WO2020143028A1

WO2020143028A1 - Method and device for determining an aging behavior of an exhaust gas after treatment system

Info

Publication number: WO2020143028A1
Application number: PCT/CN2019/071367
Authority: WO
Inventors: Marcel Kruse; Christoph Doehring; Andreas Mueller
Original assignee: Robert Bosch Gmbh
Priority date: 2019-01-11
Filing date: 2019-01-11
Publication date: 2020-07-16
Also published as: DE112019006639T5; CN113272533B; CN113272533A

Abstract

A method for determining an aging behavior of an exhaust gas after treatment system comprises: deriving first data indicative of an efficiency change of the exhaust gas after treatment system for each predetermined mileage interval based on one or more second parameter values (S2) within each of a plurality of predetermined mileage intervals, the one or more second parameter values (S2) within each predetermined mileage interval being one or more first parameter values (S1) within the predetermined mileage interval or derived from the first parameter values (S1) within at least the predetermined mileage interval, each first parameter values (S1) within each predetermined mileage interval indicative of the efficiency of the exhaust gas after treatment system at a corresponding mileage during the predetermined mileage interval; and determining second data indicative of the aging behavior of the exhaust gas after treatment system based on the derived first data for each predetermined mileage interval. By doing so, the aging of the exhaust gas after treatment system may be predicted.

Description

Method and device for determining an aging behavior of an exhaust gas after treatment system

FIELD OF THE INVENTION

The invention generally relates to exhaust gas treatment, and especially relates to after treatment of the exhaust gas.

■ BACKGROUND OF THE INVENTION

Exhaust gas emitted from such as a motor vehicle without any treatment may induce environment pollution and further has an adverse impact on people’s health. Generally, there are several methods for after treatment of the exhaust gas to reduce the adverse impact of the exhaust gas. One example of after treatment methods uses selective catalytic reduction to convert nitrogen oxides into diatomic nitrogen and water. Another example of after treatment methods uses diesel particulate filter to remove diesel particulate matter or soot from the exhaust gas.

However, an after treatment system may not always be effective as time elapses. Therefore, it needs to determine a change of an efficiency of the after treatment system over time.

According to conventional methods, the current efficiency of the after treatment system may be determined, however, there are no reliable technical means to predict future efficiency of the after treatment system.

SUMMARY OF THE INVENTION

It would be desirable to provide a method and system for determining an aging behavior of an exhaust gas after treatment system, with the determined aging behavior, the future efficiency of the after treatment system may be reliably determined.

According to one embodiment, a method for determining an aging behavior of an exhaust gas after treatment system is provided. The method comprises deriving first data indicative of an efficiency change of the exhaust gas after treatment system for each predetermined mileage interval based on one or more second parameter values within each of a plurality of predetermined mileage intervals, the one or more second parameter values within each predetermined mileage interval being one or more first parameter values within the predetermined mileage interval or derived from the first parameter values within at least the predetermined mileage interval, each first parameter value within each predetermined mileage interval indicative of the efficiency of the exhaust gas after treatment system at a corresponding mileage during the predetermined mileage interval; determining second data indicative of the aging behavior of the after treatment system based on the derived first data for each predetermined mileage interval; and outputting the second data.

With this method, the second data indicative of the aging behavior of the after treatment system may be determined based on parameters collected over a relative short distance, e.g., 50000 kilometers, from a motor vehicle in which the after treatment system is located. Since the second data may indicate the trend of the aging of the after treatment system, in particular, may indicate the efficiency change trend of the after treatment system, based on the output second data, it is possible e.g. for a user, to determine the aging trend of the after treatment system in the future, in particular, to determine a future efficiency of the after treatment system. Further, the maintenance interval may be determined and a possible failure of the after treatment system in the future may be predicted.

According to another embodiment, a system for determining an aging behavior of an exhaust gas after treatment system is provided, the system comprising a receiving unit configured to receive one or more second parameter values within each of a plurality of predetermined mileage intervals, the one or more second parameter values within each predetermined mileage interval being one or more first parameter values within the predetermined mileage interval or derived from the first parameter values within at least the predetermined mileage interval, each of the first parameter values within each predetermined mileage interval indicative of the efficiency of the after treatment system at a corresponding mileage during the predetermined mileage interval; a processor unit configured to derive first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval based on the one or more second parameter values within each of the plurality of predetermined mileage intervals and determine second data indicative of the aging behavior of the after treatment system based on the derived first data for each predetermined mileage interval; and an output unit configured to output the second data.

According to another embodiment, a computer program product is provided, the computer program product comprising program instructions, when executed by a processor, perform the method according to various embodiments of the invention.

■ DESCRIPTION OF THE DRAWINGS

The present invention will be described and explained hereinafter in more detail in combination with embodiments and with reference to the drawings, wherein:

Fig. 1 is a flow chart 10 of a method for determining an aging behavior of an exhaust gas after treatment system according to one embodiment.

