U.S. patent application number 15/834841 was filed with the patent office on 2018-04-05 for method and device for determining the load condition of an exhaust gas particulate filter.
This patent application is currently assigned to CONTINENTAL AUTOMOTIVE GMBH. The applicant listed for this patent is CONTINENTAL AUTOMOTIVE GMBH. Invention is credited to Jurgen Dingl, Roland Schwarz.
Application Number | 20180094565 15/834841 |
Document ID | / |
Family ID | 55806310 |
Filed Date | 2018-04-05 |
United States Patent
Application |
20180094565 |
Kind Code |
A1 |
Dingl; Jurgen ; et
al. |
April 5, 2018 |
METHOD AND DEVICE FOR DETERMINING THE LOAD CONDITION OF AN EXHAUST
GAS PARTICULATE FILTER
Abstract
The disclosure relates to a method and a device for determining
the load condition of an exhaust gas particulate filter that is
arranged in an exhaust gas path of an internal combustion engine
that is charged by an exhaust gas turbocharger. The behavior of a
charging pressure controller or the charging pressure of the
exhaust gas turbocharger is analyzed to determine the load
condition of the exhaust gas particulate filter.
Inventors: |
Dingl; Jurgen; (Regensburg,
DE) ; Schwarz; Roland; (Nittendorf, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CONTINENTAL AUTOMOTIVE GMBH |
Hannover |
|
DE |
|
|
Assignee: |
CONTINENTAL AUTOMOTIVE GMBH
Hannover
DE
|
Family ID: |
55806310 |
Appl. No.: |
15/834841 |
Filed: |
December 7, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2016/058198 |
Apr 14, 2016 |
|
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15834841 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02B 37/00 20130101;
F02D 41/0007 20130101; Y02T 10/47 20130101; F02D 2200/0812
20130101; F01N 9/002 20130101; F01N 3/023 20130101; F01N 2900/1606
20130101; Y02T 10/144 20130101; F01N 2900/08 20130101; Y02T 10/12
20130101; F01N 3/021 20130101; F01N 2560/05 20130101; F02D 41/029
20130101; Y02T 10/40 20130101; F01N 2900/1406 20130101; F01N 11/002
20130101; F02D 41/1402 20130101 |
International
Class: |
F01N 11/00 20060101
F01N011/00; F01N 3/021 20060101 F01N003/021 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2015 |
DE |
10 2015 211 151.2 |
Claims
1. A method for determining a load condition of an exhaust gas
particulate filter arranged in an exhaust gas path of an internal
combustion engine, the internal combustion engine is charged by an
exhaust gas turbocharger, the method comprising: analyzing a
behavior of a charging pressure controller or the charging pressure
of the exhaust gas turbocharger; and determining the load condition
of the exhaust gas particulate filter based on the analyzed
behavior of the charging pressure controller or the charging
pressure of the exhaust gas turbocharger.
2. The method of claim 1, further comprising: performing a
long-term observation of the behavior of the charging pressure
controller or the charging pressure of the exhaust gas
turbocharger; and determining the load condition of the exhaust gas
particulate filter based on the long-term observation.
3. The method of claim 1, further comprising: evaluating control
signals provided by the charging pressure controller; determining
adaptation values for a pilot control procedure of the exhaust gas
turbocharger based on the evaluated control signal; and performing
a check for determining whether a change in the adaptation values
occurs in the long term.
4. The method of claim 3, further comprising performing a check for
determining whether a characteristic change in the control signals
that are output by the charging pressure controller occurs in the
long term.
5. The method of claim 1, further comprising performing a check for
determining whether characteristic deviations occur between a
charging pressure desired value and a charging pressure actual
value in the long term.
6. The method of claim 1, further comprising selecting a point in
time directly after the exhaust gas particulate filter has been
regenerated as a starting point in time for the analysis of the
behavior of the charging pressure controller.
7. A device for determining a load condition of an exhaust gas
particulate filter that is arranged in an exhaust gas path of an
internal combustion engine that is charged by an exhaust gas
turbocharger, the device comprises a control unit configured to
execute a method, the method comprising: analyzing a behavior of a
charging pressure controller or the charging pressure of the
exhaust gas turbocharger; and determining the load condition of the
exhaust gas particulate filter based on the analyzed behavior of
the charging pressure controller or the charging pressure of the
exhaust gas turbocharger.
8. The device of claim 7, wherein the method further comprises:
performing a long-term observation of the behavior of the charging
pressure controller or the charging pressure of the exhaust gas
turbocharger; and determining the load condition of the exhaust gas
particulate filter based on the long-term observation.
