Method, computer unit and computer program for operating a combustion engine

Patent metadata

Field	Value
Publication number	US-11459930-B2
Application number	US-202117492845-A
Country	US
Kind code	B2
Filing date	Oct 4, 2021
Priority date	Oct 8, 2020
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

Operating a combustion engine with an exhaust gas aftertreatment system. In one example, a method includes determining a level of at least one exhaust gas component using a theoretical catalytic converter model in which at least one signal of a first exhaust gas sensor is input as a first signal, detecting a signal of a second exhaust gas sensor downstream of the exhaust gas catalytic converter as a second signal, determining a deviation of the second signal from a target signal, reinitializing the catalytic converter model if the deviation of the second signal from the target signal exceeds a predetermined threshold value, regulating the level by setting an air-fuel mixture supplied to the combustion engine according to a target level based on the determined level, determining a deviation between the first and the second signals, and correcting the first signal.

First claim

The invention claimed is:

1. A method ( 200 ) for the operation of a combustion engine ( 120 ) with an exhaust aftertreatment system having an exhaust gas catalytic converter ( 130 ) and at least two exhaust gas sensors ( 145 , 147 ), wherein at least one first exhaust gas sensor ( 145 ) is arranged upstream of the exhaust gas catalytic converter ( 130 ) and at least one second exhaust gas sensor ( 147 ) is arranged downstream of the exhaust gas catalytic converter ( 130 ), the method comprising:
determining ( 220 ) a level of at least one exhaust component in the exhaust gas catalytic converter ( 130 ) which can be stored in the catalytic converter ( 130 ) using a theoretical catalytic converter model in which at least one signal from the first exhaust gas sensor ( 145 ) as an input variable is input as a first signal,
detecting ( 230 ) a signal from the second exhaust sensor ( 147 ) downstream of the exhaust gas catalytic converter ( 130 ) as a second signal,
determining ( 240 ) a deviation of the second signal from a target signal, wherein the target signal corresponds to the signal which would be expected at the determined level in the catalytic converter ( 130 ),
reinitializing ( 260 ) the catalytic converter model when the deviation of the second signal from the target signal exceeds a predetermined threshold value, so that the determined level after the reinitialization ( 260 ) brings about a target signal which corresponds to the detected second signal,
regulating ( 270 ) the level in the exhaust gas catalytic converter ( 130 ) by setting an air-fuel mixture supplied to the combustion engine ( 120 ) according to a target level based on the determined level,
determining ( 280 ) a deviation between the first and the second signals following the reinitializing ( 260 ) of the catalytic converter model and following regulating ( 270 ) the level to the target level, and
correcting the first signal by means of a correction value ( 285 ) determined as a function of the deviation between the first and second signals, so that the deviation between the first and the second signals is reduced.

2. The method ( 200 ) according to claim 1 , wherein the first exhaust gas sensor ( 145 ) is a broadband lambda sensor and the second exhaust gas sensor ( 147 ) is a jump lambda sensor.

3. The method ( 200 ) according to claim 1 , wherein the at least one exhaust gas component contains oxygen.

4. The method ( 200 ) according to claim 1 , wherein the correction value ( 285 ) is calculated as a product of the deviation between the first and the second signals with an attenuation factor.

5. The method ( 200 ) according to claim 4 , wherein the attenuation factor is chosen to be smaller, the greater a difference between the second signal and the target signal.

6. The method ( 200 ) according to claim 1 , wherein the correction of the first signal is carried out by adding the correction value ( 285 ) to the first signal.