Fig. 2 shows a flow chart 200 for deriving the one or more second parameter values for each predetermined mileage interval according to one embodiment.

Fig. 3 shows a flow chart 210 for modeling for each predetermined mileage interval according to one embodiment.

Fig. 4 shows the SCR efficiency values over temperature values for each mass flow interval according to one embodiment.

Fig. 5 shows the temperature-efficiency curves for every mass flow interval according to one embodiment.

Fig. 6 shows the further temperature-efficiency curve for a predetermined mileage interval according to one embodiment.

Fig. 7 shows the SCR efficiency values over mass flow values for each temperature interval according to one embodiment.

Fig. 8 shows the mass flow-efficiency curves to be fitted for every temperature interval according to one embodiment.

Fig. 9 shows the 2D space mapped from a 3D model for a certain predetermined mileage interval according to one embodiment

Fig. 10 shows all the received SCR efficiency values for one area along all the predetermined mileage intervals according to one example.

Fig. 11 shows an example of histogram analysis for the local first data for all areas per a certain predetermined mileage interval.

Fig. 12 shows the gradients determined for each1000 kilometers according to one embodiment.

Fig. 13 shows the gradient curve fitted with an exponential function according to one embodiment.

Fig. 14 is a block diagram of a system 1 for determining an aging behavior of an exhaust gas after treatment system.

Fig. 15 shows a hardware structure diagram of a system 1000 for determining an aging behavior of an exhaust gas after treatment system.

The same reference signs in the figures indicate similar or corresponding feature and/or functionality. The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes.

■ DETAILED DESCRIPTION

Fig. 1 shows a flow chart 10 of a method for determining an aging behavior of an exhaust gas after treatment system according to one embodiment. The after treatment system may be any kinds of systems for exhaust gas after treatment. For example, the after treatment system may comprise a selective catalytic reduction device or a diesel particulate filter.

In step 100, at least first parameter values S1 each indicative of an efficiency of the exhaust gas after treatment system at a corresponding mileage are received. A first parameter value S1 may be an efficiency value itself, e.g., expressed by a percentage. For the after treatment system comprising a selective catalytic reduction (SCR) device, the first parameter value S1 may be a SCR efficiency and for the after treatment system comprising a diesel particulate filter (DPF) , the first parameter value may be a regeneration efficiency. It is well known in the art on how to determine the efficiency value and thus it will not be discussed here.

For the convenience of further processes, the first parameter values S1 may be received for each predetermined mileage interval, e.g., 1000 kilometers, and then the first parameter values received for each predetermined mileage interval may be used for further processes. Although it is possible that for each predetermined mileage interval, only one first parameter value, such as one efficiency value, is received, it would be desired to receive a plurality of first parameter values for each predetermined mileage interval, each of the first parameter values within each predetermined mileage interval indicative of an efficiency of the after treatment system at a corresponding mileage during the predetermined mileage interval. For example, during driving a motor vehicle 1000 kilometers, the first parameter values may be received continuously, each of the first parameter values corresponding to a mileage during the 1000 kilometers.

In one embodiment, third parameter values S3 and fourth parameter values S4 which correspond to the first parameter values S1 may be received also in step 100. The third parameter value S3 and the fourth parameter values S4 are respectively associated with the efficiency of the after treatment system. For example, they are those parameter values that mainly affect the efficiency of the after treatment system. For the after treatment system comprising a selective catalytic reduction (SCR) device, the third parameter values S3 may be temperature values of the exhaust gas and the fourth parameter values S4 may be mass flow values of the exhaust gas; and for the after treatment system comprising a diesel particulate filter (DPF) , the third parameter values S3 may be regeneration time values of the DPF device and the fourth parameter values S4 may be regeneration temperature values of the DPF device. Each first parameter value S1 at a mileage corresponds to one third parameter value S3 and one fourth parameter value S4 at the mileage. In particular, during a predetermined mileage interval, at a mileage, a first parameter value S1 and corresponding third and fourth parameter values S3, S4 may be acquired.

Further, it is also contemplated to receive any other parameter values which may be used to derive or associated with any of the efficiency values, third parameter values and fourth parameter values.

In step 200, the received first, optionally third and fourth, parameter values for each predetermined mileage interval are processed to derive first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval. The first data may be a gradient for each predetermined mileage interval; alternatively, it may be a representative efficiency value for each predetermined mileage, as long as it may reflect the efficiency change of the after treatment system over different mileage intervals.

In one embodiment, when the predetermined mileage interval is small enough, it is possible to receive only one first parameter value for each predetermined mileage interval, in this case, the first data, e.g, the gradient, for each predetermined mileage interval may be derived from only the received first parameter values within different predetermined mileage intervals. In this case, the received first parameter values may be deemed as second parameter values S2 and used for deriving the gradient.

