Method and apparatus for controlling an internal combustion engine

Abstract

The invention relates to a method for controlling an internal combustion engine (2) in a vehicle (1), the internal combustion engine (2) being operated with a fuel. The properties of the fuel are transmitted to a control device (3) for controlling the internal combustion engine during a refuelling process, during which fuel is filled into a tank of the vehicle (1), and are taken into consideration for controlling the internal combustion engine (2).

Description

[0001] R. 415119

[0002] - 1 -

[0003] Description

[0004] title

[0005] Method and device for controlling an internal combustion engine

[0006] State of the art

[0007] The invention relates to a method and a device for controlling an internal combustion engine in a vehicle, wherein the internal combustion engine is operated with a fuel.

[0008] A method is already known from DE 10 2017 215 247 A1 in which data relating to the fuel is transmitted to the vehicle being refueled during the refueling process. The data transmitted in this way is used to determine the aging of the vehicle's exhaust aftertreatment system.

[0009] Advantages of the invention

[0010] In contrast, the method or device according to the invention has the advantage that the operation of the internal combustion engine is adapted to the specific fuel used. This allows for improved operation of the internal combustion engine with the fuel supplied, thereby increasing the efficiency and cleanliness of the engine's operation.

[0011] Further advantages and improvements result from the features of the dependent patent claims. A particularly precise determination of the ignition angle can be achieved if the octane rating of the fuel is taken into account. Furthermore, the ignitability of the fuel, in particular a possible latest ignition angle, can be considered as a property. In particular, this allows for the optimization of the heating operation of the catalytic converter of the internal combustion engine. Cold start of the internal combustion engine R. 415119

[0012] - 2 - can be optimized by taking the fuel's vapor pressure into account. Similarly, the fuel's evaporation behavior can be used to optimize the operation of a tank venting system. This is particularly important if the tank venting system has a reservoir for storing evaporated fuel. Furthermore, the fuel composition can be considered to improve the lambda control of the internal combustion engine's exhaust gases. This is achieved, in particular, by improving the lambda value's feedforward control. Additionally, improved exhaust emission predictions can be made based on the fuel composition. Finally, the fuel's properties can be used to detect and potentially prevent incorrect refueling.Furthermore, general expected values ​​for the operation of the internal combustion engine can be determined based on the properties of the fuel and compared with the actual operation of the engine. This allows for a general diagnosis of the internal combustion engine and / or the fuel. Additionally, an environmental index, such as a CO2 footprint, can be determined based on the fuel's properties. Finally, the fuel's properties can ensure that the internal combustion engine is only operated with fuel approved for that specific engine.

[0013] Drawings

[0014] Exemplary embodiments of the invention are shown in the drawing and explained in more detail in the following description.

[0015] Figure 1 shows a vehicle with an internal combustion engine during a refueling process.

[0016] Description of the invention

[0017] Figure 1 schematically shows a vehicle 1 with an internal combustion engine 2 and a control unit 3 for controlling the internal combustion engine 2. This vehicle 1 is shown during a refueling process, in which fuel is pumped from the pump 4 into the vehicle 1 via a hose 5. In addition to liquid fuels such as gasoline or diesel, optionally with a proportion of white- R. 415119

[0018] - 3 - In addition to liquid fuels such as ethanol or methanol, gaseous fuels such as H2, CNG or LNG can also be filled into the vehicle 1 from the pump 4.

[0019] Furthermore, data is exchanged between the fuel dispenser 4 and the vehicle 1, for example via radio signals 6. This data exchange transmits information regarding the properties of the injected fuel. This fuel data was previously determined by a fuel manufacturer, for example as part of fuel quality control, and subsequently communicated to the fuel dispenser 4. Some fuel properties can also be determined by a sensor on the fuel dispenser 4 or at a filling station. Alternatively, the transmission of the injected fuel properties can also occur via other means.For example, pump 4 can only transmit a fuel type designation, and the vehicle uses the fuel type designation or batch number to determine the relevant properties from a third party who provides the corresponding data.

