阅读说明：本技术 用于识别内燃机的改变功率的操纵的方法和装置 (Method and device for detecting a power-changing operation of an internal combustion engine ) 是由 T·布克哈特 A·霍尔策德尔 于 2020-03-05 设计创作，主要内容包括：本发明涉及用于识别内燃机(100)的改变功率的操纵的方法,内燃机(100)具有进气道(110)和布置在进气道(110)中的压力传感器(116、118),该方法具有步骤：利用压力传感器(116、118)在确定的时间段上检测信号走向(440),从检测到的信号走向(440)中获知周期性重复的检测到的信号走向区段(442),其表征进气道(110)中的周期性重复的压力变化,提供在所述确定的时间段上的模型化的信号走向(430),从中获知周期性重复的模型化的信号走向区段(432),其表征进气道(110)中的预期的周期性重复的压力变化,将检测到的信号走向区段(442)的信号部分与相应的模型化的信号走向区段(432)的相应的信号部分进行比较,以识别内燃机(100)的改变功率的操纵。(The invention relates to a method for detecting a power-changing operation of an internal combustion engine (100), the internal combustion engine (100) having an intake tract (110) and a pressure sensor (116, 118) arranged in the intake tract (110), comprising the steps of: detecting a signal profile (440) over a specific time period by means of a pressure sensor (116, 118), detecting a periodically repeating detected signal profile section (442) from the detected signal profile (440), which characterizes a periodically repeating pressure change in the intake tract (110), providing a modeled signal profile (430) over the specific time period, detecting a periodically repeating modeled signal profile section (432), which characterizes an expected periodically repeating pressure change in the intake tract (110), comparing a signal portion of the detected signal profile section (442) with a corresponding signal portion of the corresponding modeled signal profile section (432) in order to detect a power-changing manipulation of the internal combustion engine (100).)

1. Method for detecting a power-changing operation of an internal combustion engine (100), wherein the internal combustion engine (100) has an intake tract (110) and a pressure sensor (116, 118) which is arranged in the intake tract (110), wherein the method has the following steps:

-detecting a signal profile (440) over a specific time period using the pressure sensor (116, 118), wherein a periodically repeating detected signal profile section (442) is derived from the detected signal profile (440), which characterizes a periodically repeating pressure change in the intake tract (110),

-providing a modeled signal profile (430) over the determined time period, from which a periodically repeating modeled signal profile section (432) is known, which characterizes an expected periodically repeating pressure change in the intake tract (110),

-comparing signal portions of the detected signal profile section (442), which are characteristic of pressure changes in the intake tract (110) of one cycle of the detected signal profile (440), with corresponding signal portions of the corresponding modeled signal profile section (432), which are characteristic of expected pressure changes in the intake tract (110) during the same cycle, for identifying a power-changing maneuver of the internal combustion engine (100).

2. The method according to claim 1, wherein the comparison of the signal portion of the detected signal profile section (442) with the corresponding signal portion of the corresponding modeled signal profile section (432) takes into account a signal portion difference corresponding to a time difference between the signal portion of the detected signal profile section (442) and the signal portion of the corresponding modeled signal profile section (432).

3. The method according to claim 2, wherein a power-changing manipulation of the internal combustion engine (100) is recognized when the signal portion difference exceeds a first threshold value.

4. Method according to one of the preceding claims, wherein a detected signal profile function is generated from the detected signal profile section (442) by means of a fourier transformation, which characterizes the periodically repeating pressure changes in the intake tract (110), and wherein the phase of the detected signal profile function is known, and wherein the known phase is compared as a signal portion of the detected signal profile section (442) with a modeled phase as a corresponding signal portion of a corresponding modeled signal profile section (432), wherein the modeled phase is provided as a signal portion of the modeled signal profile section (432).

5. Method according to claim 4, wherein a modeled signal profile function is generated from the modeled signal profile section (432) by means of a Fourier transformation, which characterizes the expected periodically repeating pressure changes in the intake tract (110), and wherein the modeled phase is derived and provided from the modeled signal profile function.

6. The method according to any one of the preceding claims, wherein the modeled signal profile (430) is provided as a characteristic field which takes into account operating parameters of the internal combustion engine (100).

7. The method according to claim 4, wherein the modeled phase of the modeled signal trend section (432) is provided as a function of at least one operating parameter of the internal combustion engine (100).

