| 摘要 |
METHOD AND SYSTEMS FOR EGR CONTROL Various methods and systems are provided for controlling exhaust gas recirculation in an engine. One embodiment for a system comprises an engine having first and second cylinder groups, and an exhaust gas recirculation (EGR) passage coupled between the first cylinder group and an intake manifold of the engine, flow of EGR through the EGR passage controlled by one or more EGR exhaust valves, and a controller configured to maintain a target intake gas concentration by adjusting the one or more EGR exhaust valves and adjusting fuel injection amounts to the first cylinder group differently than the second cylinder group. 3/'6 DETERMINE ENGINE OPERATING DETERMINE EGR FLOW TO MEET DETERMINE TOTAL FUEL SUPPLY XIREF TO MEET TORQUE LOAD DEMAND ADJUST ONE OR MORE EXHAUST DETERMINE DONOR AND NON VALVES TO MEET TARGET EGR DONOR FUEL TO ACHIEVE FLOW DESIRED SPLIT WHILE PROVIDING TOTAL FUEL SUPPLY END DETERMINE TYPICAL FUEL LIMITS FOR NON-DONOR AND DONOR CALCULATE ADDITIONAL DONOR FUEL LIMIT THAT CORRESPONDS TO DELIVERING X1 ABOVE XILL SUPPLY FUEL TO DONOR CYLINDERS AT DESIRED RATE, UP TO BUT NOT MORE THAN THE MINIMUM OF THE TYPICAL DONOR FUEL LIMIT AND ADDITIONAL LIMIT 320 FOR X1LL ADD THIS FUEL SUPPLY "MISS" TO THE DESIRED NON-DONOR FUEL YES ONOR FUEL SUPPLIE < DESIRED FUEL? SUPPLY FUEL TO NON-DONOR NO 324 CYLINDERS, UP TO BUT NOT MORE MAINTAIN DESIRED NON-DONOR THAN THE TYPICAL NON-DONOR FUEL FUEL LIMITS |
