅Φ+Lm⋅Φ˙+Φ˙⋅xμ0⋅A

[0339] The formulas contain the following parameters: the electrical control voltage U and the current l, the ohmic resistance R, the number of coil turns n, the magnetomotive voltage or force Θ, the magnetic flux Φ and its flux rate Φ' (which is the time derivative of the magnetic flux), the magnetic reluctance or magnetic resistance and the inductance Rm, Lm, the air gap distance x and its area A (of the air gap between the armature element and the core) and the magnetic constant µ0.

[0340] Based on the above, the acting electromagnetic force F_mag in the air gap can now be determined using Maxwell's tensile force formula: Fmag=Φ22⋅μ0⋅A

[0341] In a steady-state case, especially with Φ' = 0 and x = const., it can be determined that this force is proportional to the square of the driving current, i.e., Fmag ∼ I 2, where the proportionality factor depends on the geometric properties of the air gap (x and A) and the magnetic reluctance of the circuit Rm (which is variable in the case of saturation effects, which is typically the case). In conventional injector actuation systems, such a steady-state situation is typically only reached after a duration of approximately 1 ms due to armature movement, induced eddy currents, and the saturation effect. Once the steady-state situation is reached, current control concepts can provide sufficiently accurate results, i.e., for longer injection activations and larger injected fuel quantities.

[0342] However, with shorter injection activations and lower injected fuel quantities (e.g., in half-stroke operation, with multiple injection pulse control, or with lower desired fuel injection quantities), the durations or even the transient opening and closing phases typically do not scale with the control current (i.e., Fmag ≁ I). 2 This is due to the non-zero magnetic flux rate of the developed magnetic force, and the current is also not proportional to the control voltage (i.e., U ≁ I). In contrast to the steady-state situation mentioned above, this is referred to as a transient state of the fuel injector actuation system, and precise current control is no longer possible.

[0343] From the observation that the magnetic energy stored in the air gap is given by Wmag=Φ2⋅xμ0⋅A And from the further observation that the acting magnetic force can be determined from the above equation by the principle of virtual work to Fmag=δWmag / δx, it follows from the transformation of the top equation to n·Φ'=UR·I that the applied control voltage U directly influences the change in the acting magnetic force by acting on the magnetic flux rate Φ'.

[0344] Since the drive voltage U also influences the resulting drive current I, quantification in this transient state is not as clear as in the steady-state case. Therefore, in addition to considering the saturation of the magnetic components and the air gap opening, a numerical simulation is typically required to evaluate the transient behavior.

[0345] However, the ability to apply different control voltage levels over defined time periods (as in the exemplary phase profiles discussed above) allows for more precise control of the transient behavior of the applied magnetic force. This has been identified as the fundamental principle underlying the present invention, which the inventors refer to as a force dynamics control actuation strategy (FDC actuation strategy).

[0346] In the early stages, reducing noise emissions related to injection events (especially at idle, when the injection process can even be audible) was an initial task and a primary application goal of the FDC actuation strategy. Therefore, the inventors analyzed initial relevant parameters relating to structural noise sources and, based on this analysis, decided to focus on the change in the kinetic energy of moving parts for the various impact events during an injection cycle.

[0347] Based on these considerations, an actuation strategy was developed with the aim of minimizing all structural influences as much as possible, while still maintaining the necessary injection quantity for engine operation at idle. Building upon this development, a novel parameterization of the actuation strategy was found, based on the understanding that the dynamics of the electromagnetic force should preferably be controlled in a more suitable manner. It was discovered that a suitable sequence of different actuation states with appropriate durations within a phase profile leads to a modification of the needle's movement path. This modification could be controlled in such a way that it does not reach the fully open position and exhibits significantly slower closing speeds, resulting in the elimination or reduction of the respective effects (noise and vibration).Furthermore, it was found that not only could shocks during operation be reduced, but even very low injection quantities could be controlled with relatively simple phase profiles from a small number of steady-state control conditions instead of PWM control. Based on such experiments, phase profiles, as discussed in exemplary embodiments, could be developed.

[0348] As mentioned for the exemplary embodiments above, it is possible to predetermine suitable phase profiles (which specify, for example, a sequence of several control state phases and their durations), and such phase profiles for different operating states and modes can be stored in a memory of the electronic control unit, for example, for different desired injection quantities.

[0349] However, the inventors have further discovered that phase profiles can be adapted based on feedback information that specifies the motion path characteristics of the valve motion path, and it is possible to precisely control motion path characteristics such as the overall shape (e.g., based on the desired injection quantities), for example, based on monitoring and analyzing first and second (potentially filtered) time derivatives of a sampled control current I, which is referred to as I self-sensing.