9. The device of claim 7, wherein the method further comprises:
evaluating control signals provided by the charging pressure
controller; determining adaptation values for a pilot control
procedure of the exhaust gas turbocharger based on the evaluated
control signal; and performing a check for determining whether a
change in the adaptation values occurs in the long term.
10. The device of claim 9, wherein the method further comprises
performing a check for determining whether a characteristic change
in the control signals that are output by the charging pressure
controller occurs in the long term.
11. The device of claim 7, wherein the method further comprises
performing a check for determining whether characteristic
deviations occur between a charging pressure desired value and a
charging pressure actual value in the long term.
12. The device of claim 7, further comprising selecting a point in
time directly after the exhaust gas particulate filter has been
regenerated as a starting point in time for the analysis of the
behavior of the charging pressure controller.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of International
application No. PCT/EP2016/058198, filed Apr. 14, 2016, which
claims priority to German patent application No. 10 2015 211 151.2,
filed Jun. 17, 2015. The disclosures of the above applications are
incorporated herein by reference.
TECHNICAL FIELD
[0002] The disclosure relates to a method and a device for
determining the load condition of an exhaust gas particulate
filter.
BACKGROUND
[0003] Modern motor vehicles having diesel engines are generally
fitted with an exhaust gas particulate filter system for treating
exhaust gas in order to be able to comply with legal requirements
regarding particulate emissions. However, even in the case of
petrol engines legal requirements regarding exhaust gas particulate
emissions are expected to become stricter with the result that in
the future vehicles having a petrol engine may also have to be
fitted with an exhaust gas particulate filter.
[0004] Exhaust gas particulate filter systems filter out the soot
particulates that are produced during engine combustion. Since the
soot particulate storage capability of an exhaust gas particulate
filter is limited, it is necessary to regenerate the exhaust gas
particulate filter in the case of a correspondingly high load.
During this regeneration procedure, soot particulates that have
collected in the filter are burned with the result that new soot
particulates can be collected in the regenerated exhaust gas
particulate filter.
[0005] An exhaust gas particulate filter is regenerated typically
at a high temperature that either occurs during the practical
driving operation or is generated on demand by a corresponding
adjustment of engine parameters. Such an artificial regeneration
procedure is activated in general in dependence on the load
condition of the exhaust gas particulate filter, the load condition
being determined typically with reference to the exhaust gas
backpressure that increases with an increasing particulate
load.
[0006] If the exhaust gas backpressure or the differential pressure
across the particulate filter exceeds a predetermined threshold
value during the operation of the engine, the exhaust gas
temperature is increased, by a corresponding adjustment of the
engine parameters, to above the temperature at which the soot
particulates are combusted, considering further parameters such as,
by way of example, the operating temperature and the engine
rotational speed.
[0007] Determining an increase in the exhaust gas backpressure
using exhaust gas pressure sensors that are installed in the
exhaust gas system upstream and, where appropriate, also downstream
of the exhaust gas particulate filter, or using differential
pressure sensors that measure a pressure increase across the filter
system is already known.
[0008] One disadvantage of this approach resides in the fact that
the above mentioned sensors are heavily stressed owing to the high
exhaust gas temperature that is associated with the installation
position and the contamination caused by the exhaust gas. This
results, on the one hand, in high costs for suitable sensors and,
on the other hand, in an increased susceptibility to a failure of
the sensors.
[0009] A known method and a device for controlling the regeneration
procedure of a particulate filter may be used in an internal
combustion engine that includes an intake air compressor system and
is coupled in a fluidically to an exhaust gas post-treatment system
that includes a particulate filter. The method includes using
engine operating points to determine a steady-state generation rate
of the soot that is exiting the engine, setting the steady-state
generation rate of the soot that is exiting the engine as a
reaction to a transient change in a charging pressure of the intake
air compressor system and controlling the regeneration procedure of
the particulate filter as a reaction to the set steady-state
generation rate of the soot that is exiting the engine. The
controlling the regeneration of the particulate filter as a
reaction to the set generation rate of the soot that is exiting the
engine comprises chronologically integrating the set
chronologically steady-state generation rate of the soot that is
exiting the engine and ordering regeneration of the particulate
filter if the chronologically integrated set generation rate of the
soot that is exiting the engine exceeds a predetermined threshold
value.
[0010] Another known method includes performing a plausibility
check on a determined differential pressure value across a
particulate filter. This plausibility evaluation is performed using
a first measuring unit for determining the differential pressure
value and a second measuring unit that determines a charging
pressure of the internal combustion engine. A charging pressure
value of the internal combustion engine is assigned to each
differential pressure value. The two characteristic values are
stored in a characteristic diagram storage device. An erroneous
differential pressure value is identified if the measured
differential pressure value is outside a predeterminable upper and
lower threshold value range for the differential pressure value
that is stored and allocated to the respective determined charging
pressure of the internal combustion engine.
