Method for operating an internal combustion engine of a motor vehicle and motor vehicle

Abstract

The invention relates to a method for operating an internal combustion engine of a motor vehicle, in which a cascade control system is used. In this system, a first quantity of air, the first quantity of which is introduced into a combustion chamber of the internal combustion engine, and a second quantity of fuel, the second quantity of which is introduced into the combustion chamber of the internal combustion engine, are controlled by means of two controllers (4, 5) of two nested control loops (2, 3). For a first controller (4, 5), a first correction value is determined, which characterizes a first control deviation (RA1) that is applied to the first controller (4). For a second controller (4, 5), a second correction value is determined, which characterizes a second control deviation (RA2) that is applied to the second controller (5).From the correction values ​​of the controllers (4, 5), a common adaptation value is determined, which is stored in a storage network common to the controllers.

Description

[0001] The present invention relates to a method for operating an internal combustion engine of a motor vehicle. The invention further relates to a motor vehicle with such an internal combustion engine.

[0002] EP 2 002 103 B1 discloses a method for controlling the injection profile of a direct-injection internal combustion engine of a vehicle. US 7 938 101 B2 discloses an adaptive fuel supply control system. CN 1 10 352 296 B discloses an adaptive torque distribution system. DE 10 2007 012 604 B4 also discloses a method for controlling the injection of an injector of a direct-injection internal combustion engine. Furthermore, US 2012 / 0 253 638 A1, WO 01 / 38 709 A1, and US 2016 / 0 084 192 A1 are considered prior art. DE 10 2023 203 542 A1 also discloses a method for controlling the soot-NOx ratio in the exhaust gas of an internal combustion engine. A nitrogen oxide (NOx) sensor measures the actual value of the nitrogen oxides in the exhaust gas of the internal combustion engine. The deviation between this actual value and a target value is then determined.A manipulated variable is controlled based on the control deviation. Additionally, a variable in another control loop is adjusted based on the manipulated variable, with this second control loop also influencing the soot-NOx ratio.

[0003] The object of the present invention is to create a method for operating an internal combustion engine and a motor vehicle with such an internal combustion engine, so that a particularly low-emission operation of the internal combustion engine can be achieved.

[0004] This problem is solved according to the invention by a method with the features of claim 1 and by a motor vehicle with the features of claim 5. Advantageous embodiments of the invention are the subject of the dependent claims.

[0005] A first aspect of the invention relates to a method for operating an internal combustion engine, also referred to as a combustion engine, of a motor vehicle, also referred to simply as a vehicle. This means that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, has the internal combustion engine and can be driven by means of the internal combustion engine. For example, in the method, the motor vehicle is driven by means of the internal combustion engine. For example, in the method, the internal combustion engine is operated in a fired mode, that is, in a fired operation of the internal combustion engine.

[0006] The method employs a cascade control system, also known simply as control or cascaded control. The cascade control system comprises, in particular, at least or exactly, two nested controllers: a first controller and a second controller. These controllers influence a first quantity of air, also referred to as the air quantity, and a second quantity of a preferably liquid fuel, also referred to as the fuel quantity. Both the air quantity and the fuel quantity are introduced into a combustion chamber of the internal combustion engine, particularly within a single operating cycle. For example, the cascade control system can be implemented using an electronic computing device, particularly in a motor vehicle, so that the method is carried out, for example, by means of the electronic computing device.The electronic computing device is or comprises, for example, at least or exactly one control unit, particularly of a motor vehicle. More specifically, the cascade control implemented in the method according to the invention is understood to be a control system with, in particular, at least or exactly, two, especially closed, control loops, which are nested within one another. For example, the first controller is a controller of a first of the control loops, and the second controller is a controller of a second of the control loops. The feature that the controllers are nested within one another in the cascade control system means that the control loops are nested within one another. For example, the first controller provides a first controller output, which is, for example, a first manipulated variable. For example, the second controller provides a second controller output, which is, for example, a second manipulated variable.Thus, the first controller output is assigned to the first controller and vice versa, and the second controller output is assigned to the second controller and vice versa. In particular, in cascade control, it is provided that a reference input results from one of the controller outputs, specifically that the reference input is determined, and / or calculated, from the controller output, and / or that the controller output is used as the reference input. The reference input resulting from the controller output is, for example, used as the reference input for one of the controllers, specifically by feeding the reference input to that controller. In this case, for example, the controller provides the manipulated variable, which is supplied by the controller, as a function of the reference input.Thus, for example, one controller is a so-called subordinate controller, and the other controller is a so-called master controller, where, for example, the one controlled variable from which the one reference variable results, which is used for one controller, is the controller output variable of the other controller, i.e., the master controller.