8. The method according to one of claims 4 to 7, wherein, for comparing at least one signal portion of the detected signal profile section (442) with a corresponding signal portion of the corresponding modeled signal profile section (432), a phase difference is determined between a phase determined as the signal portion of the detected signal profile section (442) and a modeled phase determined as the signal portion of the corresponding modeled signal profile section (432).

9. The method according to claim 8, wherein the learned phase difference is compared with a phase difference threshold value, and wherein a power-changing maneuver of the internal combustion engine (100) is identified when the learned phase difference exceeds the phase difference threshold value.

10. Device for detecting a power-changing operation of an internal combustion engine (100), wherein the device has a control unit (200) which is provided for controlling the method according to one of the preceding claims.

Technical Field

The invention relates to a method and a device for detecting a power-changing operation of an internal combustion engine. For this purpose, the internal combustion engine has an intake tract and a pressure sensor, wherein the pressure sensor is arranged in the intake tract.

Background

The control of the internal combustion engine can be designed in such a way that the fuel quantity to be injected is calculated from the modeled cylinder air quantity. In order to achieve the desired emission behavior of the combustion, the air/fuel ratio in the cylinder before the combustion is adjusted accordingly. In this case, the fuel quantity to be injected is usually automatically adjusted on the basis of the oxygen concentration in the exhaust gas measured by the exhaust gas sensor, so that the desired air/fuel ratio is set. If the air quantity in the cylinder is increased as a result of the operation of the internal combustion engine, the fuel quantity is automatically increased, so that the desired air/fuel ratio is set. The power of the internal combustion engine can thereby be increased. Of course, due to this manipulation, the internal combustion engine is operated outside its predetermined operating range, whereby the internal combustion engine may be damaged.

For example, it is conceivable to modify the measurement signal of a pressure sensor in the intake tract of the internal combustion engine by means of the actuating device in such a way that the maximum air quantity in the cylinder can be increased. By means of such an actuating device, it is possible to transmit an incorrect pressure to the control unit, which controls the internal combustion engine in such a way that it operates outside its predetermined operating range.

An internal combustion engine operating outside its predetermined operating range may be damaged.

DE 102012001356 a1 discloses an internal combustion engine arrangement of a motor vehicle, having at least one boost pressure sensor unit, which is provided for at least indirectly detecting an actual boost pressure in an intake tract of a supercharged internal combustion engine, and having a control unit or regulating unit, which is connected in communication with the at least one boost pressure sensor unit, characterized in that the control unit or regulating unit is provided for comparing the actual boost pressure with at least one test value in at least one operating state.

Document DE 102011108697 a1 discloses a method for detecting an actuation of a motor controller of a motor vehicle, in which a calculated reference value for the acceleration is compared with a measured actual acceleration value.

Disclosure of Invention

The object of the present invention is to provide a method and a device with which a reliable detection of a power-changing operation of an internal combustion engine is achieved.

This object is achieved by the features of the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

According to the disclosure, a method for detecting a variable-power actuation of an internal combustion engine has the following steps, wherein the internal combustion engine has an intake tract and a pressure sensor arranged in the intake tract:

detecting a signal profile over a defined time period using a pressure sensor, wherein periodically repeating detected signal profile sections are detected from the detected signal profile, which represent periodically repeating pressure changes in the intake tract,

providing a modeled signal profile over a defined period of time, from which a periodically repeating modeled signal profile section is determined, which characterizes an expected periodically repeating pressure change in the intake tract,

at least one signal portion of the detected signal profile section, which is characteristic of a pressure change in the intake tract for one period of the detected signal profile, is compared with a corresponding signal portion of a corresponding modeled signal profile section, which is characteristic of an expected pressure change in the intake tract during the same period, in order to identify a power-changing maneuver of the internal combustion engine.