[0350] Several aspects related to the closed-loop operation of the introduced actuation strategy are discussed below. The inventors have found ways to compensate for the influence of operating conditions such as temperature, battery voltage, etc., or individual component tolerances (such as pulse-to-pulse variations), thus enabling robust performance in a targeted, discontinuous environment such as that found in an automobile with varying operating conditions. A cost-effective approach is to avoid using additional sensors and instead attempt to obtain or diagnose the necessary inputs for the feedback loop from appropriate processing of the already available control variables.

[0351] First, some information on the theoretical background of self-reporting for closed-loop tax approaches is presented.

[0352] Based on the equations above, the connection between accessible electrical quantities and the motion quantities of the armature can be established via the magnetic field acting in the air gap.

[0353] The last term of the second equation already contains the anchor position x, and its first time derivative makes it possible to derive an equation that includes the anchor velocity: Θag=Φ⋅xμ0⋅A⇒(Θ˙ag)=(Φ˙⋅xμ0⋅A)=Φ˙⋅x+Φ⋅x˙μ0⋅A

[0354] First, when all circuit switches of the control circuit are open (i.e., in the control state with rapid decay), the current will quickly disappear, and the following simplification results for the descriptive set of equations: I=def0⇒{U=n⋅Φ˙0=Θ=Rm⋅Φ+Lm⋅Φ˙+Φ⋅xμ0⋅A;

[0355] In this case, the voltage signal is directly linked to the magnetic flux rate and enables the detection of needle movement (valve movement) by voltage sensing.

[0356] The well-known method of variation of constants, when introducing the coefficients Tm = Lm / Rm and Karm = 1 / µ0 · A·Lm, yields the following solution for the magnetic flux Φ from the second equation: Φ(t)=Φ0⋅e−(tTm+∫xdtKarm)

[0357] Neglecting saturation and scattering effects again, it becomes clear that the magnetic flux in this state of the drive circuit can be estimated by an exponential function that depends on time and a kind of additional perturbation term resulting from the inductance due to the armature movement. Therefore, it is possible to detect armature movement from an analysis of the accessible voltage signal: The closing time of the needle is of primary interest, corresponding to the maximum velocity value and the jump in the armature's acceleration due to separation from the needle.

[0358] Secondly, the case relevant for FDC-based actuation corresponds to a state of circuit switches characterized by a constant applied voltage (i.e., an active actuation state, a boost actuation state, or a hold actuation state).

[0359] The electromagnetic-mechanical actuation system of the fuel injector can be described by the following equations: U=defU0=const.⇒{U0=R⋅I+n⋅Φ˙n⋅I=Θ=Rm⋅Φ+Lm⋅Φ˙+Φ⋅xμ0⋅A where the equation above can be transformed as follows: I=(U0−n⋅Φ˙) / R

[0360] Substituting this rearranged upper equation into the lower equation then leads to a slightly more complicated differential equation for the magnetic flux, which contains a constant term C: Φ˙=−(1T˜m+xK˜arm)⋅Φ−C

[0361] By reusing the method of variation of constants, it is possible, for example, to find an analytical solution for the magnetic flux as a function of the applied voltage V and the armature movement.

[0362] By substituting into the equation above, the connection to the current signal I is established, which enables the detection of the armature movement quantities by appropriate processing of the current signal ("I self-detection").

[0363] An additional potential advantage is that current can be measured throughout the entire activation time during the injection cycle, which for FDC-based actuation strategies can cover almost the entire duration during which the injector valve needle is not seated or the armature is in motion.

[0364] Finally, considerably higher signal strength levels can be used. In summary, this demonstrates the potential for accurate diagnoses of motion parameters, e.g., based on a combination of pattern recognition along with analytical or model-based approaches.

[0365] The inventors have discovered that by using the detected current signal and its first and second time derivatives, it is possible to observe the characteristic influence of motion variables, especially for motion events that exhibit strong discontinuities, such as impacts.

[0366] It is worth reiterating that several intrinsic properties of the FDC actuation approach are advantageous for motion detection compared to conventional current-controlled actuation. In particular, the ability to capture the current for most of the armature and needle movement, a better signal level and thus higher quality, along with the more continuous change in magnetic quantities, which is desirable for the FDC actuation approach, can be exploited. Furthermore, it is possible to define or optimize the FDC actuation parameterization to enable the best possible needle movement detection, thereby improving size management accuracy in closed-loop operation.

