Method for correcting air quantity differences in air intake line of internal combustion engine

Abstract

A method (100) for correcting a difference in the amount of air in an air intake line of an internal combustion engine (501) comprises: obtaining (120) measurement data (131, 132) indicative of a deviation of the quality of air inhaled by the internal combustion engine (501) from a modeled quality of air with respect to the rotational speed of the internal combustion engine (501); determining (140) a correction relationship, comprising multiplying a preset relationship (111) with respect to the deviation over the rotational speed by a scaling factor (S), in which the correction relationship approximates the measurement data (131, 132); the actual amount of air in the air intake line is corrected (150) based on the correction relationship.

Description

Technical Field

[0001] This invention relates to a method for correcting air volume discrepancies caused by manufacturing tolerances and aging effects in internal combustion engines.

[0002] The technical field is engine technology, specifically the optimization and correction of air volume discrepancies in the air intake circuit (Luft-Ansaugstrecke) of internal combustion engines. The problem to be solved is addressing manufacturing tolerances and aging effects, which can affect the engine's air supply and thus its performance and emissions, causing deviations from theoretical values. Background Technology

[0003] In internal combustion engines, such as Otto engines or diesel engines, the gas-fuel mixture burned in the cylinders is crucial to engine efficiency and emissions. This mixture typically consists of air and fuel (such as gasoline or diesel). The ratio between air and fuel (also known as the air-fuel ratio or combustion air ratio) significantly affects combustion. An ideal mixture (known as the stoichiometric ratio) ensures complete combustion of fuel without excess oxygen or unburned hydrocarbons. To measure the composition of the gas-fuel mixture, sensors such as λ probes are used, for example, to determine the oxygen content in the exhaust gas. Based on these measurements, the air-fuel ratio can be monitored and optimized to ensure the most efficient combustion possible with minimal harmful emissions.

[0004] Manufacturing tolerances in the air intake system of an internal combustion engine refer to deviations in the manufacture of the components responsible for supplying air to the engine. These tolerances are critical because they affect the airflow into the cylinders and, consequently, the quality of the intake air under otherwise identical conditions. Consequently, the engine's efficiency and performance capabilities also vary.

[0005] Excessive deviations can lead to eddies, pressure losses, or uneven air distribution, which can reduce performance and increase fuel consumption and emissions.

[0006] Aging effects may have similar effects, such as altering the airflow when deposits change the geometry in the intake path. Summary of the Invention

[0007] The objective of this invention is to provide an improved method, an improved control unit, and an improved means of transportation.

[0008] This task is solved by the method according to the invention as claimed in claim 1. The task is also solved by the control unit as claimed in claim 18 and by the transport vehicle as claimed in claim 19.

[0009] Further advantageous designs of the invention are derived from the dependent claims and the following description of preferred embodiments of the invention.

[0010] This invention includes the development and application of mathematical models and adaptation methods to correct for flow rate discrepancies caused by manufacturing tolerances and carbon buildup effects. In this case, adjustments based on the combustion air ratio using a lambdaregler can regulate emissions but not the generated torque. In modern Otto engines, with a few exceptions, the theoretical air-fuel ratio is always adjusted to λ = 1. The actual air volume from the fill model is used to determine the fuel quantity. The deviation between the intake air volume and the modeled air volume manifests as a mixture error (Gemischfehler), which is compensated for by the mixture regulator / lambdaregler using the fuel quantity. Therefore, the air-fuel ratio continues to be adjusted.

[0011] Therefore, the model is developed to identify deviations in intake air quality caused by manufacturing tolerances and carbon buildup from the air quality modeled for driving conditions and driver intent, and to distinguish these deviations from others. For this purpose, measurement data from an air quality meter in the intake circuit, for example, can be utilized. Furthermore, the value of the λ regulator can also be used as measurement data, as it indicates the error in the mixture between air and fuel quantities under compensated conditions. Other deviations may arise, for example, due to errors in injection or seal degradation (e.g., during increased blow-by). The goal is to incorporate manufacturing deviations into engine control to comply with regulations regarding the produced torque and emissions. Furthermore, the goal is to incorporate aging effects into engine control to achieve long-term compliance with regulations. Additionally, the goal could be to diagnose aging effects, for which the distinguishability of these effects in the model can be utilized.

[0012] The method according to the invention for correcting differences in air volume in the air intake circuit of an internal combustion engine includes: obtaining measurement data indicating a deviation between the mass of air drawn in by the internal combustion engine and a modeled mass of air with respect to the engine speed; determining a correction relationship, including multiplying a preset relationship of the deviation with respect to the engine speed by a scaling factor, wherein the correction relationship approximates the measurement data; and correcting the actual air volume in the air intake circuit based on the correction relationship.

[0013] An internal combustion engine is an engine that generates mechanical energy by burning fuel. Therefore, chemical energy is converted into mechanical energy. This energy is then used, for example, to drive a vehicle. An internal combustion engine can refer to an engine that mixes and burns air and fuel in a cylinder to move a piston and thus perform mechanical work. Typical examples of internal combustion engines are the Otto engine (gasoline engine) and diesel engines.

[0014] The air intake line is a part of an internal combustion engine through which air flows into the cylinders. This line begins at the air inlet, flows through various components such as the air filter, turbocharger (if present), throttle body, and terminates at the cylinder inlet valve. The air intake line can be configured to provide the correct amount of air for combustion in the engine. Precise control of the air supply may be necessary to ensure an optimal air-fuel ratio, which in turn affects engine efficiency and emissions. Furthermore, the amount of air flowing in can be set in relation to the amount of fuel so that the generated torque corresponds to the driver's intention.

[0015] This method allows for the optimization of air intake circuits and internal combustion engines, ensuring that the correct amount of air reaches the cylinders despite manufacturing tolerances and aging effects. This is achieved by using measurement data to identify deviations between the intake air quality and modeled air quality, and determining a correction relationship. This correction relationship is then used to match the actual amount of air in the intake circuit, keeping engine performance and emissions within desired limits.

[0016] Obtaining measurement data can mean measuring relevant data from the operation of an internal combustion engine and providing this data to the method for use, for example, without the processing unit implementing the method needing to concern itself with the acquired data. Data can also be read from memory. This data can include parameters such as the value of the λ regulator or its deviation from a reference, which is adjusted based on measurements taken by sensors such as λ probes. Furthermore, its dependence on engine speed detected by a speed sensor, or the existing load quantified by applied torque or suction pressure, is considered. The deviation of the λ regulator value from the reference can be detected as a percentage or as a quotient. This value is referred to below as the λ adjustment value. Measurement data can be transmitted (in real time) to the engine control unit (ECU), where they are stored and analyzed to identify deviations in the λ adjustment value at different speeds (and loads).

[0017] Determining the correction relation refers to the process of developing a mathematical relationship (function or mapping) to model and correct for deviations in the λ adjustment value depending on the internal combustion engine speed, for example, by adapting an engine model. Mathematically, a relation is a function or mapping that describes the dependency between two or more variables. In this case, a pre-defined relation, i.e., a pre-defined dependency, is used to approximate the deviation of the λ adjustment value with respect to engine speed. Approximation is performed by matching a scaling factor multiplied by the pre-defined relation. This scaling factor is determined through regression analysis or similar methods, where the deviation of the measured data is minimized to achieve the best possible match.

[0018] The correction relationship can be directly determined by multiplying a preset relationship by a scaling factor. Alternatively, an adaptation factor can be determined based on this scaling factor, and then multiplied by the preset relationship to obtain the correction relationship. This adaptation factor can also be determined based on other factors, such as the number of kilometers traveled or the percentage already traveled, which determines how much of the difference between the current adaptation value and the determined scaling factor actually allows for adaptation. This percentage can also again depend on the rotational speed or kilometers traveled in which the measurement data is taken. Repeated implementation of this method can lead to robustness of the adaptation.

[0019] This correction relationship enables precise matching of the actual air volume in the air intake circuit, thereby optimizing engine performance and emissions (both in the short and long term). Here, the preset relationship ensures that the matching can only successfully match effects corresponding to preset relationships with different scaling. Furthermore, matching caused by other effects or errors can therefore be excluded from this adaptation.

[0020] Actual air volume calibration refers to the process of matching the calculated amount of air that should flow into the cylinders of an internal combustion engine based on a previously determined calibration relationship. This calibration is necessary to ensure that optimal air volume is provided for combustion despite manufacturing tolerances and aging effects. The engine control unit (ECU) uses this calibration relationship to dynamically match the actual air volume with respect to engine speed by accordingly modifying control parameters such as suction pressure, throttle position, valve timing, valve stroke, and boost pressure. Through these matchings, the air-fuel ratio is optimized, resulting in more efficient combustion and ensuring compliance with emission regulations. Therefore, actual air volume calibration helps stabilize engine performance, reduce emissions, and ensure the durability of engine components.

[0021] There is an implementation scheme where the measurement data includes at least three measurement values.

[0022] Measured values ​​can be specific, quantifiable data points that can be measured and detected. Regarding methods for correcting differences in air volume in the air intake circuit of an internal combustion engine, measured values ​​refer to the detection parameters used to determine and correct the air volume. These measured values ​​can include various physical parameters related to the deviation between the analyzed and optimized intake air quality and the modeled air quality, or a λ adjustment value.