[0007] For example, the first controller output results from the first manipulated variable. For example, the second controller output results from the second manipulated variable. It is particularly conceivable that the first control loop, comprising the first controller, has a first controlled system to which, for example, the first manipulated variable is fed, and from this first controlled system, for example, a first controlled variable results. In this case, for example, the first controller output is the first controlled variable, or the first controlled variable results from the first controller output. Similarly, for example, the second controller output is the second controlled variable, or the second controlled variable results from the second controller output.It is conceivable that, particularly in the first control loop, the first controlled variable, which can be the first controller output, is fed back and compared with a first reference input, specifically by comparing the respective actual values ​​of the first controlled variable with the respective setpoint values ​​of the first reference input. Comparing the first controlled variable with the first reference input results in a first control deviation, also referred to as the first control error. Depending on the first control deviation, the first controller, for example, provides the first manipulated variable, specifically by determining, or even calculating, the first manipulated variable as a function of the first control deviation. For example, the first control deviation is fed to the first controller.

[0008] For example, the second controlled variable, which can be the second controller output, is fed back and compared with a second reference input. Here, actual values ​​of the second controlled variable are compared with setpoint values ​​of the second reference input. By comparing the second controlled variable with the second reference input, a second control deviation is determined, in particular calculated, where the second control deviation is also referred to as the second control error. For example, the second controller provides the second manipulated variable as a function of the second control deviation, where, for example, the second controller determines the second manipulated variable as a function of the second control deviation, in particular calculated. For example, the second control error is fed to the second controller. The previously mentioned reference input is one of the reference inputs, thus the first reference input or the second reference input.

[0009] The first quantity of air, for example, is a first mass of air, also referred to as air mass. The second quantity of fuel, for example, is a second mass of fuel, also referred to as fuel mass. Since the regulators influence the quantity of air and the quantity of fuel, one of the regulators is an air flow regulator, also called an air mass regulator, which is also referred to as an air mass regulator, especially when the first quantity of air is the aforementioned air mass. The other regulator is, for example, a fuel flow regulator, also referred to as a fuel mass regulator, which is also referred to as a fuel mass regulator, especially when the second quantity of fuel is the aforementioned fuel mass.

[0010] From the air and fuel, a mixture, also known as a fuel-air mixture, is formed, particularly within the combustion chamber, especially during the respective operating cycle of the internal combustion engine. This mixture is then combusted in the combustion chamber, particularly during the respective operating cycle. Specifically, the mixture is ignited and burned. For example, the mixture is ignited by external ignition, i.e., by means of an ignition device, and subsequently burned. The combustion of the mixture results in exhaust gas from the internal combustion engine. The mixture, whose air-fuel ratio is also referred to as lambda (λ), comprises at least the air and fuel quantities.Since the exhaust gas, and in particular its composition, results from the combustion of the mixture and thus from the mixture and therefore from the air-fuel ratio of the mixture, and since the mixture, and in particular its composition, results from the amount of fuel, and in particular from influencing the amount of fuel, the fuel regulator is also referred to as a lambda regulator. The amount of fuel does not necessarily have to be one of the controlled variables. However, the amount of fuel can be one of the controlled variables. The amount of air does not necessarily have to be one of the controlled variables. However, the amount of air can be one of the controlled variables. For example, the amount of fuel is one of the manipulated variables, or the amount of fuel is influenced by one of the manipulated variables. For example, the amount of air is one of the manipulated variables, or the amount of air is influenced by one of the manipulated variables. It is conceivable that the air-fuel ratio is one of the controlled variables.In particular, the air-fuel ratio is the controlled variable resulting from, and specifically provided by, the controlled system, which is part of the control loop that includes the fuel regulator, i.e., the lambda controller. Specifically, the respective controller is designed to minimize the control deviation fed to it, or to counteract the respective control deviation, especially when it is non-zero. For example, influencing the fuel quantity affects one of the controlled variables, in particular the air-fuel ratio. Similarly, influencing the air quantity affects another controlled variable. Because the control loops are nested within each other in cascade control, influencing one controlled variable affects the other.For example, each manipulated variable controls at least one actuator, thereby influencing the respective controlled variable. In other words, the first manipulated variable controls a first actuator, and the second manipulated variable controls a second actuator, thus influencing the air and fuel quantities. The fuel and air quantities influenced by the cascade control system are collectively referred to as the "influence quantities." Influencing the respective influence quantity means, in particular, varying it; that is, setting different values ​​for each influence quantity.In this process, for example, the fuel quantity is introduced into the combustion chamber in such a way that the fuel quantity, particularly within the respective operating cycle of the internal combustion engine, is introduced directly, in particular directly injected. By introducing the fuel quantity into the combustion chamber, the combustion chamber is supplied with the fuel quantity. The air quantity is introduced into the combustion chamber, for example, particularly within the respective operating cycle, in such a way that the air quantity, particularly within the respective operating cycle, is introduced into the combustion chamber. During the fired operation of the internal combustion engine, combustion processes take place in the combustion chamber, in particular such that within the respective operating cycle, a respective combustion process takes place. In the respective combustion process, a respective mixture, as previously described, is produced and burned in the combustion chamber.Preferably, the internal combustion engine is a spark-ignited internal combustion engine, in particular a gasoline engine, so that, for example, the mixture is ignited by spark ignition and thus by means of an ignition device and subsequently burned.