[0367] Finally, a possible schematic setup for a closed-loop injection actuator is outlined. A key element for accuracy is the ability to detect motion, e.g., using the I-self-detection described above (for example, by analyzing and processing the current signal and / or its first and / or second derivatives). Such a feedback loop advantageously allows for compensation of operating conditions or even part tolerances, but is also beneficial for exploiting the full potential of the introduced actuator approach in terms of flexibility and accuracy, and for enabling more advanced and complex combustion operating modes.

[0368] Since most of the mentioned influences, such as relatively slow temperature shifts, are unlikely to change on the timescale of injection cycles, it is possible to average over a relatively large number of injections, and this is suitable for increasing the accuracy of the injection quantity and reducing the computational power.

[0369] In addition, some characteristics will even remain constant or repeatable, such as variations between certain injectors mounted on a power unit, or an influence of the battery voltage level, which advantageously allows for the inclusion of suitable forward coupling compensation.

[0370] Somewhat surprisingly, the precision of the smallest injection quantities using the FDC actuation approach could be significantly improved by applying exemplary embodiments. This enables management of the injection quantity and also accuracy for repeatability, e.g., using self-sensing for closed-loop operation, and mixture preparation, e.g., by rate shaping (i.e., controlling a smooth valve motion path, for example, based on a desired target motion path) and influencing the spray pattern by controlling the valve motion path.

[0371] In summary, the main advantages, especially compared to the conventional current control approach, are the increased flexibility of fuel injection operation, which – since this can be done with standard control hardware (such as the control circuit of Fig.5) can be realized - with a relatively small increase in product costs. 8. Terminology of the present description

[0372] As used in this description and the accompanying claims, the following terms shall have the meanings given, unless the context requires otherwise: The term “injection cycle,” as used throughout this disclosure, refers to an injection cycle of the control of a single fuel injector. The injection cycle may include one or more injection pulses during the particular injection cycle, injected by the same fuel injector. Between injection cycles, the electromagnetic actuator of the fuel injector may typically be completely de-energized. The term “injection pulse”, as used throughout this present disclosure, refers to a fuel injector valve movement in which the valve / valve element first opens, causing a fuel injection flow rate to increase, and then closes again, causing a fuel injection flow rate to decrease and essentially become zero, so that essentially no fuel is injected between injection pulses. The term “valve motion path” (or needle motion path) as used throughout this present disclosure refers to fuel injection valve motion properties (displacement properties), in particular basically with respect to a position of the valve element (or a tip section thereof) as a function of time. The term “current control,” as used throughout this disclosure, refers to a conventionally known concept for controlling a fuel injector based on feedback control (e.g., closed-loop feedback) that relies on a detected current value of the current flowing through the electromagnetic actuator of the fuel injector and is typically based on a desired target current profile or waveform. Current control can be performed based on one or more desired target current values ​​and a comparison of a detected current with the desired target current value. The term “current profile” (sometimes also referred to as “current waveform”), as used throughout this disclosure, refers to target current characteristics underlying the above current control for controlling fuel injection for a given injection cycle. Typically, such a current profile may include a desired target peak current value, specifying a target value to be achieved during an initial boost phase for rapidly energizing an electromagnetic actuator at the beginning of an injection cycle, for example, as a target threshold for closed-loop control of switching off a boost drive state at the time when it is detected that the current flowing through the electromagnetic actuator has reached the target threshold.Similarly, such a current profile can include one or more desired target holding current values, which specify target values ​​during a holding state when the aim is to maintain the current in the electromagnetic actuator at the respective target holding current value through PWM control. The term “control state,” as used throughout this disclosure, refers to a stationary configuration of one, several, or even all switches of a control circuit of a fuel injector, wherein for a given control state, each switch of the control circuit has an associated switch state, such as ON or OFF. That is to say, when at least one switch of the control circuit is switched, for example, from ON to OFF or from OFF to ON, it is understood that the control circuit as a whole is switched to a different control state. The term “steady-state phase,” as used throughout this disclosure, refers to a phase in which the control circuit, in contrast to the fast switching required for PWM control, is switched to a control state and held in that control state for a longer, preferably predetermined, period of time. Typically, a “steady-state phase” may involve holding a particular control state for at least 0.01 ms, preferably at least 0.02 ms or longer, and preferably 0.05 ms or longer. Phases may even be longer than approximately 0.1 to 0.5 ms or even up to 1 ms. However, it is important to note that the phases are preferably not shorter than 0.01 ms, and such phases are typically significantly longer than the typical PWM switching time in PWM control, which, according to this terminology, does not maintain a steady-state control state.However, such a PWM controller switches quickly between at least two control states, typically with PWM switching times of less than approximately 0.01 ms. The term “actively controlled” (“active voltage control”), as used throughout this disclosure, refers to control by a control state (e.g., an active control state, sustained control state, or boost control state) in which a certain voltage value (e.g., battery voltage value, control voltage value, or boost voltage value) is applied to the electromagnetic actuator of the fuel injector to increase or at least maintain the current flowing through the electromagnetic actuator. The term “passively controlled” (“passive voltage control”), as used throughout this disclosure, refers to control by a control state (e.g., a normal-fall control state or a fast-fall control state, sometimes referred to as a reset control state) in which no active voltage value is applied to the electromagnetic actuator of the fuel injector to reduce or even shut off the current flowing through the electromagnetic actuator. The term “voltage profile”, as used throughout this disclosure, refers to a target voltage profile for a particular injection cycle, comprising only a predetermined sequence of phases of steady-state control conditions (“steady-state control phases”), i.e., phases in which control conditions of a control circuit are kept constant, for voltage control according to the exemplary embodiments. The term “phase profile” as used throughout this disclosure refers to a sequence of control phases for controlling a particular injection cycle, e.g., a predetermined sequence of control phases. Preferably, but not necessarily, each phase of a phase profile can be associated with a respective steady-state control condition (“steady-state control phase”). Likewise, each phase can either be associated with a steady-state control condition (“steady-state control phase”) or be a PWM switching phase. Preferably, a phase profile comprises one or more (even more preferably than two) phases associated with respective steady-state control conditions. In particular, in each case, a phase profile preferably comprises one or more phases associated with the control conditions corresponding to an “actively controlled” phase (e.g.,one or more phases, which are assigned, for example, to a boost control state, an active control state and / or a hold control state). 9. Miscellaneous

