Method for aftertreatment of exhaust gas from hybrid machines

Abstract

To provide an efficient method of post-processing of exhaust gas of a hybrid vehicle.SOLUTION: A method of exhaust gas post-processing of a hybrid machine including at least one electric motor 2 and one combustion engine 3 includes: operation of a hybrid machine in a first operation mode in which only the electric motor is turned on and the combustion engine is turned off; determination on whether an exhaust gas post-processing system 20 of the hybrid machine needs to be warmed; and at least temporary connection of the combustion engine to warm the exhaust gas post-processing system when warming is needed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for exhaust gas aftertreatment in a hybrid machine, as well as a computing unit and a computer program for its implementation. [Background technology]

[0002] A hybrid machine, such as a hybrid vehicle (hereafter referred to as "hybrid" for short), by definition includes a combustion engine and an electric drive.

[0003] During the switch-on process of the vehicle or machine, the electric motor is usually utilized first, and during further operation the combustion engine is at least partially engaged or operated instead of the electric motor in order to increase the overall power output, reduce power consumption and / or extend the driving distance and driving time.

[0004] The combustion engine used generates combustion gases according to the power demanded from the combustion engine, as in conventional machines. However, unlike conventional drives, the hybrid combustion engine is not forced to start when the machine is stationary, but is started frequently during driving. It is also usually the case that the higher the power demanded, the higher the engine emissions.

[0005] This means that real driving emissions (RDE) are often much higher than those detected in legal laboratory test cycles. These emissions are also regulated for hybrids by certain RDE values, as largely laid down in EU Commission Directive 2017 / 1154, which came into force on 7 June 2017. The aim is essentially to achieve emission values ​​for hybrids comparable to those for conventional drives, or at least to adhere to these limit values.

[0006] To comply with these emission limits, exhaust gas aftertreatment is essential, as in the conventional case. However, exhaust gas aftertreatment systems require a certain operating temperature to ensure the harmful gas exchange necessary for compliance with emission limits, and they only function optimally within a certain temperature range. It is therefore advantageous if the exhaust gas aftertreatment system can warm up quickly and does not fall below its minimum operating temperature during operation.

[0007] Exhaust gas aftertreatment systems are conventionally heated by the exhaust gas flow, but the flow rate of harmful substances that is not sufficiently treated by the time the operating temperature of the exhaust gas aftertreatment system is reached can be quite, and unacceptably, high. This is particularly problematic in the case of hybrids, where high power is often spontaneously and irregularly called for from the combustion engine, while only the electric motor is connected during other phases. This means that if the combustion engine is briefly connected to provide the power required for driving, the exhaust gas aftertreatment system, which is not yet (or is no longer) sufficiently heated at that time, cannot sufficiently replace the harmful gases. This situation therefore requires much more effort for exhaust gas aftertreatment than in the case of vehicles or machines with conventional drives. Summary of the Invention

[0008] According to the invention, a method for exhaust gas aftertreatment in a hybrid machine, in particular in a hybrid vehicle, as well as a computing unit and a computer program for its implementation are proposed with the features of the independent claims. Advantageous embodiments are the subject of the dependent claims and the following description. Effect of the Invention

[0009] The invention is based on a measure to check whether in a hybrid machine with an electric motor and a combustion engine it is necessary to warm up the exhaust gas aftertreatment system in order to lower the emission values ​​(which also include carbon dioxide) and accordingly to switch on the combustion engine in electric operation at least temporarily, so that by switching on the combustion engine as targeted, the exhaust gas aftertreatment system can be prepared for a higher engine power that is required at a later time.

[0010] In one embodiment, whether or not it is necessary to warm up the exhaust gas aftertreatment system can be determined based on an evaluation of measurement data, which measurement data has been obtained at least in part during previous operation of the hybrid machine and which include, for example, values ​​relating to the temperature of the exhaust gas aftertreatment system, power data of the electric motor and / or the combustion engine, or the composition of the exhaust gas flow.