[0023] Specifically, the measured values ​​may include the following: the λ adjustment value, engine speed, and engine load condition. Here, the dependent engine speed and dependent load can be associated with the λ adjustment value. This can be achieved, for example, using a delay (which simulates the path of exhaust gas from the cylinder to a sensor that measures or indicates the combustion air ratio (e.g., oxygen concentration in the exhaust gas)) and an additional delay generated by the information flow to the λ regulator and the time until the λ regulator adjusts the λ adjustment value.

[0024] Engine speed indicates how fast the crankshaft of the engine rotates, measured in revolutions per minute (U / min). The amount of air flowing into the cylinders can depend on engine speed or piston speed. The engine's load condition can be quantified by the applied torque, suction pressure, or output power (mean pressure). Load condition affects the amount of air and fuel required for efficient combustion.

[0025] Additionally, other measurements may also be relevant, such as suction line pressure (inhalation pressure) and intake air temperature. Suction line pressure is the pressure in the intake line that forces air into the cylinder. The temperature of the intake air affects the air density and, therefore, the amount of air drawn in.

[0026] By detecting and analyzing these measurements, this method can identify deviations between the intake air quality and the modeled air quality or deviations in the λ adjustment value under different engine operating conditions, and make corresponding corrections to optimize engine performance and emissions.

[0027] There is an implementation scheme where the measurement data is obtained from the λ regulator.

[0028] The λ regulator obtains measurement data from the λ probe, which indicates the air-to-fuel ratio during combustion. If the intake air quality deviates from the modeled air quality, where the injected fuel quantity is calculated based on the modeled air quality, a deviation is derived in the combustion air ratio. This deviation is measured by the λ probe and compensated for by the λ regulator. Therefore, the λ regulator's adjustment value can be used as measurement data to quantify the deviation between the intake air quantity and the modeled air quantity. The calculation of the injected fuel quality can also be incorrect (e.g., calculating the injection mass versus the onset duration). This can also lead to a deviation in the λ adjustment value. However, due to the error pattern (the speed trend), this source of error can be ruled out, thus identifying purely air modeling errors.

[0029] A λ probe, also known as an oxygen sensor, is a sensor that can be installed in the exhaust gas system of an internal combustion engine. Its primary task is to measure the oxygen content in the exhaust gas. This measurement allows for the determination of the air-fuel ratio (also known as the λ value) present in the engine cylinders.

[0030] The air-fuel ratio is the ratio of the mass of air to the mass of fuel introduced into the combustion process. The ideal air-fuel ratio for complete combustion without excess oxygen or unburned hydrocarbons is called the stoichiometric ratio. For gasoline engines, this ratio can be, for example, approximately 14.7:1, meaning 14.7 parts air to 1 part fuel.

[0031] The λ probe continuously provides data on the oxygen content in the exhaust gas to the engine control unit (ECU). This information is used to monitor and adjust the air-fuel ratio. If the ratio is too rich (too much fuel) or too lean (too much air), the ECU can adjust the fuel injection amount or air supply to ensure optimal combustion. This helps maximize engine efficiency, minimize emissions, and extend engine lifespan.

[0032] There are two main types of λ probes. Jump probes (narrow-band λ probes) can provide signals that fluctuate wildly around the stoichiometric point. They are simple and cost-effective, but only suitable for adjusting the air-fuel ratio within a narrow range around the stoichiometric point. Wide-band λ probes can accurately measure the air-fuel ratio over a wide range. They provide a more accurate signal and allow for more precise adjustment of the air-fuel ratio, which is particularly important in modern engines with variable valve timing and direct injection.

[0033] Lambda probes are crucial for emissions control and engine performance optimization. They enable modern engine control systems to aim at reducing environmental impact while simultaneously maximizing engine efficiency and performance.

[0034] One implementation scheme exists in which the measurement data is obtained from an air quality measuring instrument.

[0035] Therefore, it is possible to have quantitative measurement data of the amount of air inhaled, and thus it is possible to calculate the deviation from the modeled air volume.

[0036] The following implementation scheme exists, where the preset relationship is a parabolic function.

[0037] A parabola function is a special type of quadratic function, which is mathematically described by an equation of the following form: , Where a, b, and c are constants, and x is the independent variable. The shape of the parabola is determined by the coefficient a; if a > 0, the parabola opens upwards, and if a < 0, the parabola opens downwards.

[0038] A parabolic function can be used to model deviations in the λ adjustment value that depend on the rotational speed. For this purpose, a parabolic function with preset constants a and b (and c) can be used, multiplied by a scaling factor S: .

[0039] Here, x is, for example, the engine speed, and y(x) is the λ adjustment value, which the parabola approximates using a scaling factor. The adaptation factor, S, is determined from the scaling factor S and incorporated into the engine model of the internal combustion engine. This adaptation factor, in addition to the scaling factor, can also be based on other influences, such as those considering the robustness of the adaptation.

[0040] Therefore, a correction relationship is derived from a preset relationship (in this case, a parabolic function multiplied by an adaptation factor) that matches the measured data. This correction relationship can be used for speed-dependent matching or adaptation in an engine model (e.g., a filler model). Thus, by correcting the parameters of the intake manifold, the actual amount of air drawn in is matched to the amount of air modeled in the engine model. This matching is speed-dependent.

[0041] Through this adaptation with general preset relationships and, in particular, preset parabolic functions, these effects do not need to be compensated for by the regulator. When the speed changes rapidly, the regulator will have to match or adjust the parameters each time. Therefore, even during acceleration or gear shifting, the regulations for emissions and torque can be followed.

[0042] One implementation scheme exists in which determining the correction relationship involves adding it to the offset to approximate the measurement data.

[0043] Therefore, a constant parameter (offset d) can be added, for example, to the preset relation, before or after multiplying by the scaling factor. In the special case of the parabola as the preset relation, this results in the following formula: .

[0044] Therefore, the matching of the preset relationship to the measurement data can be improved. This can be particularly useful, for example, when the measurement data has a systematic offset caused by another error source. This offset can also be used only when matching the measurement data. However, correction can be based on a correction relationship, which itself is based on the matched preset relationship plus a scaling factor (fitting factor), rather than this offset. Thus, matching is performed against the preset relationship plus an offset, but correction or fitting is performed without this offset to reduce the impact of other errors on the fitting.

[0045] By adding this offset, the correction relationship becomes more flexible and can be matched more precisely to actual measurement data. This allows for more accurate correction of the actual amount of air in the air intake line and helps optimize the performance and emissions of internal combustion engines.

[0046] There is an implementation scheme in which measurement data is collected within a measurement range that can be defined by load and speed limits.

[0047] The measurement range refers to the range of specific operating conditions under which measurement data is collected. In internal combustion engines, the measurement range for the λ adjustment value can be defined by various parameters such as load and speed. This measurement range is crucial to ensuring that the collected data represents the actual operating conditions of the internal combustion engine. By determining an appropriate measurement range, measurement data can be made consistent and comparable, thereby improving the accuracy and reliability of the calibration relationship. This measurement range can be selected to cover typical driving conditions under which the internal combustion engine operates, achieving a realistic and practical fit. Furthermore, load and speed ranges where other errors are visible can be excluded.

[0048] Load and speed limits define the specific operating conditions in which measurement data are collected. Load limits (upper and lower limits) define the range of applied torque or suction pressure within which measurement data is used in this method. Speed ​​limits (upper and lower limits) define the range of engine speeds within which measurement data is used in this method. These limits allow it to be determined that the internal combustion engine is operating in a stable state without large fluctuations in speed or load, and that the measurement data are comparable.

[0049] A load-speed graph is a graphical representation that shows the range of measurements related to engine load and speed. In this graph, load is plotted on the y-axis and speed on the x-axis. This range of measurements can be defined either through windows or within the graph itself, where measurement data for the λ adjustment value are collected. These windows represent specific load and speed combinations relevant to the calibration relationship adaptation.

[0050] The following implementation scheme exists, in which multiple measurement ranges are set, which are separated from each other by a lower speed limit, an upper speed limit, a lower load limit, and an upper load limit.

[0051] Multiple measurement ranges can be set, each defined by specific speed and load limits. These enable detailed and precise detection of the λ adjustment value for various operating conditions of an internal combustion engine. These various operating conditions can be, for example, comparable load ranges, but also different speed ranges, thus allowing detection of the λ adjustment value with respect to speed.

[0052] These measurement ranges can be defined as separate measurement windows in the load-speed graph, where each measurement window covers a specific load and speed range.

[0053] This enables differential analysis and adaptation of the calibration relationship, which takes into account both low and high speeds as well as different load conditions. Separating the measurement range by specific lower and upper limits for speed and load ensures data collection under stable operating conditions, thereby improving the accuracy and reliability of the calibration relationship.