[0011] For example, the combustion chamber is partially delimited by a cylinder and by a piston that is movable translationally within the cylinder, so that the internal combustion engine is designed as a reciprocating piston engine. The combustion process drives the piston and thus moves it translationally within the cylinder. The piston is, for example, articulated and, in particular, connected via a connecting rod to an output shaft of the internal combustion engine, which is designed, in particular, as a crankshaft. By driving the piston, the piston drives the output shaft and thus rotates it about an output shaft axis relative to a housing element of the internal combustion engine, with the cylinder being formed, for example, by the housing element. The housing element is, for example, designed as a cylinder crankcase.By driving the output shaft, the internal combustion engine can provide a drive torque via the output shaft, so that the motor vehicle can be driven or is driven by means of the drive torque.

[0012] The aforementioned quantity of fuel is also referred to as the initial fuel quantity. Whenever the term "fuel quantity" is used before or after, it refers to the initial fuel quantity unless otherwise specified. The aforementioned quantity of air is also referred to as the initial air quantity. Whenever the term "air quantity" is used before or after, it refers to the initial air quantity unless otherwise specified.

[0013] In this procedure, a first correction value is determined for the first controller, which characterizes, that is, specifies or defines, the first control deviation fed to the first controller. A second correction value is determined for the second controller, which characterizes the second control deviation fed to the second controller. From the correction values, a common adaptation value for all controllers is determined, for example, by multiplying the first correction value by the second correction value. The adaptation value, also referred to as the first adaptation value, is stored in a memory network common to all controllers. For example, the memory network assigns, for example, a specific operating point of the internal combustion engine to the adaptation value, with the aforementioned operating point also being referred to as the first operating point.When the adaptation value is mentioned before and after, this refers to the first adaptation value unless otherwise specified. When the operating point is mentioned before and after, this refers to the first operating point unless otherwise specified. For example, the correction values ​​are determined while the internal combustion engine is operating at the first operating point, thus determining the correction values ​​for the first operating point. Alternatively or additionally, for example, the first correction value characterizes the first control deviation occurring when the internal combustion engine is operating at the first operating point, and alternatively or additionally, for example, the second correction value characterizes the second control deviation occurring when the internal combustion engine is operating at the first operating point.The characteristic that the respective correction value characterizes the respective control deviation can be understood to mean that the respective control deviation is the respective correction value, or that the respective correction value is a respective value of the respective control deviation, or that the respective correction value is influenced by the respective control deviation, for example, in such a way that the respective correction value increases with the control deviation, particularly in its absolute value. It is also conceivable that the respective correction value is a respective correction factor. The respective correction value is, for example, a respective value such that if the respective manipulated variable is corrected by the respective correction value, or would be corrected, particularly if the respective manipulated variable is multiplied by the respective correction value, the respective control deviation would be eliminated.

[0014] The aforementioned storage network is also referred to as the second storage network. Whenever the storage network is mentioned before and below, this refers to the second storage network unless otherwise specified.

[0015] Within the context of the present disclosure, ordinal words such as "first", "first", "first", "second", "second", etc., which are referred to as ordinal numbers, are not necessarily used to indicate or imply a number of elements to which the ordinal numbers refer, but fundamentally only to be able to refer unambiguously and without contradiction to the elements to which the ordinal numbers refer.

[0016] For example, the storage network is stored in a data storage device of the electronic computing unit, in particular an electrical or electronic one.

[0017] In particular, the feature that the adaptation value is stored in the storage network means that the adaptation value is stored in the data storage.

[0018] For example, in this method, the internal combustion engine is operated at several different operating points, one of which is, in particular, the aforementioned first operating point. Specifically, it is provided that the internal combustion engine is operated with combustion at each operating point; that is, the operation of the internal combustion engine at each operating point is the combustion-powered operation. Each operating point is characterized, for example, by at least one parameter or by several parameters, which are, in particular, different from one another. A first parameter characterizing each operating point is, for example, the rotational speed of the internal combustion engine.Rotational speed refers to the speed at which the output shaft rotates around its axis of rotation relative to the housing element. A second parameter characterizing the operating points is, for example, the load of the internal combustion engine, where the load specifically refers to the drive torque. In other words, the load is, for example, the torque supplied by the output shaft. A third parameter is, for example, the temperature of the internal combustion engine.

[0019] In this process, the adaptation value is output from the first storage network. Furthermore, both the first quantity of air and the second quantity of fuel are influenced depending on the adaptation value output from the storage network.

[0020] Since the adaptation value is used in the method according to the invention to influence the input quantities, in particular such that the method uses not only the controllers but also, and especially additionally, the adaptation value to influence the input quantities, the cascade control is an adaptive control system. In particular, the cascade control is or constitutes a control system, or the cascade control is formed by a control system. For example, the control system comprises the control loops. In other words, the control system, for example, has the control loops. Since the cascade control of the method according to the invention is an adaptive control system, the control system is an adaptive control system, which is also simply referred to as the adaptive system or system.For example, the cascade control system has an influencing variable, which is preferably provided or used in addition to the controlled variables, the manipulated variables, and especially the reference variables. The influencing variable is, or includes, for example, the adaptation value. In other words, the influencing variable can, for example, take on the adaptation value, thus exhibiting the adaptation value, so that, for example, the adaptation value can be a value of the influencing variable or can be used as a value of the influencing variable. Most importantly, the adaptation value is provided in addition to the controlled variables, and preferably in addition to the manipulated variables and also, most preferably, in addition to the reference variables.In particular, the influence quantities are affected depending on the adaptation value and / or the influence variable, and, for example, the influence quantities are additionally influenced by the controllers. This means, for example, that the influence of the adaptation value, especially the influence variable, on the influence quantities constitutes a further, additional influence on the influence quantities, whereby this further, additional influence on the influence quantities can be provided in addition to the influence on the influence quantities by the controllers. In particular, the influence of the adaptation value, especially the influence variable, on the influence quantities can be a feedforward control of the influence quantities or a type of feedforward control of the influence quantities.