[0373] As experts will understand, the present invention, as described above and in the accompanying figures, can be implemented as a method (e.g. a computer-implemented process or any other process), a control device (comprising a device, a machine, a system, a computer program product and / or any other device) or a combination of the foregoing.

[0374] Accordingly, embodiments of the present invention may take the form of a purely hardware implementation, a purely software implementation (including firmware, resident software, microcode, etc.), or an embodiment that combines software and hardware aspects, which are generally referred to herein as a "system." Furthermore, embodiments of the present invention may take the form of a computer program product on a computer-readable medium with computer-executable program code embodied in the medium.

[0375] Embodiments of the present invention are described above with reference to flowchart representations and / or block diagrams of methods and devices. It should be understood that each block of the flowchart and / or block diagram and / or combinations of blocks in the flowcharts and / or block diagrams can be implemented by computer-readable program code.

[0376] The computer-executable program code can be provided to a processor of a general-purpose computer, a specialized computer, or other devices for processing programmable data, such as a controller, to manufacture a particular machine, so that the program code, which is executed via the processor of the computer or other device for processing programmable data, is generated as a means of implementing the functions / operations / outputs specified in the block or blocks of the flowchart, block diagram, figures, and / or written description.These computer-executable program codes can also be stored in a computer-readable memory capable of controlling a computer or other device for processing programmable data to function in a particular manner, such that the program code stored in the computer-readable memory produces a manufactured item containing instruction means that implement the function / action / output specified in the flowchart block, block diagram block, figures and / or written description.The computer-executable program code can also be loaded onto a computer or other programmable data processing device to perform a series of operations on the computer or other programmable device in order to generate a computer-implemented process such that the program code executed on the computer or other programmable device provides steps for implementing the functions / actions / outputs specified in the flowchart, block diagram blocks, figures, and / or written description. Alternatively, steps or actions implemented by the computer program can be combined with steps or actions implemented by the operator or a human to perform an embodiment of the invention.

[0377] It should also be noted that the logical processes described herein are intended to illustrate various aspects of the invention and should not be used to limit the present invention to a specific logical process or implementation. The described logic can be divided into different logical blocks (e.g., programs, modules, functions, or subroutines) without altering the overall result or otherwise deviating from the true scope of the invention. Often, logical elements can be added, modified, omitted, executed in different orders, or implemented using different logic constructs (e.g., logic gates, loop primitives, propositional logic, and other logic constructs) without altering the overall result or otherwise deviating from the true scope of the invention.