An intake tract of an internal combustion engine delivers air to the internal combustion engine for combustion during engine operation. A pressure sensor arranged in the intake tract detects the pressure of the air present in the intake tract and which is supplied to the internal combustion engine during operation. In this regard, the pressure sensor outputs a measurement signal that is indicative of the air pressure present in the intake tract. The air pressure in the intake passage varies with time during operation of the internal combustion engine. If, for example, an air inlet valve of the internal combustion engine, which controls the air supply from the inlet channel into the cylinder, is opened, the air pressure in the inlet channel decreases accordingly. Such air pressure changes may be detected, for example, by a pressure sensor. If the internal combustion engine has a plurality of cylinders, the internal combustion engine has an associated air inlet valve for each cylinder, which in each case are actuated to admit air into the cylinders of the internal combustion engine during operation. Thus, the air pressure in the intake passage also varies depending on the manipulation and number of cylinders or intake valves. According to one embodiment, the pressure sensor is an intake pipe pressure sensor, which is arranged upstream of an air inlet valve of the internal combustion engine in the air flow direction. According to one embodiment, the intake pipe pressure sensor is arranged in the air flow direction directly upstream of an air inlet valve of the internal combustion engine. According to a further embodiment, the pressure sensor is a boost pressure sensor, which is arranged downstream of the compressor and upstream of the throttle valve of the exhaust gas turbocharger in the air flow direction. According to a further embodiment, the boost pressure sensor is arranged directly downstream of the compressor of the exhaust gas turbocharger in the air flow direction. According to a further embodiment, a plurality of pressure sensors can also be arranged in the intake tract of the internal combustion engine, wherein, for example, one of the pressure sensors can be an intake manifold pressure sensor and another of the pressure sensors can be a charge pressure sensor.

According to the present disclosure, a pressure sensor is utilized to detect the signal trend. Furthermore, periodically repeating sections of the detected signal profile are known from the detected signal profile. The detected signal profile section characterizes a periodically repeating pressure change in the airway over a determined period of time. The pressure change in the inlet duct is substantially periodic due to the open air inlet valve. A period is here the minimum time interval after the repetition of the process. If, for example, the internal combustion engine has 2 cylinders, a cycle starts, for example, when the air inlet valve of one of the two cylinders is opened for the first time, and ends as soon as the same inlet valve is about to be opened again. One cycle therefore corresponds to one working gap of the internal combustion engine. From the signal profile of the detected pressure sensor, a signal profile section can therefore be determined comparatively easily, which characterizes the periodically repeating pressure changes in the intake tract, in that the detected signal profile is correspondingly divided and assigned to the working gap. One of the detected signal profiles therefore corresponds to one period of repeated pressure changes in the intake tract.

According to the disclosure, a modeled signal profile is provided, from which periodically repeating modeled signal profile sections are known. The modeled signal profile section represents the expected periodically repeating pressure changes in the intake tract. The modeled signal profile is stored in a memory of the control unit and is read from the memory and processed further, according to one specific embodiment. The modeled signal profile is known, for example, when developing the internal combustion engine for various operating states of the internal combustion engine and is therefore stored in a memory. In the case of varying parameters of the internal combustion engine, such as rotational speed or load, and in the case of varying ambient parameters, such as ambient temperature or ambient pressure, the expected air pressure in the intake tract changes and the modeled signal profile provided is to be adjusted accordingly. According to one specific embodiment, the modeled signal profile takes into account such parameters that a corresponding modeled signal profile is provided for all operating conditions of the internal combustion engine. As the detected signal profile section is known from the detected signal profile, the modeled signal profile section is known from the modeled signal profile. According to a further embodiment, the modeled signal profile section can also be provided directly.

According to the disclosure, one of the signal portions of the detected signal profile section is compared with the corresponding signal portion of the corresponding modeled signal profile section. In this case, the detected signal profile section represents the pressure change in the intake tract during a cycle, for example during a working gap. Furthermore, the corresponding modeled signal profile section characterizes the expected pressure change in the intake tract during the same cycle. This signal portion of the detected signal profile section is therefore compared with a corresponding signal portion of a corresponding modeled signal profile section. The signal components are, for example, characteristic signal deflections, characteristic gradient changes, local or global maxima, local or global minima, amplitudes or phases of the respective signal path sections. If the signal portion of the detected signal profile section to be compared is its global maximum, the signal portion of the corresponding modeled signal profile section is also its global maximum.

The modeled signal profile can be determined, for example, on a test stand during the development of the internal combustion engine, so that the modeled signal profile can be made available relatively simply. In this way, the periodically repeated modeled signal profile sections can be derived particularly easily from the provided modeled signal profiles, preferably in such a way that the signal profile reference is divided into the modeled signal profile sections by means of the respective periods.