[0020] Furthermore, instead of fuel pump 4, a gas station can also provide the data, or the relevant properties can be determined by vehicle 1 via a direct communication connection over the internet. All solutions are possible where an infrastructure exists that transmits the fuel properties to the control unit 3 in vehicle 1, and where these properties of the dispensed fuel are used by the control unit 3 to control the internal combustion engine 2. Communication can also take place from vehicle 1 to fuel pump 4, the gas station, or the infrastructure for managing the fuel properties. In this way, measured values ​​from vehicle 1 regarding the dispensed fuel can also be transmitted back to the infrastructure for managing the fuel properties.

[0021] The properties communicated to vehicle 1 include all fuel properties according to DIN EN 228. These include the fuel density (kg / M), the calorific value (MJ / kg), the dry vapor pressure equivalent at 38°C (kPa), E70 (vol% evaporated at 70°C), E100 (vol% evaporated at 100°C), E150 (vol% evaporated at 150°C), the alcohol content by volume, and R. 415119.

[0022] - 4 -

[0023] Ethers, aromatics, and other additives, as well as other properties, may also be of interest. Other fuel properties not specified in EN228 may include the content of other hydrocarbons, the C9 aromatic content, the proportion of fuel produced using sustainable energy, and the viscosity.

[0024] These properties can then be taken into account by the control unit 3 for the control of the internal combustion engine. Specific fuel properties may be relevant for controlling individual aspects of the internal combustion engine.

[0025] The knock resistance of the fuel is particularly important for controlling the ignition timing of the internal combustion engine. This knock resistance is typically referred to as the octane rating (RON) and is determined for each gasoline fuel. The octane rating is also typically displayed as a number (usually a minimum value) directly on the fuel pump.

[0026] For controlling the heating operation of an internal combustion engine, which ensures rapid heating of the catalytic converter upon engine start, it is particularly important to determine the latest ignition angle at which combustion of the fuel can be guaranteed. This latest ignition angle is determined by the vaporization properties of the fuel, such as its vapor pressure (VP) or whether it is E70, E100, or E150. Based on the fuel's properties, an appropriately adapted heating operation for the catalytic converter of the internal combustion engine can be implemented.

[0027] The evaporation properties of the fuel are also important for implementing adapted operation during a cold start of the internal combustion engine. It is also essential that the fuel composition varies with the season to ensure reliable engine starting depending on the ambient temperature. Particularly when temperatures change very rapidly, adapted operation may be necessary depending on the fuel composition used. For example, the driver might also be informed, R. 415119

[0028] - 5 - if environmental conditions are not compatible with the properties of the fuel, the system may proactively recommend refueling.

[0029] Furthermore, internal combustion engines are equipped with a fuel tank venting system that collects fuel, which evaporates particularly when the engine is stationary, in an activated carbon filter. Upon subsequent operation, this stored fuel is then fed back into the engine for combustion. The frequency with which the activated carbon filter needs to be emptied depends on the fuel's properties, especially its evaporation behavior. Therefore, the operation of the fuel tank venting system is advantageously adapted to the fuel's evaporation characteristics.

[0030] Furthermore, during the operation of an internal combustion engine, lambda control is typically employed, meaning the fuel-air ratio is adjusted based on a measurement signal from an oxygen sensor in the exhaust gas. Knowing the fuel's properties allows for precise feedforward control, meaning that even without using feedback from the measurement signal, an accurate fuel-air ratio can be achieved. The feedback from the oxygen sensor then only needs to regulate a relatively small difference between the feedforward value and the measured values. Overall, this improves the quality and speed of the lambda control.

[0031] Furthermore, a multitude of fuel properties can be considered together to predict the exhaust emissions of the internal combustion engine. The fuel's evaporation behavior and the proportion of heavy aromatics are particularly important in this regard.

[0032] The properties of the fuel can also be used to detect or prevent misfuelling. For this to work, the fuel properties must be transmitted to the vehicle before the tank is filled. If feedback from the driver is also received... (R. 415119)

[0033] - 6 - if the material is added to the tank device, the output of faulty fuel can be suppressed immediately.

[0034] Furthermore, the fuel's properties can be stored in the vehicle over time. For this purpose, the vehicle is equipped with a corresponding storage system that records the fuel's properties and the amount of fuel dispensed each time it is refueled. Based on the fuel's properties and the stored quantity over time, it is then possible to predict the maintenance condition of individual components or the vehicle as a whole. Particularly with a variable methanol content in the fuel, the wear on the internal combustion engine can vary. Additionally, the wear on the spark plugs can differ depending on the fuel.

