EP2012004A1 - High frequency ignition device and method for its operation - Google Patents

Abstract

The method involves controlling switching units with activation frequency, which is associated with reaching of a preset level of energy supplied to a generator (12). A heuristic search method is applied for detecting the preset level, and the energy stored in the generator is detected based on three frequencies. Starting values of two frequencies are selected such that the values comprise the searched activation frequency, and the values of the three frequencies are modified to the searched optimal frequency activation relative to a continuous approximation in an iterative process. Independent claims are also included for the following: (1) a computer program with program code instructions for implementing a high frequency ignition device operating method (2) a computer program product such as storage medium with a computer program.

Description

The invention relates to a high-frequency ignition device and a method for operating such a device.

High-frequency ignition devices and corresponding operating methods are known per se and are used, for example, as ignition devices for internal combustion engines, ie, for example, gasoline engines. Exemplary becomes on EP 0 211 133 B1 and WO 03 / 046374A1 directed.

A disadvantage of known high-frequency ignition devices, however, is the insufficient possibility of tuning the resonance situation exploited for ignition with environmental and operational influences.

Accordingly, it is an object of the invention to avoid or at least reduce disadvantages of known embodiments.

This object is achieved with the features of claim 1. For this purpose, in a method for operating a high-frequency ignition, eg for an internal combustion engine or the like, wherein the Hochfrequenzzündeinrichtung comprises two coupled resonant circuits, wherein generated in a generator called the first resonant circuit of the two coupled resonant circuits, a voltage increase and in a resonator referred to as the second resonant circuit of the two coupled coupled oscillatory circuits, wherein the generator from a source, eg the electrical system of a motor vehicle comprising the internal combustion engine, fed and via an electrical switching element, in particular a circuit breaker, is excited in accordance with a control of the switching element, provided that recorded in one of the electrical resonant circuits, in particular in the resonator, stored energy and evaluated for driving the switching element, wherein the driving of the switching element takes place with an excitation frequency which is associated with reaching a predetermined or predeterminable energy level of the detected energy stored in one of the resonant circuits and wherein a heuristic search method is used to detect the predetermined or predeterminable energy level.

In the acting as a generator first resonant circuit of the two coupled resonant circuits of Hochfrequenzzündeinrichtung takes place in a conventional manner, as usual in electrical resonant circuits, a periodic exchange of electrical energy between an encompassed by the generator coil or inductor on the one hand and also from the generator included capacitor on the other hand. By coupling, in particular by a line-coupled coupling between the generator and the resonator, in which also take place a corresponding periodic energy exchange and a periodic energy exchange between the generator and resonator with each other, can be determined by the detection in one of the resonant circuits, in particular in the resonator to certain Time energy stored achieve the desired adaptation to environmental and operational influences. In particular, the resonance frequency of the resonator can be detected by detecting the energy stored in the resonator, so that activation of the switching element for excitation of the generator is always possible with the resonance frequency or at least one excitation frequency in the vicinity of the resonant frequency of the resonator. This aims at a compensation in particular of the temperature dependence of the resonance frequency the high-frequency ignition device, in particular of the resonator, so that with the temperature dependence a decisive environmental or operational influence is manageable. In addition, an adaptation of the resonance frequency to production-specific tolerances of the involved components is possible.

Advantageous embodiments of the invention are the subject of the dependent claims. This used backlinks point to the further development of the subject matter of the main claim by the features of the respective subclaim; they should not be construed as a waiver of obtaining independent, objective protection for the feature combinations of the dependent claims. Furthermore, with a view to an interpretation of the claims in a closer specification of a feature in a subordinate claim, it is to be assumed that such a restriction does not exist in the respective preceding claims.

Preferably, energy stored in one of the resonant circuits is detected by the energy stored in the resonator. Upon excitation of the above-described and explained in more detail below Hochfrequenzzündeinrichtung, ie the resonant circuits comprising the generator and resonator, namely, in the generator, a voltage increase, for example, reaches the two or three times the applied operating voltage. In the resonator, on the other hand, there is an increase in voltage, which can easily reach 200 times the voltage injected by the generator into the resonator. The stored energy in the resonator at certain times is therefore greater by orders of magnitude compared to the generator. Accordingly, a sensory detection of the energy stored in one of the resonant circuits is particularly simple if the resonator is considered for this purpose.