SUMMARY
[0011] The disclosure provides a method for determining the load
condition of an exhaust gas particulate filter that does not
require exhaust gas pressure sensors and nevertheless reliably
determines the point in time at which the regeneration procedure of
the exhaust gas particulate filter is due.
[0012] The method is provided for determining the load condition of
an exhaust gas particulate filter that is arranged in the exhaust
gas path of an internal combustion engine that is charged by a
turbocharger. The behavior of a charging pressure controller of the
exhaust gas turbocharger is analyzed in the method to determine the
load condition of the exhaust gas particulate filter.
[0013] Executing a procedure of indirectly determining the load
condition in this manner, makes it unnecessary to measure the
exhaust gas pressure upstream and downstream of the particulate
filter using exhaust gas pressure sensors. A differential pressure
sensor is not required either. Consequently, problems that occur in
the case of known methods owing to the arrangement of such sensors
in the hot exhaust tract of an internal combustion engine are
avoided.
[0014] One aspect of the disclosure provides a method for
determining the load condition of an exhaust gas particulate filter
that is arranged in the exhaust gas path of an internal combustion
engine. The internal combustion engine is charged by an exhaust gas
turbocharger. The behavior of a charging pressure controller or the
charging pressure of the exhaust gas turbocharger is analyzed to
determine the load condition of the exhaust gas particulate
filter.
[0015] Implementations of the disclosure may include one or more of
the following optional features. In some implementations, a
long-term observation of the behavior of the charging pressure
controller or the charging pressure of the exhaust gas turbocharger
is performed to determine the load condition of the exhaust gas
particulate filter. In some examples, the charging pressure
controller provides control signals for the exhaust gas
turbocharger and an evaluation of these control signals is
performed in order to determine adaptation values for a pilot
control procedure of the exhaust gas turbocharger, and a check is
performed as to whether a change in the adaptation values occur in
the long term.
[0016] In some implementations, a check is performed as to whether
a characteristic change in the control signals that are output by
the charging pressure controller occurs in the long term. A check
may be performed as to whether characteristic deviations occur
between a charging pressure desired value and a charging pressure
actual value in the long term. In some examples, a point in time
directly after the exhaust gas particulate filter has been
regenerated is selected as a starting point in time for the
analysis of the behavior of the charging pressure controller.
[0017] Another aspect of the disclosure provides a device for
determining the load condition of an exhaust gas particulate filter
that is arranged in the exhaust gas path of an internal combustion
engine that is charged by an exhaust gas turbocharger. The device
includes a control unit configured to perform the method described
above.
[0018] The details of one or more implementations of the disclosure
are set forth in the accompanying drawings and the description
below. Other aspects, features, and advantages will be apparent
from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0019] FIG. 1 illustrates a block diagram of a device for
determining the load of an exhaust gas particulate filter.
[0020] Like reference symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION
[0021] FIG. 1 shows a device for determining the load of an exhaust
gas particulate filter. The device includes an internal combustion
engine 1, an exhaust gas turbocharger 2 that includes a turbine 3
and a compressor 5, an exhaust gas particulate filter 6, a control
unit 7, an operating program storage device 8 and a data storage
device 9. The turbine 3 is supplied with the hot exhaust gas of the
internal combustion engine 1 and uses said hot exhaust gas to drive
a turbine wheel. The turbine wheel is connected in a non-rotatable
manner to a shaft 4. The shaft 4 is in turn connected in a
non-rotatable manner to a compressor wheel that is arranged in the
compressor 5 with the result that rotations of the turbine wheel
are transferred to the compressor wheel. The fresh air that is
supplied to the compressor is compressed by the rotation of the
compressor wheel. The compressed fresh air is supplied to the
internal combustion engine 1 and is used to increase the power of
the engine.
[0022] Furthermore, the illustrated device includes a control unit
7, for example, the control device of the motor vehicle. The
control unit 7 is connected to an operating program storage device
8 in which the operating program of the control unit is stored.
Furthermore, the control unit 7 is connected to a data storage
device 9 in which data is stored that corresponds inter alia to
characteristic diagrams that are required by the control unit 7
during operation of the motor vehicle.
[0023] The control unit 7 includes a charging pressure controller
7a that is used for controlling the charging pressure of the
exhaust gas turbocharger 2 during operation of the exhaust gas
turbocharger 2.