[0035] The fuel properties transmitted during refueling can also be used to determine an expected value for the operation of the internal combustion engine. Deviations between the properties transmitted during refueling and the actual operation of the internal combustion engine can then indicate that the reported fuel properties are faulty. This is particularly relevant if such deviations occur in a large number of vehicles. Therefore, any such deviation must be reported back from the vehicle to the fuel supplier to enable appropriate fuel quality control.

[0036] Furthermore, fuels produced using renewable energy sources can be used to operate an internal combustion engine. Such "e-fuels" are significantly more environmentally friendly than fuels produced by processing petroleum. Accordingly, these fuels can be assigned an environmental index or a so-called CO2 footprint, which is then attributed to the respective operation of the internal combustion engine.

[0037] Furthermore, the vehicle or the internal combustion engine 2 installed in the vehicle 1 may be designed for operation with certain approved fuels. For example, in the future, new vehicles may only be approved for operation with synthetically produced fuels from renewable sources. (See R. 415119.)

[0038] - 7 - The purpose of the fuel would then be its suitability for use in such vehicles. This property, suitability for use in specific vehicles, would then be further ensured by appropriate certification and safeguards using suitable cryptographic methods. Misfueling with conventional fuels could also be prevented.

[0039] The internal combustion engine 2 is controlled by a control unit 3. Furthermore, the vehicle 1 is equipped with additional means to communicate with the fuel dispenser 4 or an infrastructure for managing fuel properties and to store these properties within the vehicle. These functions can also be partially or completely performed by the control unit 3.

Claims

R. 415119 - 8 - Patent claims 1. Method for controlling an internal combustion engine (2) in a vehicle (1), wherein the internal combustion engine (2) is operated with a fuel, characterized in that the properties of the fuel are transmitted to a control unit (3) for controlling the internal combustion engine (2) during a refueling process in which fuel is filled into a tank of the vehicle, and that properties of the fuel are taken into account for controlling the internal combustion engine (2).

2. Method according to one of the preceding claims, characterized in that an octane number of the fuel is taken into account as a property for determining the ignition angle during the operation of the internal combustion engine (2).

3. Method according to one of the preceding claims, characterized in that a latest possible ignition angle of the fuel for a heating operation of a catalyst of the internal combustion engine (2) is taken into account as a property.

4. Method according to one of the preceding claims, characterized in that a vapor pressure of the fuel for a cold start of the internal combustion engine (2) is taken into account as a property.

5. Method according to one of the preceding claims, characterized in that the evaporation behavior of the fuel is taken into account as a property for the operation of a tank vent of the internal combustion engine (2), with a reservoir for storing evaporated fuel.

6. Method according to one of the preceding claims, characterized in that a composition of the fuel is used as a property for a pre-control of a lambda control of the exhaust gas of the internal combustion engine (2). R. 415119 - 9 - 7. Method according to one of the preceding claims, characterized in that a composition of the fuel is used as a property for predicting exhaust emissions of the internal combustion engine (2).

8. Method according to one of the preceding claims, characterized in that the properties of the fuel are used for misfuelling detection.

9. Method according to one of the preceding claims, characterized in that properties of the fuel are stored over time for a vehicle and that the stored properties of the fuel over time are used to predict necessary maintenance measures of the vehicle.

10. Method according to one of the preceding claims, characterized in that the properties of the fuel are used to determine an expected value for the operation of the internal combustion engine (2), that the expected value for the operation of the internal combustion engine (2) is compared with the actual operation of the internal combustion engine, and the properties of the fuel are checked on the basis of the comparison.

11. Method according to one of the preceding claims, characterized in that the properties of the fuel are used to determine an environmental index for the operation of the internal combustion engine (2), for example a CO2 footprint.

12. Method according to one of the preceding claims, characterized in that the properties of the fuel are used to ensure the use of a fuel approved for the operation of the internal combustion engine.

13. Device for controlling an internal combustion engine (2) in a vehicle, wherein the internal combustion engine (2) is operated with a fuel, characterized in that means are provided to adjust the properties of the fuel during a R. 415119 - 10 - The refueling process, in which fuel is filled into a tank of the vehicle (1), is transmitted to a control unit for the control of the internal combustion engine (2), and the properties of the fuel are taken into account by the control unit (3) for the control of the internal combustion engine (2).

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