[0021] The background of the invention is, in particular, that typically one of the controllers is a fast controller and the other a slow controller, which is slower than the fast controller. This means that, for example, after a certain point in time at which the respective controller provides the respective manipulated variable, the controlled variable that is influenced by the manipulated variable provided by the fast controller reacts more quickly, i.e., in a shorter time after that point in time, to the manipulated variable provided by the fast controller than the controlled variable that is influenced by the manipulated variable provided by the slow controller. Typically, the fast controller is the fuel controller or lambda controller, so that typically the slow controller is the air controller.This is usually because a so-called fuel path, through which the fuel is introduced into the combustion chamber and the fuel quantity is regulated, is not as sluggish as a so-called air path, through which the air is introduced into the combustion chamber and the air quantity is regulated. In other words, the fuel path reacts more quickly to control interventions by the fuel regulator than the air path reacts to control interventions by the air regulator. When controlling or influencing these parameters, it is desirable for the mixture to have a composition that results in a desired, advantageous air-fuel ratio, for example, an air-fuel ratio of 1.0.It is also desirable that the power output of an internal combustion engine should not vary excessively, especially compared to the specified power rating. In principle, it would be conceivable to counteract an excessively high air volume with a correspondingly high fuel quantity, thereby achieving a favorable air-fuel ratio of, for example, 1.0. This would be relatively easy to implement, particularly using the fuel regulator, as it is a fast regulator. However, such a high air volume combined with such a high fuel quantity would lead to excessively high power output and / or excessively high fuel consumption from the internal combustion engine.Therefore, it is desirable to be able to precisely control and adjust not only the fuel quantity but also the air quantity. Ideally, the system should be able to react quickly to deviations in both the fuel quantity and the air quantity. This allows the fuel and air quantities to be controlled and adjusted in such a way as to prevent excessive fuel consumption and excessive variation in the engine's power output, while simultaneously achieving a favorable mixture composition, resulting in a desired and advantageous air-fuel ratio, for example, 1.0.Both influencing factors, and therefore both controllers, affect the air-fuel ratio, since both influencing factors, and therefore both controllers, affect the mixture and thus its composition.

[0022] To avoid excessive variations in the internal combustion engine's power output and excessively high fuel consumption, and to ensure that the air-fuel ratio has an advantageous value, for example, 1.0, enabling particularly low-emission operation of the internal combustion engine, the adaptation value is used for both controllers. This means that the adaptation value is common to both controllers. This means that both controllers are adapted to the common memory network. Determining and storing the adaptation value is also referred to as learning. Outputting the adaptation value, in order to influence the control parameters based on this value, is also referred to as outputting or outputting.To summarize the invention briefly and concisely, the fast controller learns first, allowing the adaptation value to be determined quickly. The slow controller then utilizes the learning of the fast controller, so that the inherently slow controller, which could only learn slowly, also learns quickly or at least benefits from the fast controller's rapid learning. If separate adaptations were performed for each controller independently, the slow controller would only learn slowly and thus adapt slowly, and would not benefit from the fast controller's rapid learning. The adaptation error characterizes an overall error of the cascade control system.The fast controller can implement the adaptation value quickly, especially faster than the slow controller. This allows, for example, the fast controller to compensate for or counteract a deviation of the actual mixture state from a predefined, predetermined, or desired target state, also known as mixture deviation. The slow controller reacts to the adaptation value more slowly than the fast controller. When the slow controller also reacts to the adaptation value, the fast controller then withdraws its control interventions. Mixture deviations can thus be addressed quickly. In particular, cascade control helps to avoid excessive mixture deviations resulting from the combined adaptation.In other words, the fast controller essentially eliminates the entire error, primarily due to its faster control loop. This is because the fast control loop reacts more quickly to interventions from the fast controller than the slow control loop reacts to interventions from the slow controller. If the slow controller then also begins to counteract the mixture deviation with its own interventions, the fast controller reduces its interventions, as it can react quickly to changes in the mixture deviation. Overall, excessive mixture deviations can thus be avoided and / or counteracted quickly, enabling particularly low-emission operation. The process will be described in more detail using the following example: The fast controller quickly and, in particular, almost completely compensates for a mixture deviation.An air path correction also occurs, but because the air path is more sluggish than the fuel path, it happens more slowly. This means that, for example, the mixture deviation is initially corrected using the fast controller, so that the adaptation value of 0 is then set for both controllers. However, the control interventions of the slow controller then take effect, resulting in another, albeit small, mixture deviation, whereupon a slightly different adaptation value is set again.