In another embodiment, a plurality of first parameter values S1 for each predetermined mileage interval may be processed to derive one or more second parameter values S2 and then the first data for each predetermined mileage interval may be determined based on the second parameter values S2 derived from the first parameter values S1 of at least predetermined mileage interval. It may be contemplated that for a certain predetermined mileage interval, it is not necessary to use the parameter value (s) for every predetermined mileage interval to derive its first data such as its gradient. Generally, only the first/second parameter values from a predetermined mileage interval and its neighboring predetermined mileage intervals are used to derive the first data for the predetermined mileage interval. for example, the gradient for a certain predetermined mileage interval may be derived based on only the second parameter values from its neighboring predetermined mileage intervals.

Fig. 2 shows a flow chart 200 for deriving first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval according to one embodiment.

In step 210, a plurality of first parameter values for each predetermined mileage interval may be processed by modelling.

Fig. 3 shows a flow chart 210 for modelling the plurality of first parameter values for each predetermined mileage interval.

As mentioned above, each of the received one or more first parameter values corresponds to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter value are respectively associated with the efficiency of the after treatment system. In this embodiment, the received first parameter values are SCR efficiency values, the third parameter values are temperature values of the exhaust gas and the fourth parameter values are mass flow values of the exhaust gas. The embodiment will be described with reference to SCR efficiency values and corresponding temperature values and mass flow values of the exhaust gas, however, it is only for the purpose of illustration, the flow chart shown in Fig. 3 may be used for any other parameter values. In brief, the SCR efficiency values, the temperature values and mass flow values below may be replaced with the first parameter values, third parameter values and fourth parameter values from each other.

According to the flow chart 210 shown in Fig. 3, in step 211, the SCR efficiency values, the temperature values and mass flow values received in step 100 for each 1000 kilometers are processed to generate a first 2D model of the SCR efficiency values over temperature values first.

In particular, from all the SCR efficiency values, those SCR efficiency values corresponding to each predetermined mass flow interval (which may also be referred as each predetermined fourth parameter value interval) are determined, for example, the SCR efficiency values corresponding to e.g., 140-150 kg/hour, may be selected. In this case, the predetermined mass flow interval is 10kg/hour. Fig. 4 shows the SCR efficiency values over temperature values for a certain mass flow interval. In Fig. 4, X axis refers to temperature and Y axis refers to SCR efficiency. Preferably, the SCR efficiency values may be optimized by a running median method. For each mass flow interval, a temperature-efficiency curve may be fitted to the SCR efficiency values by using e.g., a third degree polynomial. It is preferred to that the number of the SCR efficiency values is enough for obtaining an accurate fitting. For example, it is preferred that the number of the SCR efficiency values for each mass flow interval is required to exceed 50. This may be determined before the fitting.

After determining temperature-efficiency curves for every mass flow interval, a plurality of temperature-efficiency curves are obtained, as shown in Fig. 5. Based on all the temperature-efficiency curves a further temperature-efficiency curve may be obtained for the predetermined mileage interval, i.e. 1000 kilometers in this embodiment, by fitting with a further third degree polynomial. Fig. 6 shows the further temperature-efficiency curve for a predetermined mileage interval according to an embodiment.

Although in this step, the fitting is described with reference to a third degree polynomial, it may be contemplated to design other functions to achieve the fitting, such as a logistic growth function.

Although as shown in Figs. 4 and 5, some SCR efficiency values are negative, it shall be understood that this may be caused by time delays during data collection. The data points shown in Figs. 4 and 5 are only used for illustrating the method of embodiments of the invention, they are not limiting.

In addition, by the particular fitting and modelling process disclosed above and will described below with respect to Fig. 3, the data points being negative may be removed.

After obtaining the further temperature-efficiency curve for a predetermined mileage interval, a first 2D model of the SCR efficiency values over temperature values is generated for the predetermined mileage interval in step 211.

Further, in step 212, the SCR efficiency values, the temperature values and mass flow values received in step 100 for each 1000 kilometers are processed to generate a second 2D model of the SCR efficiency values over corresponding mass flow values. A modelling method same to that for temperature and efficiency may be achieved for mass flow and efficiency also.

In particular, those SCR efficiency values corresponding to each predetermined temperature interval (which may also be referred as each predetermined third parameter value interval) , e.g., each 5 degrees Celsius, are determined. Fig. 7 shows the SCR efficiency values over mass flow values for each temperature interval according to one embodiment. In Fig. 7, X axis refers to mass flow and Y axis refers to SCR efficiency. For each predetermined temperature interval, a mass flow-efficiency curve may be fitted to the SCR efficiency values and finally to obtain a plurality of mass flow-efficiency curves for every predetermined temperature interval. Fig. 8 shows the plurality of mass flow-efficiency curves to be fitted according to one embodiment. All the mass flow-efficiency curves may be used to fit a further mass flow-efficiency curve to generate the second 2D model of the SCR efficiency values over corresponding mass flow values. The fitting for mass flow and efficiency may be achieved by a first degree function.

