Regeneration of a motor vehicle particulate filter

Abstract

Method for regenerating a particulate filter (19) of a motor vehicle (20), comprising the following steps: - Defining and entering a number of boundary conditions relating to a number of upcoming journeys (11-18) into a control device (21), wherein the boundary conditions include a selection from defined quantification characteristics of the vehicle load, which includes the characteristics 'low' and / or 'medium' and / or 'high', and / or a selection from defined quantification characteristics of the use of electrical equipment, which includes the characteristics 'low' and / or 'normal' and / or 'high', - Determining the loading of the particulate filter (19), - if the loading of the particulate filter (19) exceeds a specified limit value, determining the most efficient regeneration measure and its execution conditions during the number of upcoming journeys, taking into account the input boundary conditions, by means of the control device (21), and - Carrying out the specified regeneration measure when its execution conditions are met.

Description

[0001] The present invention relates to a method for regenerating a particulate filter of a motor vehicle, a device for controlling the regeneration of a particulate filter of a motor vehicle and a motor vehicle.

[0002] Reducing exhaust emissions represents a significant challenge for current combustion engines. To effectively reduce soot emissions from a diesel vehicle, for example, a soot filter (DPF - diesel particulate filter) is generally used, which must be regenerated at specific intervals. The necessary regeneration of the filter is usually initiated by measuring the pressure drop on the filter, from which the soot loading of the filter can be determined. For regeneration to occur, one of the steps required is to increase the exhaust gas temperature, which is achieved by adjusting the engine settings. The engine then operates with poorer efficiency, particularly in the low partial load range, which leads to increased fuel consumption. If regeneration could be carried out at higher loads, the consumption disadvantages would be significantly lower. In some cases, regeneration must also be aborted if the driver stops the journey or restarts the vehicle.is interrupted. In this case, the fuel consumption penalty is particularly significant.

[0003] Additional GPS (Global Positioning System) information about the current route or by entering a destination into the navigation system can be used to perform regeneration at more favorable times or engine loads. One such method is described, for example, in documents EP 2 175 110 A1 and DE 10 2012 010 189 A1. The disadvantage of this approach is that complex algorithms must be developed and appropriate computing power must be made available. Furthermore, this prediction does not take into account possible changes in the route or driving style by the driver. This means that the full potential of such a system cannot be utilized. Further prior art is disclosed in documents DE 10 2008 008 566 A1, DE 10 2015 014 813 A1 and DE 10 2006 005 505 A1.

[0004] The object of the present invention is, against the background described, to provide an advantageous method for regenerating a particulate filter of a motor vehicle, as well as a corresponding control device and a motor vehicle.

[0005] This object is achieved by a method for regenerating a particulate filter of a motor vehicle according to claim 1, a control device according to claim 10, and a motor vehicle according to claim 11. The dependent claims contain further advantageous embodiments of the invention.

[0006] The inventive method for regenerating a particulate filter, for example a diesel particulate filter, of a motor vehicle comprises the following steps: A number of boundary conditions relating to a number of upcoming journeys are defined and entered into a control device. The load of the particulate filter is determined. If the load of the particulate filter exceeds a defined limit, the most efficient regeneration measure and its execution conditions during the number of upcoming journeys are determined by means of the control device, taking the entered boundary conditions into account. The specific regeneration measure is carried out when its specific execution conditions are met. The inventive method has the advantage that the driver is actively involved in the regeneration management.The driver can individually define boundary conditions and thus contribute to increased efficiency of the regeneration process.

[0007] The boundary conditions can include a selection of predefined qualifying characteristics of the driving style. The selection can include the characteristics "restrained" and / or "normal" and / or "sporty."

[0008] The boundary conditions comprise a selection of defined quantification characteristics of the vehicle's load. The selection includes the characteristics "low," "medium," and / or "high."

[0009] Additionally or alternatively, the boundary conditions may include information on the expected journey time and / or information on the expected journey route and / or additional information on the journey route and / or information on planned journey breaks.

[0010] The boundary conditions comprise a selection of defined quantification characteristics of the planned use of electrical devices. The selection includes the characteristics "low" and / or "normal" and / or "high."

[0011] Navigation data and / or traffic reports can be used for additional information on the route and / or the expected journey time.

[0012] Entering the aforementioned boundary conditions allows a user to specify and qualify one or more planned trips in advance, making it possible to determine a suitable time or suitable conditions for optimal and, in particular, complete regeneration in advance and to carry out the regeneration measure accordingly.

[0013] When determining the most efficient regeneration measure and its execution conditions, the outside temperature and / or the engine temperature and / or the current and / or expected engine load can also be taken into account.