If the internal combustion engine has been operated, for example, in order to achieve a higher output from the internal combustion engine, it is possible to operate the internal combustion engine outside its predetermined operating range. Higher power can be achieved, for example, by increasing the pressure in the intake tract and thus also in the cylinders of the internal combustion engine. This change in pressure in the intake tract can be detected in the signal section of the detected signal profile. If the respective signal section of the detected signal profile section is now compared with the respective signal section of the respective modeled signal profile section, an increased pressure can be detected, for example, compared with the respective modeled state of the internal combustion engine. Due to the increased pressure in the intake tract, a power-changing operation of the internal combustion engine can be inferred. This identification is comparatively simple and reliable and can be carried out over the entire operating range of the internal combustion engine. It is therefore possible in a very simple and reliable manner and method to detect only by means of the pressure sensor the signal profile, to provide a modeled signal profile and to analyze both profiles to detect whether the internal combustion engine is being operated.

According to one specific embodiment, a signal portion difference is taken into account when comparing the signal portion of the detected signal profile section with the corresponding signal portion of the corresponding modeled signal profile section, said signal portion difference corresponding to the time difference between the signal portion of the detected signal profile section and the signal portion of the corresponding modeled signal profile section. If, for example, the signal portion of the detected signal profile is the global maximum of the detected signal profile and, therefore, the corresponding signal portion of the corresponding modeled signal profile is the global maximum thereof, the signal portion difference can be calculated in such a way that the point in time at which the global maximum occurs in the detected signal profile and the point in time at which the global maximum occurs in the modeled signal profile are subtracted from one another. The signal portion difference is thus the time difference between the occurrence of one global maximum and another global maximum. If, for example, the pressure sensor of the internal combustion engine and/or the transmission of the measurement signal of the pressure sensor to the control unit is controlled in such a way that a time delay with respect to the modeled signal profile can be detected in the detected signal profile, it can therefore be particularly easily recognized according to this embodiment that the internal combustion engine is controlled with varying output.

According to a further embodiment, a power-changing operation on the internal combustion engine is detected when the signal portion difference exceeds a first threshold value. The signal difference can be continuously evaluated by a control unit of the internal combustion engine according to one embodiment and the evaluation can be compared to the first threshold value accordingly. If the signal-portion difference exceeds a threshold value, a power-changing operation of the internal combustion engine can be deduced accordingly. This comparison can be carried out relatively simply and reliably to indicate whether the internal combustion engine is being operated.

According to one specific embodiment, a detected signal profile function is generated from the first signal profile section by means of a fourier transformation, which characterizes the detected signal profile section. In addition, according to this embodiment, the phase of the detected signal profile function is determined and the determined phase is compared as a signal component of the detected signal profile section with the modeled phase as a corresponding signal component of the corresponding modeled signal profile section, the modeled phase being provided as a component of the modeled signal profile section.

According to a further embodiment, the modeled phase can also be determined from the corresponding modeled signal profile section. The detected signal profile function can be generated from the detected signal profile sections by means of a fourier transformation. Accordingly, the detected signal profile function characterizes the detected signal profile section and accordingly also the pressure change in the intake tract during a cycle. The corresponding signal section of the signal progression function can be identified more easily by means of a fourier transformation, so that the comparison of the corresponding signal section from the signal progression function is simplified. Accordingly, the method for detecting a power-changing actuation of the internal combustion engine is more robust and reliable.

According to a further embodiment, the fourier transform is a discrete fourier transform.

According to one specific embodiment, exactly one phase of the detected signal profile function is compared as a signal component with the corresponding modeled phase of the corresponding modeled signal profile section. In this case, the modeled signal profile or the modeled signal profile section is provided in such a way that a modeled phase can be determined therefrom, which can be compared with the determined phase. One phase is the position of the corresponding point in the signal profile section or in the signal profile function at a specific time. If the comparison deviates from a predetermined value, a corresponding conclusion can be drawn about the operation of the internal combustion engine. The modeled phase may be stored in a memory as a signal component of the modeled signal profile section and may be provided from the memory for comparison, according to one embodiment.