As the energy stored in the resonator, a magnetic field of the inductance encompassed by the resonator, which is referred to below as a resonator inductance for the purpose of discrimination, is preferably detected. As is known, the periodically between the capacitor and inductance exchanged electrical energy in a resonant circuit alternately leads to a high current (through the inductance) or a high voltage (across the capacitor). The current through an inductance or the resulting magnetic field of the inductance, ie the generator inductance, can be measured particularly easily. In the case of the voltage overshoot occurring in the resonator, a conductor end acting as a coupling element, in which the magnetic field induces a current flow which can be evaluated as a measure of the energy stored in the resonator, is sufficient.

The control of the switching element takes place according to a preferred embodiment with an excitation frequency, which is associated with reaching a predetermined or predeterminable energy level of Resonatorinduktivität. In this way, the excitation of the generator to electrical vibrations to an achievable in the resonator energy level, namely the predetermined or predeterminable energy level can be tuned.

It is particularly preferably provided that an energy maximum is applied as the predetermined or specifiable energy level of the resonator inductance. Then, an excitation of the resonator to electrical vibrations is possible in such a way that adjusts a maximum voltage increase in the resonator, wherein the energy of the maximum voltage increase in a favorable manner for generating an ignition voltage sufficient in the resonator and for bridging an ignition distance covered by the resonator.

To detect the predetermined or predefinable energy level or the maximum energy, the high-frequency ignition device is excited during individual or all ignition processes or between successive ignition processes with different, predetermined or predefinable frequencies. The frequencies are selected so that the predetermined or predeterminable energy level or the energy maximum, hereinafter referred to collectively under the term energy maximum, is detected. This is possible because, due to a familiarity with the specification of the components encompassed by the high-frequency ignition device, ie inductances and capacitances, there is at least one theoretical value or an estimated value with regard to the resonance frequency. Accordingly, the frequencies provided for the excitation can be preset in the range of this theoretical value or this estimated value. Furthermore, because of known characteristics of electrical oscillating circuits, consideration of local maxima is not necessary, so that if an energy increase is detected after excitation with a first frequency when excited with a second frequency, the energy maximum in the direction of further increasing frequencies and vice versa can be expected , In that regard, an heuristic search, ie the approach of a strategy which accelerates the finding of solutions, is particularly efficient here for an acceleration of the search of the given or specifiable energy level or of the energy maximum.

Advantageously, as a concrete embodiment of such a heuristic search method, a method is used in which starting from a first, second and third frequency f ₁ , f ₂ , f ₃ , the stored in the generator Energy is detected, wherein start values for the first and third frequencies f ₁ , f ₃ are selected so that they include a sought optimal excitation frequency, which is associated with reaching a predetermined or predeterminable energy level, in particular the energy maximum, the generator capacity, wherein an iterative process, the values for the first, second and third frequencies f ₁ , f ₂ , f ₃ are modified with respect to a continuous approximation to the sought optimum excitation frequency. Specifically, by selecting the first and third frequencies f ₁ , f ₃ from the theoretically possible frequency range (search space) in which the generator can be operated, ie at least 0 to ∞, a frequency range is selected in which the sought optimum excitation frequency is expected can. The search space is thus already considerably limited in this way. In an iterative process, the values for the first, second and third frequencies f ₁ , f ₂ , f _{3 are} modified with respect to a continuous approximation to the sought optimum excitation frequency, so that with each iteration step the search space is reduced again, eg halved. In this way, the sought optimal excitation frequency can be found in finite time with comparatively little mathematical effort. Advantage of this approach is that the sought optimal excitation frequency is always found, the

Algorithm always converges. Another advantage is that the maximum time that is determined for finding the desired optimal excitation frequency, because the method according to the advantageous embodiment of the invention in the approach known from the so-called binary search (Binary Search) belongs to the complexity class log n and converges after a maximum of log ₂ n steps, which also applies to the approach proposed here.