After generating the first and second 2D model, a 3D model may be generated at 213. For example, the first 2D model and the second 2D model may be added and then half the mean of the both models may be subtracted from the addition of the both models, thereby a 3D model of the SCR efficiency values over the mass flow values and temperature values may be generated for each predetermined mileage interval, i.e., 1000 kilometers in this embodiment. In particular, the 3D model may be derived as below.

X=X1+X2-average (X1) /2-average (X2) /2

Where X is the 3D model of the SCR efficiency, X1 is the first 2D model, X2 is the second 2D model.

It may be contemplated that the particular interval values in this embodiment may be changed. And the particular workflow for modelling may be adjusted. Considering that the parameters from the motor vehicle may be acquired in real time during its driving, it is preferred that the individual steps in Fig. 3 are performed for each predetermined mileage interval sequentially once the data for a mileage interval is received and thus a plurality of 3D models may be obtained finally, each 3D model for each mileage interval. The process 210 shown in Fig. 3 may be performed in real time while receiving the parameters.

Returning to Fig. 2, in step 220, the 3D model for each predetermined mileage is used for deriving one or more second parameter values, e.g, SCR efficiency values for each predetermined mileage interval. In one embodiment, the second parameter values are derived from the 3D model for each predetermined mileage interval to correspond to a first predetermined range of the third parameter values and a second predetermined range of the fourth parameter values. That is to say, the third and fourth parameter values acquired corresponding to the second parameter values are required to be within the first predetermined range and the second predetermined range respectively.

It may be contemplated that above modelling step is not the only manner to process parameters received in step 100 (including the first parameter values, the third parameter values and the fourth parameter values) to derive the one or more second parameter values, for some cases, it may also be contemplated to select a part of first parameter values corresponding to a first predetermined range of the third parameter values and a second predetermined range of the fourth parameter values from the first parameter values received in step 100 as the second parameter values, this may be achieved by distinguishing only the first parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values during receiving step 100, only receiving above first parameter values in step 100 may also be contemplated. The determined second parameter values may be used for deriving first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval.

In a particular embodiment, for each predetermined mileage interval, the 3D model is mapped into a 2D space of the temperature values and the mass flow values, the predetermined range of the temperature values and the predetermined range of the mass flow values are selected from the mapped 2D space to generate a 2D map; the second parameter values may be derived from the first parameter values received in step 100 as corresponding to the 2D map, and are also SCR efficiency values. For a plurality of predetermined mileage interval, a plurality of 2D maps may be obtained.

At 230, the derived second parameter values may be used to derive first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval.

In one embodiment, a mean value of the second parameter values for each predetermined mileage interval may be derived for the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values for the predetermined mileage interval; and the first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval may be derived based on the mean values for at least a part of the plurality of predetermined mileage intervals.

In another embodiment, for each predetermined mileage interval, the first predetermined range and the second predetermined range may be divided respectively into a plurality of first sub ranges and a plurality of second sub range to obtain a plurality of areas each represented by reference data indicative of the corresponding first sub range and second sub range. The second parameter values over each area for all predetermined mileage intervals may be determined. A mean value of the second parameter values is determined over each of at least part, preferably all, of the plurality of areas. Local first data such as a gradient indicative of an efficiency change of the after treatment system for each area may be determined based on the mean values of the second parameter values over the area for neighboring predetermined mileage intervals. For example, in order to derive a gradient of area 1 for a second 1000 kilometers, the mean value of the second parameter values over the area 1 for a first 1000 kilometers and a third 1000 kilometers may be used. The first data for each predetermined mileage interval may be derived based on the local first data for the at least part of the plurality of areas of the predetermined mileage interval.

The embodiment may be further described with reference to above 3D model for each predetermined mileage interval. Fig. 9 shows the 2D space mapped from a 3D model for a certain predetermined mileage interval according to this embodiment. According to this embodiment, the third parameter values are temperature values of the exhaust gas as shown in X axis and the fourth parameter values are mass flow values of the exhaust gas as shown in Y axis. The first predetermined range and the second predetermined range may be [200, 350] and [150, 350] and are divided by a variable 10, thus, each area may correspond to an area 10*10 as indicated in Fig. 9 by arrow A. A mean value of the second parameter values may be derived for each area and replace all the data within the area, this may reduce calculation efforts.

Local first data indicative of an efficiency change of the after treatment system for each area at a current mileage interval may be determined from the derived mean values over the area for different predetermined mileage intervals, especially for several mileage intervals adjacent to the current mileage interval. The local first data may be a gradient for each area along different predetermined mileage intervals. For example, for an area referenced by a reference number 1 at a current mileage interval, themean values for the area referenced by 1 from a previous mileage interval and a following mileage interval, together with the mean value for the area from the current mileage interval, may be used to derive the local first data over the area for the current mileage interval. The local first data may be used to derive the first data for a certain predetermined mileage interval.

