Method and device for measuring the soot load in the exhaust gas systems of diesel engines
View Patent ↗A method and device for measuring the soot load in the exhaust gas systems of diesel engines using a sensor which is mounted downstream of a particulate filter and comprises a sensor element, to measure the operability of the particulate filter. According to the method, the soot load of the sensor element is measured resistively or capacitively using electrodes. The measuring voltage of the sensor element is controlled depending on at least one actual operating parameter of the diesel engine.
1. A method for measuring a soot load of an exhaust gas in an exhaust gas system of a diesel engine as a measure of functional capability of a particle filter using a sensor having a sensor element connected downstream of the particle filter, the method comprising:
measuring the soot load one of resistively and capacitively using the sensor element, wherein electrodes are formed on the sensor element;
applying a measurement voltage between the electrodes; and
controlling the measurement voltage applied between the electrodes as a function of at least one instantaneous operating parameter of the diesel engine; and
calculating at least one of a moisture of the exhaust gas and a temperature of the exhaust gas as the at least one instantaneous operating parameter of the diesel engine; and
acquiring an optimum measurement voltage of the sensor element from the at least one of the moisture of the exhaust gas and the temperature of the exhaust gas.
2. The method as claimed in claim 1 , wherein the electrodes have an inter-digital comb structure.
3. The method as claimed in claim 1 , further comprising:
measuring a current across the electrodes;
determining a value for the soot load from the current measured across the electrodes; and
acquiring a value for soot concentration in the exhaust gas over a time profile of the measured current value.
4. The method as claimed in claim 3 , wherein the electrodes have an inter-digital comb structure.
5. A method for measuring a soot load of an exhaust gas in an exhaust gas system of a diesel engine as a measure of functional capability of a particle filter using a sensor having a sensor element connected downstream of the particle filter, the method comprising:
measuring the soot load one of resistively and capacitively using the sensor element, wherein electrodes are formed on the sensor element;
applying a measurement voltage between the electrodes;
controlling the measurement voltage applied between the electrodes as a function of at least one instantaneous operating parameter of the diesel engine;
measuring a current across the electrodes;
determining a value for the soot load from the current measured across the electrodes; and
acquiring a value for soot concentration in the exhaust gas over a time profile of the measured current value.
6. A device for measuring a soot load in an exhaust gas system of diesel engines having a particle filter comprising:
a sensor element connected downstream of the particle filter, the sensor element configured to one of resistively and capacitively measure the soot load using electrodes, wherein the electrodes are formed on the sensor element and a measurement voltage is applied between the electrodes; and
sensor electronic circuits configured to measure a current that flows across the electrodes of the sensor element and determine a value for the soot load and soot concentration in the exhaust gas from the measured current value,
wherein the sensor electronic circuits are further configured to control the measurement voltage as a function of at least one instantaneous operating parameter of the diesel engine and at least one of:
A) calculate at least one of a moisture of the exhaust gas and a temperature of the exhaust gas as the at least one instantaneous operating parameter of the diesel engine; and
acquire an optimum measurement voltage of the sensor element from the at least one of the moisture of the exhaust gas and the temperature of the exhaust gas; and
B) acquire a value for soot concentration in the exhaust gas over a time profile of the measured current value.
7. The device as claimed in claim 6 , wherein the sensor electronic circuits are connected to an engine control unit via a bidirectional interface.
8. The device as claimed in claim 7 , wherein the sensor element has electrodes with a comb structure.
9. The device as claimed in claim 8 , wherein the sensor element has a heating device.
10. The device as claimed in claim 9 , wherein the sensor element is attached in the exhaust gas system by a screw-in housing.
11. The device as claimed in claim 6 , wherein the sensor element has electrodes with a comb structure.
12. The device as claimed in claim 6 , wherein the sensor element has a heating device.
13. The device as claimed in claim 6 , wherein the sensor element is attached in the exhaust gas system by a screw-in housing.