[0378] Although certain exemplary embodiments are described and shown in the accompanying drawings, it should be understood that such embodiments are only exemplary and not limiting to the broader invention, and that the embodiments of the invention are not limited to the specific designs and arrangements shown and described, since various other modifications, combinations, omissions, alterations, and substitutions are possible in addition to those presented in the preceding paragraphs. It is understood by those skilled in the art that various adaptations, modifications, and / or combinations of the embodiments described above can be formed without departing from the scope and concept of the invention. Therefore, it should be understood that the invention can be implemented differently within the scope of the appended claims than specifically described herein.For example, unless expressly stated otherwise, the steps of the processes described herein may be carried out in sequences that differ from those described herein, and one or more steps may be combined, split, or carried out simultaneously. Those skilled in the art will also understand, with regard to this disclosure, that different embodiments of the invention described herein may be combined to form other embodiments of the invention.

Claims

[1] Method for operating an electromagnetically actuated valve of a fuel injector, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position and an electromagnetic actuator designed to actuate a movement of the valve element, the method comprising: - Applying an initial voltage value during an initial time period and switching off the initial voltage value after the initial time period, and - Applying a second voltage value, which is lower than the first voltage value, for a second time period and switching off the second voltage value after the second time period, wherein the duration of the first time interval and the duration of the second time interval are determined according to a desired amount of fuel injected; the first voltage value is applied constantly during the first time period and / or the second voltage value is applied constantly during the second time period; or the first voltage value is applied constantly during the first time period, so that a current in the electromagnetic actuator increases during the first time period, in particular increases monotonically, and / or the second voltage value is applied constantly during the second time period, so that the current in the electromagnetic actuator increases during the second time period, in particular increases monotonically. [2] Method according to claim 1, wherein the duration of the first time interval and the duration of the second time interval are determined to influence the force dynamics of an electromagnetic force induced on the electromagnetic actuator in a transition state according to the desired amount of injected fuel, particularly when the desired amount of injected fuel is less than or equal to 7 mg of injected fuel per injection pulse and / or when an injection pulse determined based on the desired amount of injected fuel has a pulse width of less than or equal to 0.5 ms. [3] A method according to any one of the preceding claims, wherein the method further comprises: Determining a phase profile based on the desired amount of injected fuel, wherein the phase profile specifies several successive control phases, in particular voltage control phases, for controlling the voltage applied to the electromagnetic actuator to open and close the electromagnetically operated valve. [4] Method according to claim 3, wherein the phase profile includes a target voltage profile; wherein the target voltage profile comprises several actively voltage-controlled time periods, each actively voltage-controlled time period corresponding to a respective phase of a constant application of a respective target voltage value to the electromagnetic actuator during the respective actively voltage-controlled time period; and / or The target voltage profile further comprises one or more passively voltage-controlled time periods, each passively voltage-controlled time period corresponding to a respective phase of the phase profile during which a magnetic field of the electromagnetic actuator is allowed to collapse, and an induced voltage of the electromagnetic actuator decreases during the respective passively voltage-controlled time period, in particular decreases exponentially. [5] Method according to claim 3 or 4, wherein the phase profile includes at least a first phase during which the first voltage value is applied to the electromagnetic actuator at a constant rate for the first time period, and a second phase during which the second voltage value is applied to the electromagnetic actuator at a constant rate for the second time period. [6] Method according to any one of claims 3 to 5, wherein The phase profile includes a ramp-up phase, corresponding to the first time period of applying the first voltage value, and a first voltage holding phase, corresponding to the second time period of applying the second voltage value. wherein in particular the second time interval is after the first time interval and wherein in particular the first and the second voltage value have the same sign and the absolute value of the first voltage value is greater than or equal to the absolute value of the second voltage value. [7] Method according to claim 6, wherein determining the phase profile includes determining a duration of the first time interval and / or determining a duration of the second time interval. [8] Method according to claim 6 or 7, wherein the first and / or the second time period of the phase profile are determined such that an end time of the second time period is determined based on a desired upper position of a target movement path of the valve element between an opening and closing movement of the valve element and / or based on a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element. [9] Method according to any one of claims 6 to 8, wherein the first and / or the second time period of the phase profile are determined such that an end time of the second time period is at a time when the valve element has a position that is lower than the desired upper position of the target movement path of the valve element during the opening movement of the valve element, and / or are determined such that the end time of the second time period is during the opening movement of the valve element and before, in particular shortly before, a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element. [10] Method according to any one of claims 3 to 9, wherein the phase profile after the second time interval and during a third time interval includes a first phase with rapid decay, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse. [11] Method according to claim 10, wherein determining the phase profile includes determining a duration of the third time interval, in particular according to the desired