According to a further embodiment, a modeled signal profile function is generated from the modeled signal profile section by means of a fourier transformation, which characterizes the expected periodically repeated pressure changes in the intake tract. The modeled phase is additionally known from the modeled signal trend function and is provided. It is conceivable to store the modeled signal profile sections in a memory and to generate the modeled signal profile functions from the signal profile sections by means of a computing unit by means of a fourier transformation, so that the respective signal portions of the modeled signal profile functions can be compared in a simplified manner with the respective signal portions of the detected signal profile functions. The modeled phase required for comparison with the known phase can be determined from the modeled signal profile function, thus enabling a comparison to be carried out in order to detect whether the internal combustion engine is being operated. This ensures that the signal portions that are comparable to one another are always compared with one another.

According to one specific embodiment, the modeled signal profile is provided as a characteristic field, which takes into account operating parameters of the internal combustion engine. The operating parameter of the internal combustion engine may be, for example, the speed or the load. Depending on the operating parameters of the internal combustion engine, the modeled signal profile is adjusted according to this embodiment in such a way that the respective modeled signal profile section or the respective modeled signal profile function can be compared with the detected signal profile section or the detected signal profile function. The characteristic field may be a mathematical model which provides a modeled signal profile and/or a modeled signal profile section and/or a modeled signal profile function and/or a corresponding signal component as a function of operating parameters of the internal combustion engine and/or as a function of ambient parameters. In a particularly simple manner, it is thus achieved that the power-changing operation of the internal combustion engine can be ascertained even at different operating points of the internal combustion engine.

According to a further embodiment, the phase of the modeled signal profile section is provided as a function of at least one operating parameter of the internal combustion engine. As already described, it is conceivable for the phases of the modeled signal profiles to be provided as signal components of the respective modeled signal profiles for comparison with the known phases of the detected signal profile sections. It is conceivable that the known phase is changed as a function of operating parameters of the internal combustion engine, such as the speed and/or the load. Accordingly, the modeled phase must likewise be changed as a function of the operating parameters of the internal combustion engine, thereby making it possible to carry out a more suitable comparison for detecting a power-changing actuation of the internal combustion engine. Accordingly, a modeled phase can be provided even with changing operating parameters, so that the method can robustly and reliably detect a manipulation of the internal combustion engine even with changing operating parameters.

According to one specific embodiment, in order to compare the signal portions of the detected signal profile sections with the corresponding signal portions of the corresponding modeled signal profile sections, the phase difference between the phase determined as a signal portion of the detected signal profile section and the modeled phase determined as a signal portion of the corresponding modeled signal profile section is determined. The phase difference between the learned phase and the modeled phase is the time difference between a characteristic signal section, such as a zero crossing of the detected signal run section, and a corresponding characteristic signal section, such as a corresponding zero crossing of the corresponding modeled signal run section. The phase difference thus characterizes the time offset between the occurrence of the characteristic signal section of the modeled signal profile section and the occurrence of the corresponding characteristic signal section of the detected signal profile section. If the detected signal profile section deviates in time from the modeled signal profile section, this deviation can be detected by means of the knowledge of the phase difference. In the case of an excessively strong deviation, a manipulation of the internal combustion engine can be inferred.

According to one specific embodiment, the ascertained phase difference is compared with a phase difference threshold value, and a power-changing operation of the internal combustion engine is detected when the ascertained phase difference exceeds the phase difference threshold value. The phase difference threshold may be saved, for example, in memory and continuously compared to the learned phase difference. As soon as it is recognized that the detected phase difference exceeds the phase difference threshold value, it can be concluded that the internal combustion engine is being operated. Accordingly, it is particularly simple to ascertain by means of this comparison whether the internal combustion engine is being operated.

According to one embodiment, the threshold value of the disclosure may also be a boundary band, wherein a power-changing operation of the internal combustion engine is detected when a value to be compared with the boundary band breaks through the boundary band.

According to the invention, the device for detecting a power-changing operation of an internal combustion engine has a control unit which is provided for controlling the aforementioned method. The device may for example be a motor control unit. It is also conceivable for the device to be part of the motor control unit or to be retrofitted as an additional control unit, for example in a vehicle having an internal combustion engine.

Drawings

Embodiments of the present disclosure are illustrated in the accompanying drawings and explained in detail with reference to the following description. Wherein:

figure 1 shows a block diagram of an internal combustion engine in a schematic representation,

fig. 2 shows a diagram for identifying a power-changing operation of an internal combustion engine.

