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Inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine may comprise reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rot

Inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine may comprise reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range. Reducing the oxygen concentration of the exhaust gas supplied to the particulate filter may include any one or combination of reducing the oxygen concentration of intake air supplied to the intake manifold, reducing the air portion of the air-to-fuel ratio of the air-fuel mixture supplied to the engine and removing oxygen from the exhaust gas supplied to the particulate filter.

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What is claimed is: 1. A method of inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine with an exhaust gas recirculation valve fluidly coupled between the exhaust manifold and an intake manifold of the engine, the meth

What is claimed is: 1. A method of inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine with an exhaust gas recirculation valve fluidly coupled between the exhaust manifold and an intake manifold of the engine, the method comprising reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range, wherein reducing an oxygen concentration of the exhaust gas supplied to the particulate filter comprises reducing an oxygen concentration of intake air supplied to an intake manifold of the engine, and wherein reducing an oxygen concentration of intake air supplied to an intake manifold of the engine comprises increasing a concentration of exhaust gas in the intake air supplied to the intake manifold of the engine, and wherein increasing a concentration of exhaust gas in the intake air supplied to the intake manifold comprises controlling the exhaust gas recirculation valve to increase the concentration of exhaust gas in the intake air supplied to the intake manifold such that the oxygen concentration of the exhaust gas supplied to the particulate filter is reduced to within a target oxygen concentration range, and wherein controlling the exhaust gas recirculation valve comprises modulating exhaust gas flow through the exhaust gas recirculation valve to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between first and second oxygen concentration values that are within the target oxygen concentration range. 2. The method of claim 1 wherein controlling the exhaust gas recirculation valve comprises controlling a position of the exhaust gas recirculation valve relative to a reference position according to an open-loop control strategy as a function of a reduced oxygen concentration value that is within the target oxygen concentration range to reduce the oxygen concentration of the exhaust gas supplied to the particulate filter to the reduced oxygen value. 3. The method of claim 1 further comprising determining an oxygen concentration of the exhaust gas supplied to the particulate filter, and wherein controlling the exhaust gas recirculation valve comprises controlling a position of the exhaust gas recirculation valve relative to a reference position according to a closed-loop control strategy as a function of the determined oxygen concentration of the exhaust gas supplied to the particulate filter and a reduced oxygen concentration value that is within the target oxygen concentration range to reduce the oxygen concentration of the exhaust gas supplied to the particulate filter to the reduced oxygen value. 4. The method of claim 1 wherein modulating the exhaust gas flow through the exhaust gas recirculation valve comprises controlling the exhaust gas recirculation valve between first and second positions relative to a reference position according to an open-loop control strategy as a function of the first and second oxygen concentration values to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between the first and second oxygen concentration values. 5. The method of claim 1 further comprising determining an oxygen concentration of the exhaust gas supplied to the particulate filter, and wherein modulating the exhaust gas flow through the exhaust gas recirculation valve comprises controlling a position of the exhaust gas recirculation valve relative to a reference position according to a closed-loop control strategy as a function of the determined oxygen concentration of the exhaust gas supplied to the particulate filter and the first and second oxygen concentration values to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between the first and second oxygen concentration values. 6. A method of inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine, the engine comprising at least one of an air intake throttle that is controllable to vary a flow rate of fresh air to an intake manifold of the engine, an exhaust throttle that is controllable to vary a flow rate of exhaust gas through the particulate filter and a number of air inlet valves associated with the engine that are each controllable by controlling lift timing thereof relative to a reference lift timing to vary a flow rate of air into a corresponding one of a number of combustion chambers of the engine, the method comprising reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range, wherein reducing an oxygen concentration of the exhaust gas supplied to the particulate filter comprises reducing an air portion of an air-to-fuel ratio of an air-fuel mixture supplied to the engine to reduce an oxygen content of the air-fuel mixture and thereby the oxygen concentration of the exhaust gas supplied to the particulate filter, and wherein reducing an air portion of an air-to-fuel ratio of an air-fuel mixture supplied to the engine comprises decreasing a mass of air comprising the air-to-fuel ratio while maintaining constant fuel mass, and wherein decreasing a mass of air comprising the air-to-fuel ratio comprises controlling the at least one of an air intake throttle, an exhaust throttle and a number of air inlet valves to decrease a flow rate of the air comprising the air-to-fuel ratio such that the oxygen concentration of the exhaust gas supplied to the particulate filter is reduced to within a target oxygen concentration range. 