[0054] Especially when a parabola is used as the preset relationship, the deviation becomes higher with increasing rotational speed. Therefore, the scaling factor can be determined more accurately using a measurement range at higher rotational speeds. If a measurement range with higher rotational speeds is used in the matching, a higher percentage value (the difference between the applied value and the value determined by this method) can be allowed for correction between the scaling factor and the fit factor, thereby achieving faster fit.

[0055] There is an implementation scheme in which the actual air volume is corrected toward the calculated air volume based on the correction relationship is performed step by step, and the correction relationship already used is changed only by a portion of the difference between the current scaling factor and the scaling factor determined by the correction relationship.

[0056] Stepwise calibration can be a gradual matching process where the actual air volume in the air intake circuit is not matched abruptly, but rather in small, controlled steps. This method achieves a gradual approximation of the optimal actual air volume, thereby avoiding sudden changes and potential instabilities during engine operation. Through stepwise calibration, the engine control unit (ECU) can continuously monitor performance and emission parameters and ensure that the match is consistent with the engine's operating conditions. This gradual approach helps improve the robustness and reliability of the calibration by achieving a smooth and gradual match.

[0057] The scaling factor already used or currently used can be a value in the engine control unit (ECU) used to correct the actual air volume at the point in time when the measurement data is taken. This scaling factor can be based on previous measurements and matching and represents the current state of adaptation. The current scaling factor is continuously monitored and matched as needed to ensure that the actual air volume corresponds to the engine's actual operating conditions. By taking the current scaling factor into account, this method ensures consistent and coordinated corrections, which contributes to stable and efficient engine performance.

[0058] This difference can be the discrepancy between the current scaling factor and a new scaling factor determined through a correction relationship. This difference indicates how far the current scaling factor deviates from the optimal value required for accurate correction of the actual air volume. By stepwise matching, only a portion of this difference is corrected in each step, ensuring a smooth and controlled match. Considering this difference allows for matching in small, well-controlled steps, thereby avoiding sudden changes and potential instability. This method helps improve the accuracy and reliability of the correction and ensures continuous optimization of the actual air volume. Therefore, the method can be repeated at (predetermined) time intervals, where each execution results in a fit, and the final scaling factor, or fit value, becomes the current scaling factor upon re-execution.

[0059] An implementation scheme exists in which a fast correction range is set, which can be applied within a preset usage duration, and within this range, a larger portion of the difference is used to correct the actual air volume compared to the slow correction range outside the preset usage duration.

[0060] The rapid calibration range can be an adaptation phase that occurs immediately after the internal combustion engine is put into service, typically within the initial few days of operation or within a limited number of mileage trips. Within this range, a significant portion of the difference between the current and new scaling factors can be adapted, using a scaling factor determined through a calibration relationship to match the actual air volume. This allows for the rapid and effective correction of air volume differences caused by manufacturing tolerances. The rapid calibration range can be designed to quickly minimize initial deviations, thereby enabling the internal combustion engine to rapidly transition to its optimal operating state. Here, deviations caused by manufacturing variations can be corrected.

[0061] Slow calibration ranges take effect after fast calibration ranges and refer to a continuous adaptation phase that occurs throughout the entire lifespan of an internal combustion engine. Within this range, only a small fraction of the difference between the current and new scaling factors is used to match the actual air volume. This gradual matching allows for a smooth and continuous correction of air volume differences that may arise from aging effects such as carbon deposits / sludge. Slow calibration ranges help ensure the long-term stability and efficiency of internal combustion engines by avoiding sudden changes and potential instabilities during engine operation through gradual matching.

[0062] A preset usage duration can be a specific time period or a certain number of operating hours or kilometers, within which the actual air volume in the internal combustion engine's air intake circuit is adapted particularly intensively and rapidly (in large steps). This phase can be designed to quickly correct initial deviations caused by manufacturing tolerances in order to rapidly bring the internal combustion engine to its optimal operating condition. The preset usage duration can, for example, include an initial 4000 kilometers or an initial 50 operating hours. Within this time span, the actual air volume is matched using a large portion of the difference between the current scaling factor and a new scaling factor determined through a correction relationship. After the preset usage duration expires, the method can transition to a slower correction range, where matching can be performed incrementally and in smaller steps to ensure long-term stability and efficiency. If the internal combustion engine undergoes maintenance in the workshop and aging effects such as carbon buildup are removed, the preset usage duration can be reactivated to achieve rapid adaptation to the new state of the air intake circuit.

[0063] The following implementation scheme exists, wherein the amount of air in the air intake circuit is corrected by correcting the filling model of the internal combustion engine based on the correction relationship.

[0064] An internal combustion engine's fill model can be a mathematical model that describes the amount of air flowing into the engine's cylinders. It can take into account various parameters such as engine speed, intake pressure, intake air temperature, and the geometry of the air intake path. Therefore, the fill model can influence the air-fuel ratio, as it forms the basis for determining the required air volume to ensure optimal combustion. By continuously matching the fill model to the engine's actual operating conditions, consistent and reliable engine performance can be ensured.

[0065] Correcting the air volume in the air intake circuit of an internal combustion engine can be a process of matching the calculated or measured amount of air flowing into the cylinders to compensate for deviations caused by manufacturing tolerances or aging effects. Air volume correction can be achieved by matching the operation (adjustment) of various engine components, such as the throttle body, valve timing, or boost pressure.

[0066] An engine's fill model can be corrected using a calibration relation based on measurement data and a predetermined mathematical function (such as a parabola). This calibration relation allows for matching the actual air volume to the engine speed to compensate for deviations caused by manufacturing tolerances or aging effects, and optimizes engine performance and emissions.

[0067] There is an implementation scheme in which the calibration of the filling model of the internal combustion engine is matched to the theoretical pressure in the air intake circuit.

[0068] The stoichiometric pressure in the air intake circuit of an internal combustion engine can be considered the desired pressure (suction pipe pressure) that should be present in the intake manifold to ensure optimal air supply. This pressure can be affected by various factors, such as throttle position, turbocharger boost pressure (if present), and valve timing. Precise control of the stoichiometric pressure may be necessary to optimize the air-fuel ratio and thus control engine efficiency and emissions.

[0069] By calibrating the fill model based on a calibration relationship, the theoretical pressure in the air intake circuit can be matched to compensate for deviations caused by manufacturing tolerances or aging effects. This means that the engine control unit (ECU) can dynamically match the theoretical pressure by modifying control parameters such as throttle position, boost pressure, and valve timing. These matches ensure that the correct amount of air reaches the cylinders, resulting in more efficient combustion and reduced emissions. By continuously matching the theoretical pressure, engine performance can be stabilized and the durability of engine components can be ensured.

[0070] An implementation scheme exists in which the method further includes: diagnosing that the actual air volume correction exceeds a predetermined tolerance limit, and indicating that the predetermined tolerance limit has been exceeded.

[0071] Diagnosing actual air volume calibration exceeding predetermined tolerance limits can be a process where the system continuously monitors whether the actual air volume matching remains within acceptable limits. This monitoring can be performed by the engine control unit (ECU), which analyzes the calibration relationship and the engine's current operating conditions. If the actual air volume calibration exceeds predetermined tolerance limits, this may indicate a serious deviation that could be caused by aging effects (or manufacturing tolerances). The diagnostic system can identify these deviations and generate corresponding diagnostic information to draw attention to the problem.

[0072] Tolerance limits can be predetermined thresholds that define the maximum permissible correction for actual air quality. These limits can be determined based on technical specifications, legal requirements, or empirical values, ensuring that corrections remain within acceptable limits. And, for example, attention should be paid to component protection. Tolerance limits can be defined for both short-term and long-term deviations to account for sudden and gradual changes.

[0073] Furthermore, a pattern can be identified in time corrections, for example, the corrections always adapt in the same direction and do not oscillate around a constant value.

[0074] Indicating that a predetermined tolerance limit has been exceeded can serve as a notification to the driver or maintenance personnel regarding a problem. This indication can be given through various methods, such as warning lights on the dashboard, information on the vehicle's display screen, or notifications in the vehicle's diagnostic software. The indication provides specific information about the type and extent of the deviation, allowing appropriate actions to be taken, such as visiting the workshop and performing walnut shell blasting to remove carbon deposits. By promptly indicating that tolerance limits have been exceeded, potential problems can be identified and resolved early, ensuring engine performance and reliability.

[0075] The following implementation scheme exists, wherein the method further includes: a rationality check, checking whether the measured data corresponds to the product of the preset relationship and the scaling factor, wherein if the measured data corresponds to the product of the preset relationship and the scaling factor, then the air volume is corrected.

[0076] A rationality check ensures that the measured data actually correspond to the expected physical characteristics and patterns described by a pre-defined relation. This pre-defined relation, such as a parabolic function, represents a theoretical model of how the deviation of the λ adjustment value depends on the rotational speed. During the rationality check, the measured data can be compared to a correction relation determined by multiplying the pre-defined relation by a scaling factor. If the measured data corresponds to this correction relation, then an air volume correction is performed. This means that the measured deviation is actually caused by the effect modeled in the pre-defined relation, and therefore provides a valid basis for fitting. If the rationality check should conclude that the measured data does not correspond to the correction relation, then an air volume correction is not performed to avoid error matching. Therefore, other error profiles that also act on the λ adjustment value can be excluded from being corrected by error fitting. This step ensures that only relevant and physically reasonable deviations are corrected, thereby improving the accuracy and reliability of the method.