[0014] In an advantageous variant, the execution conditions of the regeneration measure include the time and / or location of the regeneration. As already described, this can advantageously be selected such that a complete regeneration can be carried out that is optimal for consumption, in particular for fuel consumption.

[0015] In an advantageous variant, a user is prompted to enter a number of boundary conditions relating to a number of upcoming trips. In particular, a predefined selection of features can be made available to the user for individual selection. Providing a predefined preselection allows the user to quickly enter the boundary conditions and facilitates determining the most efficient regeneration measure and its execution conditions using the control device. The prompt can be issued to a user before the boundary conditions are entered, for example, at the start of a trip.

[0016] In a further variant, information relating to regeneration can be displayed to a user, for example by means of a display device. This can be characteristics of the regeneration carried out and / or statistical evaluations, in particular evaluations of the efficiency of the regeneration measure and / or consumption. Additionally or alternatively, this can be the consumption savings achieved once and / or within a specified period. A reference to a next planned regeneration can also be displayed. The information relating to regeneration can be displayed to a user before and / or during and / or after a regeneration. The display described has the advantage of transparently showing the user the influence their selection and / or driving behavior has on fuel efficiency and the efficiency of regeneration processes.

[0017] The boundary conditions can also be entered via a personal device connected to the motor vehicle and / or a navigation device. The personal device can be, for example, a smartphone, a tablet, a notebook, a smartwatch, or another portable device. Furthermore, an automatic comparison with navigation data and / or a calendar, in particular a personal calendar, can be performed via a navigation device or a personal device. In this way, for example, additional information about the route and / or information about planned breaks in the journey can be read out, specified, and / or entered.

[0018] The device according to the invention for controlling the regeneration of a particulate filter of a motor vehicle comprises an input device for entering a number of boundary conditions and a device for determining the most efficient, in particular most fuel-efficient, regeneration features and their execution conditions during a number of upcoming journeys, taking the input boundary conditions into account. The device according to the invention is designed to carry out an inventive method described above. The control device according to the invention has the features and advantages mentioned in connection with the inventive method.

[0019] The motor vehicle according to the invention comprises a particulate filter, for example a diesel particulate filter, and a previously described device according to the invention for controlling the regeneration of a particulate filter. The motor vehicle according to the invention has the advantages already mentioned. The motor vehicle can be a passenger car, a truck, a van, a bus, a minibus, or a motorcycle.

[0020] The described invention has the overall advantage of giving the user or driver an active role in reducing fuel consumption, improving transparency regarding regeneration measures, and increasing user or driver acceptance. At the same time, awareness regarding fuel consumption and CO2 emissions is improved. As a result of the increased efficiency of the regeneration measures, CO2 emissions are reduced, and particulate filter regeneration can be carried out more effectively and in a shorter time.

[0021] The invention will be explained in more detail below using exemplary embodiments with reference to the accompanying figures. Although the invention is illustrated and described in more detail by the preferred embodiments, the invention is not limited to the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. Fig. 1 schematically shows an embodiment of a method according to the invention in the form of a flow chart. Fig. Figure 2 shows a schematic diagram of an example of regenerations during a number of trips. Fig. Figure 3 shows schematically an example of a method according to the invention during the Fig. Regeneration carried out for the number of journeys shown in Figure 2 in the form of a diagram. Fig. 4 schematically shows a motor vehicle according to the invention with a control device according to the invention.

[0022] The Fig. Figure 1 schematically shows an embodiment of a method according to the invention in the form of a flowchart. In step 1, the user is asked whether a regeneration method according to the invention, for example, as "DPF regeneration management," should be used. If the answer is no, an existing standard system for performing the regeneration of a particulate filter is used in step 2. If the answer to step 1 is yes, the method is started in step 3 and, for example, a corresponding menu is opened.

[0023] Subsequently, in step 4, a user, for example a driver, is asked to enter boundary conditions for a number of upcoming journeys, for example via an input device in a control device. The boundary conditions can be a selection from specified characteristics relating to the driving style and / or a selection from specified characteristics relating to the vehicle load and / or information on the expected journey duration and / or information on the expected journey route and / or information on additional information relating to the route and / or information on planned journey breaks and / or a selection from specified characteristics relating to the planned use of electrical devices. With regard to the driving style, for example, a selection can be made from the characteristics “restrained”, “normal” and “sporty”. A more comprehensive or fewer selectable characteristics is of course possible.Regarding the load, for example, you can choose between the attributes "low," "medium," and "high." Here, too, a different number or description of the options is possible. Regarding the use of electrical devices, for example, you can choose between "low," "normal," and "high." Here, too, a different attribute definition is possible.