7. The method of claim 6 wherein controlling the at least one of an air intake throttle, an exhaust throttle and a number of air inlet valves comprises controlling a position of the at least one of the air intake throttle and an exhaust throttle relative to a reference position, or controlling lift timing of the number of air inlet valves relative to a reference lift timing, according to an open-loop control strategy as a function of a target flow rate of the exhaust gas supplied to the particulate filter to reduce the oxygen concentration of the exhaust gas supplied to the particulate filter to a reduced oxygen concentration value that is within the target oxygen concentration range. 8. The method of claim 6 further comprising determining an oxygen concentration of the exhaust gas supplied to the particulate filter, and wherein controlling the at least one of an air intake throttle, an exhaust throttle and a number of air inlet valves comprises controlling a position of the at least one of the air intake throttle and an exhaust throttle relative to a reference position, or controlling lift timing of the number of inlet valves relative to a reference lift timing, according to a closed-loop control strategy as a function of the determined oxygen concentration of the exhaust gas supplied to the particulate filter and a reduced oxygen concentration value that is within the target oxygen concentration range to reduce the oxygen concentration of the exhaust gas supplied to the particulate filter to the reduced oxygen concentration value. 9. The method of claim 6 wherein controlling the at least one of an air intake throttle, an exhaust throttle and a number of air inlet valve comprises modulating one of fresh air flow through the air intake throttle, exhaust gas flow through the exhaust throttle and lift timing of the number of air inlet valves to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between first and second oxygen concentration values that are within the target oxygen concentration range. 10. The method of claim 9 wherein modulating one of fresh air flow through the air intake throttle, exhaust gas flow through the exhaust throttle and lift timing of the number of air inlet valves comprises modulating one of fresh air flow through the air intake throttle, exhaust gas flow through the exhaust throttle and lift timing of the number of air inlet valves according to a predetermined time-based duty cycle. 11. The method of claim 9 further comprising determining an operating temperature of the particulate filter, and wherein modulating one of fresh air flow through the air intake throttle, exhaust gas flow through the exhaust throttle and lift timing of the number of air inlet valves comprises controlling the at least one of an air intake throttle, an exhaust throttle and a number of air inlet valve such that the oxygen concentration of the exhaust gas supplied to the particulate filter is reduced to the first oxygen concentration value if the operating temperature of the particulate filter is at or higher than a threshold temperature, and otherwise controlling the at least one of an air intake throttle, an exhaust throttle and a number of air inlet valve such that the oxygen concentration of the exhaust gas supplied to the particulate filter is reduced to the second oxygen concentration value, wherein the second oxygen concentration value is greater than the first oxygen concentration value. 12. The method of claim 9 wherein modulating one of fresh air flow through the air intake throttle and exhaust gas flow through the exhaust throttle comprises controlling the at least one of an air intake throttle and an exhaust throttle between first and second positions relative to a reference position according to an open-loop control strategy as a function of first and second target flow rates of the exhaust gas supplied to the particulate filter to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between the first and second oxygen concentration values. 13. The method of claim 9 wherein modulating lift timing of the number of air inlet valves comprises varying the lift timing of the number of air inlet valves between first and second lift timing values relative to a reference timing value according to an open-loop control strategy as a function of first and second target flow rates of the exhaust gas supplied to the particulate filter to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between the first and second oxygen concentration values. 