Method and device for controlling an exhaust treatment system

• US 20030154710A1
• Filed: 03/03/2003
• Published: 08/21/2003
• Est. Priority Date: 01/08/2001
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Walter, Michael, Krautter, Andreas, Plote, Holger, Sojka, Juergen
• Granted Patent: US 6,945,037 B2
• Time in Patent Office: Days
• US Class Current: 60/277
• CPC Class Codes: F01N 2550/04 Filtering activity of particulate filters
• CPC Class Codes: F01N 3/023 using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F01N 9/002 of filter regeneration, e.g. detection of clogging
• CPC Class Codes: F01N 9/005 using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 2200/0812 Particle filter loading
• CPC Class Codes: F02D 41/029 the exhaust gas treating apparatus being a particulate filter
• CPC Class Codes: F02D 41/1448 the characteristics being an exhaust gas pressure
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method and a device for controlling an internal combustion engine having an exhaust gas aftertreatment system are described. A quantity (B) which characterizes the state of the exhaust gas aftertreatment system is determined based on at least one characteristic operating quantity of the internal combustion engine.

Claims

1. A method of controlling an exhaust gas aftertreatment system, in particular of an internal combustion engine, it being possible when first operating states of the internal combustion engine are present to predetermine a state quantity (B) characterizing the state of the exhaust gas aftertreatment system based on at least one pressure difference between the pressure upstream from the exhaust gas aftertreatment system and the pressure downstream from the exhaust gas aftertreatment system, wherein, when second operating states are present, the state quantity (B) is simulated based on at least one characteristic operating quantity of the internal combustion engine.

2. The method according to claim 1, wherein the state quantity (B) is simulated based on at least the rotational speed (N) and/or a signal (ME) which characterizes the amount of fuel injected.

3. The method according to one of claims 1 or 2, wherein the second operating state is present when a volume flow quantity which characterizes the exhaust gas volume flow is smaller than a first threshold value.

4. The method according to one of claims 1 through 3, wherein the state quantity (B) is simulated in dynamic operating states.

5. The method according to one of claims 1 through 4, wherein the dynamic operating state is present when a characteristic operating quantity which characterizes the change in the amount of fuel injected, the change in the rotational speed, the change in the driver'"'"'s intent, and/or the change in the amount of air are larger than a second threshold value.

6. The method according to one of claims 1 through 5, wherein the simulation of the state quantity includes an integration, the value of the state quantity which is predetermined based on the pressure difference being used during the transition from the first operating state to the second operating state as the starting value for the integration.

7. The method according to one of claims 1 through 6, wherein the simulation of the state quantity includes an integration, a value stored during the last shutdown being used as the starting value when the exhaust gas aftertreatment system and/or the internal combustion engine are started up.

8. The method, in particular according to one of the preceding claims, of controlling an exhaust gas aftertreatment system, it being possible to predetermine a state quantity (B) characterizing the state of the exhaust gas aftertreatment system based on at least one pressure difference between the pressure upstream from and the pressure downstream from the exhaust gas aftertreatment system,

wherein in addition to the pressure difference a volume flow quantity which characterizes the exhaust gas volume flow is taken into account.

9. The method according to claim 8, wherein it is possible to predetermine the volume flow quantity based on characteristic operating quantities which characterize the amount of air taken in and/or the amount of fuel injected.

12. A computer program having program code means in order to carry out all the steps of any of claims 1 through 11 when the program is executed on a computer, in particular on a control device for an internal combustion engine.

13. A computer program product having program code means which are stored on a computer-readable data carrier in order to carry out the method according to any of claims 1 through 11 when the program product is executed on a computer, in particular on a control device for an internal combustion engine.

10. A device for controlling an exhaust gas aftertreatment system, in particular of an internal combustion engine, having means which, when first operating states of the internal combustion engine are present, predetermine a state quantity (B) characterizing the state of the exhaust gas aftertreatment system based on at least one pressure difference between the pressure upstream from the exhaust gas aftertreatment system and the pressure downstream from the exhaust gas aftertreatment system, wherein means are provided which, when second operating states are present, simulate the state quantity (B) based on at least one characteristic operating quantity of the internal combustion engine.

11. The device, in particular according to claim 10, for controlling an exhaust gas aftertreatment system having means which predetermine a state quantity (B) characterizing the state of the exhaust gas aftertreatment system based on at least one pressure difference between the pressure upstream from and the pressure downstream from the exhaust gas aftertreatment system,

wherein means are provided which, in addition to the pressure difference, take into account a volume flow quantity which characterizes the exhaust gas volume flow.