Simple and favorable conditions for the implementation of the method in a computer-implemented or computer-implemented software algorithm result if the values for the first, second and third frequencies f ₁ , f ₂ , f ₃ are equidistant at least at the start time, in particular remain equidistant during the entire iterative process.

The method described above and further explained below is preferably implemented in the form of a computer program with computer-executable program code instructions. In that regard, the invention also relates to such a computer program or a computer program product with such a computer program. As a computer program product, in particular, a storage medium, such as e.g. a memory module, as it may be included by a central control unit of an engine electronics for controlling an internal combustion engine and the like, into consideration. In such a controller, the computer program is executed by a dedicated processing unit such as a processor or the like. As a computer program product is also a so-called ASIC (user-specific integrated shading), a DSP (digital signal processor) or a combination of ASIC and DSP into consideration. Such components function in terms of each realized functionality as a memory module. The present in the memory module in the broadest sense as software implementation of the method is present in the ASIC or DSP as so-called firmware. The peculiarity of such computer program products is that they virtually take over the execution of the stored functionality in the manner of a processor, in the DSP even in parallel processing.

The invention further relates to a high-frequency ignition device, which is provided for the execution of and for use with the method outlined above and further described below, and is prepared. The high-frequency ignition device is intended in particular for use with or for use with an internal combustion engine, such as a gasoline engine, and comprises two coupled electrical oscillating circuits, the first oscillating circuit of the two coupled oscillating circuits designated as a generator for generating a voltage increase and for coupling it, in particular to the line-connected one Coupling, is provided in the designated as a resonator second resonant circuit of the two coupled resonant circuits, the generator to a source, such as an electrical system of the internal combustion engine motor vehicle, connected and via an electrical switching element, in particular a circuit breaker, according to a control of the switching element excitable is, wherein a stored in one of the resonant circuits, in particular in the resonator, recorded energy by means of a coupling element acting as a sensor and a sensor signal as a measure of the generator in the generator it is possible to generate energy that can be generated, and by means of control electronics an excitation frequency can be generated on the basis of the sensor signal, with which the switching element can be acted upon. The sensor signal is a measure of the energy stored in the high-frequency ignition device, in particular in the resonator. The excitation frequency is thus directly dependent on the energy actually stored. Thus, the stored energy is detected by means of the sensor and evaluated for driving the switching element by the control electronics based on the sensor signal, the excitation frequency is generated, with which the switching element is acted upon and thus finally fed to the generator according to the excitation frequency from the source becomes.

If the sensor is associated with the Resonatorinduktivität included by the resonator, resulting from the resulting in the resonator Voltage overshoot particularly simple conditions with regard to the sensory detection of the energy stored there. In the simplest case, a conductor end of the resonator inductance functioning as a coupling element can be suitably associated with respect to spatial proximity and orientation and used as a sensor, ie as a magnetic field sensor, after the magnetic fields generated by the resonator inductance are readily sufficient, in the conductor end a current flow which can be evaluated as a sensor signal induce. This leads to equipment-wise and metrologically simple conditions with regard to the detection of the energy stored in the resonator without disturbing distortions of the measurement data due to the sensors used being to be expected.

The or each embodiment is not to be understood as limiting the invention. Rather, numerous modifications and variations are possible within the scope of the present disclosure, in particular those variants and combinations, for example, by combination or modification of individual features described in the general or specific description part as well as in the claims and / or the drawing Elements or process steps for the expert with regard to the solution of the problem can be removed and lead by combinable features to a new subject or to new process steps or process steps, even as far as they eg Testing and working procedures.

An embodiment of the invention will be explained in more detail with reference to the drawing. Corresponding objects or elements are provided in all figures with the same reference numerals.

Fig. 1

eine schematisch vereinfachte Darstellung einer bekannten Hochfrequenzzündeinrichtung,

Fig. 2

eine schematisch vereinfachte Darstellung einer Hochfrequenzzündelnrichtung gemäß der Erfindung und

Fig. 3

eine Darstellung zur Veranschaulichung des Auffindens einer gesuchten optimalen Anregungsfrequenz zur Ansteuerung/Anregung der Hochfrequenzzündeinrichtung.