In a preferred embodiment, it is required to determine if the local first data shall be calculated for an area before determining the local first data. According to this embodiment, a curve may be generated based on the second parameter values over a particular area along the plurality of predetermined mileage intervals. A slope of each curve is derived to correspond to a largest mileage which is available, for example 50000 kilometers, for the area. The slope for the area is compared with a first predetermined threshold, in one embodiment, the first predetermined threshold refers to a threshold range, e.g., [-0.0001, 0.0001] . The area is determined as one of the at least part of the plurality of areas for deriving the local first data based on the comparing result, for example, if the slope is within the above threshold range, the area will be determined as one of the at least part of the plurality of areas for deriving the local first data. The calculation of the slope and the comparing may be performed for every area. And then the part of the areas which may be used to deriving the gradient may be determined.

Fig. 10 shows all the received SCR efficiency values for one area along different predetermined mileage intervals according to one example. In Fig. 10, x axis refers to distance in kilometers and y axis refers to efficiency. The area is represented by the mass flow 230 and temperature 320. A curve may be fitted to the received SCR efficiency values for the area. The slope for the curve at the largest mileage may be compared with the first predetermined threshold. If the slope is within first predetermined threshold range, then the local first data, e.g., the gradient, is derived for the area along different mileage intervals, otherwise, all the data from the area along different mileage intervals will be omitted, and further the determination of the local first data will be omitted for such an area also. It is preferred to have enough number of mean values from different areas for further processing. In particular, it is required to have over 50 mean values of different areas in each 2D map for further processing, even some areas in each 2D map may be omitted.

In a further embodiment, after the local first data, e.g., the gradients, are derived for each area, and calculated for each predetermined mileage interval, e.g., every 1000 kilometers, for each predetermined mileage, a plurality of local first data may be divided into different sets, each set corresponding to different value ranges of local first data. The amount of the local first data in each set may be compared with a second predetermined threshold; anda set of local first data may be determined for deriving the first data for each predetermined mileage interval if the amount of the local first data in the set exceeds the second predetermined threshold.

Especially, this embodiment may be achieved by histogram analysis. Fig. 11 shows an example of histogram analysis for the local first data for all areas per a certain predetermined mileage interval. In Fig. 11, x axis refers to gradients for all areas for a certain predetermined mileage interval, y axis refers to amount of each gradient value occurred, which corresponds to the amount of the areas which has each gradient value. Generally, in Fig. 11, the block with more frequently occurred gradients will be selected and a plurality of local first data, e.g., gradients, within this block will be used for deriving the gradient data for the predetermined mileage interval.

The first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval may be determined from above derived local first data for each area by e.g. running median. The process of flow chart 200 ends.

It may be contemplated the method is described as above mainly referring to gradients, however, this is not a limit, it is also possible to calculate a representative efficiency for each 2D map based on the mean values for each areas in the 2D map, by means of e.g., running median.

Returning to Fig. 1, if the first data refer to representative efficiency values, a curve may be fitted to the first data for different mileage intervals directly at 300, thereby an aging curve indicative of the aging behavior of the efficiency of an exhaust gas after treatment system may be determined as second data indicative of the aging behavior of the after treatment system.

Otherwise, if the first data refer to the gradients, which reflect the aging rate of the efficiency of an after treatment system along different mileages, a gradient curve may be fitted, thereby obtaining second data indicative of the aging behavior of the after treatment system at step 300. Fig. 12 shows the gradients determined for each 1000 kilometers, wherein x represents the number of 1000-kilometer intervals and y refers to gradients. Fig. 13 shows the gradient curve fitted with an exponential function according to one embodiment. In the embodiment, before generating the gradient curve as shown in Fig. 13, the data shown in Fig. 12 may be processed with a statistical filter.

Although the second data indicative of the aging behavior of the after treatment system is described with reference to the gradient curve and the aging curve only, it would be understood that the second data may be discrete data points also, as long as it may reflect the aging behavior of the after treatment system by showing the efficiency change of the after treatment system over such as driving distance.

The gradient curve may be converted into an aging curve indicative of the aging behavior of the efficiency of an exhaust gas after treatment system for. This may be done with initial efficiency values for a certain mileage. The aging curve may be converted into the gradient curve also, e.g., by calculating the slopes of the aging curve.

After the second data indicative of the aging behavior of the after treatment system are determined, the second data may be output for use by a user. Since the second data, such as the efficiency aging curve and the gradient curve, may reflect overall aging behavior of the exhaust gas after treatment system, with the second data determined by parameters from a motor vehicle over a certain driving distance, e.g, 50000 kilometers, the efficiency of the after treatment system in the future, e.g., at a mileage of 200000 kilometers, may be determined by the user. Or, the second data may be output to a processor for further analysis on its property, e.g., its inflection point.

The method of the invention is described with respect to above embodiments for illustration. One or more steps of the method may be removed/amended/combined for obtaining different advantages. The order of the steps are not limiting, it may be adjusted according to different embodiments.