[0023] This slight mixture deviation is then corrected by the fast controller, which also adjusts the air path accordingly, but only slightly, since the adaptation value is now smaller than before. It is evident that this process allows the system to stabilize at a deviation of, or at least nearly, zero, provided no new disturbance occurs.

[0024] To achieve particularly low-emission operation, one embodiment of the invention provides that, during the first operation of the internal combustion engine at the first operating point, the first correction value, which characterizes the first control deviation occurring at the first operating point, and the second correction value, which characterizes the second control deviation occurring at the first operating point, are determined. The adaptation value determined from the correction values ​​is stored in a first memory network, which assigns the adaptation value to the first operating point.

[0025] During a second operation of the internal combustion engine, particularly one immediately following the first operation, at a second operating point different from the first, the adaptation value is transferred from the first storage network to the second storage network and stored there. The second storage network then assigns the adaptation value to the first operating point. Specifically, the storage networks are located within the data storage system, so that, for example, when the adaptation value is stored in the respective storage network, it is also stored in the data storage system. The transfer of the adaptation value from the first storage network to the second does not necessarily mean that the adaptation value is deleted from the first storage network; rather, the adaptation value may, for example, remain stored there.For example, when the adaptation value is stored in the first memory network, it is stored at a first position in the data memory. Similarly, when the adaptation value is stored in the second memory network, it is stored at a second position in the data memory that differs from the first position.

[0026] The preceding and following explanations regarding the first storage network can readily be applied to the second storage network and vice versa.

[0027] The respective storage network is, for example, a specific characteristic curve or map, or a type of characteristic curve or map. In other words, the respective storage network is or comprises, for example, an assignment rule by which the adaptation value is assigned to the first operating point.

[0028] For example, if the parameter characterizing the operating points has a first value, this means that the internal combustion engine is operating at the first operating point. If the parameter has a second value that differs from the first, this means, for example, that the internal combustion engine is operating at the second operating point.

[0029] The first operation of the internal combustion engine at the first operating point does not necessarily mean that, in relation to its entire lifespan or existence, the engine is being operated at the first operating point for the very first time, and that it had never been operated at the first operating point before this first operation. Rather, the internal combustion engine may have been operated at the first operating point at least once or several times before this first operation. Similarly, the second operation of the internal combustion engine at the second operating point does not necessarily mean that, in relation to its lifespan or existence, the engine had only been operated at the second operating point once before this second operation.Rather, it is possible that the internal combustion engine was operated at the first operating point several times before its first operation. Furthermore, it is conceivable that the internal combustion engine was operated at the second operating point not at all or several times before its second operation at that point. This means that the ordinal numbers used to describe the operation of the internal combustion engine at the operating points do not, in principle, indicate frequency, but are used solely to clearly and consistently refer to the respective operation of the internal combustion engine at each operating point.Thus, it can be expressed simply and precisely that the internal combustion engine is first operated at the first operating point and then at the second operating point, such that the second operation follows the first operation in time, and therefore the first operation precedes the second operation in time. Preferably, it is provided that the second operation immediately follows the first operation, so that, for example, the start of the second operation coincides with the end of the first operation, and thus the second operation begins at the same time as the first operation ends.

[0030] During a third operation of the internal combustion engine at the first operating point, following the second operation, the adaptation value from the second storage network is output, and the influence quantities are adjusted depending on the adaptation value output from the second storage network. Thus, the third operation of the internal combustion engine at the third operating point means that the engine is first operated at the first operating point, then at the second operating point, and then again at the first operating point, so that the second operation follows the first, and so that the third operation follows both the first and second operations.

[0031] It is evident that in this embodiment, the adaptation value is stored in the first storage network when the internal combustion engine is operated at the first operating point. If the internal combustion engine is then operated at the second operating point, the adaptation value from the first storage network is stored in the second storage network. If the internal combustion engine is then operated again at the first operating point, the adaptation value from the second storage network, and preferably not from the first, is output. This means that when the internal combustion engine is operated again at the first operating point (i.e., during the third operation of the internal combustion engine), the control quantities are influenced depending on the adaptation value output from the second storage network and, for example, also or additionally by the controllers.For example, the respective correction value is determined by calculating the respective control deviation, particularly using the electronic computing device. This calculation, for instance, determines the correction value that characterizes the respective control deviation. Since this embodiment utilizes both the first and second memory networks, such that the first adaptation value is stored and learned in the first memory network, and the adaptation value is output from the second memory network and not, for example, from the first, this embodiment provides for decoupling the learning process from the output and vice versa. This allows for a particularly high learning speed.The learning speed refers to the rate at which, for each of the multiple, distinct operating points of the internal combustion engine, a specific adaptation value can be learned and thus stored in the first memory network. Decoupling the learning process from the output prevents undesirable impairment of the controller resulting from the high learning speed.