Show in it

Fig. 1

a schematically simplified representation of a known high-frequency ignition device,

Fig. 2

a schematically simplified representation of a Hochfrequenzzündelnrichtung according to the invention and

Fig. 3

a representation to illustrate the finding of a sought optimal excitation frequency for driving / excitation of the high-frequency ignition device.

Fig. 1 shows a schematically simplified representation of a basically known Hochfrequenzzündeinrichtung 10. This includes a generator 12 and a resonator coupled thereto 14, and as an example of a switching element, a circuit breaker 16 and possibly a non-illustrated voltage transformer comprehensive current or voltage source, hereinafter briefly as Designated source 18.

Electrically, generator 12 and resonator 14 are coupled oscillating circuits. For this purpose, generator 12 comprises at least one coil designated as generator inductor 20 and a capacitor designated as generator capacitor 22. In the illustrated example, generator inductance 20 and generator capacitance 22 are shown as constituents of a series resonant circuit, which is otherwise not shown. The resonator 14 comprises a coil designated as a resonator inductor 24 for distinguishing it from the generator inductor 20 and an ignition path 25, e.g. a known spark plug with ignition electrodes.

If a coupling, for example the coupling of generator 12 and resonator 14, is used here and below, this means every possible type of coupling, for example an inductive or capacitive coupling, in particular but a wired coupling. The double arrows in Fig. 1 (but also in the below Fig. 2 ) represent such couplings schematically simplified graphically.

In order to excite the generator 12, that is, to excite the resonant circuit comprised thereof, the power switch 16, e.g. in an embodiment as a power MOSFET transistor 26, provided. This is taken from source 18, e.g. the on-board network of a motor vehicle, in particular a motor vehicle battery and / or a Krattfahrzeuglichtmaschine 28, fed. Alternatively, also, e.g. if the capacitance of the MOSFET transistor 26 is utilized as the generator capacitance 22, it is provided that the generator inductance 20 is supplied on one side with the voltage of the electrical system and a triggering of the power switch 16 short-circuits the generator capacitance 22, that is to say the capacitance of the MOSFET transistor 26 , causes.

The control of the circuit breaker 16 by means of an electronic control unit 30. This is by periodic control of the circuit breaker 16, a frequency at which the generator 12 is excited from the source 18 before.

Fig. 2 shows a schematically simplified representation of a high-frequency ignition device 10 according to the invention, this corresponds in detail to the in Fig. 1 shown high-frequency ignition device 10, so that reference is made to the description there. In the high-frequency ignition device 10 in Fig. 2 is one of the resonant circuits, in the illustrated embodiment the resonator 14, more precisely the Resonatorinduktivität 24, acting as a sensor 32 coupling element, such as a conductor end assigned, which functions in the illustrated situation as a magnetic field sensor by the magnetic field of Resonatorinduktivität 24 a induced as sensor signal 34 evaluable current in the conductor end. It is essential that the energy stored in one of the resonant circuits, ie generator 12 or resonator 14, is detected with the sensor 32. In this regard, alternatively, a sensory detection of, for example, the energy stored in the generator inductance 20 comes into consideration (not shown).

The stored energy in the resonator 14 is evaluated for driving the circuit breaker 16. A sensor signal 34 emitted by the sensor 32 and evaluatable by the control electronics 30 is a measure of the total energy stored in the high-frequency ignition device, in particular in the resonator 14. To excite the generator 12, the control electronics 30 generates an excitation frequency 36, with which the power switch 16 is acted upon. By the control electronics 30, the excitation frequency 36 is now changed so that the stored energy in the generator 12 and thus, due to a suitable vote of each involved components, ie capacitances and inductances, and the energy stored in the resonator 14 is maximum. Thus, the excitation frequency 36 is determined, which leads to a maximum voltage increase in the resonator 14 and thus to particularly favorable conditions for the ignition. Voltage overshoot is known to occur in an electrical resonant circuit when the voltage across the coil or capacitor reaches a value that significantly exceeds the value of the total voltage. In a series resonant circuit as a special form of an electrical resonant circuit flows due to the series connection in coil and capacitor while the same current, the sinusoidal waveform of the voltage across the coil and capacitor, but phase-shifted by a total of 180 ° (coil: 90 °, capacitor: -90 °) , This effect can be used for a given total voltage by the voltage across one of the two energy storage, in the case shown above Resonatorinduktivität 20, tapped for generating a spark over the firing line 25.