[0011] Deciding whether or not it is necessary to warm up the exhaust gas aftertreatment system may also involve a prediction of future measurement data expected within a certain time, where the prediction is calculated based on stored measurement data, for example from previous driving or from vehicle data collected with other vehicles. Alternatively or in addition, the prediction could be based on data determining the necessary and foreseeable driving power within a certain future time. Such data may be the time of day, the calendar date, the interior and exterior temperature and weather data (temperature, humidity, light intensity, amount of precipitation, measurements of rolling resistance and slippage of the vehicle wheels), optical traffic sign recognition, the state of charge of the energy accumulator ("battery") and predictions (for example local weather forecasts). Such data may also be navigation data, for example on which the road geometry, speed limits, gradients, curves and / or stops are known. Such data may also be based on the real traffic situation, measured for example by a range radar, or based on or calculated from the predicted traffic situation of the section to be traveled, its traffic density, average speed (for example congestion forecasts). Further examples that can be used for predicting future measured values ​​include the vehicle settings actually chosen by the driver (in particular the so-called "drive mode", e.g. autonomous driving, partially autonomous driving, assisted driving or purely manual driving, fuel-optimized driving, comfort-oriented driving, time-optimized driving or dynamic driving), the driver profile based on historical data (in particular driving dynamic characteristics such as acceleration behavior, distance-keeping behavior, stopping behavior, braking behavior, especially when this leads to power recall or electrical energy recovery), and preferences for temperature regulation and air conditioning (e.g. pre-cooling or standard heating) before and during vehicle operation (especially when these require high power).

[0012] The application of the measured and calculated data is not necessarily limited to individual machines. Direct or indirect communication of two, a few or more machines in a group or groups connected to each other is advantageous. It is advantageous to connect the machines to the Internet in order to transmit, store and evaluate these data for later similar or other applications. The evaluation, according to one embodiment, preferably compares the measured and / or predicted data with at least one given threshold value and determines that warming is necessary when this at least one given threshold value is below or above (e.g. the temperature of the exhaust gas aftertreatment system is too low). In this way, it can be ensured that the exhaust gas aftertreatment system always remains within a minimum or optimal operating temperature range, or at least at a predetermined minimum temperature at which a sufficiently fast re-warming can be initiated.

[0013] In a further embodiment, the combustion engine can be switched on at a predefined time and / or within a predefined time period, which can be stored and can be adhered to separately or in combination with further evaluations and predictions. Optionally, this predefined time and / or time period can be changed during operation depending on stored or known measurement data. This change can be made once or can be stored as a permanent change.

[0014] In a further embodiment, electrical heating of at least a portion of the exhaust gas aftertreatment system can be carried out within a given time before the combustion engine is switched on for warming the exhaust gas aftertreatment system, so that the time during which the combustion engine must be switched on for warming purposes can be kept short or a small power output can be called for from the combustion engine during this time.

[0015] It is also advantageous to implement the method according to the invention in the form of a computer program or computer program product with a program code for performing all the method steps, since this can be implemented with particularly low costs, and is particularly advantageous when the running control device is still used for further functions and is therefore in any case at hand. Suitable data carriers for providing the computer program are in particular magnetic, optical and electrical memories, such as hard disks, flash memories, EEPROMs, DVDs and others. Downloading of the program via a computer network (Internet, intranet, mobile radio communication, etc.) is also possible.

[0016] A computing unit according to the invention, for example a control device of a motor vehicle, is set up, in particular in terms of program technology, to carry out a method according to the invention.