Detailed Description

Fig. 1 shows a schematic representation of an internal combustion engine 100 having a plurality of cylinders 102, wherein the internal combustion engine 100 is provided, for example, for driving a vehicle. The internal combustion engine 100 has an intake passage 110. The intake passage 110 delivers air 140 to the engine during operation. To control the air supply during operation of the internal combustion engine 100, the intake tract 110 has a throttle valve 112.

The internal combustion engine 100 additionally has an exhaust gas tract 120. The exhaust gas duct has an exhaust gas catalyst 122. The exhaust gas duct 120 additionally has an exhaust gas pressure sensor 124 and an exhaust gas sensor 126. An exhaust gas pressure sensor 124 is provided for detecting the pressure of the exhaust gas 150 in the exhaust gas duct. The exhaust gas sensor 126 is provided for detecting a measurement signal which is characteristic for the oxygen content in the exhaust gas 150. The internal combustion engine 100 according to this embodiment has an exhaust gas turbocharger 130. The exhaust gas turbocharger 130 has a compressor 132 and a turbine 134. The compressor 132 and the turbine 134 are mechanically connected by means of a shaft 136. The turbine 134 is arranged in the flow path of the exhaust gas 150 and is driven by means of the exhaust gas 150. The compressor 132 compresses air 140 during operation of the internal combustion engine 100 before delivering the air to the cylinders 102.

The intake duct 110 has pressure sensors 116, 118 according to this embodiment. One of the pressure sensors 116, 118 is an intake pipe pressure sensor 116 and the other of the pressure sensors 116, 118 is a boost pressure sensor 118. An intake pipe pressure sensor 116 is arranged between the throttle valve 112 and an intake valve of the cylinder 102 in the flow path of the air 140. Boost pressure sensor 118 is disposed in the flow path of air 140 upstream of throttle valve 112 and downstream of compressor 132. The intake pipe pressure sensor 116 and the charge pressure sensor 118 detect the pressure of the air 140 present at the respective attachment points of the sensors 116, 118 during operation of the internal combustion engine 100.

The internal combustion engine 100 according to the present exemplary embodiment additionally has a control unit 200, which has a computing unit 210, a program memory 220, a data memory 230 and a fault memory 240. The control unit 200 is also provided to process the measurement signals of the intake manifold pressure sensor 116, the boost pressure sensor 118, the exhaust gas pressure sensor 124 and the exhaust gas sensor 126 and to control the internal combustion engine 100 accordingly.

The control of the internal combustion engine 100 can take place, for example, by means of the control of a throttle valve 112. If, for example, the exhaust gas sensor 126 detects that the oxygen content in the exhaust gas 150 is relatively low during operation of the internal combustion engine 100, it is recognized by the control unit that an excessively rich combustion has taken place in the internal combustion engine 100, and the internal combustion engine 100 is controlled in such a way that the air supply is increased. In this respect, the throttle valve 112 can be correspondingly actuated in such a way that a desired air/fuel ratio for a desired combustion in the cylinder 102 is correspondingly set.

The control unit 200 is provided for controlling the internal combustion engine 100 by means of a computing unit 210, which controls the internal combustion engine 100 by means of a program from a program memory 220, by means of data from a data memory 230 and by means of data from sensors of the internal combustion engine 100 in such a way that the internal combustion engine 100 is operated in a predetermined operating range in which a reliable operation of the internal combustion engine 100 can be ensured. In the event that it is recognized that the internal combustion engine 100 is operating outside its predetermined operating range, a fault input into the fault memory 240 can be made. The internal combustion engine 100 additionally has a fault display 300, which can be actuated by the control unit 200, if the control unit 200 recognizes that the internal combustion engine 100 is operated with varying output.

If the internal combustion engine 100 is operated such that the air quantity in the cylinder 102 is increased, for example, with the goal of increasing the maximum power of the internal combustion engine 100, the fuel quantity is automatically increased such that the desired air/fuel ratio is set. The motor power increases accordingly. Of course, the internal combustion engine 100 is thus operated outside its predefined operating range, which can damage the internal combustion engine 100.