[0024] The boundary conditions can be entered, for example, via a navigation device and / or a connected personal device such as a smartphone, smartwatch, tablet, notebook, or other device. Furthermore, automatic synchronization with a navigation device and / or calendar can be performed.

[0025] In addition to entering boundary conditions, the particulate filter load is also determined in step 4. Subsequently, in step 5, the particulate filter regeneration is optimized. If the particulate filter load exceeds a specified limit, the most efficient regeneration measure and its execution conditions are determined during the number of upcoming trips, taking the entered boundary conditions into account. This is done, for example, using a control device.

[0026] Regeneration is then carried out in step 6. In step 7, for example, the achieved fuel consumption savings can be displayed to a user. In particular, a statistical analysis can be carried out using an evaluation device or the control device and corresponding information can be provided to a user, for example a driver. The displays can read, for example: "Savings during the last regeneration due to DPF regeneration management: 1.0 litres / 100 km" or "Savings since the last refueling due to DPF regeneration management: 0.15 litres / 100 km" or "Next DPF regeneration required in approx. 70 km → plan 15 minutes of continuous driving with increased load" or "Last regeneration carried out 480 km ago, DPF load before regeneration 92%" or similar.

[0027] In the Fig. Figure 2 shows a schematic diagram illustrating the regeneration of a diesel particulate filter according to a standard procedure. Fig. Figure 3 shows a corresponding diagram by way of example for regeneration according to the method according to the invention. The time and distance are plotted on the x-axes of the diagrams. The diesel particulate filter loading and the amount of soot are plotted on the y-axis. Bars 11 to 18 indicate individual, consecutive trips, with the width of the respective bar characterizing the duration and the distance traveled. Line 8 indicates 100% particulate filter loading. Line 9 indicates 80% loading. The bars are labeled 11 for trip 1, 12 for trip 2, 13 for trip 3, and so on, up to 18 for trip 8.

[0028] Curve 10 indicates the particulate filter loading as a function of time and distance traveled. The soot loading increases during driving. A state-of-the-art regeneration strategy with two thresholds for the particulate filter loading is assumed, with the absolute position of the thresholds depending on the application. In the variant shown, the upper threshold of 100% is designated by reference number 8 and the lower threshold of 80% by reference number 9.

[0029] Below, for example, 80% soot loading, no regeneration is planned in the example shown, because it would impair the filter's storage capacity and result in a waste of fuel. From, for example, 80% soot loading, DPF regeneration is enabled, meaning it is performed provided suitable driving conditions exist. These typically include reaching a minimum coolant temperature and sufficient engine load, which allows the temperatures required for soot combustion to be reached through additional measures. At 100% soot loading, regeneration must occur even under unfavorable conditions to avoid overloading the filter and thus the risk of component damage.

[0030] In the Fig. 2, the 80% threshold (9) is reached during the first trip. Since favorable conditions arise shortly before the end of the trip, a DPF regeneration is performed. However, this is interrupted after a short time when the engine is turned off, so it remains ineffective and only a small amount of soot is removed. Therefore, a regeneration occurs again in trip 4 with a similar result. The long and possibly fast trip (5) remains unused, so another regeneration occurs as early as trip 7.

[0031] By the method according to the invention, for example the method according to the flow chart in Fig. 1 “DPF regeneration management” activated in step 3 is ignored by the system, as described in Fig. 3, the supposedly advantageous conditions shortly before the end of runs 1 to 4 are ignored and a regeneration is performed in run 5 instead. Due to the sufficient time and higher loads, this is much more efficient than the sum of the aborted regenerations.

[0032] The Fig. 4 schematically shows a motor vehicle 20 according to the invention. The motor vehicle 20 according to the invention comprises a particle filter, for example a diesel particle filter 19 and a control device 21 according to the invention. The control device 21 according to the invention comprises an input and output device 22. The control device 21 is designed to carry out a method according to the invention for regenerating the particle filter 19.

[0033] Two exemplary embodiments are described below. The first variant concerns a 6 km commute within a city. The engine cold start occurs, for example, at 15°C. The driver activates the method according to the invention, for example called "DPF regeneration management," or it has already been activated. The driver is prompted to enter boundary conditions and enters the following boundary conditions: driving style "restrained," load "light," expected journey time "12 minutes," shorter vehicle use / distance (for example, < 10 km), planned in "0 km," longer vehicle use / distance (for example, > 10 km), planned in "120 km," additional information on the route "after 3 minutes or 3 km, vehicle stop for 1 minute," and use of electrical systems "normal."In the following, the optimal time for regeneration is determined using the method according to the invention in order to keep the consumption disadvantage as low as possible.