14. The method of claim 9 further comprising determining an oxygen concentration of the exhaust gas supplied to the particulate filter, and wherein modulating one of fresh air flow through the air intake throttle and exhaust gas flow through the exhaust throttle comprises controlling a position of the at least one of the air intake throttle and an exhaust throttle between first and second positions relative to a reference position according to a closed-loop control strategy as a function of the determined oxygen concentration of the exhaust gas supplied to the particulate filter and first and second target flow rates of the exhaust gas supplied to the particulate filter to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between the first and second oxygen concentration values. 15. The method of claim 9 further comprising determining an oxygen concentration of the exhaust gas supplied to the particulate filter, and wherein modulating lift timing of the number of air inlet valves comprises varying the lift timing of the number of air inlet valves between first and lift second timing values relative to a reference timing value according to a closed-loop control strategy as a function of the determined oxygen concentration of the exhaust gas supplied to the particulate filter and first and second target flow rates of the exhaust gas supplied to the particulate filter to cycle the oxygen concentration of the exhaust gas supplied to the particulate filter between the first and second oxygen concentration values. 16. The method of claim 6 further comprising an engine speed sensor configured to produce a speed signal corresponding to rotation speed of the engine, wherein the method further comprises processing the speed signal to determine engine rotational speed and determining that the engine speed drops to an idle speed range if the engine rotational speed drops below a speed threshold. 17. The method of claim 6 further comprising a vehicle sensor configured to produce a speed signal corresponding to road speed of a vehicle carrying the engine, wherein the method further comprises processing the speed signal to determine vehicle road speed and determining that the engine speed drops to an idle speed range if the vehicle road speed drops below a speed threshold. 18. The method of claim 6 further comprising a mass air flow sensor configured to produce a flow signal corresponding to a flow rate of fresh air supplied to an intake manifold of the engine, wherein the method further comprises processing the flow signal to determine the flow rate of fresh air supplied to the intake manifold and determining that the engine speed drops to an idle speed range if the flow rate of fresh air supplied to the intake manifold drops below a flow rate threshold. 19. A method of inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine with an oxidation catalyst fluidly coupled between the exhaust manifold and the particulate filter and a fuel system configured to supply fuel to the engine, the method comprising: determining an oxygen concentration of the exhaust gas supplied to the particulate filter, and reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range, wherein reducing an oxygen concentration of the exhaust gas supplied to the particulate filter comprises removing oxygen from the exhaust gas supplied to the particulate filter, and wherein removing oxygen from the exhaust gas supplied to the particulate filter comprises consuming at least some of the oxygen present in the exhaust gas supplied to the particulate filter, and wherein consuming at least some of the oxygen present in the exhaust gas supplied to the particulate filter comprises introducing hydrocarbons into the exhaust gas supplied to the oxidation catalyst so that the oxidation catalyst reacts with the introduced hydrocarbons and consumes at least some of the oxygen present in the exhaust gas supplied to the particulate filter such that the oxygen concentration of the exhaust gas supplied to the particulate filter is reduced to within a target oxygen concentration range, and wherein introducing hydrocarbons into the exhaust as supplied to the oxidation catalyst comprises controlling the fuel system to inject fuel into the exhaust gas supplied to the oxidation catalyst according to a closed-loop control strategy as a function of the determined oxygen concentration of the exhaust gas supplied to the particulate filter and a reduced oxygen concentration value that is within the target oxygen concentration range to reduce the oxygen concentration of the exhaust gas supplied to the particulate filter to the reduced oxygen value. 20. The method of claim 19 wherein introducing hydrocarbons into the exhaust gas supplied to the oxidation catalyst comprises introducing the hydrocarbons into the exhaust gas supplied to the oxidation catalyst for a predetermined time period. 21. The method of claim 19 further comprising determining an operating temperature of the particulate filter, and wherein introducing hydrocarbons into the exhaust gas supplied to the oxidation catalyst comprises introducing the hydrocarbons into the exhaust gas supplied to the oxidation catalyst only if the operating temperature of the particulate filter is at or higher that a threshold temperature, and otherwise not introducing hydrocarbons into the exhaust gas supplied to the oxidation catalyst. 22. The method of claim 19 further comprising a fuel system configured to supply fuel to the engine, wherein introducing hydrocarbons into the exhaust gas supplied to the oxidation catalyst comprises controlling the fuel system to inject fuel into the exhaust gas supplied to the oxidation catalyst according to an open-loop control strategy as a function of a reduced oxygen concentration value that is within the target oxygen concentration range to reduce the oxygen concentration of the exhaust gas supplied to the particulate filter to the reduced oxygen value.