[0017] The invention is depicted diagrammatically in the drawing by way of an embodiment and will be explained in more detail below with reference to the drawing. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of an exhaust gas aftertreatment system according to one embodiment of the present invention; [Diagram 2] 1 is an example of a flowchart of an overall method according to an embodiment of the present invention. [Diagram 3] 1 is a flow chart of exemplary steps of a method according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 1 shows a schematic diagram of an example of a system, for example a vehicle, in which the method according to the invention can be applied. Here, a drive system 1 is operated as a hybrid combination of an electric motor 2 and a combustion engine 3. The exhaust gases of the combustion engine are led via a ducting system 22 to an exhaust gas aftertreatment system 20. Optionally, an electric heater 24 may be provided for heating parts of the exhaust gas aftertreatment system.

[0020] The control device 10 can be employed for controlling the motor 2 / engine 3 and can also be used for controlling and monitoring the operating temperature of an exhaust gas aftertreatment system 20 within the meaning of the present invention. Although the control device is depicted here as a single module, it can also be several separate or combined modules with different roles. A suitable memory device 11 can be connected to the control device.

[0021] For example, the exhaust gas aftertreatment system 20, motor 2 / engine 3 may be fitted with different sensors 31, 32, 33, 34 in the exhaust gas line 22 or at other suitable locations, the data of which may be read by the control device or transferred to the control device from other locations.

[0022] The basic flow of a method according to the invention is illustrated in FIG.

[0023] In a first embodiment of the hybrid machine, the hybrid is first operated in electric drive mode in step 200, i.e. only the electric motor 2 is used while the combustion engine 3 is switched off. Typically, the control device 10 or another hybrid control device controls when and for how long the combustion engine is engaged, for example to increase drive power or to save electrical energy.

[0024] In one embodiment, in step 210 it is first determined whether or not it is necessary to warm up the exhaust gas aftertreatment system 10. If so, in step 230 the connection of the combustion engine can be started in order to warm up the exhaust gas aftertreatment system. Optionally, a heating 220 of the components can already take place prior to this, for example via an electric heater, as will be explained in more detail further below.

[0025] For example, in a simple embodiment, it can be decided that in the electric drive mode, the combustion engine is connected for warming purposes at defined time intervals. The duration of the combustion engine connection and the operating state of the combustion engine selected for this can also be predefined, resulting in an irregular connection or a regular periodic connection. Alternatively, the combustion engine can be operated for a longer time, optionally with a power call that varies depending on the situation and in operating states that vary accordingly, until a constant connection (for example at a defined power in a selected operating state) is achieved, in particular when the required operating temperature of the exhaust gas aftertreatment system cannot be reached. In this way, a time rule for which the combustion engine connection is to be performed can be determined and stored. The control device can call this rule again and initiate the combustion engine connection accordingly.

[0026] For example, in one embodiment, it can be decided that in the electric drive mode the combustion engine is connected for heating purposes and that the power generated therein is either used for propelling the vehicle (or, correspondingly, for mechanical work in agricultural or civil engineering machinery) or for charging an electric energy store ("battery") depending on the situational conditions. The combustion engine can then be operated in a particularly favorable manner in terms of heat rejection to the exhaust gas aftertreatment system, emissions and fuel consumption. This is particularly successful even in situations where the power output of the combustion engine is not or hardly useful for the performance of mechanical work (e.g. propulsion). The duration of the combustion engine connection and the operating states of the combustion engine selected therefor can likewise be predetermined, resulting in an irregular connection or a regular periodic connection.

[0027] Similarly, the control device can determine whether heating is required and control the combustion engine connection based on measured or stored data, and can also change the predetermined conditions for the combustion engine connection during operation based on such data.

[0028] There are various ways of evaluating the data and controlling the connections. In Fig. 3, an example of a detailed flow of the decision step 210 from Fig. 2 is shown in the form of a further process flow diagram, where the steps are not necessarily required to be performed in full or in the exact order shown. Also, further method steps not depicted in the diagram may be performed. The flow described describes only one possible embodiment.

[0029] The control device receives measurement data from the sensor in step 310. Alternatively, this data can be read from and transferred to another device.

