Procedure for operating a particle sensor that is arranged downstream after a particle filter and device for implementing this procedure

• US 7,963,143 B2
• Filed: 05/14/2008
• Issued: 06/21/2011
• Est. Priority Date: 05/14/2007
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Baumann, Thomas, Baars, Enno, Koehnlein, Harald, Schumacher, Herbert, Kamp, Bernhard
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): Frank; Rodney T
• Application Number:
  US12/120,559
• Publication Number:
  US 20090013758A1
• Time in Patent Office: 1,133 Days
• Field of Search: 73/10.1, 735/142.5
• US Class Current: 73/1.01
• CPC Class Codes: B01D 46/442 by measuring the concentration of particles
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 2560/05 the means being a particulate sensor
• 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 41/1466 the characteristics being a soot concentration or content
• CPC Class Codes: F02D 41/1494 Control of sensor heater
• CPC Class Codes: G01N 15/0606 by collecting particles on a support
• CPC Class Codes: G01N 15/0656 using electric, e.g. electrostatic methods or magnetic methods by investigating individual particles G01N15/1031, G01N15/12
• CPC Class Codes: G01N 2015/0046 in gas, e.g. smoke
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A procedure for operating a particle sensor that is arranged downstream after a particle filter, at which an ash contamination can occur, and a device for implementing the procedure, are suggested. A remaining operating time determination determines the remaining operating time of the particle sensor related to an ash contamination. Alternatively or additionally the remaining operating time determination provides a correction signal, with which the sensitivity loss of the particle sensor caused by the ash contamination can be considered.

Claims

1. A method of operating a particle sensor arranged downstream after a particle filter wherein an ash contamination of the particle sensor can occur, the method comprising:

determining a remaining operating time of the particle sensor related to the ash contamination via a remaining operating time determination, whereby a correction signal is provided such that a sensitivity loss of the particle sensor due to the ash contamination is considered.

2. A method according to claim 1, wherein determining includes determining the remaining operating time of the particle sensor from a first activation of the particle sensor.

3. A method according to claim 1, wherein determining includes determining after a detection of a particle filter defect, wherein an assessment of a particle sensor-sensor signal is used to detect the particle filter defect.

4. A method according to claim 3, wherein the assessment includes a comparison of the particle sensor-sensor signal with an absolute threshold value and/or a gradient threshold value.

5. A method according to claim 1, further comprising determining an efficiency of the particle filter by the remaining operating time determination as a defect intensity.

6. A method according to claim 5, wherein determining an efficiency includes:

a) determining by a particle sensor measuring signal related to an entire operating time of a combustion engine, wherein the particle filter and the particle sensor are arranged in an exhaust gas area of the combustion engine and relating to a driving distance that has been covered by a motor vehicle, wherein the motor vehicle provides a combustion engine as a drive.

7. A method according to claim 5, wherein determining an efficiency includes determining via a particle sensor measuring signal and an ash emission of the combustion engine that has been calculated by an ash model.

8. A method according to claim 1, wherein determining includes considering an ash emission of a combustion engine that has been determined by means of an ash model.

9. A method according to claim 8, wherein the ash model considers at least:

a) a fuel type of the combustion engine;

b) a measure of an oil consumption of the combustion engine;

c) an oil quality of the combustion engine;

d) a load of the combustion engine;

e) a temperature of the combustion engine; and

f) an entire operating time of the combustion engine.

10. A method according to claim 1, wherein determining includes considering an entire operating time of the particle sensor or the driving distance that has been covered by a motor vehicle, wherein the drive of the motor vehicle is a combustion engine, wherein a particle filter and the particle sensor are arranged in the exhaust gas area of the combustion engine.

11. A method according to claim 1, further comprising at least partially minimizing an operating voltage of the particle sensor in order to minimize an ash accumulation.

12. A method according to claim 1, wherein the particle sensor is provided at least temporally with a sensor heating voltage in order to minimize an ash accumulation.

13. A device, comprising:

a customized controller constructed and configured to operate a particle sensor arranged downstream after a particle filter, wherein an ash contamination of the particle sensor can occur, and to determine a remaining operating time of the particle sensor related to the ash contamination via a remaining operating time determination, whereby a correction signal is provided such that a sensitivity loss of the particle sensor due to the ash contamination is considered.

14. A device according to claim 13, wherein at least one customized controller is provided additionally to a combustion engine controller as a separate sensor controller, wherein the sensor controller contains at least a remaining operating time determination.

15. A device according to claim 14, wherein the at least one controller contains a measuring signal assessment, a defect intensity determination and an ash model.

16. A computer-implemented method for operating a particle sensor arranged downstream after a particle filter, wherein an ash contamination of the particle sensor can occur, the computer-implemented method comprising the step of:

determining a remaining operating time of the particle sensor related to the ash contamination via a remaining operating time determination, whereby a correction signal is provided such that a sensitivity loss of the particle sensor due to the ash contamination is considered.

17. A computer program product with a program code stored on a machine readable device and executed on a customized controller, for operating a particle sensor arranged downstream after a particle filter, wherein an ash contamination of the particle sensor can occur, the program code including instructions for determining a remaining operating time of the particle sensor related to the ash contamination via a remaining operating time determination, whereby a correction signal is provided such that a sensitivity loss of the particle sensor due to the ash contamination is considered.