Particle filter diagnostic device
AssigneeVitesco Technologies GmbH
InventorSteven Maertens
Life of this patent
Estimating the term…
Abstract
A device for diagnosing a particulate filter suitable for: determining a measured pressure time profile, and a theoretical pressure time profile upstream of the filter, implementing, on each profile: low-pass filtering to obtain a first filtered time profile, second low-pass filtering of the first filtered time profile to obtain a second filtered time profile, calculating a difference between the second filtered time profile and the first filtered time profile, obtaining an absolute value of the calculated difference, and calculating an integral of the absolute value, and, from a comparison between the two integrals, a diagnosis of the particulate filter.
Claims11
A device for diagnosing a particulate filter of an exhaust circuit of an internal combustion engine, the exhaust circuit comprising the particulate filter and a pressure sensor suitable for measuring an exhaust gas pressure upstream of the particulate filter, the device comprising a computer configured to implement:
- determining a measured pressure time profile upstream of the particulate filter from the pressure sensor,
- determining a theoretical pressure time profile upstream of the particulate filter,
- implementing a process for each of the time profile of the measured pressure time profile and the theoretical pressure time profile, the process comprising:
- first low-pass filtering of the time profile to obtain a first filtered time profile,
- second low-pass filtering of the first filtered time profile to obtain a second filtered time profile,
- calculating a difference between the second filtered time profile and the first filtered time profile,
- obtaining an absolute value of the calculated difference, and
- calculating an integral of the absolute value,
- wherein the integral calculating step is implemented if the difference or the absolute value obtained from the theoretical pressure time profile exceeds a first threshold value and if the first filtered theoretical pressure time profile exceeds a second threshold value, and
- establishing a diagnosis of the particulate filter from a comparison between the calculated integrals of the measured pressure time profile and the theoretical pressure time profile.
A method for diagnosing a particulate filter in an exhaust circuit of an internal combustion engine, the exhaust circuit comprising the particulate filter and a pressure sensor suitable for measuring an exhaust gas pressure upstream of the particulate filter, the method being implemented by a computer and comprising:
- determining a measured pressure time profile upstream of the particulate filter from the pressure sensor,
- determining a theoretical pressure time profile upstream of the particulate filter,
- implementing a process for each of the time profile of the measured pressure time profile and the theoretical pressure time profile, the process comprising:
- first low-pass filtering of the time profile to obtain a first filtered time profile,
- second low-pass filtering of the first filtered time profile to obtain a second filtered time profile,
- calculating a difference between the second filtered time profile and the first filtered time profile,
- obtaining an absolute value of the calculated difference, and calculating an integral of the absolute value,
- wherein the integral calculating step is implemented if the difference or the absolute value obtained from the theoretical pressure time profile exceeds a first threshold value and if the first filtered theoretical pressure time profile exceeds a second threshold value, and
- establishing a diagnosis of the particulate filter from a comparison between the calculated integrals of the measured pressure time profile and the theoretical pressure time profile.
Dependencies are inferred from the claim text.