amount of fuel injected. [12] Method according to claim 10 or 11, wherein The first, second, and / or third time interval of the phase profile are determined such that a start time of the third time interval and / or an end time of the second time interval is based on a desired upper position of a target movement path of the valve element between an opening and a closing movement of the valve element, and / or based on a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element, and / or the first, second and / or third time interval of the phase profile are determined such that the start time of the third time interval and / or the end time of the second time interval is at a time when the valve element has a position that is lower than the desired upper position of the target movement path of the valve element during the opening movement of the valve element, and / or are determined such that the start time of the third time interval and / or the end time of the second time interval during the opening movement of the valve element is before, in particular shortly before, a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element. [13] Method according to any one of claims 10 to 12, wherein the phase profile includes a second voltage holding phase of a constant application of a fourth voltage value during a fourth time period after the third time period; where the fourth voltage value is equal to the second voltage value, the second and fourth voltage values ​​have the same sign, and / or the first and fourth voltage values ​​have the same sign, and the absolute value of the first voltage value is higher than the absolute value of the fourth voltage value. [14] Method according to claim 13, wherein determining the phase profile includes determining a duration of the fourth time interval, in particular according to the desired amount of fuel injected. [15] Method according to claim 13 or 14, wherein The first, second, third, and / or fourth time interval of the phase profile are determined such that a start time of the fourth time interval and / or an end time of the third time interval are determined based on a desired upper position of a target movement path of the valve element between an opening and a closing movement of the valve element, based on a desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movements of the valve element, and / or based on a desired closing slope of the target movement path of the valve element during the closing movement of the valve element; and / or The first, second, third and / or fourth time intervals of the phase profile are determined such that the start time of the fourth time interval and / or the end time of the third time interval is at a time when the valve element has a lower position than the desired upper position of the target movement path of the valve element during the closing movement of the valve element, and / or are determined such that the start time of the fourth time interval and / or the end time of the third time interval is after, in particular shortly after, the desired time specification at which the valve element reaches the upper position of the target movement path of the valve element between the opening and closing movement of the valve element. [16] Method according to claim 14 or 15, wherein The first, second, third and / or fourth time interval of the phase profile are determined such that an end time of the fourth time interval is determined based on a desired closing slope of a target movement path of the valve element during the closing movement of the valve element and / or based on a desired or actual time specification at which the valve element reaches the closed position at the end of the target movement path of the valve element; and / or The first, second, third and / or fourth time interval of the phase profile are determined such that the end time of the fourth time interval is essentially the same as a desired or actual time specification at which the valve element reaches the closed position at the end of the target movement path of the valve element. [17] Method according to any one of claims 13 to 16, wherein the phase profile after the fourth time interval comprises a second phase with rapid decay, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse. [18] Method according to any one of claims 13 to 17, wherein the phase profile includes a normal decay phase in which a fifth voltage value is held constantly during a fifth time interval between the first and the second time interval, wherein the fifth voltage value is smaller than the first and the second voltage value and the fifth voltage value is in particular less than or equal to zero. [19] Method according to any one of claims 3 to 18, comprising determining the phase profile: - Determining one or more target movement paths of the valve element between an opening and closing movement of the valve element for an injection cycle, - Determining one or more actual motion paths of the valve element between the opening and closing motion of the valve element during the current and / or one or more previous injection cycles and / or modifying the phase profile based on a comparison of the determined one or more target motion paths of the valve element with the one or more determined actual motion paths of the valve element. [20] Method according to claim 19, wherein the one or more target motion paths of the valve element are determined on the basis of properties that specify a desired shape of the one or more target motion paths of the valve element and / or on the basis of the desired amount of fuel injected, which is either the desired amount of injection per injection cycle or the desired amount of injection per motion path. [21] Method according to claim 19 or 20, wherein the one or more actual movement paths of the valve element are determined based on processing at least one of the following signals: - a current signal that indicates a current in the electromagnetic actuator as a function of time, - a pressure signal indicating fuel pressure upstream of a fuel injector as a function of time, and - a position signal that indicates the position of the valve element as a function of time. [22] Method according to claim 21, wherein the processing of the current strength signal indicating a current strength in the electromagnetic actuator comprises at least one of the following operations: - Processing the current signal to obtain a first time derivative of the current in the electromagnetic actuator as a function of time, and - Processing the current signal to obtain a second time derivative of the current in the electromagnetic actuator as a function of time. [23] Method according to claim 22, wherein the one or more actual movement paths of the valve element are determined by determining at least one of the following parameters based on the first and / or second time derivative of the current in the electromagnetic actuator obtained: - an opening time specification for the start of the opening movement