Although the method is described with predetermined mileage intervals, it may be contemplated that each predetermined mileage interval is represented by a time interval, such as a time interval during which a motor vehicle may be driven a predetermined mileage interval.

In one embodiment, each of the one or more first parameter values corresponding to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter values are respectively associated with the efficiency of the after treatment system, in this case, it is possible to derive the second parameter values from the first parameter values by means of a third parameter and a fourth parameter.

In particular, a first predetermined range of the third parameter values and a second predetermined range of the fourth parameter values may be respectively specified by e.g., a user through an interface, the first predetermined range may be different from the second predetermined range. The second parameter values may be derived to correspond to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values. The first data for each predetermined mileage interval is derived based on only the derived second parameter values. It may also be contemplated to receive the first predetermined range and the second predetermined range before receiving any parameter values at 100 and then only the parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values are received at 100. In some embodiments, if the mileage interval is selected small enough, the second and fourth parameter values may not be considered in an embodiment of the invention.

It may be contemplated that the second parameter values for a predetermined mileage interval may be derived from the first parameter values for the predetermined mileage interval; however, it is also possible to derive the second parameter values for a predetermined mileage interval from the first parameter values for neighboring predetermined mileage intervals.

Fig. 14 is a block diagram of a system 1 for determining an aging behavior of an exhaust gas after treatment system. The system comprises a receiving unit 2 and a processor unit 3. The receiving unit 2 is configured to receive one or more second parameter values within each of a plurality of predetermined mileage intervals, the one or more second parameter values within each predetermined mileage interval being one or more first parameter values within the predetermined mileage interval or derived from first parameter values within at least the predetermined mileage interval, each of the first parameter values within each predetermined mileage interval indicative of the efficiency of the after treatment system at a corresponding mileage during the predetermined mileage interval. The processor unit 3 is configured to derive first data indicative of an efficiency change of the after treatment system for each predetermined mileage interval based on the one or more second parameter values within each of the plurality of predetermined mileage intervals and determine second data indicative of the aging behavior of the after treatment system based on the derived first data for each predetermined mileage interval. The system 1 may also comprise an output unit (not shown) that outputs the second data for a user or to a further processor.

Each of the one or more second parameter values corresponding to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter values are respectively associated with the efficiency of the after treatment system. In one embodiment, the processor unit 3 derives the first data for each predetermined mileage interval based on the second parameter values corresponding to a first predetermined range of the third parameter values and a second predetermined range of the fourth parameter values.

Each of the one or more first parameter values corresponding to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter value are respectively associated with the efficiency of the after treatment system. In one embodiment, the processor unit 3 further comprises a modelling unit 4 configured to for each predetermined mileage interval, generate a first 2D model of the one or more first parameter values over corresponding third parameter values; for each predetermined mileage interval, generate a second 2D model of the one or more first parameter values over corresponding fourth parameter values; and for each predetermined mileage interval, generate a 3D model of the first parameter values over the corresponding third parameter values and fourth parameter values based on the first and second 2D models, the 3D model for each predetermined mileage interval being used for deriving the one or more second parameter values within the predetermined mileage interval.

Although as shown in Fig. 14, the modelling unit 4 is shown in the processor unit 3, it can be contemplated that modelling is performed at a location other than the system 1 of the invention, in this case, the receiving unit 2 may only receive the 3D model from the modelling unit at a remote location for further processing in the processor unit 3.

In one embodiment, the processor unit 3 is further configured to derive the second parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values for each predetermined mileage interval; derive a mean value of the second parameter values for each predetermined mileage interval based on the second parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values for the predetermined mileage interval; and derive the first data indicative of the change of the efficiency of the after treatment system for each predetermined mileage interval based on the mean value of the second parameter values for at a part of the plurality of predetermined mileage intervals.

In another embodiment, the processor unit 3is further configured to for each predetermined mileage interval, divide the first predetermined range and the second predetermined range respectively into a plurality of first sub ranges and a plurality of second sub range to obtain a plurality of areas each represented by reference data indicative of the corresponding first sub range and second sub range; determine the second parameter values over each area for all predetermined mileage intervals; determine a mean value of the second parameter values over each of at least part of the plurality of areas; derive local first data indicative of local change of the efficiency of the after treatment system for each area based on the mean values of the second parameter values over the area for different predetermined mileage intervals; and derive the first data for each predetermined mileage interval based on the local first data for the at least part of the plurality of areas.

In another embodiment, the processor unit 3 is further configured to generate a curve based on the second parameter values over an area along the plurality of predetermined mileage intervals; derive a slope of each curve corresponding to a largest mileage for the area; compare the slope for the area with a first predetermined threshold; and determine the area as one of the at least part of the plurality of areas based on the comparing result. The processor unit 3 may repeat above process for each area.