[0077] The following implementation scheme exists, wherein the rationality test includes checking the regression goodness of the product of the preset relationship and the scaling factor and the measurement data, and when the regression goodness exceeds the predetermined value, the fit of the measurement data is reasonable.

[0078] The goodness of regression is usually determined by the coefficient of determination (R²). 2 The goodness-of-regression (FOR) is a statistical measure that quantifies the quality of a model's fit to observed data. FOR describes how well a pre-defined relationship (e.g., a parabolic function) matches the measured data after being multiplied by a scaling factor.

[0079] The correspondence between measured data and the product of the predefined relationship and the scaling factor (model) can be determined using regression goodness of reference. This can be achieved through a high R-squared value. 2 The value indicates this. R 2 A value of 1 indicates a perfect match, while a value of 0 indicates that the model has no explanatory power regarding data variability. Regression goodness of fit R0 2 Defined as: .

[0080] Here, These are observed values. It is the value predicted by the model. It is the average of the observed values. n R represents the number of observations. 2 The value indicates how much of the variance of the dependent variable can be explained by the model. Alternative methods for determining whether a model can explain the measurements are: mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), mean absolute percentage error (MAPE), adjusted R-squared (which takes into account the number of predictors in the model), Akaike Information Criterion (AIC), and Bayesian Information Criterion (BIC).

[0081] To correct for differences in air volume, a plausibility test can be performed to check whether the measured data corresponds to a pre-defined relationship (e.g., a parabolic function) multiplied by a scaling factor. If the goodness of regression R... 2 If the predetermined threshold is exceeded, it is assumed that the measured data corresponds to a preset relationship. This means that the deviation of the λ adjustment value is actually caused by the effect, which is modeled in the preset relationship and thus constitutes a valid basis for adaptation.

[0082] There is an implementation scheme in which the preset relation is a function, a family of functions is generated by multiplying multiple different scaling factors with the preset relation, and the rationality check also includes determining whether the measured data corresponds to the functions in the family of functions.

[0083] This predefined relation can be used to model the deviation of the λ adjustment value from the rotational speed. This predefined relation is a function that generates a family of functions by multiplying it by different scaling factors. A family of functions is a series of functions that can adopt different shapes by changing one or more parameters (in this case, the scaling factor). A plausibility test involves determining whether the measured data corresponds to a function in this family of functions. This means that the measured data must be consistent with one of the functions modified by the scaling factor (e.g., by using regression goodness of regression R0). 2 This ensures that the biases caused only by effects actually modeled in the predefined relationships are corrected, thereby improving the accuracy and reliability of the method. Therefore, matching can be simplified, and the scaling factor that gives the function the highest regression goodness in the family of functions can be easily determined, for example, when the regression goodness exceeds a threshold.

[0084] An implementation scheme exists, wherein the method further includes: checking whether the prerequisites for collecting measurement data are met; wherein, if the prerequisites for collecting measurement data are met, then air volume correction is performed.

[0085] The prerequisites for collecting measurement data can be the specific operating conditions of the internal combustion engine, which ensure that the collected data is representative and consistent. These prerequisites may include the engine operating under stable conditions, without sudden load or speed changes, and without additional influences such as fuel tank ventilation or other temporary disturbances. Checking these prerequisites ensures that the measurement data is free from interference factors and thus provides an accurate and reliable basis for determining calibration relationships.

[0086] The following implementation scheme exists, wherein the prerequisites include at least one of the following: fluctuations in the performance of the internal combustion engine, a fuel tank ventilation device within a preset range, a crankcase ventilation device within a preset range, or actual air volume correction exceeding a predetermined limit.

[0087] Prerequisites for collecting measurement data may include a specific operating state of the internal combustion engine, ensuring that the collected data is representative and consistent. Such a prerequisite could be, for example, that the internal combustion engine operates under stable conditions without sudden fluctuations in performance or speed. This means that the engine control unit (ECU) checks whether the engine's performance remains constant within a certain range and whether there are any sudden changes that could distort the measurement data. By ensuring stable operating conditions, the measurement data can provide an accurate and reliable basis for determining calibration relationships.

[0088] Another prerequisite is that, during data acquisition, either the tank ventilator or the crankcase ventilator operates within a preset range. This preset range can be defined as the normal operating range for each. Increased tank ventilator activity may cause temporary fluctuations in the air-fuel ratio by introducing additional steam into the intake line. Similarly, the crankcase ventilator may introduce oil droplets and other particles into the intake line, which could distort the measurement data. By checking and ensuring that either the tank ventilator or the crankcase ventilator operates within its respective preset range during data acquisition, the accuracy and reliability of the measurement data are improved. Furthermore, a prerequisite is that the correction factor used to match the actual air volume is within predetermined limits. This ensures that the adaptation is not based on extreme deviations that could be attributed to other sources of error. By adhering to these prerequisites, the method ensures that air volume correction is performed accurately and effectively.

[0089] The control unit according to the invention is designed to implement a method according to one of the above embodiments.

[0090] The control unit may be an engine controller (ECU) specifically designed to implement a method for correcting air volume discrepancies in the air intake circuit of an internal combustion engine, according to one of the above embodiments. The control unit may receive data from multiple sensors that continuously monitor data regarding engine operating conditions, including λ adjustment values, engine speed, load status, and other relevant parameters. The control unit may be equipped with a microprocessor capable of processing complex mathematical models and algorithms in real-time (deterministically). By implementing the described correction relationship based on a preset mathematical function, the control unit can precisely match the actual air volume (in the fill model) to compensate for deviations caused by manufacturing tolerances and aging effects. Furthermore, the control unit may have diagnostic capabilities that can identify exceedances of tolerance limits and transmit appropriate warnings to the driver or maintenance personnel.

[0091] The transportation vehicle according to the present invention includes a control unit and an internal combustion engine according to the above embodiment.

[0092] The vehicle may include a control unit designed to implement a method for correcting differences in air volume in the air intake circuit of an internal combustion engine, according to the above-described embodiment. This control unit is integrated into the vehicle and operates in real time to continuously monitor and match the engine's operating parameters.

[0093] Real-time here can mean that the control unit deterministically calculates the model in different calculation grids (1 ms, 2 ms, 5 ms, 10 ms, etc., or speed synchronization). Therefore, for example, there are new values ​​for each work cycle.

[0094] The transportation vehicle may include an internal combustion engine. This engine may be an Otto engine or a diesel engine and is controlled by a control unit, for example, based on a filler model or a torque model. The engine may be equipped with various sensors that detect important operating parameters, such as engine speed, load condition, and air-fuel ratio, and the resulting λ adjustment value, and transmit these to the control unit.

[0095] Transportation vehicles can be, for example, passenger cars or commercial vehicles. Transportation vehicles may include: trucks (Lkw), semi-trailer tractors, light trucks, dump trucks, garbage trucks, fire trucks, ambulances (Ambulanz), trailers, engineering vehicles, buses, motorboats, yachts, fishing boats, ferries, cargo ships, tankers, tugboats, patrol boats, propeller aircraft, helicopters, agricultural aircraft, military aircraft, tractors, and combine harvesters. Attached Figure Description

[0096] Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings.

[0097] Figure 1 The functional structure of a method for correcting differences in air volume in the air intake circuit of an internal combustion engine according to one embodiment is shown; Figure 2 The comprehensive characteristic curves of an internal combustion engine with a measurement range according to one embodiment are shown; Figure 3 A family of standard parabolas according to one embodiment is shown; Figure 4a The regression of measurement data with a preset relationship and scaling factor according to one embodiment is shown; Figure 4b The regression of measurement data with a preset relationship and scaling factor according to one embodiment is shown; Figure 5 A preset relationship with offset is shown according to one embodiment; Figure 6 A stepwise correction with fast and slow correction ranges is shown according to one embodiment; Figure 7 A stepwise correction with fast and slow correction ranges is shown according to one embodiment; Figure 8a The actual torque related to the rotational speed is shown according to one embodiment; Figure 8b The actual fill amount (Ist-Füllung) calculated according to a rotational speed-dependent method is shown in one embodiment; Figure 8c The theoretical suction tube pressure related to rotational speed is shown according to one embodiment; Figure 8d The speed-related λ adjustment value according to one embodiment is shown; Figure 9 The speed-dependent performance of an internal combustion engine with varying filler weights is shown. Figure 10a The flow coefficient related to valve stroke for the inlet valve is shown; Figure 10b The flow coefficient related to valve stroke for the outlet valve is shown; Figure 11a The valves of an internal combustion engine are shown; Figure 11b The pressure ratio through the valve is shown as a function of flow rate. Figure 11c The valve stroke and mass flow are shown as dependent on the crankshaft angle of the internal combustion engine; Figure 12 An internal combustion engine is shown; Figure 13a The λ adjustment values ​​for load and speed are shown; Figure 13b The amount of fuel injected with respect to the injection time is shown; Figure 14a The λ adjustment values ​​for load and speed are shown; Figure 14b The amount of fuel injected with respect to the injection time is shown; Figure 15a The λ adjustment values ​​for load and speed are shown; Figure 15b The λ adjustment value for the rotational speed is shown; Figure 16a The λ adjustment values ​​for load and speed are shown; Figure 16b The actual air mass flow is shown in relation to the calculated air mass flow; Figure 17a The λ adjustment values ​​for load and speed are shown; Figure 17b The air mass with respect to the phase position of the inlet camshaft is shown; Figure 18a The λ adjustment values ​​for load and speed are shown; Figure 18b The air quality is shown in relation to exhaust pressure; and Figure 19 A means of transport according to one embodiment is shown. Detailed Implementation

[0098] Figure 1 The functional structure of a method for correcting differences in air volume in the air intake circuit of an internal combustion engine, according to one embodiment, is shown.