Known actuating systems can modify the detected measurement signals of the pressure sensors 116, 118 by means of an operating system, so that the maximum air quantity in the cylinders can be increased. By means of such a control system, the measurement signals detected by the pressure sensors 116, 118 are reduced, for example, by subtracting a certain value from the detected measurement signals and transmitting the reduced measurement signals to the control unit 200. The control unit 200 will compensate for the assumed too low air pressure in the cylinder 102 and for example operate the throttle valve 112 so that the amount of air fed in is increased. Accordingly, the air pressure in the cylinder 102 increases, thereby adjusting the fuel injection. Accordingly, the internal combustion engine 100 is operated outside its predefined operating range and its output is increased. The internal combustion engine 100 is operated.

The control unit 200 is of course designed to recognize such a manipulation of the internal combustion engine 100.

Fig. 2 shows a diagram for identifying a power-changing operation of the internal combustion engine 100. In this diagram, time is plotted on the X-axis 410 and values, which characterize the pressure in the inlet 110, are plotted on the Y-axis 420. The modeled signal profile 430 and the detected signal profile 440 are shown in graph 400. The modeled signal profile 430 may be divided into modeled signal profile sections 432. The detected signal profile 440 may be divided into detected signal profile sections 442. The modeled signal profile section 432 and the detected signal profile section 442 correspond to one cycle of the respective signal profiles 430, 440. The control unit 200 shown in fig. 1 is designed to recognize from the signal paths 430, 440 whether the internal combustion engine 100 is being operated. For this purpose, periodically repeating detected signal profiles 442 are detected from the signal profiles 440 detected by the pressure sensors 116, 118. The detected signal profile section 442 represents a periodically repeating pressure change in the intake tract 110. In addition, a modeled signal profile 430 is provided, for example, from program memory 220 of control unit 200 and/or from data memory 230, from which a periodically repeating modeled signal profile section 432 is determined. The modeled signal profile section 432 characterizes expected periodically repeating pressure changes in the intake tract 110. The control unit 200 then compares at least one signal portion of the detected signal profile section 442 with a corresponding signal portion of the corresponding modeled signal profile section 432. For this comparison, the corresponding signal traces for the same cycle are compared 432, 442. If, for example, the internal combustion engine 100 is operated such that the pressure measured by the pressure sensors 116, 118 is transmitted to the control unit 200 too low, the detected signal profile 442 deviates in time from the modeled signal profile 432. This deviation in time can be detected and can be compared with one another as a respective signal portion of the respective signal profile section 432, 442. If the deviation deviates too far from a predefined threshold value, for example, it can be recognized that the internal combustion engine 100 is being operated. Accordingly, the control unit 200 may store a fault in the fault memory 240. In addition, the control unit 200 can accordingly operate the fault display device 300 to display the manipulation.

It is conceivable that the detected signal profile section 442 is developed into a detected signal profile function by means of a fourier transformation. Furthermore, it is also conceivable for the modeled signal profile section 432, which is stored, for example, in the data memory 230 of the control unit 200, to be developed into a modeled signal profile function by means of a fourier transformation. The comparison of the respective signal portions of the detected signal profile function with the respective signal portions of the modeled signal profile function can be simplified, since the resulting signal profile function can be processed more simply by means of a fourier transformation. It is also contemplated that the fourier transform is a discrete fourier transform.

According to one specific embodiment, the modeled signal profile 430 and/or the modeled signal profile section 432 and/or the modeled signal profile function are provided as a characteristic field, which takes into account operating parameters of the internal combustion engine 100. This characteristic field can be stored, for example, in the data memory 230 of the control unit 200 and accordingly takes into account operating parameters of the internal combustion engine 100, such as the rotational speed and/or the load.

According to one specific embodiment, the phases of the detected signal profile section 442 or of the detected signal profile function as signal components are compared with the modeled signal profile section 432, with the modeled signal profile section 432 and/or with the phases of the modeled signal profile function as corresponding signal components. In this case, in particular, the difference between the two phases can be compared with one another and it can be recognized that the internal combustion engine 100 is being operated when the phase difference exceeds a certain phase difference threshold value. Loading the pressures detected by the pressure sensors 116, 118 with values for operating the internal combustion engine 100 results in a temporal deviation in the data detection. The deviation is visible as a phase difference in the comparison. The operation of the internal combustion engine 100 can thus be recognized in a simple and robust manner. If it is detected that the internal combustion engine 100 is being operated, a fault input into the fault memory 240 of the control unit 200 can additionally also be carried out.