In another embodiment, the processor unit 3 is further configured to for each predetermined mileage, divide a plurality of local first data into different sets, each set corresponding to different ranges of local first data; compare the amount of the local first data in each set with a second predetermined threshold; and determine a set of local first data for deriving the first data for each predetermined mileage interval if the amount of the local first data in the set exceeds the second predetermined threshold.

It may be contemplated that the individual units of the system of the invention as shown in Fig. 14 may be achieved by any one of software, hardware or firmware. Furthermore, a machine-readable storage medium may store instructions for performing the method of the invention.

As one example, Fig. 15 shows a hardware structure diagram of a system 1000 for determining an aging behavior of an exhaust gas after treatment system. The system 1000 comprises a processor 1100, an interface 1200, a memory 1300 and a storage 1400. Computer-executable program instructions may be stored in the storage 1400, the interface 1200 may receive inputs from any of a user and a remote device including but not limited to a motor vehicle or a remote processor or a sever. The processor 1100 may run the computer-executable program instructions to perform the method steps according to various embodiments of the invention.

It shall be noticed that the hardware structure shown in Fig. 15 is only an example but not for limiting. Actually, some processes according to various embodiments may be achieved at a remote location and then the processed results may be input to the system 1000 for further processing.

For example, in a preferable embodiment, receiving original parameter values including the efficiency values, temperature values and mass flow values as well as modelling based on the original parameter values may be achieved in real time at a processor unit at a motor vehicle or at a location relatively adjacent to the motor vehicle, and then a further process may be achieved at the processor 1100 after all models are generated.

Please note that, the system and the method according to the present invention should not be limited to that mentioned above only. They will be apparent to those skilled in the art that the various aspects of the invention claimed may be practiced in other examples that depart from these specific details.

Furthermore, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art would be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” does not exclude the presence of elements or steps not listed in a claim or in the description. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. In the product claims enumerating several units, several of these units can be embodied by one and the same item of software and/or hardware. The usage of the words first, second and third, et cetera, does not indicate any ordering. These words are to be interpreted as names.

Claims

A method for determining an aging behavior of an exhaust gas after treatment system comprising

deriving first data indicative of an efficiency change of the exhaust gas after treatment system for each predetermined mileage interval based on one or more second parameter values within each of a plurality of predetermined mileage intervals, the one or more second parameter values within each predetermined mileage interval being one or more first parameter values within the predetermined mileage interval or derived from the first parameter values within at least the predetermined mileage interval, each first parameter values within each predetermined mileage interval indicative of the efficiency of the exhaust gas after treatment system at a corresponding mileage during the predetermined mileage interval;

determining second data indicative of the aging behavior of the exhaust gas after treatment system based on the derived first data for each predetermined mileage interval; and

outputting the second data.
The method of claim 1 wherein

each of the one or more second parameter values corresponding to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter values are respectively associated with the efficiency of the exhaust gas after treatment system;

and wherein the first data for each predetermined mileage interval is derived based on the second parameter values corresponding to a first predetermined range of the third parameter values and a second predetermined range of the fourth parameter values.
The method of claim 1 wherein

each of the one or more first parameter values corresponding to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter value are respectively associated with the efficiency of the exhaust gas after treatment system;

the method further comprising

for each predetermined mileage interval, generating a first 2D model of the one or more first parameter values over corresponding third parameter values;

for each predetermined mileage interval, generating a second 2D model of the one or more first parameter values over corresponding fourth parameter values; and

for each predetermined mileage interval, generating a 3D model of the first parameter values over the corresponding third parameter values and fourth parameter values based on the first and second 2D models, the 3D model for each predetermined mileage interval being used for deriving the one or more second parameter values within the predetermined mileage interval.
The method of claim 2 or 3 further comprising

determining the second parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values, for each predetermined mileage interval;

deriving a mean value of the second parameter values for each predetermined mileage interval based on the second parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values, for the predetermined mileage interval; and

deriving the first data indicative of the change of the efficiency of the exhaust gas after treatment system for each predetermined mileage interval based on the mean values for at least some of the plurality of predetermined mileage intervals.
The method of claim 2 or 3 further comprising

for each predetermined mileage interval, dividing the first predetermined range and the second predetermined range respectively into a plurality of first sub ranges and a plurality of second sub range to obtain a plurality of areas each represented by reference data indicative of the corresponding first sub range and second sub range;

determining the second parameter values over each area for all predetermined mileage intervals;

determining a mean value of the second parameter values over each of at least part of the plurality of areas;

deriving local first data indicative of change of the efficiency of the exhaust gas after treatment system for each area based on the mean values of the second parameter values over the area for different predetermined mileage intervals; and

deriving the first data for each predetermined mileage interval based on the local first data for the at least part of the plurality of areas.
The method of claim 5 further comprising

generating a curve based on the second parameter values over an area along the plurality of predetermined mileage intervals;

deriving a slope of each curve corresponding to a largest mileage for the area;