[0099] Correcting air volume discrepancies in the air intake circuit of an internal combustion engine aims to correct for air volume deviations caused by manufacturing tolerances and aging effects. This method is based on mathematical modeling and adaptation, which ensures optimal air volume is provided for combustion to optimize engine performance and emissions.

[0100] The method 100 includes a family of standard parabolas 110, residual determination 120, rationality test 130, determination of the degree of air volume difference 140, and correction of the filling model 150.

[0101] This family of standard parabolic curves 110 forms the mathematical foundation function for correcting for air volume discrepancies. This foundation function simulates the deviation of the λ adjustment value from its reference and its dependence on engine speed. This foundation function is typically a parabolic function, described by equations of the form already discussed above: , Where a, b, and c are constants, and x is the independent variable. The shape of the parabola is determined by the coefficient a; if a > 0, the parabola opens upwards, and if a < 0, the parabola opens downwards.

[0102] To form this family, the foundation function is multiplied by different scaling factors S to test the model's reasonableness against deviations from actual measurement data, and the model is filled by matching the foundation function (pre-defined relationship) and scaling factors. The scaling foundation function is described by the following equation: .

[0103] The residual is determined by measuring or acquiring measurement data, for example, within a specific measurement range defined by load and speed limits. These measurement ranges are called adaptation windows and represent a specific combination of load and speed associated with the adaptation of the correction relationship. Here, the load can always be within the same limit or the same range, but the speed can increase from one measurement range to the next. This is because the air quality difference to be adapted (corrected) increases with speed. The residual is the deviation between the measurement data and a reference, for example, a previously determined adaptation that is current at the time the method is implemented, consisting of a base function and a scaling or adaptation factor.

[0104] Reasonableness check 130 examines whether the measurement data corresponds to the scaling basis function. This is done through regression goodness of reference R. 2 The goodness-of-regression (BOR) is used to check how well the baseline function matches the measured data. If the BOR exceeds a predetermined threshold, air volume correction is performed. Additionally, an offset, which is not considered for later fitting of the fill model, can be taken into account when fitting and determining the BOR. Offset error sources, i.e., those that act on the λ adjustment value but are independent of the engine speed or whose speed dependence is outside the measurement range, therefore have no effect on the final correction for air volume discrepancies.

[0105] The degree of air volume variation was determined by establishing a scaling factor that best approximates the measured data using a fundamental function (preset relationship). For this purpose, the goodness of regression R can be utilized or redefined. 2 The results are then determined. The extent to which the air volume difference 140 should be corrected is then determined, thereby enabling robust continuous correction. Therefore, in the desired correction, the correction relationship between the base function and the fit value is determined. This fit value can correspond to a determined scaling factor, but greater robustness can be achieved if the fit value corresponds to a percentage share of the scaling factor.

[0106] The calibration of the fill model 150 is based on the determined calibration relation. The fill model of the internal combustion engine is matched using this calibration relation. This fill model describes the amount of air flowing into the engine cylinders and thus affects the air-fuel ratio. By calibrating this fill model, for example, the actual amount of air in the air intake line is matched to compensate for deviations caused by manufacturing tolerances or aging effects.

[0107] Furthermore, stepwise adaptation or correction can also be achieved by measuring the residuals relative to a baseline, where the final adaptation becomes the baseline for re-adaptation. Therefore, the adaptation of the actual air volume is carried out stepwise, i.e., in small, controlled steps (because the adaptation factor then corresponds to a percentage share of the scaling factor). The existing correction relationship only changes a portion of the difference between it and the new correction relationship with the determined scaling factor.

[0108] In addition, two calibration ranges can be provided: a fast calibration range, which is used within a preset usage duration (running hours, mileage) and allows for larger matching steps within it, and a slow calibration range, which is used outside the usage duration and performs only smaller matching steps within it. The fast calibration range can quickly correct manufacturing tolerances, while the slow calibration range can continuously match aging effects such as carbon buildup.

[0109] In addition, diagnostic functions can be set up. If the actual air volume correction exceeds the predetermined tolerance limit, a diagnostic will be performed, and a corresponding warning will be sent to the driver or maintenance personnel. This allows for early identification and resolution of potential problems to ensure engine performance and reliability.

[0110] Figure 2 The comprehensive characteristic curves of an internal combustion engine with a measurement range according to one embodiment are shown.

[0111] The composite characteristic curve shows the residual determination 120. The λ adjustment values ​​are plotted with respect to load on the y-axis and rotational speed on the x-axis. λ adjustment values ​​below the load limit 121 are indicated by lines 122a to f, each representing the same λ adjustment value. Ideally, the λ adjustment value should be 1 (if it is calculated as a quotient to its reference). Here, line 122a is shown, for example, as λ adjustment value 1, line 122b as 0.98, line 122c as 0.95, line 122d as 0.94, line 122e as 0.88, and line 122f as 0.8.

[0112] The measurement ranges F1 to F5 each have the same lower load limit 124 and upper load limit 123. In addition, the measurement ranges F1 to F5 have different upper speed limits 126a to 126e and lower speed limits 125a to 125e.

[0113] The λ adjustment value deviates further from its ideal value of 1 as the engine speed increases, for example. This error graph corresponds to the difference in air volume to be corrected. Therefore, the measurement range F1 to F5 can measure the difference as the engine speed increases. This air volume difference can be modeled using a preset relationship, such as a parabolic function, and then corrected in the same way.

[0114] For this method to be implemented, the internal combustion engine does not necessarily need to operate across all speed ranges where the measurement ranges are defined. However, to implement the method with sufficient accuracy, measurements from the first three measurement ranges F1 to F3 should be available. Measurement ranges F1 to F3 can be below 4000 rpm, which corresponds to fuel-efficient driving behavior.

[0115] Figure 3 A family of standard parabolas according to one embodiment is shown.

[0116] A graph is shown where the relative fill volume difference with respect to a baseline is plotted on the y-axis, and the rotational speed is plotted on the x-axis. Therefore, the y-axis is based on the deviation between the intake air volume and the modeled air volume, i.e., the deviation between the λ adjustment value and its baseline. This deviation can be converted into air volume using known methods. This correlation generally applies to these figures.

[0117] The family of standard parabolas 110 includes, for example, parabolas 111a to 111g. The parabolas 111a to 111g shown have scaling factors from bottom to top, for example, from 1 to -0.4, in steps of 0.2. Therefore, this standard parabola (fundamental function or preset relation) opens downwards and has a dependence on rotational speed, for example, as well as on air volume differences. This air volume difference is, for example, expressed through a line of λ adjustment values ​​associated with this air volume difference. Figure 2 This is indicated by 122a to f). Therefore, the constant a is negative, and the constant b can be positive, for example. Constants a and b are predetermined values. They are determined, for example, by matching the parabola to a large amount of data or simulations with errors in air volume.

[0118] By multiplying by a scaling factor, the standard parabola (fundamental function or preset relation) can be scaled to depend on aging effects such as the degree of carbon buildup. The scaling factor can be used for adaptation as described above, but an adaptation factor can also be determined based on the scaling factor, thereby enabling stepwise correction or approximation to the ideal state. Stepwise approximation improves the robustness of the method. If an adaptation factor is determined, it is multiplied by the standard parabola (fundamental function or preset relation) to determine the correction relation, which is then applied.

[0119] Figure 4a The regression of measurement data with a preset relationship and scaling factor according to one embodiment is shown.

[0120] The diagram shows the relative fill difference with respect to a reference on the y-axis and the rotational speed on the x-axis. Therefore, the y-axis is based on the deviation of the λ adjustment value from its reference.

[0121] This regression can be used not only for rationality testing130 but also for determining correction relationships140.

[0122] The parabola 111f is approximated to the measurement point 131 by changing the scaling factor until the error function that quantifies the distances of all measurements 131 to the parabola 111f reaches its minimum.

[0123] The measured value 131 was distributed across the speed range. Notably, fewer measurements were observed at higher speeds, suggesting a fuel-efficient driving behavior.

[0124] Figure 4b The regression of measurement data with a preset relationship and scaling factor according to one embodiment is shown.

[0125] The diagram shows the relative fill difference with respect to the baseline plotted on the y-axis and the rotational speed plotted on the x-axis. Therefore, the y-axis is based on the deviation of the λ adjustment value from the baseline.

