Cold start emission reduction strategy for coordinated torque control systems
View Patent ↗A cold-start control system for an internal combustion engine includes a heat estimation module, a torque request module and a propulsion torque determination module. The heat estimation module determines an exhaust system temperature and estimates heat required to heat an exhaust system to a predetermined temperature. The torque request module generates a torque request based on the estimated heat. The propulsion torque determination module determines a desired engine torque based on the torque request.
1. A cold-start control system for an internal combustion engine comprising:
a heat estimation module that determines an exhaust system temperature and that estimates heat required to heat an exhaust system to a predetermined temperature; and
a torque request module that generates a torque request based on the heat; and
a propulsion torque determination module that determines a desired engine torque based on the torque request.
2. The cold-start control system of claim 1 further comprising a heat/torque conversion module that converts the estimated heat into a torque value.
3. The cold-start control system of claim 2 wherein the torque request module generates the torque request based on the torque value.
4. The cold-start control system of claim 3 wherein the torque request corresponds to a torque reserve.
5. The cold-start control system of claim 4 wherein the torque reserve is a function of an engine speed and the desired engine torque.
6. The cold-start control system of claim 2 further comprising a heating control module that includes the heat estimation module, the heat/torque conversion module, and the torque request module.
7. The cold-start control system of claim 6 wherein the heating control module is actuated when the exhaust system temperature is below a threshold temperature.
8. The cold-start control system of claim 6 wherein the heating control module is deactivated after the exhaust system reaches a light-off temperature.
9. The cold-start control system of claim 6 wherein the heating control module is deactivated after the engine has run for a predetermined period of time.
10. The cold-start control system of claim 6 wherein the predetermined temperature is a light-off temperature.
11. A method of controlling an engine during engine cold-start comprising:
determining an exhaust system temperature;
estimating heat required to heat an exhaust system to a predetermined temperature;
generating a torque request based on the heat; and
determining a desired engine torque based on the torque request.
12. The method of claim 11 further comprising converting the heat into a torque value.
13. The method of claim 11 wherein the torque request corresponds to a torque reserve.
14. The method of claim 13 wherein the torque reserve is a function of the desired engine torque and an engine speed.
15. The method of claim 11 wherein the predetermined temperature is a light-off temperature.