For this purpose, it is provided that the generator 12 is excited with three frequencies, in particular with three equidistant frequencies, f ₁ , f ₂ and f ₃ , where f ₁ <f ₂ <f ₃ . For each of these frequencies f ₁ , f ₂ , f ₃ , the oscillating circuits encompassed by the high-frequency ignition device, in particular in response to the resonator 14, oscillating between the respective components involved and, to that extent, in the oscillating circuits, in particular in the Resonator 14, "stored" energy detected. The values of the sensor signal 34 associated with the frequencies f ₁ , f ₂ , f ₃ are referred to hereinafter as FB ₁ , FB ₂ and FB ₃ , where FB stands for "feedback".

With these values, if f ₁ and f ₃ are chosen such that they include an optimum excitation frequency with which the sought energy maximum is reached, this optimum excitation frequency can be determined.

betrachtet. Mit der Bedingung f₁ < f₂ < f3 liefert der Nenner der o.g. Beziehungen stets ein negatives Vorzeichen, so dass für die Betrachtung der Vorzeichen auch die Betrachtung von FB₂-FB₁ bzw. FB₃-FB₂ ausreicht. Je nach Vorzeichenkombination ergeben sich dann neue Werte für die Frequenzen f₁, f₂, f₃ nach folgendem Schema: Vorzeichen Slope₁ Vorzeichen Slope₂ + - $$f_1=\frac{f_1^{ʹ}+f_2^{ʹ}}{2}$$

$$f_2=f_2^{ʹ}$$

$$f_3=\frac{f_2^{ʹ}+f_3^{ʹ}}{2}$$

- + kein Maximum zwischen f₁ und f₃ + + $$f_1=f_2^{ʹ}$$

$$f_2=\frac{f_2^{ʹ}+f_3^{ʹ}}{2}$$

$$f_3=f_3^{ʹ}$$

- - $$f_1=f_1^{ʹ}$$

$$f_2=\frac{f_1^{ʹ}+f_2^{ʹ}}{2}$$

$$f_3=f_2^{ʹ}$$

In addition shows Fig. 3 a possible course of the electrical energy stored in the RF generator 12 as a function of ablated on the abscissa different excitation frequencies 36. In order to find an optimal excitation frequency at which results in the resonator 14, a maximum voltage increase and thus a maximum stored electrical energy, the Generator 12 sequentially excited with three different frequencies f ₁ , f ₂ , f ₃ and the resulting system responses FB ₁ , FB ₂ , FB ₃ evaluated. It is important that f ₁ , f ₂ , f ₃ are chosen so that the sought optimal excitation frequency of the frequencies f ₁ and f ₃ is included. Then, by means of a slope of the energy profile between f ₁ and f ₂ or f ₂ and f ₃ with a possible redetermination of single or multiple values of the frequencies f ₁ , f ₂ , f _3, an approximation to the position of the sought optimal excitation frequency. In addition, the signs of the ascertained gradients become concrete $$\begin{array}{cc}{\mathit{Slope}}_1=\frac{F{B}_1-F{B}_2}{f_1-f_2}.& {\mathit{Slope}}_2=\frac{F{B}_2-F{B}_3}{f_2-f_3}\end{array}$$

considered. With the condition f ₁ <f ₂ <f3, the denominator of the above relations always gives a negative sign, so that the consideration of the signs is also sufficient to consider FB ₂ -FB ₁ or FB ₃ -FB ₂ . Depending on the sign combination, new values then result for the frequencies f ₁ , f ₂ , f ₃ according to the following scheme: Sign Slope ₁ Sign Slope ₂ + - $$f_1=\frac{f_1^{\text{'}}+f_2^{\text{'}}}{2}$$