[0032] In conventional, especially adaptive, control systems, the same memory network is used to store and output the adaptation value. In other words, in conventional, especially adaptive, control systems, the adaptation value is stored in the same memory network from which it is then output. This can lead to a situation where, during the same operation of the internal combustion engine at one of the operating points, the adaptation value is stored in the same memory network and, in particular, immediately output from the same memory network. Therefore, in conventional, especially adaptive, control systems, the learning speed is severely limited, or the learning speed must be deliberately limited, because otherwise, i.e., at an excessively high learning speed, an undesirable and excessive impairment of the controller would occur.This means that if the learning speed is excessively high in conventional, especially adaptive, control systems, the controllers will overcompensate for the influence of the adaptation value on the input quantities, potentially leading to overshoot of the respective controller. This is conventionally avoided by significantly limiting the learning speed, particularly in a targeted manner. However, by decoupling the learning process from the output and vice versa, a very high, and in particular at least virtually unlimited, learning speed can be achieved, since the adaptation value is stored in the first memory network and output from the second.This prevents the adaptation value learned during the same operation of the internal combustion engine from being immediately output and thus used to influence the parameters being controlled. Instead, for example, during the first operation of the internal combustion engine at the first operating point, the adaptation value is learned as a new adaptation value and stored in the first memory network. A different, previously learned adaptation value stored in the second memory network is then output and used to influence the parameters being controlled.Then, and specifically only then, when the internal combustion engine is operated at the second operating point after the first operation, is the new, i.e., newly learned and initially stored in the first memory network, stored in the second memory network, specifically replacing the old adaptation value. Thus, for example, the old adaptation value initially stored in the second memory network is replaced by the new, i.e., newly learned, adaptation value. In other words, the new adaptation value is stored in the second memory network instead of the old adaptation value. If the internal combustion engine is then operated again at the first operating point, the newly learned adaptation value from the second memory network can be output during the third operation and used to influence the control variables.It is conceivable that during the third operation of the internal combustion engine, a further new adaptation value is learned for the first operating point and thus stored in the first memory network. For example, if after the third operation the internal combustion engine is operated at a different operating point than the first, the further new adaptation value is stored in the second memory network, specifically instead of the first new adaptation value, and so on. This allows the control system to learn, particularly at least almost continuously, and at a very high learning rate, without this very high learning rate undesirably impairing the controllers.This very high, achievable learning speed allows for particularly advantageous control and operation of the internal combustion engine, resulting in exceptionally low emissions. In other words, the high learning speed allows for particularly advantageous control of the respective input quantity, thus preventing, for example, excessive deviations of the actual mixture from the target mixture. As a rule, exceptionally low emissions can be achieved in the operation of the internal combustion engine.

[0033] In order to operate the internal combustion engine with particularly low emissions, a further embodiment of the invention provides that, during a fourth operation of the internal combustion engine following the third operation, particularly immediately, the first correction value is subtracted from the first controller value provided by the first controller and intended to influence the first quantity at the first operating point, thereby calculating a third correction value for the first operating point. Furthermore, the second correction value is subtracted from the second controller value provided by the second controller and intended to influence the second quantity, thereby calculating a fourth correction value for the first operating point. A second adaptation value is determined from the third and fourth correction values, for example, by multiplying the third correction value by the fourth correction value.The second adaptation value is stored in the first storage network during the fourth operation of the internal combustion engine at the first operating point, replacing the first adaptation value. This second adaptation value is then assigned to the first operating point. Thus, for example, the second adaptation value is the aforementioned new adaptation value. During a fifth operation of the internal combustion engine, particularly one immediately following the fourth operation, at the second operating point or at a third operating point different from both the first and second operating points, the second adaptation value is transferred from the first storage network to the second storage network and stored there in place of the first adaptation value. This second storage network then assigns the second adaptation value to the first operating point.The preceding and following explanations regarding the first adaptation value can readily be applied to the second adaptation value, and vice versa. During a sixth operation of the internal combustion engine at the first operating point, following the fifth operation, the second adaptation value is output from the second storage network, and the input quantities are adjusted accordingly. This allows for a very high learning speed, as the control system can learn quickly and, in particular, at least almost continuously, without unduly or undesirably influencing the controllers. Thus, particularly low-emission operation can be achieved.

[0034] Another embodiment is characterized by the fact that a sensor device detects, i.e., measures, the residual oxygen content in the exhaust gas of the internal combustion engine. The sensor device is, or comprises, for example, at least or exactly one lambda sensor. Depending on the detected residual oxygen content, the air-fuel ratio of the mixture, and thus of the internal combustion engine, is determined. The determined air-fuel ratio is used as one of the controlled variables in the cascade control system. One of the control deviations is a deviation of the controlled variable from one of the reference variables. In particular, determining the respective controlled variable means that the actual values ​​of the respective controlled variable, especially the air-fuel ratio, are determined, so that, for example, the respective controlled variable exhibits the respective actual values.The respective reference variable is or includes respective target values ​​for the respective controlled variable, so that the respective control deviation is a respective deviation of the respective actual value from the respective, associated target value.

[0035] A second aspect of the invention relates to a motor vehicle, also referred to simply as a vehicle, and preferably configured as a motor car, in particular as a passenger car, which has an internal combustion engine by means of which the motor vehicle can be driven. The motor vehicle is configured to carry out a method according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0036] The invention is based in particular on the following findings and considerations: Modern internal combustion engines, especially those designed as Otto cycle engines, use a so-called MSLAM system to optimize the combustion process and emissions. This typically involves a cascaded control system consisting of two control loops: a fast fuel regulator and a slower air regulator. Each of these subsystems has its own sources of disturbance that must be compensated for. In particular, if the slow control system or the slow regulator overrides the fast control system or the fast regulator, this can lead to errors in the air-fuel mixture and consequently to poor emissions performance.