[0030] In step 320, this data is evaluated and processed, for example averaged over a particular time period, or brought into a given form, or converted into a suitable value by a predetermined calculation method.

[0031] Subsequently, in step 330, this obtained value is averaged together with one or more limit values. If the value is within a predefined range, the control device continues to examine the measured values, evaluates the next set of measurement data and returns to step 310 (or alternatively 320). However, if a predefined limit value or threshold is exceeded, indicating that it is essential to warm up the exhaust gas aftertreatment system, this warming is initiated in step 340. The initiation of the warming can be an immediate connection of the combustion engine, a pre-heating of the exhaust gas aftertreatment system or a specific time for starting the warming. The following steps then correspond to steps 220, 230 in FIG. 2.

[0032] Similarly, rather than smoothing the evaluated real measurement data with a threshold in step 330, or simply smoothing directly, it is also possible to instead predict future values ​​based on the values ​​at hand using various calculation methods (step 370).

[0033] Once a suitable prediction has been made, the values ​​thus obtained can again be compared with the thresholds for a certain future time or duration in step 380. If the calculated future values ​​are within given limits, no warming is planned, further values ​​are evaluated or predicted and step 370 is repeated. However, if at least one of the predicted values ​​important for the decision is outside the given limits (above and / or below the limits depending on the value), a warming of the exhaust gas aftertreatment system is started in step 340. Here again, this can be an immediate warming, a decision when to start the warming or when to switch on the combustion engine or a change in the rules governing the connection and warming. It is obvious that real measurement data can also flow into the prediction in step 370 from step 310 or step 320.

[0034] Instead of or in addition to the evaluation or prediction based on the actual measurement data in steps 320 and 370, the control device can also use further data in its decision, obtained from other sources or stored in the control device or connected to it. The control device obtains these data in step 360 via a recall from a storage device or a communication connection. These data can then be fed into the threshold smoothing process, either directly or after prior secondary processing, alone or together with the actual data.

[0035] For example, measurement data obtained during the operation of the hybrid to date can be acquired (310) from sensors 31, 32, 33, 34 and other elements and evaluated (320). In addition, it is possible to use values ​​that are continuously measured in real time and / or to use data that have been measured and stored over a longer period of time or that are at the disposal of the system via a communication connection. Such measurements can include, for example, the temperature at one or more points in the exhaust system, in particular the temperature measured by sensor 31 at a suitable point in the exhaust gas aftertreatment system, but alternatively or in addition also the temperature of the exhaust gas stream at sensor 33 before or sensor 34 after the exhaust gas aftertreatment system. The measurements can further include exhaust gas characteristic values ​​related to the exhaust gas stream and in particular data related to the composition and / or concentration and / or volume and / or composition of harmful substances contained therein or that can be inferred therefrom. These can likewise be measured by sensor 32 before and / or after the exhaust gas aftertreatment system or calculated from data. Power data of the motor and engine, such as the average power over a given time period or the maximum power called, can also be evaluated, as can the energy consumption and the fuel consumption for the drive. All these and further data can be evaluated individually or in combination in order to control the heating of the exhaust gas aftertreatment system. The data can be present in a stored form or can be called up in an adaptive manner (360) to complement the actual measured data. It is self-evident that the evaluation of the measured values ​​can be applied in combination with a defined time interval, as described above.

[0036] One or more thresholds can then be applied in step 330 to determine whether heating is necessary and what measures to take for heating. When a threshold (e.g. required or optimal operating temperature) is fallen below and / or when a threshold (e.g. of harmful substances in the exhaust gas stream) is exceeded, a decision can be made in step 340 whether and when to switch on the combustion engine. Optionally, the system can identify which thresholds are valid for the currently traveled section, for a given section or for a currently predicted future section. If the vehicle is, for example, in a particular area with a particular administrative control (e.g. legislation), which is known via the vehicle's side-location system, the currently used thresholds can be adapted accordingly, for example to localizable boundaries of a particular regional zone, for example urban living spaces such as city centers, rural and agricultural areas (e.g. areas where combines are operated in a different mode than on country roads outside rural areas to cultivated fields), coastal areas, harbors (as distinguished from free water and open sea waters). In this way, it is possible to take into account operational limitations of the combustion engine which are, for example, time-specific or, for example, location-specific in a city center.

