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Systems and methods for controlling regeneration of a particulate filter positioned downstream of an engine in a vehicle are provided herein. One exemplary method includes, during combusting engine conditions, directing exhaust from the engine to a three-way catalyst and then to the particulate filt

Systems and methods for controlling regeneration of a particulate filter positioned downstream of an engine in a vehicle are provided herein. One exemplary method includes, during combusting engine conditions, directing exhaust from the engine to a three-way catalyst and then to the particulate filter, and during non-combusting engine conditions and while the vehicle is in motion, directing fresh ram-air to between the particulate filter and the catalyst to regenerate the particulate filter. Thus, vehicle motion may be used to introduce the ram-air.

대표청구항 ▼

1. A method for controlling regeneration of a particulate filter of an engine of a vehicle, comprising: during combusting engine conditions, directing exhaust from the engine to a three-way catalyst and then to the particulate filter positioned downstream of the three-way catalyst;during non-combust

1. A method for controlling regeneration of a particulate filter of an engine of a vehicle, comprising: during combusting engine conditions, directing exhaust from the engine to a three-way catalyst and then to the particulate filter positioned downstream of the three-way catalyst;during non-combusting engine conditions and while the vehicle is in motion, directing fresh ram-air to between the particulate filter and the catalyst to regenerate the particulate filter, the ram-air introduced by vehicle motion; andduring at least some combusting engine conditions and while the vehicle is in motion, adjusting a ram-air flow valve to direct ram-air into an exhaust passage based on a pressure of the exhaust passage being less than a threshold pressure value, regenerating the particulate filter, and closing the ram-air flow valve based on the pressure of the exhaust passage exceeding the threshold pressure value, the ram-air flow valve adjusted responsive to regeneration of the particulate filter. 2. The method of claim 1, where directing fresh ram-air includes adjusting the ram-air flow valve based on a vehicle speed. 3. The method of claim 2, where adjusting the ram-air flow valve includes increasing an opening of the ram-air flow valve as vehicle speed decreases, and decreasing the opening of the ram-air flow valve as vehicle speed increases to compensate for changes in excess oxygen flowing to the particulate filter as a result of changes in ram-air pressure. 4. The method of claim 3, further comprising during a portion of an engine shutdown while the engine is spinning, adjusting a high-pressure exhaust gas recirculation valve opening to adjust excess oxygen directed to the particulate filter. 5. The method of claim 1, further comprising, during regeneration of the particulate filter during at least some combusting engine conditions, adjusting one or more of an air-fuel oscillation amplitude, a lean duration, and a rich duration in one or more combusting cylinders based on a vehicle speed during regeneration. 6. The method of claim 5, where adjusting includes increasing the lean duration as vehicle speed decreases, and increasing the rich duration as vehicle speed increases. 7. The method of claim 5, where adjusting includes increasing oscillation amplitude as vehicle speed decreases. 8. The method of claim 1, further comprising, during non-combusting engine conditions, controlling engine speed with an energy conversion device coupled to the engine. 9. A system for controlling regeneration of a particulate filter in a vehicle, comprising: a plurality of cylinders;an emission control device positioned downstream of the plurality of cylinders;a particulate filter positioned downstream of the emission control device; andan electronic controller including a computer-readable storage medium with instructions to: regenerate the particulate filter during at least some non-combusting engine conditions and while the vehicle is in motion by opening a ram-air flow valve to increase excess oxygen directed upstream of the particulate filter and downstream of the emission control device, including adjusting the ram-air flow valve based on whether exhaust pressure is less than a threshold pressure value, and discontinuing ram-air flow to the particulate filter when the exhaust pressure is greater than the threshold pressure value; andduring non-particulate filter regeneration conditions, decrease the excess oxygen directed upstream of the particulate filter,wherein an opening of the ram-air flow valve is increased to increase the excess oxygen and reduced to decrease the excess oxygen. 10. The system of claim 9, where the emission control device is a three-way catalyst. 11. The system of claim 9, further comprising an oxygen sensor positioned upstream of the particulate filter and configured to detect an amount of excess oxygen, where the electronic controller is further configured to adjust the ram-air flow valve based on the amount of excess oxygen detected at the particulate filter. 12. The system of claim 9, further comprising a temperature sensor positioned upstream of the particulate filter, where the electronic controller is further configured to adjust the ram-air flow valve based on a temperature at the particulate filter detected by the temperature sensor. 13. The system of claim 9, further comprising an energy conversion device coupled to the engine, where the energy conversion device is configured to spin the plurality of cylinders, and thus control engine speed. 14. A method for controlling regeneration of a particulate filter, comprising: during non-combusting engine conditions and during vehicle motion, directing ram-air via a ram-air flow valve to a position upstream of the particulate filter and downstream of a three-way catalyst to regenerate the particulate filter, the ram-air introduced by vehicle motion; andduring engine combusting conditions, adjusting the ram-air flow valve based on whether exhaust pressure is less than a threshold pressure value, and discontinuing ram-air flow to the particulate filter when the exhaust pressure is greater than the threshold pressure value. 15. The method of claim 14, further comprising, during non-combusting engine conditions, controlling an engine speed with an energy conversion device coupled to an engine. 16. The method of claim 15, further comprising regenerating the particulate filter during the non-combusting engine conditions and during the engine combusting conditions. 17. The method of claim 16, where the non-combusting engine conditions follow the engine combusting conditions, and where the regenerating starts during the engine combusting conditions and continues during the non-combusting engine conditions. 18. A method for controlling regeneration of a particulate filter in a vehicle, comprising: regenerating the particulate filter by directing ram-air to the particulate filter during combusting engine conditions while the vehicle is in motion or during non-combusting engine conditions while the vehicle is in motion, the ram-air introduced to the particulate filter by vehicle motion, including, adjusting a ram-air flow valve based on whether exhaust pressure is less than a threshold pressure value, and discontinuing ram-air flow to the particulate filter when the exhaust pressure is greater than the threshold pressure value.