of the valve element, - an opening gradient of the opening movement of the valve element, - a point in time at which the upper position is reached between the opening and closing movement of the valve element, - a closing gradient of the closing movement of the valve element and - a closing time specification for the end of the closing time of the valve element. [24] Method according to any one of claims 3 to 23, wherein Then, if the desired injected fuel quantity is below a predetermined threshold, and the injection of the desired injected fuel quantity below the predetermined threshold requires a half-stroke movement path of the valve element as the target motion path, which is determined based on the desired injected fuel quantity. According to this movement path, the valve element opens at a desired opening time specification, reaches the upper position of the motion path at a position lower than a fully open position of the valve element at a desired time specification for the upper position, and closes at a desired closing time specification, the phase profile is determined such that it includes: - an initial voltage holding phase to keep the initial voltage value constant for the initial period before applying a boost voltage, - a first voltage holding phase to keep the second voltage value constant for a second time period after the first time period to control an opening movement of the valve element, - a first phase with rapid decay after the second time period and during a third time period, during which an induced voltage decreases with the opposite sign compared to the sign of the first and second voltage values, in particular decreasing exponentially by allowing the magnetic field of the electromagnetic actuator to collapse in order to actuate a change in the direction of movement of the valve element from the opening direction to the closing direction, - a second voltage holding phase to maintain a constant fourth voltage value for a fourth time interval after the third time interval to control a closing movement of the valve element and - a second phase with rapid decay after the fourth time interval, during which an induced voltage decreases with the opposite sign compared to the sign of the first and second voltage values, in particular decreasing exponentially by allowing the magnetic field of the electromagnetic actuator to collapse; where the desired opening time specification of the half-stroke movement path is during the first time period, wherein a start time of the third time period, in particular a start time of the application of the third voltage value, is before, in particular shortly before, the reaching of the upper position of the target movement path by the valve element and / or before, in particular shortly before, the desired time specification for the upper position and where a start time of the second phase with rapid decline is essentially the same as the desired closing time; or Then, if the desired injected fuel quantity is above a predetermined threshold, and an injection of the desired injected fuel quantity above the predetermined threshold as the target motion path, which is determined based on the desired injected fuel quantity, requires a full-stroke motion path of the valve element according to which the valve element opens at a desired opening time specification, reaches the fully open position of the motion path, maintains the fully open position for a desired fully open time period, and closes at a desired closing time specification, the phase profile is determined such that it includes: - an initial voltage holding phase to keep the initial voltage value constant for the initial period before applying a boost voltage, - a first voltage holding phase to keep the second voltage value constant for the second time period after the first time period to control an opening movement of the valve element towards the fully open position and to hold the valve element in the fully open position for the desired fully open time period, - a first phase with rapid decay after the second time period and during a third time period, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse in order to actuate a closing movement of the valve element from the fully open position to the closed position, - a second voltage holding phase of a constant holding of a fourth voltage value for a fourth time interval after the third time interval to control a closing movement of the valve element and - a second phase with rapid decay after the fourth time interval, during which an induced voltage decreases with the opposite sign compared to the sign of the first and second voltage values, in particular decreasing exponentially by allowing the magnetic field of the electromagnetic actuator to collapse; where the desired opening time specification of the full-stroke movement path is during the first time period, wherein a start time of the third time period, in particular a start time of the application of the third voltage value, is before, in particular shortly before, the expiry of the desired fully open time period and where a start time of the second phase with rapid decay, in particular a start time of the application of the third voltage value, is essentially the desired closing time specification. [25] Method according to any one of claims 3 to 24, wherein, in order to control multiple injections per injection cycle based on the desired amount of fuel injected or several desired amounts of fuel injected per injection cycle, the injection cycle comprising several target movement paths of the valve element within a single injection cycle, according to which the valve element opens at a respective desired opening time specification, reaches the upper position of the respective target movement path at a position lower than a fully open position of the valve element at a respective desired time specification for the upper position and closes at a respective desired closing time specification, the phase profile is determined such that it comprises: - a ramp-up phase to maintain the initial voltage value constantly for the first period of time when applying a ramp-up voltage, - a first tension holding phase to maintain a constant second tension value for a second time period after the first time period to control an opening movement of the valve element for a first movement path of the several target movement paths, - a first phase with rapid decay after the second time interval and during a third time interval, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially by allowing the magnetic field of the electromagnetic actuator to collapse in order to actuate a change in the direction of movement of the valve element from the opening direction to the closing direction during the first movement path, and - a final phase with rapid decay, during which an induced voltage decreases with the opposite sign compared to the sign of the first and second voltage values, in particular by decreasing exponentially, by allowing the magnetic field