[0024] The control unit 7 determines and outputs, during operation
of the motor vehicle, control signals s1, s2 and s3 that depend on
the sensor signals se1 that are supplied to the control unit 7
using the operating program and with the aid of the data that is
stored in the storage device 9. The control signals s1 are used to
control the internal combustion engine 1, the control signal s2 for
controlling the actuators of the turbine 3 and the control signal
s3 for controlling the actuators of the compressor 5. A wastegate
valve or a variable turbine geometry is associated with the
actuators of the turbine 3, and the opening state of the valves is
altered on demand by the control signal s2. A bypass valve is
associated with the actuators of the compressor 5 and compressed
air is supplied via the bypass valve back to the input of the
compressor 5 on demand. The opening state of this bypass valve is
set by the control signal s3.
[0025] The abovementioned control signals se1 include inter alia
the output signal of an accelerator pedal sensor that indicates an
actuation of the accelerator pedal, the output signal of one or
multiple temperature sensors that each provides information
regarding a temperature that is measured at a predetermined
location on the exhaust gas turbocharger, and the output signal of
a pressure sensor that provides information regarding the pressure
of the compressed air that is present at the output of the
compressor.
[0026] Controlling the actuators of the exhaust gas turbocharger 2
is inter alia dependent on the exhaust gas backpressure since the
output power of the turbine 3 is determined from the drop in the
pressure across the turbine. This drop in the pressure across the
turbine is defined by the exhaust gas backpressure downstream of
the outlet valve or outlet valves of the internal combustion engine
and by the exhaust gas backpressure downstream of the turbine,
i.e., the exhaust gas backpressure upstream of the particulate
filter 6. In the case of an identical operating point of the
internal combustion engine, an increase in the exhaust gas
backpressure upstream of the particulate filter 6 as a result of an
increased flow resistance in the particulate filter 6 therefore
leads to a reduced pressure drop across the turbine. Consequently,
the power that is output by the turbine is less than the power that
is determined by the control unit 7 using the stored characteristic
diagrams, since the stored engine characteristic diagram was
created based on the drop in pressure across the turbine in the
case of an unloaded exhaust gas particulate filter. During
operation of the internal combustion engine the desired charging
pressure that is requested by the control unit for the engine
operating point that is to be set is not entirely realized with a
pilot control procedure that relates to the stored engine
characteristic diagram. Consequently, there is a difference between
the desired charging pressure and the actual charging pressure, the
difference being compensated by the charging pressure controller 7a
that is present in the control unit. This leads to a controller
deviation that is also dependent upon the load condition of the
exhaust gas particulate filter 6.
[0027] The behavior of the charging pressure controller 7a may
therefore be used to determine the load condition of the exhaust
gas particulate filter 6. Consequently, the point in time of a
required regeneration procedure of the exhaust gas particulate
filter may be determined using an analysis of the behavior of the
charging pressure controller 7a.
[0028] There are different possibilities for this analysis of the
behavior of the charging pressure controller 7a. In general, the
procedure of loading the exhaust gas particulate filter to the
point in time at which it is necessary to regenerate the exhaust
gas particulate filter takes a relatively longer time.
Consequently, it is necessary to perform long-term observation of
the behavior of the charging pressure controller 7a and therefore
also of the pilot control requirement of the exhaust gas
turbocharger 2. An analysis of the required adaptations of the
pilot control procedure of the exhaust gas turbocharger is suitable
for such long-term observation. Long-term observation of charging
pressure overshoots and charging pressure undershoots is also
suitable.
[0029] A point in time directly after the execution of a
regeneration procedure is selected in an advantageous manner as a
starting point in time for a long-term observation of this type. At
this point in time the above mentioned adaptation values for the
pilot control of the turbocharger are reset. Starting from this
point in time, new long-term observation of the adaptation values
for the preset control procedure of the exhaust gas turbocharger is
to be performed.
[0030] Alternatively or in addition thereto, it is also possible to
perform a check as to whether characteristic changes of the control
signals that are output by the charging pressure controller occur
in the long term. Furthermore, alternatively or in addition thereto
it is possible to perform a check as to whether characteristic
deviations occur between the charging pressure desired value and
the charging pressure actual value in the long term.
[0031] All the above-mentioned checking procedures are performed in
dependence on changes that occur in the exhaust gas
backpressure.
[0032] It follows that the present invention provides a method and
a device in which a conclusion is drawn that it is necessary to
perform modified pilot control of the exhaust gas turbocharger in
response to a change in the drop in pressure across the turbine as
a result of an increase in the exhaust gas backpressure in the
exhaust gas particulate filter, the increase being caused by
increased loading of the exhaust gas particulate filter.
[0033] A number of implementations have been described.
Nevertheless, it will be understood that various modifications may
be made without departing from the spirit and scope of the
disclosure. Accordingly, other implementations are within the scope
of the following claims.
* * * * *