comparingthe slope for the area with a first predetermined threshold; and

determining the area as one of the at least part of the plurality of areas based on the comparing result.
The method of claim 5 further comprising

for each predetermined mileage, dividing a plurality of local first data into different sets, each set corresponding to different value ranges of the local first data;

comparing the amount of the local first data in each set with a second predetermined threshold; and

determining a set of local first data for deriving the first data for each predetermined mileage interval if the amount of the local first data in the set exceeds the second predetermined threshold.
The method of claim 1 wherein the exhaust gas after treatment system comprises a selective catalytic reduction device;

and wherein the first parameter value comprises an efficiency value of a selective catalytic reduction catalyst, the third parameter value comprises a temperature value of the exhaust gas and the fourth parameter value comprises a mass flow of the exhaust gas.
The method of claim 1 wherein the exhaust gas after treatment system comprises a diesel particulate filter;

and wherein the first parameter value comprises a regeneration efficiency of the diesel particulate filter, the third parameter value comprises a regeneration time of the diesel particulate filter and the fourth parameter value comprises a regeneration temperature of the diesel particulate filter.
A system for determining an aging behavior of an exhaust gas after treatment system comprising

a receiving unit configured to receive one or more second parameter values within each of a plurality of predetermined mileage intervals, the one or more second parameter values within each predetermined mileage interval being one or more first parameter values within the predetermined mileage interval or derived from the first parameter values within at least the predetermined mileage interval, each of the first parameter values within each predetermined mileage interval indicative of the efficiency of the exhaust gas after treatment system at a corresponding mileage during the predetermined mileage interval;

a processor unit configured to derive first data indicative of an efficiency change of the exhaust gas after treatment system for each predetermined mileage interval based on the one or more second parameter values within each of the plurality of predetermined mileage intervals and determine second data indicative of the aging behavior of the exhaust gas after treatment system based on the derived first data for each predetermined mileage interval; and

an outputting unit configured to output the second data.
The system of claim 10 wherein

each of the one or more second parameter values corresponding to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter values are respectively associated with the efficiency of the exhaust gas after treatment system;

and wherein the processor unit derives the first data for each predetermined mileage interval based on the second parameter values corresponding to a first predetermined range of the third parameter values and a second predetermined range of the fourth parameter values.
The system of claim 10 wherein

each of the one or more first parameter values corresponding to a third parameter value and a fourth parameter value, the third parameter value and the fourth parameter value are respectively associated with the efficiency of the exhaust gas after treatment system;

wherein the processor unit further comprises a modelling unit configured to

for each predetermined mileage interval, generate a first 2D model of the one or more parameter values over corresponding third parameter values;

for each predetermined mileage interval, generate a second 2D model of the one or more first parameter values over corresponding fourth parameter values; and

for each predetermined mileage interval, generate a 3D model of the first parameter values over the corresponding third parameter values and fourth parameter values based on the first and second 2D models, the 3D model for each predetermined mileage interval being used for deriving the one or more second parameter values within the predetermined mileage interval.
The system of claim 11 or 12 wherein the processor unit is further configured to

determine the second parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values, for each predetermined mileage interval;

derive a mean value of the second parameter values for each predetermined mileage interval based on the second parameter values corresponding to the first predetermined range of the third parameter values and the second predetermined range of the fourth parameter values, for the predetermined mileage interval; and

derive the first data indicative of the change of the efficiency of the exhaust gas after treatment system for each predetermined mileage interval based on the mean values for at least some of the plurality of predetermined mileage intervals.
The system of claim 11 or 12 wherein the processor unit is further configured to

for each predetermined mileage interval, divide the first predetermined range and the second predetermined range respectively into a plurality of first sub ranges and a plurality of second sub range to obtain a plurality of areas each represented by reference data indicative of the corresponding first sub range and second sub range;

determine the second parameter values over each area for all predetermined mileage intervals;

determine a mean value of the second parameter values over each of at least part of the plurality of areas;

derive ocal first data indicative of change of the efficiency of the exhaust gas after treatment system for each area based on the mean values of the second parameter values over the area for different predetermined mileage intervals; and

derive the first data for each predetermined mileage interval based on the local first data for the at least part of the plurality of areas.
The system of claim 14 wherein the processor unit is further configured to

generate a curve based on the second parameter values over an area along the plurality of predetermined mileage intervals;

derive a slope of each curve corresponding to a largest mileage for the area;

compare the slope for each area with a first predetermined threshold; and

determine the area as one of the at least part of the plurality of areas based on the comparing result.
The system of claim 14 wherein the processor unit is further configured to

for each predetermined mileage, divide a plurality of local first data into different sets, each set corresponding to different value ranges of local first data;

compare the amount of the local first data in each set with a second predetermined threshold; and

determine a set of local first data for deriving the first data for each predetermined mileage interval if the amount of the local first data in the set exceeds the second predetermined threshold.
A computer program product comprising program instructions, when executed by a processor, perform the method according to any one of claims 1-9.