Granted Patent B2

US 8,256,220 · App. 12/437,890 · Granted Sep 4, 2012

Assignees: GM Global Technology Operations LLC; General Electric Company

Abstract

Claims (12)

1. A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve, comprising:

determining a mass flow of exhaust exiting an engine;

determining a desired exhaust pressure based on the mass flow of exhaust;

comparing the desired exhaust pressure to an exhaust pressure; and

determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve, and the bypass valve diverts a portion of the exhaust gas to an exhaust pipe.

2. The method of claim 1 wherein the determining the mass flow of exhaust is based on at least one of, a measured intake airflow, a measured fuel flow, a modeled intake airflow, a modeled fuel flow, and a measured exhaust flow.

3. The method of claim 1 wherein the determining the mass flow of exhaust further comprises adjusting the mass flow of exhaust for a time delay based on engine speed.

4. The method of claim 1 wherein the determining the desired exhaust pressure is further based on a one-dimensional lookup map indexed by the mass flow of exhaust.

5. The method of claim 1 further comprising limiting the control value based on at least one of engine coolant temperature and exhaust gas temperature.

6. The method of claim 1 further comprising determining the exhaust pressure based on an exhaust pressure at a first location relative to an exhaust pressure at a second location.

7. The method of claim 1 wherein the comparing further comprises determining a difference between the desired exhaust pressure and the exhaust pressure, and wherein the determining the control value is based on the difference.

8. The method of claim 7 further comprising applying proportional and integral gains to the control value.

Assignments (9)

Continuity (1)