Method for monitoring an exhaust gas system of a motor vehicle
View Patent ↗A method for monitoring a vehicle exhaust system may include (1) measuring exhaust-gas temperature at an outlet side of an exhaust pipe section which is intended to accommodate a component with a purifying activity, (2) measuring exhaust-gas temperature at an inlet side of the exhaust pipe section, and (3) comparing a time curve of the outlet-side temperature with a time curve of the inlet-side temperature, wherein the comparison comprises determining a time derivative of the outlet-side temperature or of the inlet-side temperature. Alternatively, the method may include (1) measuring exhaust-gas temperature at an outlet side of an exhaust pipe section which is intended to accommodate a component with a purifying activity, (2) determining a calculated value for the exhaust-gas temperature at the outlet side based on at least one of the heat-storing and fluid-dynamic action of the component, and (3) comparing a time curve of the measured outlet-side temperature with a time curve of the calculated value.
1. A method for monitoring an exhaust system of a motor vehicle, comprising:
measuring exhaust-gas temperature at an outlet side of an exhaust pipe section which is intended to accommodate a component with a purifying activity;
determining a calculated value for the exhaust-gas temperature at the outlet side of the exhaust pipe section on the basis of at least one of the heat-storing and fluid-dynamic action of the component with a purifying activity; and
comparing a time curve of the measured outlet-side exhaust-gas temperature with a time curve of the calculated value for the exhaust-gas temperature at the outlet side.
2. The method as claimed in claim 1 , further comprising determining the time derivative of the outlet-side exhaust-gas temperature, the time derivative of the calculated temperature, and the difference between the derivatives.
3. The method as claimed in claim 2 , further comprising generating a signal which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the derivatives is outside a predetermined range of values.
4. The method as claimed in claim 1 , determining the time derivative of the outlet-side exhaust-gas temperature, the time derivative of a measured inlet-side exhaust-gas temperature at an inlet side of the exhaust pipe section, and the time derivative of the calculated value for the exhaust-gas temperature at the outlet side of the exhaust pipe section, and generating a signal which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the derivatives is outside a predetermined range of values and the time derivative of the inlet-side exhaust-gas temperature is outside a predetermined range of values.
5. The method as claimed in claim 1 , further comprising determining the time derivative of the outlet-side exhaust-gas temperature, the time derivative of a measured inlet-side exhaust-gas temperature at an inlet-side of the exhaust pipe section, and the time derivative of a calculated value for the exhaust-gas temperature at the outlet-side of the exhaust pipe section, and generating a signal which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the time derivatives of the calculated and the measured value for the outlet-side exhaust-gas temperature is outside a predetermined range of values and the time derivative of the inlet-side exhaust-gas temperature is outside a predetermined range of values.
6. A method for monitoring an exhaust system of a motor vehicle having an internal combustion engine and having monitoring electronics, a temperature sensor for measuring an outlet-side exhaust-gas temperature being arranged at the outlet side of an exhaust pipe section which is intended to accommodate a component with a purifying activity, and the monitoring electronics compare a time curve of the outlet-side exhaust-gas temperature with a time curve of a calculated value for the exhaust-gas temperature at the outlet side of the exhaust pipe section, wherein the calculated value is determined on the basis of the heat-storing and/or fluid-dynamic action of the component with a purifying activity.
7. The method as claimed in claim 6 , wherein the monitoring electronics determine the time derivatives and of the outlet-side exhaust-gas temperature and of the calculated temperature and the difference between the derivatives.
8. The method as claimed in claim 7 , wherein the monitoring electronics generate a signal which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the derivatives is outside a predetermined range of values.
9. The method as claimed in claim 6 , wherein the monitoring electronics determine the time derivatives and of the inlet-side exhaust-gas temperature and of the outlet-side exhaust-gas temperature and also the time derivative of the calculated value for the exhaust-gas temperature at the outlet side of the exhaust pipe section and generate a signal which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the derivatives is outside a predetermined range of values and the time derivative of the inlet-side exhaust-gas temperature is outside a predetermined range of values.
10. The method as claimed in claim 6 , wherein the monitoring electronics determine the time derivatives of the outlet-side exhaust-gas temperature and of the calculated temperature and the difference between the derivatives.
11. The method as claimed in claim 10 , wherein the monitoring electronics generate a signal which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the derivatives is outside a predetermined range of values.
12. The method as claimed in claim 6 , wherein the monitoring electronics determine the time derivatives of an inlet-side exhaust-gas temperature and of the outlet-side exhaust-gas temperature and also the time derivative of the calculated value for the exhaust-gas temperature at the outlet-side of the exhaust pipe section and generate which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the derivatives of the calculated and the measured value for the outlet-side exhaust-gas temperature is outside a predetermined range of values and the time derivative of the inlet-side exhaust-gas temperature is outside a predetermined range of values.
13. A method for monitoring an exhaust system of a motor vehicle, comprising:
measuring an exhaust-gas temperature at an outlet side of an exhaust pipe section which can accommodate a component with a purifying activity;
measuring an exhaust-gas temperature at an inlet side of the exhaust pipe section;
carrying out a comparison of a time curve of the outlet-side exhaust-gas temperature with a time curve of the inlet-side exhaust-gas temperature; and
generating a signal if an evaluation of said comparison indicates the absence of the component with a purifying activity or the presence of an incorrect component.
14. The method as claimed in claim 13 , wherein the comparison of the time curves comprises the determination of a time derivative of the outlet-side exhaust-gas temperature or of the inlet-side exhaust-gas temperature.
15. The method as claimed in claim 14 , further comprising determining both the time derivative of the measured outlet-side and inlet-side exhaust-gas temperature, and determining the difference between the tine derivatives.
16. The method as claimed in claim 15 , wherein the signal is generated if the difference between the derivatives is within a predetermined range of values.
17. The method as claimed in claim 15 , wherein the signal is generated if the difference between the derivatives is within a predetermined range of values and the time derivative of the inlet-side exhaust-gas temperature is outside a predetermined range of values.
18. The method as claimed in claim 14 , further comprising determining the time derivative of the measured outlet-side and inlet-side exhaust-gas temperatures, and the time derivative of a calculated value for the exhaust-gas temperature at the outlet-side of the exhaust pipe section, wherein the signal is generated if the difference between the time derivatives of the calculated and the measured value for the outlet-side exhaust-gas temperature is outside a predetermined range of values and the time derivative of the inlet-side exhaust-gas temperature is outside a predetermined range of values.
19. A method for monitoring an exhaust system of a motor vehicle having an internal combustion engine and having monitoring electronics, a temperature sensor for measuring an outlet-side exhaust-gas temperature being arranged at the outlet-side of an exhaust pipe section which is intended to accommodate a component with a purifying activity, and the monitoring electronics compare a time curve of the outlet-side exhaust-gas temperature with a time curve of an inlet-side exhaust-gas temperature at the inlet side of the exhaust pipe section, wherein the monitoring electronics;
determine the time derivatives of the inlet-side exhaust-gas temperature and the outlet-side exhaust-gas temperature and the difference between the derivatives, and
generate a signal which indicates the absence of the component with a purifying activity or the presence of an incorrect component if the difference between the derivatives is within a predetermined range of values.
20. The method as claimed in claim 19 , wherein the signal is generated if the difference between the derivatives is within a predetermined range of values and the time derivative of the inlet-side exhaust-gas temperature is outside a predetermined range of values.