Method and system for controlling an engine during diesel particulate filter regeneration warm-up

1. A method comprising:

initiating a regeneration cycle of a diesel particulate filter (DPF);

generating an oxygen level signal corresponding to an oxygen level in exhaust input to the DPF;

generating a DPF inlet temperature signal corresponding to a DPF inlet temperature;

in response to a first determination that an engine is not idling and a second determination that the DPF inlet temperature is less than a predetermined temperature, determining an oxygen level setpoint for the regeneration cycle based on the oxygen level and the DPF inlet temperature; and

controlling the oxygen level in the exhaust based on the oxygen level setpoint during the regeneration cycle.

2. A method as recited in claim 1 further comprising, in response to the first and second determinations, determining the oxygen level setpoint for the regeneration cycle further based on an engine speed and an engine load.

3. A method as recited in claim 1 further comprising, in response to the first and second determinations:

determining a first oxygen level setpoint as a function of engine speed and engine load;

determining a multiplier as a function of the DPF inlet temperature and the oxygen level; and

determining the oxygen level setpoint as a function of the first oxygen level setpoint and the multiplier.

4. A method as recited in claim 1 further comprising, in response to at least one of a determination that the engine is idiling and a determination that the DPF inlet temperature is greater than the predetermined temperature:

determining a second oxygen level setpoint for the regeneration cycle independent of the oxygen level and the DPF inlet temperature; and

controlling the oxygen level in the exhaust based on the second oxygen level setpoint during the regeneration cycle.

5. A method as recited in claim 1 wherein generating an oxygen level signal comprises generating the oxygen level signal based on an engine load.

6. A method as recited in claim 1 wherein generating an oxygen level signal comprises generating the oxygen level signal based on an engine speed.

7. A method as recited in claim 1 wherein generating an oxygen level signal comprises generating the oxygen level signal based on an engine load and engine speed.

8. A method as recited in claim 1 wherein controlling the oxygen level comprises controlling exhaust gas recirculation.

9. A method as recited in claim 1 wherein controlling the oxygen level comprises controlling intake throttle.

10. A method as recited in claim 1 wherein controlling the oxygen level comprises controlling intake throttle and exhaust gas recirculation.

11. A control module for an engine comprising:

a diesel particulate filter (DPF) regeneration request module that generates a DPF regeneration request signal for initiating a regeneration cycle of a DPF; and

a DPF regeneration control module that, in response to a first determination that the engine is not idling and a second determination that a DPF inlet temperature is less than a predetermined temperature:

determines an oxygen level setpoint for the regeneration cycle based on an oxygen level in exhaust input to the DPF and the DPF inlet temperature; and

controls the oxygen level in an exhaust based on the oxygen level setpoint during the regeneration cycle.

12. A control module as recited in claim 11 wherein the DPF regeneration control module, in response to the first and second determinations, determines the oxygen level setpoint for the regeneration cycle further based on an engine speed and an engine load.

13. A control module as recited in claim 11 wherein the DPF regeneration control module, in response to the first and second determinations:

determines a first oxygen level setpoint as a function of engine speed and engine load;

determines a multiplier as a function of the DPF inlet temperature and the oxygen level; and

determines the oxygen level setpoint as a function of the first oxygen level setpoint and the multiplier.

14. A control module as recited in claim 11 wherein, in response to at least one of a determination that the engine is idling and a determination that the DPF inlet temperature is greater than the predetermined temperature, the DPF regeneration control module:

determines a second oxygen level setpoint for the regeneration cycle independent of the oxygen level and the DPF inlet temperature; and

controls the oxygen level in the exhaust based on the second oxygen level setpoint during the regeneration cycle.

15. A control module as recited in claim 11 wherein the oxygen level is generated based on an engine load.

16. A control module as recited in claim 11 wherein the oxygen level is generated based on an engine speed.

17. A control module as recited in claim 11 wherein the oxygen level is generated based on an engine load and engine speed.

18. A control module as recited in claim 11 wherein an exhaust gas recirculation control module controls exhaust gas recirculation to control the oxygen level in the exhaust.

19. A control module as recited in claim 11 wherein a throttle control module controls an intake throttle to control the oxygen level in the exhaust.

20. A control module as recited in claim 11 wherein an exhaust gas recirculation control module controls exhaust gas recirculation and a throttle control module controls an intake throttle to control the oxygen level in the exhaust.