[0126] and Figure 4a Unlike in China, in Figure 4b In the measurement, value 131 is detected within the measurement range F1 to F5, as these measurement ranges are within... Figure 2 As shown in the diagram. Furthermore, an average value 132 was determined for the measurements 131 for each measurement range F1 to F5. Therefore, this average value can also be used for regression of the parabola 111f with a scaling factor.

[0127] In order to implement this method, not all measurement ranges F1 to F5 need to be considered or have a measurement value 131. Furthermore, regression can also be performed directly on the measurement data 131 from the measurement ranges. Moreover, forming an average is not always meaningful, for example, when only one value (F5) is measured within the measurement range.

[0128] Figure 5 A preset relationship with offset is shown according to one embodiment.

[0129] The chart shows the air volume difference with respect to the difference on the y-axis and the engine speed on the x-axis. Therefore, the y-axis is based on the deviation of the λ adjustment value from its reference.

[0130] Parabola 111f can be shifted by means of the offsets shown by arrows 114 and 115 to achieve an improved match for the measurement data, which have further deviations in the λ-adjustment value due to other error sources. Thus, the shifted parabolas 111f1 and 111f2 are obtained.

[0131] Figure 6 A stepwise correction with fast and slow correction ranges is shown according to one embodiment.

[0132] The chart shown plots the traffic adaptation factor on the y-axis and the travel distance (Fahrstrecke) on the x-axis. This traffic adaptation factor is an adaptation factor based on the scaling factor.

[0133] Therefore, the correction of the fill model 150 can be a stepwise correction. The applied fit factor 153 changes in larger steps before reaching the preset usage duration 154 than afterward. Thus, there is a faster correction range before the preset usage duration 154 and a slower correction range after the preset usage duration 154.

[0134] Since the x-axis represents the distance traveled, such as the distance traveled since the delivery of the vehicle or internal combustion engine, the planned usage duration is the distance traveled, for example, in kilometers. Therefore, the method is implemented, for example, with a fast correction range for the initial 4000 kilometers, and then with a slow correction range thereafter.

[0135] Limits 151 and 152 define a range in which there exists an optimal fit factor compared to no fit at all. This optimal fit factor may be given by manufacturing tolerances, but may also be unknown.

[0136] The stepwise correction changes the applied fit factor 153 to the range between limits 151 and 152 in larger steps within the fast correction range.

[0137] If the preset usage duration 154 is exceeded, the applied adaptation factor 153 fluctuates between limits 151 and 152 with small step sizes (stabilizing state). This is the slow correction range. The larger step sizes in the fast correction range allow for rapid initial matching of air volume differences due to manufacturing tolerances, and the slow correction range improves the robustness of the method.

[0138] Figure 7 A stepwise correction with fast and slow correction ranges is shown according to one embodiment.

[0139] The chart shown plots the traffic adaptation factor on the y-axis and the travel distance on the x-axis. This traffic adaptation factor is an adaptation factor based on the scaling factor.

[0140] This section shows the stepwise correction of the applied fit factor 153, which has not stabilized around a constant value. This may be due to aging effects (such as carbon buildup). Only the slow correction range is shown.

[0141] If this pattern is identified or the threshold for the application's fit factor is exceeded, the diagnostic function can indicate it as an error, such as carbon buildup in the inhalation tube near the inlet valve.

[0142] Figure 8a The actual torque related to the rotational speed is shown according to one embodiment.

[0143] The graph is shown, where torque is plotted on the y-axis and rotational speed is plotted on the x-axis.

[0144] If the actual amount of air entering the cylinder deviates from the calculated amount, a difference in air volume will occur as engine speed increases. This results in an actual torque 155b that is, for example, lower than the calculated torque 155a, which may be preset by the driver's intention regarding engine speed. This deviation also increases in torque as engine speed increases. Now, if the filler model is corrected using this method, the internal combustion engine will also output the calculated torque 155a as the actual torque.

[0145] Here and in the following Figure 8b , 8c The curves shown in 8d with the suffix 'b' can also be mirrored from the curves marked with 'a', and therefore deviate in the opposite direction, because the error is also based on manufacturing tolerances.

[0146] Figure 8b The actual fill amount calculated according to one embodiment is shown.

[0147] The graph is shown, where the calculated fill amount is plotted on the y-axis and the rotational speed is plotted on the x-axis.

[0148] The calculated filler mass 156a initially increases with engine speed, and then decreases again more slowly. Using this calculated filler mass 156a, the internal combustion engine can generate torque (…). Figure 8a 155a).

[0149] In cases of error sources such as carbon buildup or minor manufacturing deviations (e.g., due to burrs forming on the walls of the intake line), the cylinder is filled with less air than calculated. This effect increases with engine speed, as shown by the actual fill amount 156b.

[0150] The difference in fill weight can be measured using this method by adjusting the λ value, and can be correlated with fill weight error (and not fuel quantity error). With correction, the calculated fill weight of 156a can be achieved again across all speed ranges.

[0151] Figure 8c The theoretical suction tube pressure related to rotational speed is shown according to one embodiment.

[0152] The graph is shown, where the suction tube pressure is plotted on the y-axis and the rotational speed is plotted on the x-axis.

[0153] The suction pipe pressure 157a initially increases with engine speed, and then decreases again more slowly. Under normal conditions (no carbon buildup or production deviations), an internal combustion engine can achieve the calculated fill volume using this suction pipe pressure 157a. Figure 8b (156a in the text), and thus a torque is generated ( Figure 8a 155a).

[0154] In cases of error sources such as carbon buildup or minor manufacturing deviations (e.g., due to burrs forming on the walls of the intake line), the cylinder is filled with less air than calculated because the error source restricts airflow, which produces increasingly stronger deviations at higher flow rates (and therefore higher piston speeds and rotational speeds).

[0155] The difference in fill weight can be measured using this method by adjusting the λ value, and can be correlated with fill weight error (and not fuel quantity error). With the help of correction, the theoretical pressure in the suction pipe can be increased in a speed-dependent manner, as shown by the adapted theoretical suction pipe pressure 157b, and then the calculated fill weight 156a can be achieved again across all speed ranges. Thus, the limitation on the airflow into the cylinder is compensated for by increasing the pressure in the suction pipe.

[0156] The pressure in the suction pipe is provided, for example, by a turbocharger. For such components, there are usually component protection functions that are responsible for complying with load limits 157c, such as thermal load limits caused by exhaust gas temperature or load limits caused by turbocharger speed.

[0157] Figure 8d The speed-related λ adjustment value is shown according to one embodiment.

[0158] The graph is shown, where the λ adjustment value is plotted on the y-axis and the rotational speed is plotted on the x-axis.

[0159] The ideal value for the λ adjustment, 158a, is 1 or at least fluctuates around 1. This indicates that no significant adjustment is required to achieve the stoichiometric ideal combustion ratio.

[0160] The deviation of the λ adjustment value 158b, i.e., the air volume difference, is shown as a parabolic deviation. Through the above correction, since the deviation in the actual air volume is corrected, the λ adjustment value can be restored to the value of λ adjustment value 158a across all speed ranges.

[0161] This method is generally used, but especially when using Figures 8a to 8d This embodiment allows for the adjustment of the theoretical torque and thus theoretical performance of the internal combustion engine, while also adapting to speed-related deviations in the air-fuel mixture. Therefore, it satisfies not only the maximum deviation requirements for performance specifications but also emission regulations. Adjusting λ alone would only meet emission regulations and might exacerbate torque deviations.

[0162] Figure 9 The speed-dependent performance of an internal combustion engine with varying filler weights is shown.

[0163] The graph is shown, in which the performance of the internal combustion engine is plotted on the y-axis and the engine speed is plotted on the x-axis.

[0164] Performance curve 161 also relates to a type of internal combustion engine and is caused by deviations in the fill weight (cylinder fill weight). Therefore, in the operation of an internal combustion engine, there are differences in the amount of air flowing into the cylinder, and thus there are differences in the amount of air that this method corrects for.

[0165] The deviation of performance curve 116 increases with speed, and is particularly prominent in the plateau range of 160 at high speeds.

[0166] Figure 10a The flow coefficients related to the valve stroke of the inlet valve are shown.

[0167] A graph is shown, in which the flow coefficient (Alpha) through the inlet valve is plotted on the y-axis. k The valve stroke is plotted on the x-axis.

[0168] Flow coefficient (Alpha) k ,α k The direction of )162 in the valve stroke is displayed, and the flow coefficient (Alpha) k ,α k The dispersion of )162 increases with the increase of valve stroke.

[0169] Figure 10b The flow coefficient related to the valve stroke of the outlet valve is shown.

[0170] A graph is shown, in which the flow coefficient (Alpha) through the outlet valve is plotted on the y-axis. k ,α k The valve stroke is plotted on the x-axis.

[0171] The flow coefficient (Alpha) at the outlet valve k ,α k )163 observations and at the inlet valve (e.g. Figure 10a As shown and referenced Figure 10a The observations discussed correspond to those observed.

[0172] Figure 11a The valves of an internal combustion engine are shown.