$$f_2=f_2^{\text{'}}$$

$$f_3=\frac{f_2^{\text{'}}+f_3^{\text{'}}}{2}$$

- + no maximum between f ₁ and f ₃ + + $$f_1=f_2^{\text{'}}$$

$$f_2=\frac{f_2^{\text{'}}+f_3^{\text{'}}}{2}$$

$$f_3=f_3^{\text{'}}$$

- - $$f_1=f_1^{\text{'}}$$

$$f_2=\frac{f_1^{\text{'}}+f_2^{\text{'}}}{2}$$

$$f_3=f_2^{\text{'}}$$

For the in Fig. 3 The situation then shows that the sign of Slope _{1 is} positive and that of Slope _{2 is} negative. Accordingly, the frequencies f elected ₁ and f _2, in which results in new values of the frequencies f _1, f _2, f ₃ on the basis of previous values of these frequencies f _1, f _2, f _3, to distinguish (with a line f ') Marked are. The new values for the frequencies f ₁ and f ₂ cause the interval defined by the frequencies f ₁ and f _{2 to be} reduced, with the now reduced interval still being the one searched for includes optimal excitation frequency. If, by successively further constriction of the interval defined by the frequencies f ₁ and f ₂ , a situation is finally reached in which FB ₃ becomes greater than FB ₂ , the signs of the two slope values or slope indicators considered are positive. Accordingly, (see table above) the previous value of f ₂ becomes the lower limit of the considered interval, while the upper limit of the considered interval remains and the new value of f ₂ lies in the middle of the once again reduced interval thus defined includes the sought optimal excitation frequency.

This process is continued until the sought optimal excitation frequency or a sufficient approximation of the same is found. Since the method for finding the optimum excitation frequency, which is preferred according to a particular aspect of the invention, is based on the algorithm known in the state of the art as binary search or "binary search", for which convergence is detected after log ₂ N steps, the termination criterion for the above-described iterative method is given a maximum number of iteration steps. The excitation frequency found after processing the predetermined or predefinable number of iteration steps is then used as the sought optimal excitation frequency.

If the sought optimal excitation frequency was found in this way, this can be used as the excitation frequency 36 for exciting the generator 12. The advantage of the enclosure method described above, which is due to the so-called binary search, with the difference that in the binary search an item to be found is already known in advance, whereas with the modification described here the position of one in advance is not known maximum, is mainly in the fast convergence. That is, a maximum of Log ₂ N iterations are required according to the scheme described above to determine the desired optimal excitation frequency. At different bandwidths, ie the distance between the initial values for f ₁ and f ₃ , and a resolution of 50 Hz, the following listed numbers of iterations and at a mean time of 22μs for an iteration on a constructed as control electronics 30 for simulation purposes Hardware the also listed total computing times until the searched optimal excitation frequency is determined: bandwidth Number of iterations Total computing time 100 kHz 11 244μs 50 kHz 10 222μs 25 kHz 9 200μs 1 kHz 4 89μs

As a predetermined or predefinable maximum number of iteration steps, therefore, the number of iterations can be entered at which the algorithm is guaranteed to converge under the respective boundary conditions. In individual cases, a slightly reduced number of iteration steps may be provided, because this still leads to a sufficiently accurate approximation of the sought optimal excitation frequency with a linear reduced total computing time.

With the determination of the desired optimal excitation frequency by the control electronics 30 and with their subsequent use as the excitation frequency 36 for the generator 12 results in an automatic adjustment of the excitation frequency 36 to the resonant situation of the resonator 12 and / or the resonance situation of the coupled resonant circuits Generator 12 and resonator 14. Environmental and operating influences such as pressure, temperature, etc. are compensated.

Fig. 4 shows one compared to Fig. 3 detailed form of a possible realization of the high-frequency ignition device. The first resonant circuit or generator 12 is a so-called class E amplifier, wherein the capacity of the acting as a circuit breaker MOSFET transistor 26 is used as the generator capacitance 22. The generator inductance 20 is connected to the vehicle electrical system voltage U _{B of} the motor vehicle. Via a center tap between the generator capacitance 22 and generator inductance 20, a point at which, for example, 2 × U _B can be tapped in the case of resonance of the generator 12, the voltage increase generated in the generator 12 is coupled into the resonator 14. The coupling takes place according to the illustrated embodiment on a wired path, where appropriate, a known per se impedance detection, a so-called "match box" 38 is interposed. Due to the operating situation in which the resonator is operated in accordance with the excitation of the high-frequency ignition device 10, parasitic capacitances, that is, capacitances, can be represented as capacitors of each winding of the resonator inductance 24 to ground are, not avoid. These capacitances actually supplement the resonator to form an electrical resonant circuit. A sensor end arranged in the region of the resonator inductance 24, in which a current evaluable as a sensor signal 34 is induced by the magnetic field of the resonator inductance 24, acts as a sensor 32.