[0037] The measured and / or predicted data can also be used in step 340 to change already determined rules for the combustion engine connection. For example, if the evaluation of the measured data shows that a limit value or threshold value determined according to the rules is reached in a particular situation, the predefined time until the next connection for heating can be adapted or temporarily shortened accordingly in the power call. This adaptation can also be determined permanently. Thus, the connection rules can be variably adapted in hybrid operation, in particular in the manner of a feedback control, which continuously checks whether the currently applied rules correspond to the optimal operation of all components or if the rules are adapted. Different rules can be determined for different operating modes, i.e. for purely electric operation, for purely combustion engine operation and for combined operation of electric motor and combustion engine.

[0038] Besides directly evaluating the measured data and taking a decision on the basis of the results, in one possible embodiment of the invention, a prediction can also be made in step 370. The prediction can involve a numerical extrapolation based on the measured data for a defined future time, but also more complex prediction and feedback methods, for example fuzzy logic or neural networks. If it is known (360), for example from previous operation or from stored data, how the exhaust emission values ​​increase or decrease depending on the combustion engine connection, this data can be used to assess by suitable calculations the behavior of the temperature and emission values ​​to be expected in the future, and on this basis a rule for the combustion engine connection can be determined (370). In addition, the predicted data is again compared with the limit values ​​in step 380. This step can be compared with step 330 on the actual measured values.

[0039] Deciding whether heating is necessary and making a corresponding prediction for a given time can also be based on navigation data, traffic forecasts, weather forecasts and similar predictions. If it is possible to determine, for example via the vehicle's navigation system, which section the vehicle is in, data on this predicted section can be derived for at least a limited time, for example the time until the next turnoff. Such data may include information on the speed profile of the vehicle there, deceleration due to congestion, traffic lights, field signs, marine signs, etc. and / or section profiles such as climbs, gradients, speed limits, etc., as well as additional information via communication connections, for example local weather conditions from the Internet. The vehicle settings selected by the driver (for example autonomous or fuel-optimized driving), a typical driver profile or the user's own preferences, for example the cabin air conditioning, acceleration and braking behavior, etc., can also be used for such predictions. Based on these, the system can assess the power values ​​to be called up at the next time and determine according to defined rules whether and when the operating temperature of the exhaust gas aftertreatment system is predicted to fall below a threshold value, whether and when heating is required. Here again, in order to be able to predict the values ​​as accurately as possible, such data can be combined with real measured values ​​or with previous measured values ​​obtained from driving the hybrid as described above. Also, certain characteristic data can be stored in the system beforehand or can be called up via a communication connection, so that, for example, the manufacturer can explain the relationship between temperature, power and emission values ​​taking into account the additional information mentioned above and apply them in the calculations and predictions.

[0040] Alternatively or in addition to local regulations, the measurement data can be transmitted via a communication connection to another location, for example a central processing unit, which evaluates the data and / or calculates corresponding predictive data and sends only the resulting engine connection rules back to the local control device.

[0041] A further means for achieving the requisite operating temperatures consists in directly heating parts of the exhaust gas aftertreatment system (or the entire system), preferably by means of an electric heater 24. Thus, for example, sensors, gas mixing elements, catalysts, piping and other components could be electrically heated within certain ranges or all together. This has already been successfully achieved with low-voltage hybrids, but higher voltages would still be advantageous.