[0037] A key disadvantage of conventional solutions is the mutual interference between the two control loops within the system. The slow controller, which is typically responsible for adapting or regulating the air path, can override the fast controller. This can lead to an imbalance, potentially resulting in excessive emissions if no countermeasures are taken. Furthermore, both control loops are usually based on the same measurement of the residual oxygen content, making it difficult to pinpoint the source of any error if the system malfunctions. The invention avoids these problems and disadvantages. It aims to at least reduce interactions between the nested and thus cascaded control loops through the described combined adaptation. This involves synchronizing the two control loops during adaptation.This results in the controllers no longer operating independently, but rather implementing their respective adaptation strategies in a joint process within the shared storage network, also known as the adaptation network. This allows for particularly precise and advantageous adjustment of the mixture, i.e., its composition. This leads to more efficient combustion of the mixture, enabling particularly low-emission operation. In essence, the invention combines the learning of both controllers or control loops with respect to mixture corrections to create a common, advantageous adaptation basis. This synchronization according to the invention makes stoichiometry adaptation more effective during, and in particular at least nearly, all operating phases, including cold starts and catalyst heating phases, compared to conventional solutions.The method not only enables precise presetting of the controllers and thus advantageous feedforward control, but also advantageous monitoring of the mixture. This allows potential sources of error in multi-point and / or port injection or direct injection to be detected and addressed early, which is particularly advantageous for on-board diagnostics (OBD). The invention allows at least the following advantages to be realized: - Reduction of interactions between the two control loops - Improved forward control and improved emissions results through linked adaptation - Correction of the fuel quantity, depending on a proportion of the air correction

[0038] Further details of the invention will become apparent from the following description of a preferred embodiment with the accompanying drawing. The only illustration shown is... Fig. 1. A block diagram illustrating a method for operating an internal combustion engine of a motor vehicle.

[0039] The following will be based on the only Fig. 1. A method for operating an internal combustion engine of a motor vehicle is described. For example, the method is carried out using an electronic computing device, in particular in the motor vehicle. The method employs a cascade control system 1, which has a first, in particular closed, control loop 2 and a second, in particular closed, control loop 3. The control loops 2 and 3 are cascaded, i.e., nested within each other. The first control loop 2 has a first controller 4, and the second control loop 3 has a second controller 5. It is evident that the control loops 2 and 3, and thus the controllers 4 and 5, are cascaded, i.e., nested within each other.

[0040] The first control loop 2 has a first controlled system 6. The first controller 4 provides a first manipulated variable SG1, which influences the controlled system 6, specifically by supplying the manipulated variable SG1 to the controlled system 6. The manipulated variable SG1 is thus a first manipulated variable of the first control loop 2. From the controlled system 6 and the fact that the controlled system 6 is influenced by the manipulated variable SG1, a first controlled variable RG1 of the first control loop 2 results. For example, the controlled system 6 provides the first controlled variable RG1. The first controlled variable RG1 of the first control loop 2 is fed back and compared with a first reference input FG1. By comparing the controlled variable RG1 with the first reference input FG1, a first control deviation RA1 is determined, for example, by subtracting the controlled variable RG1 from the reference input FG1.The reference input FG1 is a reference input for control loop 2 and for the first controller 4. Depending on the first control deviation RA1, controller 4 provides the manipulated input SG1, for example, by supplying controller 4 with the control deviation RA1. It can be seen that the first manipulated input SG1 of the first controller 4 is a first controller output RAG1 of the first controller 4.

[0041] The second control loop 3 comprises the second controller 5 and a second controlled system 7. It can be seen that controller 5 provides a second manipulated variable SG2, which is used as the reference input FG1 for controller 4. The manipulated variable SG2 is a second controller output RAG2 of controller 5, and this second controller output RAG2 of controller 5 is used as the reference input FG1 for controller 4. The controlled variable RG1 results in an input EG, which influences the controlled system 7, for example, by feeding the input EG into the controlled system 7. The controlled system 7, and the fact that it is influenced by the input EG, results in a second controlled variable RG2 of the second control loop 3. The second controlled variable RG2 is fed back and compared with a second reference input FG2. The second reference input FG2 is a reference input for controller 5 and a reference input of control loop 3.By comparing the controlled variable RG2 with the reference variable FG2, a second control deviation RA2 of the control loop 3 is determined, in particular by subtracting the second controlled variable RG2 from the second reference variable FG2. Controller 5 already adjusts the manipulated variable SG2, and thus the reference variable FG1 and the controller output RA2, as a function of the control deviation RA2, with the control deviation RA2 being fed to controller 5.