Thus, the invention can be briefly described as follows: A method for operating a high-frequency ignition device and such a high-frequency ignition device are specified, which are used as generator 12 and resonator 14 comprise two coupled electrical resonant circuits, of which the generator is fed via an electrical switching element and excited in accordance with a control of the switching element, is provided in which or in the compensation of Betrlebs- and / or environmental influences that stored in the generator 12 energy detected and evaluated for driving the switching element.

Claims (10)

Method for operating a high-frequency ignition device (10) for an internal combustion engine, wherein the high-frequency ignition device (10) comprises two coupled electrical oscillating circuits,
wherein a voltage overshoot is generated in a first oscillating circuit of the two coupled resonant circuits which acts as a generator (12) and is coupled into a second resonant circuit of the two coupled oscillator circuits acting as a resonator (14),
wherein the generator (12) is fed from a source (18) and excited via an electrical switching element, in particular a power switch (16), in accordance with a control of the switching element,
wherein an energy stored in one of the oscillating circuits (12, 14) is detected and evaluated for driving the switching element,
wherein the driving of the switching element with an excitation frequency (36), which is associated with a reaching a predetermined or predeterminable energy level of the detected, stored in one of the oscillating circuits (12, 14) energy.
wherein a heuristic search method is used to detect the predetermined or predeterminable energy level. Method according to claim 1, wherein energy stored in one of the oscillating circuits (12, 14) is detected by the energy stored in the resonator (14). Method according to claim 2, wherein energy stored in the resonator (14) is detected as a magnetic field of an inductance encompassed by the resonator (14) and referred to as resonator inductance (24). Method according to Claim 3, wherein an energy maximum is set as the predetermined or specifiable energy level of the resonator inductance (24). Method according to one of claims 1 to 4,
wherein starting from a first, second and third frequency f ₁ , f ₂ , f ₃ for each frequency f ₁ , f ₂ , f _3, the energy stored in the generator (12) is detected,
wherein start values for the first and third frequencies f ₁ , f ₃ are selected such that they include a sought optimal excitation frequency, which is associated with reaching a predetermined or predeterminable energy level of the generator capacity (22),
wherein, in an iterative process, the values for the first, second and third frequencies f ₁ , f ₂ , f ₃ are modified with respect to a continuous approximation to the sought optimal excitation frequency. The method of claim 5, wherein the values for the first, second and third frequencies f ₁ , f ₂ , f _{3 are} equidistant. A computer program comprising computer executable program code instructions for implementing the method of any one of claims 1 to 6 when the computer program is run on a computer. Computer program product, in particular storage medium, having a computer-executable computer program according to claim 7. High-frequency ignition device (10) with two coupled electrical oscillating circuits, in particular for an internal combustion engine,
wherein a first oscillation circuit of the two coupled oscillation circuits, which functions as a generator (12), is provided for generating a voltage superelevation and for coupling it into a second oscillation circuit of the two coupled oscillation circuits acting as a resonator (14),
wherein the generator (12) is connected to a source (18) and can be excited via an electrical switching element, in particular a power switch (16), in accordance with a control of the switching element,
wherein a stored energy in one of the resonant circuits, in particular in the resonator (14), can be detected by means of a sensor (32) and by means of the sensor (32) a sensor signal (34) can be generated as a measure of the energy stored in one of the oscillator circuits, and
wherein by means of control electronics (30) on the basis of the sensor signal (34) an excitation frequency (36) can be generated, with which the switching element can be acted upon,
wherein the control electronics (30) comprises a computer program product according to claim 8. High-frequency ignition device according to claim 9, wherein the sensor (32) is associated with a Resonatorinduktivität (24) encompassed by the resonator (14).

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