[0042] In particular, electrical heating of parts of the exhaust gas aftertreatment system can already be carried out when the combustion engine is not or has not yet been connected (see step 220 in FIG. 2). The electrical heating can then be carried out before the machine is started or before the combustion engine is connected, either continuously at defined intervals or with a modulated power that is always constant within a limited time. The electrical heating can then be carried out regardless of whether the combustion engine is connected in order to increase the drive power or, as in the invention, to increase the temperature of the exhaust gas aftertreatment system. For example, the above-mentioned predictive model can be used in order to preheat the system for drive purposes already by electrical heating when a high drive power is expected and therefore the connection of the combustion engine is expected.

[0043] As soon as the control device determines that the combustion engine is to be connected soon, it can send a signal for electrical heating of the corresponding elements. Alternatively, it could determine, for example, that electrical heating is to be performed at certain time intervals when the combustion engine is cut off, even when the combustion engine is not connected at the expected time or is not reliably connected. Likewise, any temperature measurement can again be incorporated into the electrical heating decision, so that when the threshold temperature is lowered, electrical heating of the exhaust gas aftertreatment system is performed until a desired minimum temperature is reached. When the minimum temperature is reached, the combustion engine can be switched on in addition or instead. In one possible embodiment of the invention, a signal for the combustion engine connection is sent only when the exhaust gas aftertreatment system reaches a predetermined temperature.

[0044] It is also possible that when the engine control device decides or plans to switch on the combustion engine at high power, a first stage of switching on the combustion engine for warming purposes is always performed first, where the combustion engine is operated at low power, and the remaining drive power is subsequently provided by the electric motor. Then, after a certain time or after the exhaust gas aftertreatment system has reached the desired operating temperature, the power of the combustion engine can be increased. Similarly, the power of the combustion engine could be increased stepwise or continuously from the warming stage.

[0045] The control device which takes over the connection of the combustion engine for warming purposes, the identification of the control data, the prediction of the data and, for example, the monitoring of temperature values, may be a control device of the engine, but it may also be another control device or a separate control device which takes over other roles or is set up solely for control purposes.

[0046] When the combustion engine is to be connected to heat the exhaust gas aftertreatment system, the control device then ideally allows only such an output that the emissions always remain below a predefined limit value. In other words, the emissions resulting from the connection of the combustion engine should be constantly integrated into the heating control so that the limit value is not exceeded. The combustion engine runs at a relatively low output for the heating. The remaining power required by the vehicle is preferably subsequently provided by the electric motor.

[0047] Thus, in one possible embodiment, after connection to the combustion engine, the volume and / or composition of the exhaust gas flow is at least temporarily and partially measured by one or more sensors or calculated from stored data or data called up via a communication connection. This calculation can be performed continuously or at defined intervals. A control device, for example an engine control device, processes the sensor signals and monitors whether the threshold values ​​are adhered to. As threshold values, locally defined limit values, i.e. for example statutory limit values, as well as other or additional, different threshold values ​​(for example defined by the manufacturer) can be used. To determine the introduction of various measures for improving the emission values, it would be conceivable, for example, to use threshold values ​​with different stages below the statutory limit values.

[0048] The threshold value is preferably stored in a memory unit of the processing controller.

[0049] If the measured sensor signal received by the control device indicates that a threshold value in the exhaust gas flow is exceeded, the control device can then implement additional measures that may lead to minimizing the operating temperature of the exhaust gas aftertreatment system or to a specific desired operating temperature.

[0050] In this case, various methods are possible for further warming up the exhaust gas aftertreatment system: for example, a limited, particularly suitable for warming, exhaust gas flow can be conducted into the exhaust gas aftertreatment system continuously or for a limited time, for example for a time shorter than 600 seconds, preferably for a time shorter than 60 seconds, particularly preferably for only a few seconds, which exhaust gas flow can warm up the exhaust gas aftertreatment system for the subsequent, hotter exhaust gas flow.

