Method and device for operating a particle sensor

Patent metadata

Field	Value
Publication number	US-10066566-B2
Application number	US-201415038134-A
Country	US
Kind code	B2
Filing date	Nov 12, 2014
Priority date	Nov 20, 2013
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

The invention relates to a method and to a device, in particular a control and evaluating unit, for operating a particle sensor ( 20 ) for determining a particle content in a gas flow, wherein the particle sensor ( 20 ) has, on the surface of the particle sensor, a sensor structure for determining a soot load and at least one heating element ( 26 ) separated from the sensor structure by an insulating layer, by means of which at least one heating element the particle sensor ( 20 ) can be heated up in a regeneration phase and in the process a soot load on the particle sensor ( 20 ) can be removed, and by means of the heating element ( 26 ) a heating phase can be performed at least at times before the regeneration phase, wherein in said heating phase a temperature that is significantly lower than the regeneration temperature is set, wherein short-term temperature drops as a result of wetting with water can be detected by means of a temperature sensor ( 27 ) integrated in the particle sensor ( 20 ). According to the invention, during the heating phase before the regeneration phase, the duration of the heating phase is extended if a temperature deviation from a certain temperature bandwidth around a temperature target value is detected for a certain time. Thus, it can be achieved that the sensor element is always completely dried throughout the sensor element, such that regeneration can be performed at high temperatures without damage as a result of thermal shock to the sensor element.

First claim

The invention claimed is:

1. A method for operating a particle sensor ( 20 ) for determining a particle content in a gas flow, wherein the particle sensor ( 20 ) comprises on a surface thereof a sensor structure for determining a soot load and at least one heating element ( 26 ) that is separated by an insulating layer from the sensor structure, the heating element being configured to heat up the particle sensor ( 20 ) in a regeneration phase to remove a soot load on the particle sensor ( 20 ), and the heating element being configured to carry out a heating phase at least at times before the regeneration phase, wherein a significantly lower temperature is controlled in said heating phase compared to a temperature of the regeneration phase, wherein a temperature sensor ( 27 ) is configured to detect brief drops in temperature as a result of wetting by water, the temperature sensor ( 27 ) being integrated within the particle sensor ( 20 ), the method comprising, during said heating phase before the regeneration phase, extending the duration of said heating phase whenever a temperature deviation from a defined temperature bandwidth about a target temperature value is detected for a certain time, wherein a timer is provided for control of the duration of the heating phase before the regeneration phase, wherein the timer is reset and/or restarted whenever a temperature deviation from the defined temperature bandwidth about the target temperature value is detected.

2. The method as claimed in claim 1 , characterized in that the temperature bandwidth about the target temperature value is predefined.

3. The method as claimed in claim 1 , characterized in that during each resetting and/or restarting of the timer, a counter is incremented and the count is analyzed to enable the regeneration phase.

4. The method as claimed in claim 3 , characterized in that, on reaching an applicable number of reset and/or restart processes, the regeneration phase is blocked for a defined driving cycle.

5. The method as claimed in claim 3 , characterized in that using a frequency of the reset and/or restart processes of the timer, heavy wetting by water of an exhaust system ( 17 ) of an internal combustion engine ( 10 ) is detected.

6. The method as claimed in claim 1 , wherein the particle sensor ( 20 ) is disposed in an exhaust system ( 17 ) of an internal combustion engine ( 1 ), further comprising performing an on-board diagnosis of a particle filter.

7. The method as claimed in claim 6 , wherein the internal combustion engine is a diesel engine.

8. The method as claimed in claim 6 , wherein the internal combustion engine is a gasoline engine.

9. A method for operating a particle sensor ( 20 ) for determining a particle content in a gas flow, wherein the particle sensor ( 20 ) comprises on a surface thereof a sensor structure for determining a soot load and at least one heating element ( 26 ) that is separated by an insulating layer from the sensor structure, the heating element being configured to heat up the particle sensor ( 20 ) in a regeneration phase to remove a soot load on the particle sensor ( 20 ), and the heating element being configured to carry out a heating phase at least at times before the regeneration phase, wherein a significantly lower temperature is controlled in said heating phase compared to a temperature of the regeneration phase, wherein a temperature sensor ( 27 ) is configured to detect brief drops in temperature as a result of wetting by water, the temperature sensor ( 27 ) being integrated within the particle sensor ( 20 ), the method comprising, during said heating phase before the regeneration phase, extending the duration of said heating phase when a temperature deviation from a defined temperature bandwidth about a target temperature value is detected for a certain time, characterized in that using a frequency of reset and/or restart processes of a timer, heavy wetting by water of an exhaust system ( 17 ) of the particle sensor installed in an internal combustion engine ( 10 ) is detected.

10. A method for operating a particle sensor ( 20 ) for determining a particle content in a gas flow, wherein the particle sensor ( 20 ) comprises on a surface thereof a sensor structure for determining a soot load and at least one heating element ( 26 ) that is separated by an insulating layer from the sensor structure, the heating element being configured to heat up the particle sensor ( 20 ) in a regeneration phase to remove a soot load on the particle sensor ( 20 ), and the heating element being configured to carry out a heating phase at least at times before the regeneration phase, wherein a significantly lower temperature is controlled in said heating phase compared to a temperature of the regeneration phase, wherein a temperature sensor ( 27 ) is configured to detect brief drops in temperature as a result of wetting by water, the temperature sensor ( 27 ) being integrated within the particle sensor ( 20 ), the method comprising, during said heating phase before the regeneration phase, extending the duration of said heating phase if a temperature deviation from a defined temperature bandwidth about a target temperature value is detected for a certain time, characterized in that a timer for control of the duration of the heating phase before the regeneration phase is reset and/or restarted whenever a temperature deviation from the defined temperature bandwidth about the target temperature value is detected.

Assignees

• Bosch Gmbh Robert

Inventors

• Knuebel Andreas
• Baars Enno
• Bessen Michael

Classifications

• G01N15/0606 Primary

  by collecting particles on a support · CPC title

• F01N11/002

  the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus · CPC title

• F01N2560/05

  the means being a particulate sensor · CPC title

• F01N2560/20

  Sensor having heating means · CPC title

• F01N3/021

  by means of filters · CPC title