[0173] The valve 200 includes a valve seat in the cylinder head 201 and a valve disc with a valve tappet 202.

[0174] The valve is shown in the open position. Inflowing air 203 is shown by lines. The air flows through a preset geometry, subject to manufacturing deviations, via a cylinder head 201 with a valve seat and a valve disc with a valve tappet 202. Furthermore, this geometry may also be subject to deviations due to deposits (e.g., carbon buildup).

[0175] The geometry produces a geometric cross-section of 205 (A)geom Furthermore, the incoming air continues to focus after passing through the valve, creating an effective flow cross-section 204 (A). eff The correlation between these two factors is expressed by the flow coefficient (α). k This is described in the following formula: .

[0176] Flow coefficient (α) k )yes Figure 10a The flow coefficients shown are as follows.

[0177] Figure 11b The pressure ratio through the valve is shown as a function of flow rate.

[0178] The graph is shown, where the flow rate through the inlet valve is plotted on the y-axis and the pressure ratio of the pressure in the inlet channel to the pressure in the cylinder is plotted on the x-axis.

[0179] The flow function has a constant section 211 until a certain pressure ratio 212 is reached. After exceeding this pressure ratio 212, the flow function's trajectory 210 becomes parabolic.

[0180] Effective flow cross section ( Figure 11a Variations in the effective flow cross-section, such as those due to manufacturing deviations or aging effects, directly impact the mass flow into the cylinder through the inlet valve. A smaller effective flow cross-section results in a greater pressure difference between the inlet passage and the cylinder. Consequently, the velocity of sound is reached more quickly at the throttling point, limiting the mass flow. This limitation becomes increasingly pronounced at higher speeds because the piston speed, which acts as the driving force for air intake, also increases further. Therefore, differences in the effective flow area and their effects become particularly noticeable at higher speeds.

[0181] This determines the rotational speed dependence of the error source being corrected in this method, and why a preset relationship, such as a parabola, can be used for correction.

[0182] Figure 11c This shows that the valve stroke and mass flow of an internal combustion engine depend on the crankshaft angle.

[0183] The diagram shows the valve stroke and mass flow plotted on the y-axis and the crankshaft angle plotted on the x-axis.

[0184] In the case of valve stroke, the valve stroke 214 of the outlet valve extends by a near-normal distribution before a 360° crankshaft angle. Furthermore, this also applies to the valve stroke 215 of the inlet valve after a 360° crankshaft angle. In the region around the 360° crankshaft angle, an overlap is derived, in which both valves are slightly open.

[0185] Accordingly, a mass flow 216 of exhaust gas exiting the cylinder occurs before a 360° crankshaft angle, and a mass flow 217 of air entering the cylinder occurs after a 360° crankshaft angle. Within the overlapping range, there is back-and-forth oscillation of exhaust gas and air.

[0186] However, within the overlap range, the valve stroke is very small, thus the error sources from production deviations and aging effects (in) Figures 9 to 11b (As discussed in the text) There is no significant impact within this range. However, there is a significant impact within the range of the maximum valve stroke of the inlet valve, which is 215.

[0187] Figure 12 An internal combustion engine is shown.

[0188] The internal combustion engine 250 includes piping from the fuel tank ventilation system 251 and the crankcase ventilation system 252, a suction pipe 253, a compressor 254a of a turbocharger, a pressure sensor 255, a suction bend 265, an inlet valve 257, an injector 258, an outlet valve 255, an outlet manifold 260, a turbine 254b of the turbocharger, a probe 261 before the catalytic converter, a catalytic converter 262, a probe 263 after the catalytic converter, a cylinder head 264, a cylinder 265, a piston 266, and a connecting rod 267.

[0189] Steam from the tank vent 251 and crankcase vent 252 can be directed into the suction pipe 253. Fresh air is drawn in through the suction pipe 253. The fresh air and any steam are compressed in the compressor 254a and delivered into the suction bend 256. The boost pressure is monitored by the pressure sensor 255.

[0190] Compressed air flows into the cylinder (the space between cylinder head 264, cylinder 265, and piston 266) through the open inlet valve 257 from the intake bend 256. Here, the piston moves downwards during the intake stroke. With inlet valve 257 closed, the piston moves upwards to compress the intake air, and fuel is injected into it by injector 258. The air-fuel mixture is ignited, and the piston moves downwards during the power stroke. Then, upon resuming its upward movement and with outlet valve 259 open, exhaust gas is expelled into outlet manifold 260. With outlet valve 259 closed and inlet valve 257 open, a reference is obtained. Figure 11c The scope of overlap in the discussion.

[0191] The exhaust gas drives the turbine 254b of the turbocharger, which in turn drives the compressor 254a via a shaft (not shown). Following the turbine 254b, the exhaust gas flows through a λ probe 261 before the catalytic converter, the catalytic converter 262, and a λ probe 263 after the catalytic converter. Here, the combustion air ratio for the air-fuel mixture is determined, along with the resulting λ adjustment value. If a deviation in the λ adjustment value is determined by this method, an air volume difference can be identified and corrected using the adaptation theory that the intake manifold pressure depends on the engine speed. For this purpose, any of the aforementioned adjustment possibilities for the intake manifold can be used.

[0192] Figure 13a The values ​​for λ adjustment related to load and speed are shown in the figure.

[0193] A graph showing the λ adjustment values ​​for load on the y-axis and rotational speed on the x-axis is presented.

[0194] The λ adjustment value below the load limit 301 is shown by lines 302 to 308, which should respectively show the value of the λ adjustment value of 0.98.

[0195] Therefore, a 2% plane deviation of the λ adjustment value is measured across the entire load-speed graph. There is no speed dependence. This deviation is matched as an offset in this method but not corrected, because it is caused, for example, by an incorrect slope of the injected fuel quantity with respect to the injection time.

[0196] Figure 13b The amount of fuel injected is shown in relation to the injection time.

[0197] A graph showing the injection volume on the y-axis and the injection time on the x-axis is displayed.

[0198] belong Figure 13a The error graph of the deviation discussed is the slope of the deviation of the injected fuel quantity from the reference 400 with respect to the injection time 401. Here, the fuel quantity can be adapted, but the air quantity cannot, at least not when it should correspond to the torque desired by the driver.

[0199] This deviation is matched as an offset in this method but is not corrected because it is caused, for example, by the offset of the amount of injected fuel with respect to the injection time. This error may also be completely undetectable by the measurement range in this method.

[0200] Figure 14a The values ​​for λ adjustment related to load and speed are shown in the figure.

[0201] A graph showing the λ adjustment values ​​for load on the y-axis and rotational speed on the x-axis is presented.

[0202] The λ adjustment value is the error (e.g., quotient) between the actual injected fuel quantity and the calculated fuel quantity.

[0203] The λ adjustment value below the load limit 301 is shown by lines 302 to 308. Lines 302 to 305 represent a λ adjustment value of 1. Furthermore, line 306 represents a λ adjustment value of 0.98, and line 307 represents a λ adjustment value of 0.94.

[0204] Therefore, the deviation of the λ adjustment value is measured under low load. There is no speed dependence.

[0205] Figure 14b The amount of fuel injected is shown in relation to the injection time.

[0206] A graph showing the injection volume on the y-axis and the injection time on the x-axis is displayed.

[0207] belong Figure 14a The error graph of the deviation discussed is the offset of the injected fuel quantity with respect to the injection time 401 compared to the reference 400. Here, the fuel quantity can be adapted, but the air quantity cannot, at least not when it should correspond to the torque desired by the driver.

[0208] Figure 15a The values ​​for λ adjustment related to load and speed are shown in the figure.

[0209] A graph showing the λ adjustment values ​​for load on the y-axis and rotational speed on the x-axis is presented.

[0210] The λ adjustment values ​​below the load limit 301 are shown by lines 302 to 308. Here, line 302 indicates, for example, a λ adjustment value of 1, line 303 is 0.98, line 304 is 0.95, line 305 is 0.94, line 306 is 0.88, and line 307 is 0.8.

[0211] Therefore, the deviation between the measured λ adjustment value and its reference increases with rotational speed. This deviation is corrected in this method.

[0212] Figure 15b The value of λ adjustment for rotational speed is shown in the figure.

[0213] A graph showing the λ adjustment factor on the y-axis and the injection time on the x-axis is presented.

[0214] belong Figure 15a The error graph of the deviation discussed is the air volume difference, which causes a deviation in the λ adjustment value 401 (similar to the λ adjustment factor). The method corrects this deviation to a reference 400, which here corresponds to the x-axis.

[0215] Figure 16a The values ​​for λ adjustment related to load and speed are shown in the figure.

[0216] A graph showing the λ adjustment values ​​for load on the y-axis and rotational speed on the x-axis is presented.

[0217] The λ adjustment values ​​below the load limit 301 are shown by lines 302 to 305. Here, line 302 indicates, for example, a λ adjustment value of 1, line 303 is 0.98, line 304 is 0.95, and line 305 is 0.9.

[0218] Therefore, the deviation in the measured λ adjustment value increases with lower speed and lower load. This deviation indicates a leak or blow-by problem.