[0051] For this purpose, for example, various substances suitable for increasing the temperature of the exhaust gas aftertreatment system can be added to the exhaust gas stream. On the one hand, it is possible to feed combustible substances to the exhaust gas stream inside the engine or directly to the exhaust gas aftertreatment system, so that they can be at least partially converted to heat through a combustion process. Such substances are, for example, fuels, nitrogen oxides (NO), methanol and other additives well known to those skilled in the art, which can be injected at suitable locations. Alternatively or in addition, adsorbable / absorbent substances can be added to the combustion gas and / or fed to the exhaust gas stream, leading to said substances at least partially heating the exhaust gas aftertreatment system. Suitable substances for this are also known, for example water, hydrogen urea solution (HWL), ammonia (NH3), nitrogen oxides (NO, NO2), etc. It is desirable to regenerate the adsorption / absorption sites of the exhaust gas aftertreatment system at a later time.

[0052] It is also advantageous to combine various measures for heating the exhaust gas aftertreatment system with one another, for example - not necessarily completely and not necessarily in this chronological order - electronic heating measures in order to bring at least one (possibly only later) gas-flowing, preferably functional unit (e.g. mixing tube, gas mixer, catalyst, etc.) to a minimum operating temperature, measures to generate absorption heat by molecular absorption in the exhaust gas aftertreatment system, for example as a result of the metering of reducing agents (e.g. NH3, HWL, propene, etc.) and / or as a result of the supply and absorption of incompletely combusted fuel, measures inside the engine to increase the exhaust gas temperature, including high-pressure AGR (exhaust gas feedback) and / or low-pressure AGR (exhaust gas feedback), measures to supply oxidizable molecules (hydrocarbons, incompletely combusted fuel, NH3, etc.) to an oxidation catalyst component in order to generate combustion heat in the exhaust gas aftertreatment system.

[0053] The method according to the invention is relevant for any type of hybrid machine, in particular hybrid cars, such as low voltage hybrids, high voltage hybrids, plug-in hybrids, range extender hybrids, etc. Likewise, the described method is independent of the type of hybrid machine, such as low duty (LD) hybrids, medium duty (MD) hybrids, high duty (HD) hybrids (including buses), off-highway (OHW) machines (including motorboats), aircraft, such as small planes, locomotives or large engines (mostly marine). The method is applicable to hybrids using any type of combustion engine, in particular hybrids equipped with diesel, gasoline, gas-fired or methanol-fired engines.

[0054] Since all exhaust gas aftertreatment systems require a minimum temperature above ambient temperature for the displacement of harmful gases, the described method is applicable to any exhaust gas aftertreatment method of hybrids and all combinations thereof, in particular to NOx storage catalysts such as NSC (NOx storage converter) or three-way catalysts (TWC), NH3 storage bodies such as e.g. SCR (selective catalytic reduction) catalysts, oxidation catalysts such as DOC (diesel oxidation catalyst), NSC, TWC, AMOX (NH3 oxidation catalyst), and reduction catalysts such as SCR, NSC, TWC, particulate filters with and without an oxidation or reduction coating. The limit temperature may be set according to the essential and optimal operating temperatures.

[0055] Thus, the method may incorporate any components of the exhaust gas aftertreatment, in particular in the acquisition of measurement data, heating of elements and control of additions and operating conditions, such as gas mixers and two-substance mixers, liquid atomizers and liquid vaporizers (hydraulic, mechanical and electrical, including their connections), cables and software, catalyst housings (canning), filters, cyclones, gas scrubbers, piping, decoupling elements, mixing chambers and other metallic components which may be separated from one another in any case, sensors (sensing volumetric flow, temperature, NOx, particles, lambda, NH3, O2, NO, NO2, N2O, absolute pressure, differential pressure, oxidation potential, conductivity, etc., including their connections), cables and software, as well as any combination thereof.