[0034] The second variant concerns a weekend trip, for example, a 150 km journey. The engine cold start occurs at 25°C, for example. The driver activates the "DPF regeneration management" or this has already been activated. Optionally, consumption optimization can be selected, for example, "predictive heat management." The user or driver is prompted to enter the following boundary conditions: "normal" driving style, "heavy" load, "90 minutes" expected journey time, "150 km" for shorter vehicle use / distance (< 10 km), "0 km" for longer vehicle use / distance (> 10 km), "none" for additional information on the journey, and "high" for use of electrical systems or devices. The control unit then determines the optimal time for regeneration based on the entered boundary conditions in order to keep the fuel consumption penalty as low as possible.

[0035] Should the driver need to deviate from the selected boundary conditions, they can optionally switch the system off or enter the changed boundary conditions. Information can then be displayed, for example how the regeneration performed differs from the "standard regeneration" and what one-off fuel savings were achieved. Furthermore, fuel savings can also be displayed over a longer period of time and statistically evaluated, for example during refueling. In addition, the system can continuously point out the next scheduled regeneration, which the driver can take into account in their long-term planning of vehicle use. For example, it can display that the next regeneration of the particulate filter is scheduled in 80 km based on the current driving profile. The driver can take this into account in their long-term planning, for example in connection with a longer journey at the weekend. List of reference symbols 1 Use “DPF regeneration management”? 2 Use standard system 3 Start “DPF regeneration management” 4 Request to enter boundary conditions, determination of the loading of the particulate filter 5 Determine the most efficient regeneration measure and its execution conditions during the number of upcoming trips, taking into account the entered boundary conditions 6 Regeneration of the particulate filter 7 Statistical evaluation and issuing of information 8 Particle filter loading 100% 9 Particle filter loading 80% 10 Particle filter loading depending on time or distance traveled 11 Trip 1 12 Trip 2 13 Trip 3 14 Trip 4 15 Trip 5 16 Trip 6 17 Trip 7 18 Trip 8 19 Particle filters 20 motor vehicles 21 Control device 22 Input and output device 23 Device for determining the most efficient regeneration measure and its implementation conditions

Claims

[1] Method for regenerating a particle filter (19) of a motor vehicle (20), comprising the following steps: - specifying and entering a number of boundary conditions relating to a number of upcoming journeys (11-18) into a control device (21), wherein the boundary conditions comprise a selection of specified quantification features of the load of the motor vehicle, which includes the features "low" and / or "medium" and / or "high", and / or a selection of specified quantification features of the use of electrical devices, which includes the features "low" and / or "normal" and / or "high", - Determining the loading of the particulate filter (19), - if the loading of the particulate filter (19) exceeds a specified limit value, determining the most efficient regeneration measure and its execution conditions during the number of upcoming journeys, taking into account the input boundary conditions, by means of the control device (21), and - Carrying out the specific regeneration measure if the conditions for its implementation are met. [2] Method according to claim 1, characterized by that the boundary conditions include a selection of specified qualification characteristics of the driving style and / or information on the expected journey time and / or information on the expected journey route and / or additional information on the journey route and / or information on planned journey breaks. [3] Method according to claim 2, characterized by that the selection from defined qualification characteristics of the driving style includes the characteristics “reserved” and / or “normal” and / or “sporty”. [4] Method according to one of claims 1 to 3, characterized by that the conditions for carrying out the regeneration measure include the time and / or place of the regeneration. [5] Method according to one of claims 1 to 4, characterized by that a user is prompted to enter a number of constraints relating to a number of upcoming trips. [6] Method according to one of claims 1 to 5, characterized by that information concerning regeneration is displayed to a user. [7] Method according to claim 6, characterized by that characteristics of the regeneration carried out and / or statistical evaluations and / or the fuel consumption savings achieved once or over a specified period and / or an indication of a next planned regeneration are displayed. [8] Method according to one of claims 1 to 7, characterized bythat the particulate filter (19) is a diesel particulate filter. [9] Method according to one of claims 1 to 8, characterized by that the boundary conditions are entered via a personal device and / or a navigation device connected to the motor vehicle (20) and / or an automatic comparison with a calendar and / or a navigation device is carried out. [10] Device for controlling (21) the regeneration of a particle filter (19) of a motor vehicle (20), which device comprises an input device (22) for inputting a number of boundary conditions and a device (23) for determining the most efficient regeneration measure and its execution conditions during a number of upcoming journeys, taking into account the input boundary conditions, wherein the device (21) is designed to carry out a method according to one of claims 1 to 9. [11] Motor vehicle (20) comprising a particle filter (19) and a device (21) according to claim 10.

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