[0219] Figure 16b The actual air mass flow is shown in the figure, which relates to the calculated air mass flow.

[0220] A graph showing the actual air mass flow on the y-axis and the calculated air mass flow on the x-axis is presented.

[0221] belong Figure 16a The error profile of the deviation discussed herein represents a leak or blow-by problem. This deviation is not corrected by the air-fuel mixture, but must be identified by this method as not requiring correction. The deviation of the actual air mass flow 401 from the reference 400 (diagonal) is particularly noticeable at small air mass flows and is therefore irrelevant at high speeds. Thus, it is also irrelevant to this method and only affects the determination of the offset.

[0222] Figure 17a The values ​​for λ adjustment related to load and speed are shown in the figure.

[0223] A graph showing the λ adjustment values ​​with respect to the load on the y-axis and the rotational speed on the x-axis is presented.

[0224] The λ adjustment values ​​below the load limit 301 are shown by lines 302 to 305. Here, line 302 indicates, for example, a λ adjustment value of 1, line 303 is 0.98, and line 304 is 0.95.

[0225] Therefore, there is a deviation in the λ adjustment value, which forms an island at low speeds and low loads. This deviation indicates the presence of valve drive tolerances or adaptation errors.

[0226] Figure 17b The figure shows the air mass with respect to the phase position of the inlet camshaft.

[0227] A graph showing the air mass on the y-axis and the phase position of the inlet camshaft on the x-axis is presented.

[0228] belong Figure 17a The error profile of the deviation discussed herein is a valve drive tolerance or fit error. This deviation is not corrected by the method according to the invention, but must be identified by the method as not to be corrected.

[0229] Figure 18a The values ​​for λ adjustment related to load and speed are shown in the figure.

[0230] A graph showing the λ adjustment values ​​with respect to the load on the y-axis and the rotational speed on the x-axis is presented.

[0231] The λ adjustment values ​​below the load limit 301 are shown by lines 302 to 305. Here, line 302 indicates, for example, a λ adjustment value of 1, line 303 is 0.98, and line 304 is 0.95.

[0232] Therefore, there is a deviation in the λ adjustment value, which forms an island at low speeds and high loads. This deviation indicates a modeling error in the filler model or a pressure sensor error.

[0233] Figure 18b The figure shows the air quality with respect to exhaust pressure.

[0234] A graph showing air mass on the y-axis and exhaust gas pressure on the x-axis is displayed.

[0235] belong Figure 18a The error graph of the deviation discussed is either the modeling error of the infill model or the pressure sensor error. This deviation is not corrected by the mixture of air and fuel, but must be identified by this method as not to be corrected. The deviation of air quality 401 from reference 400 shows different slopes with respect to exhaust pressure.

[0236] Figure 19 A means of transport according to one embodiment is shown.

[0237] The vehicle 500 includes a control unit 502 and an internal combustion engine 501. The control unit 502 is designed to implement the method.

[0238] List of reference numerals 100: Method 110: Standard family of parabolas 120: Residual Determination 130: Reasonableness Test 140: Determining the degree of difference in air volume 150: Correction of the infill model 121: Load Limit 122a-f: Linear adjustment value of λ 123: Load Limit 124: Lower limit of load 125a-e: Lower limit of rotational speed 126a-e: Upper limit of rotational speed F1-F5: Measurement range 111a-g: Parabola 131: Measurement point 132: Average value 114, 115: Arrows (Offset) 111f1, 111f2: The parabola after the movement 151, 152: Limits 153: Application Adaptability Factor 154: Scheduled usage duration 155a: Calculated torque 155b: Actual torque generated 156a: Calculated fill volume 156b: Actual filler volume 157a: Suction tube pressure 157b: Compatible suction tube pressure 157c: Load Limit 158a: Ideal value of λ adjustment value 158b: Deviation of λ adjustment value 160: Platform Scope 161: Performance Curve 162: Flow coefficient 200: Valve 201: Cylinder head 202: Valve disc with valve tappet 203: Inflowing air 204: Effective flow cross section 205: Geometric cross-section 210: The direction of the flow function 211: Constant Section 212: Pressure Ratio 214: Valve stroke of the outlet valve 215: Valve stroke of the inlet valve 216: Mass flow of exhaust gas 217: Mass flow of air 250: Internal combustion engine 251: Fuel tank ventilation device 252: Crankcase ventilation device 253: Suction tube 254a: Compressor for turbochargers 254b: Turbine of the turbocharger 255: Pressure sensor 256: Suction bend 257: Inlet valve 258: Injector 259: Outlet valve 260: Export manifold 261: Lamb probe in front of the catalyst 262: Catalyst 263: Lamb probe after the catalyst 264: Cylinder head 265: Cylinder 266: Piston 267: Linkage 301: Load Limit 302-308: Lines for λ adjustment values 400: Benchmark 401: Curve 500: Means of transport 501: Internal Combustion Engine 502: Control Unit

Claims

1. A method (100) for correcting differences in air volume in the air intake circuit of an internal combustion engine (501), comprising: Obtain (120) measurement data (131, 132), which indicates the deviation between the mass of air drawn in by the internal combustion engine (501) and the modeled mass of air with respect to the rotational speed of the internal combustion engine (501); Determining (140) a correction relationship includes multiplying a preset relationship (111) of the deviation with respect to the rotational speed with a scaling factor (S), wherein the correction relationship approximates the measurement data (131, 132); The actual amount of air in the air intake circuit is corrected (150) based on the correction relationship.

2. The method (100) according to claim 1, wherein, The measurement data (131, 132) includes at least three measurements.

3. The method (100) according to any one of the preceding claims, wherein, The measurement data (131, 132) were obtained by the λ regulator.

4. The method (100) according to any one of claims 1 or 2, wherein, The measurement data (131, 132) were obtained from an air quality measuring instrument.

5. The method (100) according to any one of the preceding claims, wherein, The preset relationship (111) is a parabolic function.

6. The method (100) according to any one of the preceding claims, wherein, Determining the correction relationship (140) involves adding it to the offset (114, 115) to approximate the measured data (131, 132).

7. The method (100) according to any one of the preceding claims, wherein, The measurement data (131, 132) are collected within a measurement range (F1-F5) that can be defined by load and speed limits (123, 124, 125, 126).

8. The method (100) according to claim 6, wherein, Multiple measurement ranges (F1-F5) are set, which are separated from each other by the lower speed limit (125a-e), the upper speed limit (126a-e), the lower load limit (124), and the upper load limit (123).

9. The method (100) according to any one of the preceding claims, wherein, The actual air volume is progressively corrected toward the calculated air volume based on the correction relationship (150), and the correction relationship already used only changes a portion of the difference between the current scaling factor and the scaling factor (S) determined by the correction relationship.

10. The method (100) according to claim 9, wherein, A fast correction range is set, which can be applied within a preset usage duration (154), and within this correction range, a larger portion of the difference is used to correct the actual air volume compared to the slow correction range outside the preset usage duration (154).

11. The method (100) according to any one of the preceding claims, wherein, The amount of air in the air intake line is corrected (150) by correcting the filling model of the internal combustion engine (501) based on the correction relationship.

12. The method (100) according to claim 11, wherein, The calibration (150) of the filling model of the internal combustion engine (501) matches the theoretical pressure in the air intake circuit.

13. The method (100) according to any one of the preceding claims further comprises: The diagnosis indicates that the correction (150) for the actual air volume exceeds the predetermined tolerance limit, and This indicates that the predetermined tolerance limit has been exceeded.

14. The method (100) according to any one of the preceding claims further comprises: Reasonableness check (130): Whether the measured data (131, 132) corresponds to the product of the preset relationship (111) and the scaling factor (S), wherein... If the measured data (131, 132) corresponds to the product of the preset relationship (111) and the scaling factor (S), then the air volume correction (150) is performed.

15. The method (100) according to claim 14, wherein, The rationality test (130) includes checking the goodness of regression (R²) between the product of the preset relationship (111) and the scaling factor (S) and the measurement data (131, 132). 2 ), and when the regression goodness (R 2 When the value exceeds the preset value, the matching of the measurement data (131, 132) is reasonable.

16. The method (100) according to claim 14 or 15, wherein, The preset relationship (111) is a function. A family of functions (111a-g) is generated by multiplying multiple different scaling factors (S) with the preset relation (111), and the rationality check (130) also includes, Determine whether the measurement data (131, 132) corresponds to a function from the family of functions (111a-g).

17. The method (100) according to any one of the preceding claims further comprises: Check whether the prerequisites for acquiring the measurement data (131, 132) are met; If the prerequisites for acquiring the measurement data (131, 132) are met, then an air volume correction (150) is performed.

18. The method (100) according to claim 17, wherein, The prerequisites include at least one of the following: fluctuations in the performance of the internal combustion engine (501), a fuel tank ventilation device within a preset range, a crankcase ventilation device within a preset range, or a correction (150) of the actual air volume exceeding a predetermined limit.

19. A control unit (100) configured to implement the method (100) according to any one of the preceding claims.

20. A means of transport (500) comprising a control unit (502) according to claim 19 and the internal combustion engine (501).

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