초록 ▼

Methods and systems are provided for managing particulate emissions in an engine including a particulate filter and a CO2 sensor downstream of the filter. A CO2 sensor may be used to infer the presence of particulate matter in the exhaust, downstream of the filter. By sensing particulate matter in t

Methods and systems are provided for managing particulate emissions in an engine including a particulate filter and a CO2 sensor downstream of the filter. A CO2 sensor may be used to infer the presence of particulate matter in the exhaust, downstream of the filter. By sensing particulate matter in the post-filter exhaust, filter degradation may be identified.

대표청구항 ▼

1. A method for controlling an engine with a particulate filter, comprising, exhausting particulate matter from the particulate filter to a downstream substrate;controlling temperature of the substrate via a heater, exhausted particulate matter being oxidized on the substrate upstream of a CO2 senso

1. A method for controlling an engine with a particulate filter, comprising, exhausting particulate matter from the particulate filter to a downstream substrate;controlling temperature of the substrate via a heater, exhausted particulate matter being oxidized on the substrate upstream of a CO2 sensor;indicating filter degradation based on a CO2 signature of the oxidized, post-filter exhaust particulate matter indicated by the CO2 sensor; andcontrolling filter regeneration in response to the CO2 signature. 2. The method of claim 1, wherein the CO2 signature is based on a CO2 level estimated by the CO2 sensor positioned downstream of the substrate, the method further comprising determining an amount of exhausted PMs from the particulate filter based on the CO2 level. 3. The method of claim 2, wherein oxidizing exhaust PMs on the substrate includes operating the substrate heater to heat the substrate, and oxidizing exhaust PMs on the heated substrate using oxygen from exhaust gas downstream of the particulate filter. 4. The method of claim 2, wherein the CO2 signature includes an estimated CO2 level that is generated during a filter storing operation. 5. The method of claim 4, wherein controlling filter regeneration includes initiating filter regeneration in response to the CO2 level being higher than a threshold during filter storing. 6. The method of claim 4, wherein the indication includes, indicating filter degradation when the CO2 level is greater than a threshold. 7. The method of claim 4, wherein the indication includes, indicating degradation when the estimated CO2 level is greater than an expected CO2 level, the expected CO2 level determined based on engine operating conditions. 8. A method of operating a turbocharged engine exhaust system including a particulate filter and a downstream electrically heated substrate, comprising, during substrate non-heating, adjusting an engine boost amount based on an exhaust CO2 level estimated by a sensor; andduring substrate heating, oxidizing post-filter particulate matters (PMs) on the substrate, and initiating particulate filter regeneration based on a CO2 signature from the sensor indicative of PM levels downstream of the particulate filter. 9. The method of claim 8, wherein the engine is a gasoline engine. 10. The method of claim 9, wherein the sensor is a CO2 sensor, and the substrate is upstream of the CO2 sensor, and wherein during the non-heating condition, the filter is storing and the substrate is not oxidizing and during the heating condition, the filter is storing and the substrate is oxidizing. 11. The method of claim 10, wherein the exhaust PMs are oxidized on the heated substrate using oxygen from exhaust gas. 12. The method of claim 9, wherein initiating filter regeneration includes initiating filter regeneration when the estimated CO2 level of oxidized, post-filter exhaust PMs is greater than a threshold. 13. The method of claim 12, further comprising, indicating filter degradation based on the CO2 signature indicating a level of oxidized, post-filter exhaust PMs. 14. The method of claim 13, wherein the indication includes determining an expected CO2 level based on engine operating conditions, comparing the expected CO2 level to the estimated CO2 level, and indicating filter degradation when the estimated CO2 level is greater than the expected CO2 level, wherein indicating filter degradation includes setting a diagnostic code. 15. An engine exhaust system, comprising: a particulate filter;a turbocharger;a CO2 sensor coupled downstream of the filter;a substrate positioned upstream of the CO2 sensor and downstream of the particulate filter; anda controller having instructions thereon to,during filter storing,heat the substrate;estimate a CO2 level corresponding to exhaust PMs oxidized on the heated substrate;initiate filter regeneration based on the estimated CO2 level;determine filter degradation based on the estimated CO2 level; andadjust engine boost amount based on the CO2 sensor. 16. The system of claim 15, wherein heating the substrate includes, turning on a substrate heater when an exhaust gas temperature is below a threshold to electrically heat the substrate; andturning off the substrate heater when the exhaust gas temperature is above the threshold to non-electrically heat the substrate using heated exhaust gas.