of the electromagnetic actuator to collapse after the desired closing time of a final movement path of the multiple target movement paths, wherein the phase profile between the first rapid decay phase and the last rapid decay phase further comprises several voltage holding phases of a constant holding of the second voltage value for a respective holding time period to control a closing movement of the valve element of a respective movement path of the several target movement paths and to control an opening movement of a respective next movement path of the several target movement paths, and wherein the phase profile further includes for each nth motion path with n > 1 a further phase with rapid decay, during which an induced voltage with the opposite sign to the sign of the first and second voltage values ​​decreases, in particular decreases exponentially, by allowing the magnetic field of the electromagnetic actuator to collapse at a time specification before, in particular shortly before, a respective desired time specification for the upper position of the respective nth motion path, in order to actuate a change in the direction of movement of the valve element from the opening direction to the closing direction during the nth motion path. [26] Method according to any one of claims 3 to 25, wherein the electromagnetically actuated valve includes an armature element that is movable between a rest position which is lower than the open position of the valve element and an open position of the valve element, wherein the electromagnetic actuator is designed to actuate a movement of the armature element, and the armature element is designed to move the valve element. wherein the phase profile is determined such that the armature element moves from the rest position to the open position until it comes into contact with the valve element at a first time and remains in contact with the valve element in the closed position until a second time which is greater than the first time, in particular according to a desired time interval between the first and second times and / or according to the desired first and second times, and the armature element and the valve element begin an opening movement from the closed position to the open position at or after the second time; and / or wherein the phase profile is determined such that the anchor element and the valve element move from the open position to the closed position until they reach the closed position at a third time, the anchor element remains in contact with the valve element in the closed position after the third time, in particular according to a desired time interval between the third and a fourth time which is greater than the third time, and / or according to the desired first and fourth times, and the anchor element begins to move from the closed position towards the rest position at or after the fourth time. [27] Method according to one of the preceding claims, wherein the electromagnetic actuator is controlled by a control circuit having multiple switches and the control circuit is designed to have multiple control states which are controlled based on different switching configurations of the multiple switches, wherein a first control state of the multiple control states is activated during the first time period and a second control state of the multiple control states is activated during the second time period. [28] Method for operating an electromagnetically actuated valve of a fuel injector, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position and an electromagnetic actuator designed to actuate a movement of the valve element, the method comprising: - Applying an initial voltage value through active voltage control during an initial time period and switching off the initial voltage value after the initial time period, and - Applying a second voltage value, less than or equal to the first voltage value, by means of active voltage control during a second time period and switching off the second voltage value after the second time period, wherein the duration of the first time interval and the duration of the second time interval are determined according to a desired amount of fuel injected; where the first voltage value is applied constantly during the first time period and / or the second voltage value is applied constantly during the second time period; or the first voltage value is applied constantly during the first time period, so that a current in the electromagnetic actuator increases during the first time period, in particular increases monotonically, and / or the second voltage value is applied constantly during the second time period, so that the current in the electromagnetic actuator increases during the second time period, in particular increases monotonically. [29] Method for operating an electromagnetically actuated valve of a fuel injector, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position and an electromagnetic actuator designed to actuate a movement of the valve element, the method comprising: - Applying an initial voltage value through active voltage control during an initial time period and switching off the initial voltage value after the initial time period, - Applying a second voltage value, less than or equal to the first voltage value, by means of active voltage control during a second time period and switching off the second voltage value after the second time period, and - Allowing an induced voltage in the electromagnetic actuator to decrease through passive voltage control during a third time period, wherein the duration of the first time interval, the duration of the second time interval and / or the duration of the third time interval are determined according to a desired amount of fuel injected; where the first voltage value is applied constantly during the first time period and / or the second voltage value is applied constantly during the second time period; or the first voltage value is applied constantly during the first time period, so that a current in the electromagnetic actuator increases during the first time period, in particular increases monotonically, and / or the second voltage value is applied constantly during the second time period, so that the current in the electromagnetic actuator increases during the second time period, in particular increases monotonically. [30] Device, in particular a controller, for operating an electromagnetically actuated valve of a fuel injector, wherein the electromagnetic valve comprises a valve element movable between a closed position and an open position and an electromagnetic actuator designed to actuate a movement of the valve element, wherein the device is designed to control the execution of a method according to one of the preceding claims. [31] Computer program product comprising a computer program containing computer program instructions designed to cause a controller to perform the steps of a method according to any one of claims 1 to 29.

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