7. The method ( 200 ) according to claim 1 , wherein the first and the second signals contain lambda values.

8. A computing unit ( 140 ) configure to operate a combustion engine ( 120 ) with an exhaust aftertreatment system having an exhaust gas catalytic converter ( 130 ) and at least two exhaust gas sensors ( 145 , 147 ), wherein at least one first exhaust gas sensor ( 145 ) is arranged upstream of the exhaust gas catalytic converter ( 130 ) and at least one second exhaust gas sensor ( 147 ) is arranged downstream of the exhaust gas catalytic converter ( 130 ), by:
determining ( 220 ) a level of at least one exhaust component in the exhaust gas catalytic converter ( 130 ) which can be stored in the catalytic converter ( 130 ) using a theoretical catalytic converter model in which at least one signal from the first exhaust gas sensor ( 145 ) as an input variable is input as a first signal,
detecting ( 230 ) a signal from the second exhaust sensor ( 147 ) downstream of the exhaust gas catalytic converter ( 130 ) as a second signal,
determining ( 240 ) a deviation of the second signal from a target signal, wherein the target signal corresponds to the signal which would be expected at the determined level in the catalytic converter ( 130 ),
reinitializing ( 260 ) the catalytic converter model when the deviation of the second signal from the target signal exceeds a predetermined threshold value, so that the determined level after the reinitialization ( 260 ) brings about a target signal which corresponds to the detected second signal,
regulating ( 270 ) the level in the exhaust gas catalytic converter ( 130 ) by setting an air-fuel mixture supplied to the combustion engine ( 120 ) according to a target level based on the determined level,
determining ( 280 ) a deviation between the first and the second signals following the reinitializing ( 260 ) of the catalytic converter model and following regulating ( 270 ) the level to the target level, and
correcting the first signal by means of a correction value ( 285 ) determined as a function of the deviation between the first and second signals, so that the deviation between the first and the second signals is reduced.

9. A non-transitory, computer-readable medium containing instructions that when executed by a computer cause the computer to operate a combustion engine ( 120 ) with an exhaust aftertreatment system having an exhaust gas catalytic converter ( 130 ) and at least two exhaust gas sensors ( 145 , 147 ), wherein at least one first exhaust gas sensor ( 145 ) is arranged upstream of the exhaust gas catalytic converter ( 130 ) and at least one second exhaust gas sensor ( 147 ) is arranged downstream of the exhaust gas catalytic converter ( 130 ), by:
determining ( 220 ) a level of at least one exhaust component in the exhaust gas catalytic converter ( 130 ) which can be stored in the catalytic converter ( 130 ) using a theoretical catalytic converter model in which at least one signal from the first exhaust gas sensor ( 145 ) as an input variable is input as a first signal,
detecting ( 230 ) a signal from the second exhaust sensor ( 147 ) downstream of the exhaust gas catalytic converter ( 130 ) as a second signal,
determining ( 240 ) a deviation of the second signal from a target signal, wherein the target signal corresponds to the signal which would be expected at the determined level in the catalytic converter ( 130 ),
reinitializing ( 260 ) the catalytic converter model when the deviation of the second signal from the target signal exceeds a predetermined threshold value, so that the determined level after the reinitialization ( 260 ) brings about a target signal which corresponds to the detected second signal,
regulating ( 270 ) the level in the exhaust gas catalytic converter ( 130 ) by setting an air-fuel mixture supplied to the combustion engine ( 120 ) according to a target level based on the determined level,
determining ( 280 ) a deviation between the first and the second signals following the reinitializing ( 260 ) of the catalytic converter model and following regulating ( 270 ) the level to the target level, and
correcting the first signal by means of a correction value ( 285 ) determined as a function of the deviation between the first and second signals, so that the deviation between the first and the second signals is reduced.

Assignees

• Bosch Gmbh Robert

Inventors

• Fey Michael

Classifications

• F01N11/007 Primary

  the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus · CPC title

• F01N9/005 Primary

  using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly · CPC title

• F02D41/1441 Primary

  Plural sensors · CPC title

• F01N9/00

  Electrical control of exhaust gas treating apparatus (monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00) · CPC title

• F01N2560/025

  for measuring or detecting O2, e.g. lambda sensors · CPC title