[0056] It should be emphasized again that the listed method steps, such as connecting the combustion engine in a defined manner, predicting the power peak, evaluating the measurement data, predicting future measurement data, changing the defined connection rules, etc., can be used in any combination with one another or in parallel in order to easily achieve an optimal emission behavior at a desired drive power and optimal fuel consumption. [Explanation of symbols]

[0057] 1. Drive system 2 Electric motor 3. Combustion Engine 10 Control device 20 Exhaust Gas Aftertreatment System 22 Pipeline System 24 Electric heater 31 Sensors 32 Sensors 33 Sensors 34 Sensors

Claims

1. A method for exhaust gas aftertreatment in a hybrid machine including at least one electric motor (2) and one combustion engine (3), comprising: operating (200) the hybrid machine in a first operating mode in which only the electric motor (2) is switched on and the combustion engine (3) is switched off; Measuring physical quantities related to the composition of the exhaust gas stream; determining (210) whether it is necessary to warm up an exhaust gas aftertreatment system (20) of the hybrid machine; and if it is necessary to warm up the exhaust gas aftertreatment system (20), at least temporarily connecting (230) the combustion engine (3) to warm up the exhaust gas aftertreatment system (20), operating said combustion engine (3) in such a way that, when at least temporarily connecting (230) said combustion engine (3), the power output of said combustion engine (3) is increased stepwise or continuously based on said physical quantity such that the amount of harmful substances emitted in said exhaust gas flow does not exceed a predetermined limit value; A method of exhaust gas aftertreatment comprising electrically heating (220) at least a portion of said exhaust gas aftertreatment system (20) for a given time prior to at least temporary connection (230) of said combustion engine (3).

2. 2. The method for exhaust gas aftertreatment according to claim 1, wherein the decision (210) as to whether or not it is necessary to warm up the exhaust gas aftertreatment system (20) is made based on an evaluation (320) of measurement data, the measurement data having been obtained at least in part during the operation of the hybrid machine to date, and comprising at least one of the following: a temperature of the exhaust gas aftertreatment system, power data of the electric motor, power data of the combustion engine, and values ​​relating to the composition of the exhaust gas flow.

3. The measurement data is compared (330) with a predetermined threshold value, and based on the comparison result, it is determined (210) whether or not warming up of the exhaust gas aftertreatment system (20) is necessary. The method for exhaust gas aftertreatment according to claim 2.

4. 3. The method of claim 2, wherein the decision (210) of whether it is necessary to warm up the exhaust gas aftertreatment system (20) includes a prediction (370) of future measurement data expected within a specific time, the prediction (370) being based on stored data and / or data accessible via a communication connection and / or the measurement data.

5. 5. The method of claim 4, wherein the prediction (370) is based on data determining a foreseeable drive power requirement within a particular future time.

6. 6. The method for exhaust gas aftertreatment according to claim 4 or 5, further comprising comparing (380) predicted data obtained by the prediction (370) with a predetermined threshold value, and determining (210) whether or not it is necessary to warm up the exhaust gas aftertreatment system (20) based on the comparison result.

7. 7. The method for exhaust gas aftertreatment according to claim 2, wherein the connection (230) of the combustion engine (3) is performed at a defined time and / or within a defined time period and / or with a defined power output.

8. 8. The method for exhaust gas aftertreatment according to claim 7, wherein the predetermined time and / or the predetermined duration and / or the predetermined power emission are changed during operation in response to at least one of stored data, transmitted data and the measurement data.

9. 9. The method for exhaust gas aftertreatment according to claim 1, further comprising electrically heating (220) at least a portion of the exhaust gas aftertreatment system (20) for a given time while the combustion engine (3) is connected (230) to warm the exhaust gas aftertreatment system (20).

10. A computing unit configured to perform all the method steps of the method according to any one of claims 1 to 9.

11. A computer program which, when executed on a computing unit, instructs said computing unit to perform all the method steps of the method according to any one of claims 1 to 9.

12. A machine-readable storage medium storing the computer program according to claim 11.

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