[0042] In cascade control 1, a first quantity of air, also referred to as air quantity, and a second quantity of a preferably liquid fuel, also referred to as fuel quantity, are influenced by means of the nested controllers 4 and 5. The air quantity and the fuel quantity are introduced into a combustion chamber of the internal combustion engine, particularly within a single operating cycle. The air quantity and the fuel quantity are also referred to as input quantities. The manipulated variable SG2, the manipulated variable SG1, the controlled variable RG1, and the controlled variable RG2 are collectively referred to as quantities. It is conceivable that a first input quantity is a first quantity and a second input quantity is a second quantity. The input quantities are influenced by the controllers 4 and 5.

[0043] In this procedure, a first correction value is determined for the first controller 4, which characterizes, that is, specifies or defines, the first control deviation RA1. A second correction value is determined for the second controller 5, which characterizes the second control deviation RA2. The characteristic that the respective correction value characterizes the respective control deviation RA1, RA2 means, in particular, that the respective correction value depends on the respective control deviation RA1, RA2 and is thus influenced, for example, in that a fluctuation or variation in the respective control deviation RA1, RA2 is accompanied by a fluctuation or variation in the respective correction value. An adaptation value common to controllers 4 and 5 is determined from the correction values, specifically by multiplying the correction values ​​together.The adaptation value is stored in a memory network common to controllers 4 and 5, and thus, for example, in an electrical or electronic data storage device of the electronic computing unit. The adaptation value is output from the memory network, whereby both the first and second input quantities are influenced depending on the adaptation value output from the memory network. This ensures particularly low-emission operation of the internal combustion engine. Reference symbol list 1 Cascade regulation 2 first control loop 3 second control loop 4 first regulator 5 second controller 6 first control loop 7 second control loop Ground floor entrance size FG1 first control variable FG2 second control variable RA1 first rule deviation RA2 second rule deviation RAG1 first controller output variable RAG2 second controller output variable SG1 first control variable SG2 second control variable

Claims

Method for operating an internal combustion engine of a motor vehicle, in which: - a cascade control is carried out, in which, by means of two controllers (4, 5) of two nested control loops (2, 3), a first quantity of air, the first quantity of which is introduced into a combustion chamber of the internal combustion engine, and a second quantity of fuel, the second quantity of which is introduced into the combustion chamber of the internal combustion engine, are influenced; - for a first controller (4, 5), a first correction value is determined, which characterizes a first control deviation (RA1) that is fed to the first controller (4); - for a second controller (4, 5), a second correction value is determined, which characterizes a second control deviation (RA2) that is fed to the second controller (5);- an adaptation value common to the controllers (4, 5) is determined from the correction values ​​and stored in a storage network common to the controllers; - the adaptation value is output from the storage network; and - both the first quantity of air and the second quantity of fuel are influenced depending on the adaptation value output from the storage network.; The method according to claim 1, characterized in that: - during a first operation of the internal combustion engine at a first operating point of the internal combustion engine, the first correction value, which characterizes the first control deviation (RA1) occurring during the first operation of the internal combustion engine at the first operating point, and the second correction value, which characterizes the second control deviation (RA2) occurring during the first operation of the internal combustion engine at the first operating point, are determined; - the adaptation value determined from the correction values ​​is stored in a first memory network, which assigns the adaptation value to the first operating point;- during a second operation of the internal combustion engine following the first operation, at a second operating point different from the first, the adaptation value is transferred from the first storage network to a second storage network and stored in the second storage network, which assigns the adaptation value to the first operating point; and - during a third operation of the internal combustion engine following the second operation, at the first operating point: ◯ the adaptation value is output from the second storage network; and ◯ both the first quantity and the second quantity are influenced depending on the adaptation value output from the second storage network.; The method according to claim 2, characterized in that: - during a fourth operation of the internal combustion engine following the third operation at the first operating point: ◯ the first correction value is subtracted from a first controller value provided by the first controller (4) and intended to influence the first quantity, thereby calculating a third correction value for the first operating point; and ◯ the second correction value is subtracted from a second controller value provided by the second controller (5) and intended to influence the second quantity, thereby calculating a fourth correction value for the first operating point;- a second adaptation value is determined from the third and fourth correction values, which, during the fourth operation of the internal combustion engine at the first operating point, is stored in the first storage network instead of the adaptation value, which assigns the second adaptation value to the first operating point; - during a fifth operation of the internal combustion engine following the fourth operation at the second operating point or at a third operating point of the internal combustion engine that differs from the first and second operating points, the second adaptation value is transferred from the first storage network to the second storage network and stored in the second storage network instead of the first adaptation value, which assigns the second adaptation value to the first operating point;and- during a sixth operation of the internal combustion engine following the fifth operation at the first operating point:◯ the second adaptation value is output from the second storage network; and◯ both the first quantity and the second quantity are influenced depending on the second adaptation value output from the second storage network.; A method according to claim 2 or 3, characterized in that: - a residual oxygen content in the exhaust gas of the internal combustion engine is detected by means of a sensor device; - a combustion air ratio of the internal combustion engine is determined as a function of the detected residual oxygen content; - the determined combustion air ratio is used as a control variable of the cascade control; and - one of the control deviations is a deviation of the controlled variable from a predetermined or predeterminable reference variable of the cascade control. Motor vehicle, with an internal combustion engine by means of which the motor vehicle can be driven, wherein the motor vehicle is designed to carry out a method according to one of the preceding claims.

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